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Sample records for abandoned carbonate reservoir

  1. Reservoirs 3 carbonates

    SciTech Connect

    Beaumont, E.A.; Foster, N.H.

    1988-01-01

    This book covers the topics of Carbonates; Carbonate depositional environments and Carbonate diagenesis. Included are the following papers: pore geometry of carbonate rocks as revealed by pore casts and capillary pressure; a review of carbonate reservoirs; the chemistry of dolomitization and dolomite precipitation.

  2. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

    2003-06-01

    The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plant that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration are being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the US.

  3. Reservoirs III carbonates

    SciTech Connect

    Beaumont, E.A.; Foster, N.H.

    1988-01-01

    This text is part of a three volume set on petroleum and natural gas reservoir rocks. This volume deals with carbonate rocks and their properties as they relate to oil and gas production. Papers deal specifically with depositional environments, diagenesis, and chemical and physical properties of the rock.

  4. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    SciTech Connect

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum

  5. Carbonate petroleum reservoirs

    SciTech Connect

    Roehl, P.O.; Choquette, P.W.

    1985-01-01

    This book presents papers on the geology of petroleum deposits. Topics considered include diagenesis, porosity, dolomite reservoirs, deposition, reservoir rock, reefs, morphology, fracture-controlled production, Cenozoic reservoirs, Mesozoic reservoirs, and Paleozoic reservoirs.

  6. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Hickman, Scott T.; Justice James L.; Taylor, Archie R.

    1999-10-28

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs.

  7. Tertiary carbonate reservoirs in Indonesia

    SciTech Connect

    Nayoan, G.A.S.; Arpandi; Siregar, M.

    1981-01-01

    Hydrocarbon production from Tertiary carbonate reservoirs accounted for ca. 10% of daily Indonesian production at the beginning of 1978. Environmentally, the reservoirs appear as parts of reef complexes and high-energy carbonate deposits within basinal areas situated mainly in the back arc of the archipelago. Good porosities of the reservoirs are represented by vugular/moldic and intergranular porosity types. The reservoirs are capable of producing prolific amounts of hydrocarbons: production tests in Salawati-Irian Jaya reaches maximum values of 32,000 bpd, and in Arun-North Sumatra tests recorded 200 MMCF gas/day. Significant hydrocarbon accumulations are related to good reservoir rocks in carbonates deposited as patch reefs, pinnacle reefs, and platform complexes. Exploration efforts expand continuously within carbonate formations which are extensive horizontally as well as vertically in the Tertiary stratigraphic column.

  8. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olson; Deanna Combs; Dhiraj Dembla

    2004-06-01

    The Bureau of Economic Geology (BEG) and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology (BEG) and the Department of Petroleum and Geosystems Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data were to be generated during the demonstration phase to improve the accuracy of the reservoir model. The demonstration phase has been delayed by Goldrus because of funding problems. Since the first of the year, Goldrus has been active in searching for partners to help finance the project. To this end it has commissioned several small consulting studies to technically support its effort to secure a partner. After financial support is obtained, the demonstration phase of the project will proceed. Since just after the beginning of the year, BEG has curtailed project activities and spending of DOE funds except for the continued support of one engineering student. This student has now completed his work and has written a thesis describing his research (titled ''Stimulating enhanced oil recovery (EOR) by high-pressure air injection (HPAI) in west Texas light oil reservoir''). We plan to recommence our work on the project as soon as the operator obtains necessary funding to carry out the demonstration phase of the project. In order to complete all activities specified in the proposal, it will be necessary to request

  9. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olson

    2005-01-01

    The Bureau of Economic Geology (BEG) and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology (BEG) and the Department of Petroleum and Geosystems Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data were to be generated during the demonstration phase to improve the accuracy of the reservoir model. The demonstration phase has been delayed by Goldrus because of funding problems. Since the first of the year, Goldrus has been active in searching for partners to help finance the project. After financial support is obtained, the demonstration phase of the project will proceed. Since just after the beginning of the year, BEG has curtailed project activities and spending of DOE funds except for the continued support of one engineering student. This student has now completed his work and his thesis was reported on in the last semi-annual report. We plan to recommence our work on the project as soon as the operator obtains necessary funding to carry out the demonstration phase of the project. In order to complete all activities specified in the proposal, we requested and received an extension of the project to September 30, 2005. We are confident that Goldrus will obtain the necessary funding to continue and that we can complete the project by the end of the extension data. We strongly believe that the results of

  10. Global Carbon Reservoir Oxidative Ratios

    NASA Astrophysics Data System (ADS)

    Masiello, C. A.; Gallagher, M. E.; Hockaday, W. C.

    2010-12-01

    Photosynthesis and respiration move carbon and oxygen between the atmosphere and the biosphere at a ratio that is characteristic of the biogeochemical processes involved. This ratio is called the oxidative ratio (OR) of photosynthesis and respiration, and is defined as the ratio of moles of O2 per moles of CO2. This O2/CO2 ratio is a characteristic of biosphere-atmosphere gas fluxes, much like the 13C signature of CO2 transferred between the biosphere and the atmosphere has a characteristic signature. OR values vary on a scale of 0 (CO2) to 2 (CH4), with most ecosystem values clustered between 0.9 and 1.2. Just as 13C can be measured for both carbon fluxes and carbon pools, OR can also be measured for fluxes and pools and can provide information about the processes involved in carbon and oxygen cycling. OR values also provide information about reservoir organic geochemistry because pool OR values are proportional to the oxidation state of carbon (Cox) in the reservoir. OR may prove to be a particularly valuable biogeochemical tracer because of its ability to couple information about ecosystem gas fluxes with ecosystem organic geochemistry. We have developed 3 methods to measure the OR of ecosystem carbon reservoirs and intercalibrated them to assure that they yield accurate, intercomparable data. Using these tools we have built a large enough database of biomass and soil OR values that it is now possible to consider the implications of global patterns in ecosystem OR values. Here we present a map of the natural range in ecosystem OR values and begin to consider its implications. One striking pattern is an apparent offset between soil and biospheric OR values: soil OR values are frequently higher than that of their source biomass. We discuss this trend in the context of soil organic geochemistry and gas fluxes.

  11. Bioaccumulation of cesium-137 in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned nuclear reactor reservoir

    SciTech Connect

    McCreedy, C.D.; Glickman, L.T.; Jagoe, C.H.; Brisbin, I.L. Jr.

    1997-02-01

    Bioaccumulation of {sup 137}Cs was investigated in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned reactor reservoir, Pond B, Savannah River Site, Barnwell Co., South Carolina. The authors collected fish by trap-netting, and determined ages from pectoral spines. Muscle and other tissues were assayed for {sup 137}Cs by NaI-scintillation. Music {sup 137}Cs was unrelated to sex or mass of fish, but was related to age. Examination of least-squares means suggested that {sup 137}Cs in muscle increased up to about age 3, but did not increase with greater age. A modified Richards model showed equilibrium {sup 137}Cs concentration in muscle was acquired in approximately 2.4 years. Growth differed between sexes and the time to asymptotic body mass was longer than the time to attain equilibrium {sup 137}Cs concentration. Males attained an asymptotic mass of 577 g in approximately 6.3 years; females attained an asymptotic mass of 438 g in approximately 5.9 years. The cumulative {sup 137}Cs burden of the population was 4.9 {times} 10{sup 6} Bq, representing <0.001% of the {sup 137}Cs inventory of the reservoir. Concentration of {sup 137}Cs varied among tissues with gill and muscle the lowest and highest. Concentration of {sup 137}Cs in ovaries declined with increasing ovary mass. Until equilibrium is attained in these fish, {sup 137}Cs concentration is directly related to increasing age rather than size.

  12. Carbon emission from global hydroelectric reservoirs revisited.

    PubMed

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs. PMID:24943886

  13. Post-Soviet cropland abandonment and carbon sequestration in European Russia, Ukraine, and Belarus

    NASA Astrophysics Data System (ADS)

    Schierhorn, Florian; Müller, Daniel; Beringer, Tim; Prishchepov, Alexander V.; Kuemmerle, Tobias; Balmann, Alfons

    2013-12-01

    Widespread cropland abandonment occurred after the collapse of socialism across the former Soviet Union, but the rates and spatial patterns of abandoned lands are not well known. As a result, the potential of this region to contribute to global food production and estimates of the carbon sink developing on currently idle lands are highly uncertain. We developed a spatial allocation model that distributes yearly and subnational sown area statistics to the most agriculturally suitable plots. This approach resulted in new, high-resolution (1 km2) annual time series of cropland and abandoned lands in European Russia, Ukraine, and Belarus from 1990 to 2009. A quantitative validation of the cropland map confirms the reliability of this data set, especially for the most important agricultural areas of the study region. Overall, we found a total of 87 Mha of cropland and 31 Mha of abandoned cropland in European Russia, Ukraine, and Belarus combined, suggesting that abandonment has been severely underestimated in the past. The abandonment rates were highest in European Russia. Feeding our new map data set into the dynamic vegetation model LPJmL revealed that cropland abandonment resulted in a net carbon sink of 470 TgC for 1990 to 2009. Carbon sequestration was generally slow in the early years after abandonment, but carbon uptake increased significantly after approximately 10 years. Recultivation of older abandoned lands would be associated with high carbon emissions and lead to substantial amounts of carbon not being sequestered in vegetation formations currently developing on idle croplands. Our spatially and temporally explicit cropland abandonment data improve the estimation of trade-offs involved in reclaiming abandoned croplands and thus in increasing agricultural production in this globally important agricultural region.

  14. Quantification of geologic descriptions for reservoir characterization in carbonate reservoirs

    SciTech Connect

    Lucia, F.J.; Vander Stoep, G.W. )

    1990-05-01

    Recognition that a large volume of oil remains in carbonate reservoirs at the end of primary depletion and waterflooding has prompted the reevaluation of the reserve-growth potential of many existing carbonate reservoirs. Types of numerical data required include porosity, absolute permeability, relative permeability, fluid saturation, and capillary pressure, all of which are related to the size and distribution of pore space. Rock fabrics control the size and distribution of pore space and define facies that best characterize carbonate reservoirs. Thus, the link between facies descriptions and numerical engineering data is the relationship between pore-size distribution and present carbonate rock fabric. The most effective way to convert facies descriptions into engineering parameters is by considering three basic rock-fabric categories. The first category is interparticle pore space (both intergranular and intercrystalline pore types) with pore-size distribution controlled primarily by the size and shape of grains or crystals. Grain or crystal size is the key geologic measurement and, along with porosity, provides the basis for converting geologic descriptions into values for permeability, saturation, and capillarity. The second category is separate-vug pore space, such as moldic or intraparticle pore space. Separate-vug pore space adds porosity but little permeability to the reservoir rock. The contribution to saturation and capillarity depends upon the size of the separate-vug pore space. For example, moldic separate vugs will be saturated with oil, whereas microporous grains will be saturated with water. The third category is touching-vug pore space, which is vuggy pore space that is interconnected on a reservoir scale. The engineering parameters for this category are related to three diagenetic and tectonic factors.

  15. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Wier, Don R. Chimanhusky, John S.; Czirr, Kirk L.; Hallenbeck, Larry; Gerard, Matthew G.; Dollens, Kim B.; Owen, Rex; Gaddis, Maurice; Moshell, M.K.

    2002-11-18

    The purpose of this project was to economically design an optimum carbon dioxide (CO2) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO2 horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields.

  16. C02 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Mark Kovar; Scott Wehner

    1998-01-31

    The principal objective of this CO2 Huf-n-Puff (H-n-P) project is to determine the feasibility and practicality of the technology in a waterflooded shallow shelf carbonate environment. The results of parametric simulation of the CO2 H-n-P process, coupled with reservoir characterization components are to be used to determine if this process is technically and economically feasible for field implementation. The technology transfer objective of the project is to disseminate the knowledge gained through an innovative plan of increasing oil production and deferring abandonment of shallow shelf carbonate reservoirs.

  17. New and improved recovery of oil from an abandoned reservoir: Round Tank-San Andres pool. Final report

    SciTech Connect

    Foster, R.W.

    1983-05-01

    The purpose of this field program was to determine the potential for recovery of additional oil from a reservoir where primary production had been depleted. The selected pool, Round Tank in Chaves County, had yielded minor amounts of oil from seventeen wells completed in the Slaughter zone of the San Andres Formation. It was not known whether the small yields were the result of isolated pockets of oil-saturated porosity or lack of adequate reservoir pressure. Geologic studies indicated that there was continuity of porosity in a number of zones. To verify this it was planned to inject water into selected intervals in one of the abandoned wells where casing had been left in the hole. If water could be injected then a waterflood program would have the potential for recovery of additional oil. The well was reentered and an attempt made to cement holes in the casing in order to continue with selected injection of water. This proved impossible because of the condition of the casing and the project was terminated to avoid further expenditures. A new well will be required to determine if a waterflood program can result in recovery of additional oil at Round Tank. The report includes information on 195 abandoned oil reservoirs in New Mexico and a discussion of possible additional recovery of oil from some of these reservoirs. 42 figures, 11 tables.

  18. Models for naturally fractured, carbonate reservoir simulations

    SciTech Connect

    Tuncay, K.; Park, A.; Ozkan, G.; Zhan, X.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    This report outlines the need for new tools for the simulation of fractured carbonate reservoirs. Several problems are identified that call for the development of new reservoir simulation physical models and numerical techniques. These include: karst and vuggy media wherein Darcy`s and traditional multi-phase flow laws do not apply; the need for predicting the preproduction state of fracturing and stress so that the later response of effective stress-dependent reservoirs can be predicted; and methods for predicting the fracturing and collapse of vuggy and karst reservoirs in response to draw-down pressure created during production. Specific research directions for addressing each problem are outlined and preliminary results are noted.

  19. Land abandonment, fire recurrence and soil carbon content in the Macizo del Caroig, Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdá, A.; González Peñaloza, F.; Santín, C.; Doerr, S. H.

    2012-04-01

    During the last 50 years two main forces have driven the fate of Mediterranean landscapes: land abandonment and forest fires (MacDonald et al., 2000; Moreira et al., 2001). Due to the economical changes suffered by the of the Mediterranean countries after the Second World War, the population migrated from the rural to the urban areas, and from South to North Europe. The land abandonment allowed the vegetation to recover and, as a consequence, an increase in forest fire took place. The soils of the abandoned land recovered the vegetation and litter layers, and consequently changes in soil properties have being found. One of these changes is the increase of soil carbon content, which is due both to vegetation recovery and to fire occurrence that increases the ash and pyrogenic carbon content in soils. Twenty plots were selected in the Macizo del Caroig in Eastern Spain on soils developed on limestone. The period of abandonment and the forest fires that had affected each plot were determined by interviews with the owners, farmers and shepherds. In addition, six (three + three) plots were selected as forest (no plough) and cultivated control plots. Each plot was sampled (10 random samples) and the organic carbon content determined. The results show that the cultivated plots have organic matter contents of 1.02 %, and the forest (Quercus ilex sp.) plots reach the highest value: 14.98 %. Within those we found values that range from 2.34 %, in the recently abandoned plots (10 year abandonment), to values of 8.23 % in the 50 year old abandoned fields.The results demonstrate that there is a recovery of the organic carbon in abandoned soils and that the forest fires do no affect this trend. The increase of soil organic matter after abandonment is a result of the recovery of vegetation(Debussche et al., 2001), which is the consequence of the end of the disturbance of forest that have affected the Mediterranean for millennia (Barbero et al., 1990). The colonization of the

  20. Post-Soviet farmland abandonment, forest recovery, and carbon storage potential in Ukraine

    NASA Astrophysics Data System (ADS)

    Olofsson, P.; Kuemmerle, T.; Baumann, M.; Radeloff, V. C.; Woodcock, C. E.; Hostert, P.

    2010-12-01

    Land use is a critical factor in the global carbon cycle, but land use effects on carbon fluxes are poorly understood in many regions. One such region is the former Eastern Bloc, where land use intensity decreased substantially after the collapse of the Soviet Union, resulting in widespread farmland abandonment and forest regrowth. The aim of this study was to examine how land use trends altered net carbon fluxes in Western Ukraine (57,000 km2) for the communist (1945-1991) and the post-communist period (1991-2007), and to assess the regions’ future carbon sequestration potential. Forest disturbance and farmland abandonment between 1988 to 2007 was estimated from Landsat imagery in former study. Historical land use change rates were obtained from forest inventories to reconstruct forest trends back to the mid-1800s. Using a carbon book-keeping model, we quantified net carbon fluxes from land use change and assessed potential future carbon fluxes for a range of reforestation and logging scenarios. Our results suggest that the low-point in forest cover occurred in the 1920s. Forest expansion in the second half of the 20th century turned the region from a carbon source to a sink, despite heavy logging during Soviet times. The current land-use related sink strength is about 1.5 Tg of carbon per year. Sequestration potential on abandoned farmland is enormous, even when assuming that only a minor fraction of the currently abandoned land will revert to forests. Beyond our study area, farmland abandonment has been widespread throughout Eastern Europe and the former Soviet Union, suggesting that a substantial proportion of the regions’ industrial carbon emissions may be offset by reforesting farmland.

  1. Advances in carbonate exploration and reservoir analysis

    USGS Publications Warehouse

    Garland, J.; Neilson, J.; Laubach, S.E.; Whidden, Katherine J.

    2012-01-01

    The development of innovative techniques and concepts, and the emergence of new plays in carbonate rocks are creating a resurgence of oil and gas discoveries worldwide. The maturity of a basin and the application of exploration concepts have a fundamental influence on exploration strategies. Exploration success often occurs in underexplored basins by applying existing established geological concepts. This approach is commonly undertaken when new basins ‘open up’ owing to previous political upheavals. The strategy of using new techniques in a proven mature area is particularly appropriate when dealing with unconventional resources (heavy oil, bitumen, stranded gas), while the application of new play concepts (such as lacustrine carbonates) to new areas (i.e. ultra-deep South Atlantic basins) epitomizes frontier exploration. Many low-matrix-porosity hydrocarbon reservoirs are productive because permeability is controlled by fractures and faults. Understanding basic fracture properties is critical in reducing geological risk and therefore reducing well costs and increasing well recovery. The advent of resource plays in carbonate rocks, and the long-standing recognition of naturally fractured carbonate reservoirs means that new fracture and fault analysis and prediction techniques and concepts are essential.

  2. Litter contribution to soil organic carbon in the agriculture abandons processes

    NASA Astrophysics Data System (ADS)

    Novara, Agata; Francaviglia, Dario; La Mantia, tommaso; Gristina, Luciano; La Bella, Salvatore; Tuttolomondo, Teresa

    2015-04-01

    Mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in ecosystem functioning as it regulates the cycle of soil organic matter (SOM), CO2 emission into the atmosphere, carbon sequestration into the soil. In this study, it was investigated the contribution of litters of different stages of Mediterranean secondary succession on Carbon sequestration, analyzing the role of earthworms on translocation of SOM into soil profile. For this purpose δ13C difference between meadow C4-C soil and C3-C litter were used in a field experiment. Four undisturbed litters of different stages of succession were collected (45, 70, 100 and 120 since agriculture abandon) and placed on the top of isolated soil cores. The litter contribution to C stock was affected by plant species and increased with the age of the stage of secondary succession. The soil organic carbon after 1 year since litter position increased up to 40% in comparison to no litter treatment in soil with litter of 120 years since abandon. The new carbon derived from C3-litter was decomposed and transferred into soil profile thanks to earthworms and dissolved organic carbon leaching. After 1 years the carbon increase attributed to earthworm activity ranged from 6% to 13% in soil under litter in field abandoned since 120 and 45 years, respectively.

  3. Litter contribution to soil organic carbon in the agriculture abandons processes

    NASA Astrophysics Data System (ADS)

    Novara, A.; Rühl, J.; La Mantia, T.; Gristina, L.; La Bella, S.; Tuttolomondo, T.

    2015-02-01

    Mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in ecosystem functioning as it regulates the cycle of soil organic matter (SOM), CO2 emission into the atmosphere, carbon sequestration into the soil. In this study, it was investigated the contribution of litters of different stages of Mediterranean secondary succession on Carbon sequestration, analyzing the role of earthworms on translocation of SOM into soil profile. For this purpose δ13C difference between meadow C4-Csoil and C3-Clitter were used in a field experiment. Four undisturbed litters of different stages of succession were collected (45, 70, 100 and 120 since agriculture abandon) and placed on the top of isolated soil cores. The litter contribution to C stock was affected by plant species and increased with the age of the stage of secondary succession. The soil organic carbon after 1 year since litter position increased up to 40% in comparison to no litter treatment in soil with litter of 120 years since abandon. The new carbon derived from C3-litter was decomposed and transferred into soil profile thanks to earthworms and dissolved organic carbon leaching. After 1 years the carbon increase attributed to earthworm activity ranged from 6 to 13% in soil under litter in field abandoned since 120 and 45 years, respectively.

  4. Diagenetic capping of carbonate reservoir facies

    SciTech Connect

    Lighty, R.G.

    1984-04-01

    The diagenetic model proposed involves the effect of submarine cementation on previously lithified carbonates, such as submerged relict shelf-margin buildups (e.g., drowned reefs, ooid shoals) or previously subaerially exposed formations (e.g., dune ridges) that were submerged by later sea level rise. These deposits generally have pronounced topographic relief (visible on seismic), good reservoir geometries, and high internal porosity of either primary or secondary origin. Petrologic studies on examples of both of these situations, a submerged early Holocene barrier reef off Florida and a 175-km (110-m) long submerged Pleistocene eolian ridge in the Bahamas, show that their exposed surface and uppermost facies (0.1 m, or 0.3 ft, below top) are further infilled and cemented, creating an extensively lithified, low porosity/low permeability zone or diagenetic cap rock. Quantitative mineralogic studies of occluding cements reveal an exponential reduction in porosity while moving upward into the seal zone. Submarine cements effectively infill and form a surficial permeability barrier that acts to impede further diagenesis and porosity reduction within underlying potential reservoir facies. To form this diagenetic seal only requires that the original carbonate buildup be resubmerged for some brief period of time prior to subsequent burial by sediments. If buildup accumulation later resumes without intermediate sediment burial, a common stratigraphic situation, the diagenetic seal would represent a disconformity separating two similar facies. The early formation of a diagenetic cap rock lends support to models of early hydrocarbon migration and emplacement. Prediction and recognition of submarine diagenetic seals will aid in exploration and development of obvious buildup reservoirs as well as subtle intraformational traps.

  5. Soil, vegetation and total organic carbon stock development in self-restoring abandoned vineyards

    NASA Astrophysics Data System (ADS)

    József Novák, Tibor; Incze, József; Spohn, Marie; Giani, Luise

    2016-04-01

    Abandoned vineyard's soil and vegetation development was studied on Tokaj Nagy-Hill, which is one of the traditional wine-producing regions of Hungary, it is declared as UNESCO World Heritage site as cultural landscape. Spatial distribution and pattern of vineyards were changing during the last several hundreds of years, therefore significant part of abandoned vineyards were subjected to long-term spontaneous secondary succession of vegetation and self-restoration of soils in absence of later cultivation. Two chronosequences of spontaneously regenerating vineyard abandonments, one on south (S-sequence) and one on southwest (SW-sequence) slope with differing times since their abandonment (193, 142, 101, 63, 39 and 14 years), were compiled and studied. The S-sequence was 25-35% sloped and strongly eroded, and the SW-sequence was 17-25% sloped and moderately eroded. The sites were investigated in respect of vegetation characteristics, soil physico-chemical characteristics, total organic carbon stocks (TOC stocks), accumulation rates of total organic carbon (TOC accumulation rates), and soil profiles, which were classified according to the World Reference Base (WRB) 2014. Vegetation development resulted in shrub-grassland mosaics, supplemented frequently by protected forb species and forest development at the earliest abandonment in S-sequence, and predominantly to forest vegetation in SW-sequence, where trees were only absent at the 63 and 14 years old abandonment sites. In all sites soils on level of reference groups according to WRB were classified, and Cambisols, Regosols, Calcisols, Leptosols, Chernozems and Phaeozems were found. Soils of the S-sequence show shallow remnants of loess cover with colluvic and redeposited soil materials containing 15-65% skeletal volcanic rock of weathering products coated by secondary calcium carbonates. The SW-sequence profiles are developed on deep loess or loess derivatives. The calcium-carbonate content was higher in profiles of

  6. Litter contribution to soil organic carbon in the processes of agriculture abandon

    NASA Astrophysics Data System (ADS)

    Novara, A.; Rühl, J.; La Mantia, T.; Gristina, L.; La Bella, S.; Tuttolomondo, T.

    2015-04-01

    The mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in the functioning of the ecosystem, as they regulate the cycle of soil organic matter (SOM) and CO2 emission into the atmosphere. In this study the contribution of litters of different stages of Mediterranean secondary succession on carbon sequestration was investigated, analyzing the role of earthworms in the translocation of SOM into the soil profile. For this purpose the δ13C difference between meadow C4-C soil and C3-C litter was used in a field experiment. Four undisturbed litters of different stages of succession (45, 70, 100 and 120 since agriculture abandon) were collected and placed on the top of isolated C4 soil cores. The litter contribution to C stock was affected by plant species and it increased with the age of the stage of secondary succession. One year after the litter position, the soil organic carbon increased up to 40% in comparison to soils not treated with litter after 120 years of abandon. The new carbon derived from C3 litter was decomposed and transferred into soil profile thanks to earthworms and the leaching of dissolved organic carbon. After 1 year the carbon increase attributed to earthworm activity was 6 and 13% in the soils under litter of fields abandoned for 120 and 45 years, respectively.

  7. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Stephen C. Ruppel

    2006-02-01

    The field operator, Goldrus Producing Company, has been unable to secure funding needed to continue the field demonstration phase of the project. Accordingly, we have temporarily halted all project activities until necessary funding is obtained. Goldrus felt confident that funds could be acquired by third quarter 2005 at which time it would have been necessary to request a project extension to complete the originally designed study. A project extension was granted but it appears Goldrus will have difficulty securing funds. We Bureau of Economic Geology are investigating a new approach on how to fulfill our initial objectives of promoting high-pressure air injection of Ellenburger reservoirs.

  8. Pennsylvanian carbonate buildups, Paradox basin: Increasing reserves in heterogeneous, shallow-shelf reservoirs

    USGS Publications Warehouse

    Montgomery, S.L.; Chidsey, T.C., Jr.; Eby, D.E.; Lorenz, D.M.; Culham, W.E.

    1999-01-01

    Productive carbonate buildups of Pennsylvanian age in the southern Paradox basin, Utah, contain up to 200 million bbl remaining oil potentially recoverable by enhanced recovery methods. These buildups comprise over 100 satellite fields to the giant Greater Aneth field, where secondary recovery operations thus far have been concentrated. Several types of satellite buildups exist and produce oil from the Desert Creek zone of the Paradox Formation. Many of the relevant fields have undergone early abandonment; wells in Desert Creek carbonate mounds commonly produce at very high initial rates (>1000 bbl/day) and then suffer precipitous declines. An important new study focused on the detailed characterization of five separate reservoirs has resulted in significant information relevant to their future redevelopment. Completed assessment of Anasazi field suggests that phylloid algal mounds, the major productive buildup type in this area, consist of ten separate lithotypes and can be described in terms of a two-level reservoir system with an underlying high-permeability mound-core interval overlain by a lower permeability but volumetrically larger supramound (mound capping) interval. Reservoir simulations and related performance predictions indicate that CO2 flooding of these reservoirs should have considerable success in recovering remaining oil reserves.Productive carbonate buildups of Pennsylvanian age in the southern Paradox basin, Utah, contain up to 200 million bbl remaining oil potentially recoverable by enhanced recovery methods. These buildups comprise over 100 satellite fields to the giant Greater Aneth field, where secondary recovery operations thus far have been concentrated. Several types of satellite buildups exist and produce oil from the Desert Creek zone of the Paradox Formation. Many of the relevant fields have undergone early abandonment; wells in Desert Creek carbonate mounds commonly produce at very high initial rates (>1000 bbl/day) and then suffer

  9. How do soil properties and soil carbon stocks change after land abandonment in Mediterranean mountain areas?

    NASA Astrophysics Data System (ADS)

    Nadal Romero, Estela; Cammeraat, Erik; Pérez Cardiel, Estela; Lasanta, Teodoro

    2016-04-01

    Land abandonment and subsequent revegetation processes (due to secondary succession and afforestation practices) are global issues with important implications in Mediterranean mountain areas. Moreover, the effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions, and afforestation practices are increasingly viewed as an environmental restorative land use change prescription and are considered one of the most efficient carbon sequestration strategies currently available. The MED-AFFOREST project aims to gain more insight into the discussion by exploring the following central research questions: (i) what is the impact of land abandonment on soil properties? and (ii) how do soil organic carbon change after land abandonment? The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil properties and soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, meadows, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees were analysed. Results showed that changes in soil properties after land abandonment were limited, even if afforestation practices were carried out and no differences were observed between natural succession and afforestation. The results on SOC dynamics showed that: (i) SOC contents were higher in the PN sites in the topsoil (10 cm), (ii) when all the profile was considered no significant differences were observed between meadows and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) meadows should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration

  10. Organic carbon burial efficiency in a large tropical hydroelectric reservoir

    NASA Astrophysics Data System (ADS)

    Mendonça, Raquel; Sobek, Sebastian; Kosten, Sarian; Cole, Jonathan; Cardoso, Simone; Roland, Fábio

    2014-05-01

    Because hydroelectric reservoirs receive relatively high inputs of sediments when compared to lakes and oceans, these systems are important sites for organic carbon (OC) accumulation. Nevertheless, the actual magnitude of carbon accumulating in reservoirs is poorly known due to a lack of whole-system studies of carbon burial. Hydroelectric reservoirs are also particularly heterogeneous systems in terms of organic carbon sources and sedimentation rates. Such heterogeneity leads to strong variations on carbon fluxes, even though the effect on OC burial has not yet been discussed. The aim of this paper was to determine the OC burial rate and efficiency in a large tropical reservoir and evaluate the importance of spatial heterogeneity affecting OC burial. Burial rates were determined through a novel approach which combines sediment sample analyses and a seismic survey. Our results confirm the major effect of sedimentation heterogeneity on OC burial efficiency which varied from 9 to 89% in the reservoir. In addition to the river-dam gradient of sedimentation, our data reinforce the importance of basin morphometry in determining the patterns of sediment deposition and carbon accumulation. No carbon accumulation occurred along the margins of the reservoir and irregular bottom morphology leaded to irregular carbon deposition. An integrative analysis, including the reservoir's heterogeneity, indicated that the whole system accumulates 42.2 g C m-2 yr-1 and that roughly 67% of the total OC load to the sediments is actually buried. The data also suggest that the sediment of the reservoir is mainly composed of terrestrial OC and that the heterogeneity in OC sources plays a minor role determining OC burial efficiency, which was strongly determined by sediment accumulation rate. Finally, our results in combination with literature data suggest that the high sedimentation rates cause hydroelectric reservoirs to accumulate carbon more efficiently than lakes, regardless of

  11. Soil organic carbon accumulation in afforested/abandoned arable fields in Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Han; Cheng, Chih-Hsin; Huang, Yu-Hsuan

    2016-04-01

    Afforestation or abandonment of arable fields has been proposed as a way to increase terrestrial carbon storage and mitigate anthropogenic carbon emissions. When the arable fields are afforested or abandoned, the accumulation in soil organic carbon (SOC) is a key pool to sequestrate carbon. However, high uncertainties still exist in the tropics and subtropics because of fast SOC turnover rates and variable land use managements in these areas. In this study, a total of eleven sites with afforested/abandoned age over 15 years and elevation ranging from 16 to 2,056 m were investigated. We examined the increments of SOC by comparing with the adjacent tilled (e.g. croplands) and non-tilled (e.g. tea plantation or orchards) fields in two sampling layers, 0 - 10 and 10 - 20 cm in depth. In addition, density fractionation of SOC was also conducted in order to differentiate SOC into light fraction, intra-aggregate fraction, and heavy fraction to gain more information about the mechanism of SOC sequestration. Our results indicated that the increments of SOC concentration and stock varied with elevation, land use management, and soil depth. For the sites with elevation below 500 m, the SOC concentration and stock in the abandoned fields were 14.3 ± 0.9 mg C g‑1 and 14.6 ± 4.6 Mg C ha‑1 higher than the adjacent tilled fields, and 10.2 ± 6.3 mg C g‑1and 6.4 ± 6.2 Mg C ha‑1 higher than the adjacent non-tilled fields for surface 0-10 cm. For the sites with elevation above 500 m, the SOC concentration in the abandoned arable fields were 22.8 ± 12.8 mg C g‑1 higher than the adjacent tilled fields, but the SOC stock might not be different due to high stone content in abandoned field. Moreover, the SOC concentration and stock in abandoned field were not different or even less than non-tilled fields where organic amendments were frequently applied. The increments of SOC for 10-20 cm soils were less evident than those for surface 0-10 cm soils, and the differences were

  12. Quantification of functional soil organic carbon pools in a chronosequence of land abandonment in southern Spain.

    NASA Astrophysics Data System (ADS)

    Trigalet, Sylvain; Gabarrón-Galeote, Miguel A.; Van Oost, Kristof; van Wesemael, Bas

    2015-04-01

    Land abandonment is the dominant land use change in the Mediterranean, and determines the soil organic carbon (SOC) as the vegetation recovers during secondary succession. The rate of SOC recovery is influenced by environmental factors such as precipitation, soil properties or other local factors. Using aerial photographs taken in 1956, 1977, 1984, 1998, 2001 and 2009, a chronosequence of crop land abandonment was designed and topsoil samples were taken at each stage of recovery in a region North of Málaga. As SOC is a mixture of functional pools, it is important to isolate organic carbon with distinct functional properties to better understand the overall dynamic over decades. Using fractionation scheme introduced by Zimmermann et al. (2007), five fractions were isolated based on particle size, density and resistance: particulate organic matter (POM), dissolved organic carbon (DOC), SOC linked to silt and clay (s & c), SOC attached to sand particles or occluded in aggregates (S+A) and a chemically resistant fraction obtained by NaOCl oxidation (rSOC). Although there were no significant changes in particle-size distribution between the recovery stages (except for the croplands), there was a significant increase of S+A fraction over time (16 to 38%) at the expense of the s & c fraction (84 to 58%), indicating aggregation processes. Carbon concentrations within fractions S+A or rSOC did not change over time. Rather, carbon associated with silt and clay particles (s &c) was significantly affected after a few decades of abandonment. It increased from 5.7 gC.kg-1 in croplands to 10.3 gC.kg-1 in semi-natural plots. The chronosequence showed that carbon can be stored in more stable fractions. Taking into account active carbon (DOC + POM) and intermediate carbon (s & c, S+A) as indicators for carbon dynamics, we showed that the proportion of active carbon increased from 11% to 34% within the chronosequence. On the other hand, the proportion of slow cycling carbon

  13. Carbon Storage in Biologic and Oceanic Reservoirs: Issues and Opportunities

    NASA Astrophysics Data System (ADS)

    Caldeira, K.

    2007-12-01

    Most discussion of carbon capture and storage have focused on geologic reservoirs because these are the reservoirs most likely to provide for long-term storage with a minimum of adverse environmental consequences. Nevertheless, there is interest in storage in other reservoirs such as the biosphere or the oceans. Storage in biological reservoirs such as forests or agricultural soils may in many cases be relatively inexpensive. Because this biological storage involves carbon dioxide removal from the atmosphere, it can potentially offset emissions from the transportation sector. Biological storage can be politically popular because it can be deployed with simple technologies, can be deployed in developing countries, and in many cases involves other environmental co-benefits. However, total capacity is limited. Furthermore, biological storage is temporary unless the store is actively maintained forever. Such temporary storage can be valuable, although it is clearly not as valuable as the quasi-permanent storage offered by good geologic storage reservoirs Ocean storage options fall into two main classes. The first involves conventional separation and compression of carbon dioxide from large point sources which would then be piped into the deep ocean and released either into the water or as a lake on the sea floor. In either case, the carbon dioxide would eventually interact with the atmosphere and contribute to ocean acidification. However, there is potential for the development of long-term engineered containment of carbon dioxide on or in the sea floor. The second main ocean storage option involves increasing ocean alkalinity, probably by dissolving carbonate minerals. This approach may offer safe, quasi- permanent, and cost-effective storage in settings where coastal carbon dioxide point sources are co-located with carbonate mineral deposits. Not every location or carbon dioxide source is suitable for geologic storage of carbon dioxide. At this early stage, it is

  14. How do soil organic carbon stocks change after cropland abandonment in Mediterranean humid mountain areas?

    PubMed

    Nadal-Romero, E; Cammeraat, E; Pérez-Cardiel, E; Lasanta, T

    2016-10-01

    The effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions. Afforestation is increasingly viewed as an environmental restorative land use change prescription and is considered one of the most efficient carbon sequestration strategies currently available. Given the large quantity of CO2 that soils release annually, it is important to understand disturbances in vegetation and soil resulting from land use changes. The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, permanent pastureland, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees, were analysed. SOC dynamics have been studied in the bulk soil, and in the fractions separated according to two methodologies: (i) aggregate size distribution, and (ii) density fractionation, and rates of carbon mineralization have been determined by measuring CO2 evolution using an automated respirometer. The results showed that: (i) SOC contents were higher in the PN sites in the topsoil (10cm), (ii) when all the profiles were considered no significant differences were observed between pastureland and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) pastureland should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration experiments did not show evidence of SOC stabilization. SOC mineralization was higher in the top layers and values decreased with depth. These results gain insights into which type of land management is most appropriate after land abandonment for SOC

  15. Effect of land abandonment on soil organic carbon fractions along a precipitation gradient in Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Gabarron-Galeote, Miguel A.; Trigalet, Sylvain; van Wesemael, Bas

    2015-04-01

    Land abandonment has been the main land use change in rural European Mediterranean areas over the last decades. The secondary succession process following land abandonment is strongly affected by precipitation, which in consequence determines the parallel change of soil organic carbon (SOC) and other soil properties. SOC is usually assumed to increase due to the intensification of plant residues inputs to soil, above as well below ground. However, SOC is composed of different fractions with contrasting resistance to decomposition that can have different responses to land abandonment. The objectives of this study are: i) to determine the net effect of land abandonment on the different soil organic carbon fractions; ii) to assess the relation between vegetation evolution and SOC fractions; iii) to establish the conditions with the greater potential to store stable SOC along a precipitation gradient. Three field sites with contrasting annual precipitation (GAU: 1080.5 mm yr-1- ALM: 650 mm yr-1- GER: 350 mm yr-1) were selected. On each site Fields abandoned in different periods, as verified on aerial photographs taken in 1956, 1977, 1984, 1998, 2001, 2004 and 2009, were selected using a chronosequence approach. The fractionation protocol implemented was based on the separation of different soil particle sizes, which are associated to SOC pools with different degree of stability. Samples of the first 10 cm of soil were added to a sodium-hexametaphosphate (HMP) solution (40 g L-1) and shaken horizontally for 1h (150 r.p.m.). The soil solution was then sieved consecutively through two meshes of 250 µm and 50 µm, obtaining the following fractions: i) >250 µm (coarse fraction), it contains coarse particles (coarse sand) and plant residues (particulate organic matter, POM), easily decomposable, that constitute the more labile SOC pool; ii) 50 - 250 µm (mid fraction), it contains fine sand, fine POM easily decomposable and stable microaggregates, that contains SOC

  16. Secondary pores in carbonate reservoirs on Arabian Peninsula

    SciTech Connect

    Nurmi, R.; Waterhouse, M.; Watfa, M.

    1987-05-01

    Nearly all of the giant carbonate reservoirs on the Arabian Peninsula have both primary and secondary pore systems. There are, however, significant stratigraphic and geographic variations of origin, volume, and reservoir importance of secondary pores. The Permian Khuff reservoir zones generally has more secondary porosity than any younger, or shallower, reservoir formations. Highly permeable idiotopic (sucrosic) dolomites are commonly developed in zones which originally contained primary pores. The zones with the highest porosity often contain secondary pores, with calcite-free oomoldic dolomites having higher permeability than oomoldic limestones. Fractures resulting from halokinetics and/or salt dissolution are generally the most important secondary pores in Khuff reservoirs. The prolific Jurassic Arab reservoir zones, generally have lesser amounts of secondary pores than Khuff reservoirs, but a variety of secondary pores are present. Commonly the Arab C zone contains the greatest volume of secondary pores, generally of a moldic (grain and/or skeletal) nature. Secondary porosity associated with dolomitization is regionally more common in the eastern Gulf. Cretaceous (rudist) reefal and chalk reservoirs often contain zones of secondary porosity with enhanced permeability resulting from the leaching of aragonitic and high-magnesium calcite skeletal material. Secondary porosity is present in the western gulf in both the Minagish grainstones and dolomitized Shuaiba Formation, whereas the grainstones of the eastern gulf have little secondary porosity. Large fracture systems are present everywhere in low-permeability chalks and wackestones. An unusually high degree of porosity heterogeneity appears to be ubiquitous in Cretaceous sequences.

  17. Organic carbon burial efficiency in a large tropical hydroelectric reservoir

    NASA Astrophysics Data System (ADS)

    Mendonça, R.; Kosten, S.; Sobek, S.; Cardoso, S. J.; Figueiredo-Barros, M. P.; Estrada, C. H. D.; Roland, F.

    2015-11-01

    Hydroelectric reservoirs bury significant amounts of organic carbon (OC) in their sediments. Many reservoirs are characterized by high sedimentation rates, low oxygen concentrations in bottom water, and a high share of terrestrially derived OC, and all of these factors have been linked to a high efficiency of OC burial. However, investigations of OC burial efficiency (OCBE, i.e. the ratio between OC buried and deposited) in reservoirs is limited to a few studies, none of which include spatially resolved analyses. In this study we determined the spatial variation in OCBE in a large tropical reservoir and related it to sediment characteristics. Our results show that the sediment accumulation rate explains up to 92 % of the spatial variability in OCBE, outweighing the effect of other variables, such as OC source and oxygen exposure time. OCBE at the pelagic sites varied from 48 to 86 % (mean 67 %) and decreased towards the dam. At the margins, OCBE was lower (9 to 17 %) due to the low sediment accumulation in shallow areas. Our data show that the variability in OCBE both along the rivers-dam and the margin-pelagic axes must be considered in whole-reservoir assessments. Combining these results with a spatially resolved assessment of sediment accumulation and OC burial in the studied reservoir, we estimated a whole-basin OC burial efficiency of 57 %. Being the first whole-basin assessment of OCBE in a reservoir, these results suggest that reservoirs may bury OC more efficiently than natural lakes.

  18. Organic carbon burial efficiency in a subtropical hydroelectric reservoir

    NASA Astrophysics Data System (ADS)

    Mendonça, Raquel; Kosten, Sarian; Sobek, Sebastian; Jaqueline Cardoso, Simone; Figueiredo-Barros, Marcos Paulo; Henrique Duque Estrada, Carlos; Roland, Fábio

    2016-06-01

    Hydroelectric reservoirs bury significant amounts of organic carbon (OC) in their sediments. Many reservoirs are characterized by high sedimentation rates, low oxygen concentrations in bottom water and a high share of terrestrially derived OC, and all of these factors have been linked to a high efficiency of OC burial. However, investigations of OC burial efficiency (OCBE, i.e., the ratio between buried and deposited OC) in reservoirs are limited to a few studies, none of which include spatially resolved analyses. In this study we determined the spatial variation in OCBE in a large subtropical reservoir and related it to sediment characteristics. Our results show that the sediment accumulation rate explains up to 92 % of the spatial variability in OCBE, outweighing the effect of other variables, such as OC source and oxygen exposure time. OCBE at the pelagic sites varied from 48 to 86 % (mean 67 %) and decreased towards the dam. At the margins, OCBE was lower (9-17 %) due to the low sediment accumulation in shallow areas. Our data show that the variability in OCBE both along the rivers-dam and the margin-pelagic axes must be considered in whole-reservoir assessments. Combining these results with a spatially resolved assessment of sediment accumulation and OC burial in the studied reservoir, we estimated a spatially resolved mean OC burial efficiency of 57 %. Being the first assessment of OCBE with such a high spatial resolution in a reservoir, these results suggest that reservoirs may bury OC more efficiently than natural lakes.

  19. CARVE: The Carbon in Arctic Reservoirs Vulnerability Experiment

    NASA Technical Reports Server (NTRS)

    Miller, Charles E.; Dinardo, Steven J.

    2012-01-01

    The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is a NASA Earth Ventures (EV-1) investigation designed to quantify correlations between atmospheric and surface state variables for the Alaskan terrestrial ecosystems through intensive seasonal aircraft campaigns, ground-based observations, and analysis sustained over a 5-year mission. CARVE bridges critical gaps in our knowledge and understanding of Arctic ecosystems, linkages between the Arctic hydrologic and terrestrial carbon cycles, and the feedbacks from fires and thawing permafrost. CARVE's objectives are to: (1) Directly test hypotheses attributing the mobilization of vulnerable Arctic carbon reservoirs to climate warming; (2) Deliver the first direct measurements and detailed maps of CO2 and CH4 sources on regional scales in the Alaskan Arctic; and (3) Demonstrate new remote sensing and modeling capabilities to quantify feedbacks between carbon fluxes and carbon cycle-climate processes in the Arctic (Figure 1). We describe the investigation design and results from 2011 test flights in Alaska.

  20. Electrolyte reservoir for carbonate fuel cells

    DOEpatents

    Iacovangelo, C.D.; Shores, D.A.

    1984-05-23

    An electrode for a carbonate fuel cell and method of making same are described wherein a substantially uniform mixture of an electrode-active powder and porous ceramic particles suitable for a carbonate fuel cell are formed into an electrode with the porous ceramic particles having pores in the range of from about 1 micron to about 3 microns, and a carbonate electrolyte is in the pores of the ceramic particles.

  1. Electrolyte reservoir for carbonate fuel cells

    DOEpatents

    Iacovangelo, Charles D.; Shores, David A.

    1985-01-01

    An electrode for a carbonate fuel cell and method of making same wherein a substantially uniform mixture of an electrode-active powder and porous ceramic particles suitable for a carbonate fuel cell are formed into an electrode with the porous ceramic particles having pores in the range of from about 1 micron to about 3 microns, and a carbonate electrolyte is in the pores of the ceramic particles.

  2. Carbonate reservoir plays in the South Atlantic and worldwide analogs

    NASA Astrophysics Data System (ADS)

    Mohriak, Webster

    2015-04-01

    This work presents a summary of the geological, geophysical and petrophysical challenges for interpretation of post-salt and presalt carbonate rocks that constitute one of the main reservoirs in the hydrocarbon accumulations in the South Atlantic, particularly in the Campos and Santos basins offshore Brazil and in the Angola -Gabon conjugate margins. Carbonate rocks associated with salt tectonics constitute one of the main exploratory plays in several basins worldwide, and recently have yielded large petroleum discoveries in the southeastern Brazilian continental margin (Santos Basin) and also in Angola (Kwanza Basin) . The presalt microbialite reservoirs are sealed by evaporites and the origin of these rocks is still controversial. One current of interpretation assumes they are associated with reefs and carbonate buildups formed during periods of sea-level rises in a desiccating basin. Other currents of interpretation assume that these rocks might be associated with hydrothermal fluids and chemical precipitation of carbonates in a basin affected by volcanic episodes, resulting in travertine deposits with secondary biogenic growth. We present examples of post-salt oil fields involving Albian carbonates in the South Atlantic, and also discuss the presalt plays recently drilled in ultradeep waters. The presalt carbonate reservoirs are compared with possible microbialite analogs in the sedimentary basins of Brazil dating from Neoproterozoic to Recent, and their similarities and differences in terms of depositional setting and petrophysical parameters from the Late Aptian presalt carbonate rocks that have been sampled in the Santos and Kwanza basins.

  3. Lowstand carbonate reservoirs: Upper Pennsylvanian sea level changes and reservoir development adjoining Horseshoe Atoll

    SciTech Connect

    Mazzullo, S.J. ); Reid, A.M.; Reid, S.T.

    1990-02-01

    The majority of carbonate reservoirs comprising the Horseshoe Atoll were deposited as reefs and skeletal sand banks during sea level highstands of glacio-eustatic origin, during Canyon (Missourian) and Cisco (Virgilian) deposition. During lowstands, previously deposited carbonate rocks were exposed subaerially to intense meteoric dissolution and karstification creating the pore systems typical of most Horseshoe Atoll fields. Detailed biostratigraphic and sedimentologic studies and recent discoveries adjoining the Horseshoe Atoll have documented the deposition of in-situ and associated intraclastic limestone reservoirs deposited in former slope and basin locations concomittant with periods of sea level lowstand. The authors data suggest that the deposition of such reservoirs occurred throughout the Late Pennsylvanian and accompanied sea level drops of as great as 200 m. To date, productive lowstand reservoirs have been identified in rocks of the middle lower, upper lower, and upper middle Missourian, and the lower lower Virgilian. These deposits are represented by porous reefs, skeletal sandstones, and porous-to-tight intraclastic limestones previously referred to as satellite or pinnacle reefs. These deposits, subsequently onlapped and buried by deepwater shales, comprise potentially prolific stratigraphic-trap reservoirs in basinal areas seaward of the Horseshoe Atoll.

  4. ENHANCEMENT OF TERRESTRIAL CARBON SINKS THROUGH RECLAMATION OF ABANDONED MINE LANDS IN THE APPALACHIAN REGION

    SciTech Connect

    Gary D. Kronrad

    2002-12-01

    The U.S.D.I. Office of Surface Mining (OSM) estimates that there are approximately 1 million acres of abandoned mine land (AML) in the Appalachian region. AML lands are classified as areas that were inadequately reclaimed or were left unreclaimed prior to the passage of the 1977 Surface Mining Control and Reclamation Act, and where no federal or state laws require any further reclamation responsibility to any company or individual. Reclamation and afforestation of these sites have the potential to provide landowners with cyclical timber revenues, generate environmental benefits to surrounding communities, and sequester carbon in the terrestrial ecosystem. Through a memorandum of understanding, the OSM and the U.S. Department of Energy (DOE) have decided to investigate reclaiming and afforesting these lands for the purpose of mitigating the negative effects of anthropogenic carbon dioxide in the atmosphere. This study determined the carbon sequestration potential of northern red oak (Quercus rubra L.), one of the major reclamation as well as commercial species, planted on West Virginia AML sites. Analyses were conducted to (1) calculate the total number of tons that can be stored, (2) determine the cost per ton to store carbon, and (3) calculate the profitability of managing these forests for timber production alone and for timber production and carbon storage together. The Forest Management Optimizer (FORMOP) was used to simulate growth data on diameter, height, and volume for northern red oak. Variables used in this study included site indices ranging from 40 to 80 (base age 50), thinning frequencies of 0, 1, and 2, thinning percentages of 20, 25, 30, 35, and 40, and a maximum rotation length of 100 years. Real alternative rates of return (ARR) ranging from 0.5% to 12.5% were chosen for the economic analyses. A total of 769,248 thinning and harvesting combinations, net present worths, and soil expectation values were calculated in this study. Results indicate that

  5. Distribution, origin and prediction of carbon dioxide in petroleum reservoirs

    SciTech Connect

    Thrasher, J.; Fleet, A.J.

    1995-08-01

    High concentrations of carbon dioxide (CO{sub 2}) in petroleum reservoirs can significantly reduce the value of the discovery, by diluting any hydrocarbons, and by increasing production costs because of the increased likelihood of corrosion and scale formation. Huge volumes of CO{sub 2} have been found, for example in the Indonesian Natuna d-Alpha structure (estimated 240 tcf gas, of which around 70% is CO{sub 2}). This study reviews the possible sources of CO{sub 2} in the petroleum system, and the geological and geochemical data from some CO{sub 2} {open_quotes}polluted{close_quotes} reservoirs, to improve future predictions of the exploration risk of finding significant CO{sub 2}. A number of case studies show that the most common geological circumstances for the occurrence of high concentrations of CO{sub 2} include: carbonates associated with post-trap igneous activity (e.g. Ibleo Platform, Sicily); reservoir close to hot basement (e.g. Cooper-Eromanga Basin, Australia) and deep faults close to traps (e.g. Gulf of Thailand). Less common circumstances for high proportions of CO{sub 2} in gas include: post-trap igneous activity and coals (e.g. Taranaki, New Zealand) and reservoirs associated with pre-oil window coaly kerogen (e.g. Malay Trough), although the volumes of CO{sub 2} generated from kerogen are usually low relative to volumes of hydrocarbons generated from kerogen.

  6. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    SciTech Connect

    Stephen C. Ruppel

    2005-02-01

    Despite declining production rates, existing reservoirs in the US contain large quantities of remaining oil and gas that constitute a huge target for improved diagnosis and imaging of reservoir properties. The resource target is especially large in carbonate reservoirs, where conventional data and methodologies are normally insufficient to resolve critical scales of reservoir heterogeneity. The objectives of the research described in this report were to develop and test such methodologies for improved imaging, measurement, modeling, and prediction of reservoir properties in carbonate hydrocarbon reservoirs. The focus of the study is the Permian-age Fullerton Clear Fork reservoir of the Permian Basin of West Texas. This reservoir is an especially appropriate choice considering (a) the Permian Basin is the largest oil-bearing basin in the US, and (b) as a play, Clear Fork reservoirs have exhibited the lowest recovery efficiencies of all carbonate reservoirs in the Permian Basin.

  7. Seismic imaging a carbonate reservoir: The Paris Basin Dogger

    SciTech Connect

    Mougenot, D.

    1995-08-01

    Within the Dogger project, seven partners joined forces (CGG, DHYCA, EAP, ESSO-REP, IFP, TOTAL, TRITON France) to develop an appropriate seismic acquisition, processing and interpretation methodology in order to improve the description of the main oil reservoir (30 m) lying at the top of the Dogger carbonates in the Paris Basin, at a depth of 1900 m. High-resolution 2D Vibroseismic is used to record high frequencies (up to 100 Hz) at the level of the target, and provides sufficiently adequate vertical resolution for the reflections at the top and at the base of the reservoir not to interfere. The upper frequency content of the 3D seismic (70 Hz) is more difficult to enhance. Yet the essential contribution made by the 3D is to evidence, via horizon attributes, sub-meridian lineaments corresponding to faults with throw of several meters which is too weak to be detected on vertical sections. The distribution of these faults, via which water tends to invade the reservoir, and the organization of the amplitudes at the top reservoir reflector, which seems to suggest lateral variations in porosity, are a valuable guide for setting up wells. Three-component seismic (2D-3c) and S-wave emissions did not produce any reflections beyond 30 Hz at the level of the target which is a poor reflector (PS & SS). Only borehole seismic (VSP, offset VSP), where high frequencies are much less attenuated than with surface seismic, provides detailed imaging of the reservoir in converted mode (up to 110 Hz in PP and in PS). The combination of a continuous spatial sampling, such as that obtained in 3D, and of a Vibroseis emission adapted to frequency attenuation, such as that used in 2D, can supply useful information about the thin and discontinuous Dogger reservoir which cannot he provided by mere correlation of the borehole data.

  8. Carbon Sequestration in Unconventional Reservoirs: Geophysical, Geochemical and Geomechanical Considerations

    NASA Astrophysics Data System (ADS)

    Zakharova, Natalia V.

    In the face of the environmental challenges presented by the acceleration of global warming, carbon capture and storage, also called carbon sequestration, may provide a vital option to reduce anthropogenic carbon dioxide emissions, while meeting the world's energy demands. To operate on a global scale, carbon sequestration would require thousands of geologic repositories that could accommodate billions of tons of carbon dioxide per year. In order to reach such capacity, various types of geologic reservoirs should be considered, including unconventional reservoirs such as volcanic rocks, fractured formations, and moderate-permeability aquifers. Unconventional reservoirs, however, are characterized by complex pore structure, high heterogeneity, and intricate feedbacks between physical, chemical and mechanical processes, and their capacity to securely store carbon emissions needs to be confirmed. In this dissertation, I present my contribution toward the understanding of geophysical, geochemical, hydraulic, and geomechanical properties of continental basalts and fractured sedimentary formations in the context of their carbon storage capacity. The data come from two characterization projects, in the Columbia River Flood Basalt in Washington and the Newark Rift Basin in New York, funded by the U.S. Department of Energy through Big Sky Carbon Sequestration Partnerships and TriCarb Consortium for Carbon Sequestration. My work focuses on in situ analysis using borehole geophysical measurements that allow for detailed characterization of formation properties on the reservoir scale and under nearly unaltered subsurface conditions. The immobilization of injected CO2 by mineralization in basaltic rocks offers a critical advantage over sedimentary reservoirs for long-term CO2 storage. Continental flood basalts, such as the Columbia River Basalt Group, possess a suitable structure for CO2 storage, with extensive reservoirs in the interflow zones separated by massive impermeable

  9. Vertical stacking of reservoirs in Silurian carbonates of Appalachian basin

    SciTech Connect

    Smosna, R.; Conrad, J.M.; Maxwell, T.C.

    1988-08-01

    The distribution of modern reefs and oolites is controlled to a large degree by sea-floor topography. Likewise, paleotopographic highs in the Silurian Lockport Dolomite and underlying Keefer Sandstone provided optimum sites for the deposition of boundstone and grainstone reservoir facies. The Keefer Sandstone in western West Virginia was deposited as a series of subtidal sand waves with a relief of a few meters. During initial Lockport sedimentation, the turbulence, water chemistry, and light intensity were most favorable in shallow water over the Keefer sand waves, encouraging growth of coral-stromatoporoid patch reefs. Skeletal banks in the upper Lockport of eastern Kentucky also were established over topographic highs of earlier Lockport mounds. In a similar fashion, the upper Lockport of West Virginia was deposited as oolitic shoals that formed atop exposed mud mounds in the middle member. A slight rise of sea level created the agitated subtidal environment above the now-submerged mud mounds, and oolite bars developed. The reef, skeletal-bank, and oolite facies of the Lockport, and the Keefer Sandstone, are all petroleum reservoirs. Carbonate reservoirs can be identified in the subsurface by thicks on isopach maps, by their clean gamma-ray signature, and by a relatively high log porosity. Based on these criteria, seven potential fairways have been mapped in Kentucky. Because the distribution of buildups was greatly influenced by that of their predecessors, five of the fairways contain vertically stacked reservoir facies. These are particularly attractive because they can be drilled as multistory targets.

  10. Carbonate reservoirs at the Mesozoic-Tertiary unconformity, northeast Spain

    SciTech Connect

    Esteban, M.

    1988-08-01

    Carbonates at the Mesozoic-Tertiary unconformity in northeast Spain show four types/stages of evolution of reservoir properties: karstification, coastal reworking, Miocene organic buildups, and Pliocene burial. Subaerial exposure during Paleogene-early Miocene rifting developed a complex fracture-controlled paleokrast facies, showing up to three evolution levels with well-developed cavern and vuggy porosity (1). During the Miocene, the paleokrast profile was intensively reworked into a variety of breccias, conglomerates, and calcarenites in both alluvial and coastal depositional settings. Gravitational displacement of largely karstified hillsides was common. These reworked paleokarst deposits (2) present excellent reservoir properties. The Miocene formations onlap the karstified Mesozoic and the reworked facies; these formations include coral reefs and foramalgal buildups (3) with primary and secondary porosity. Finally, a late fracture event (attributed to the Pliocene) affected the buried and lithified paleokarst deposits and lower-middle Miocene formations (4). This fracture event is associated with vuggy corrosion, dolomitization, ore mineralization, and leaching of Mesozoic to middle Miocene carbonates. Several horizons with chalky microporosity are also tentatively related to this Pliocene event. These four phases of reservoir evolution are also recognized in northern Morocco and southern Italy.

  11. Wellbore stability analysis during the production of a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Alves, J.-L.; Coehlo, L.; Baud, P.; Guevara Junior, N.

    2009-04-01

    Carbonate reservoirs represent a major part of the world oil and gas reserves. During production, the extraction of hydrocarbons reduces pore pressure and thus causes an increase in the effective stress and mechanical compaction in the reservoir. The compactive deformation and failure may be spatially extensive or localized to the vicinity of the wellbore, but in either case the consequences can be economically severe involving surface subsidence, well failure and various production problems. The analysis of wellbore stability and more generally of deformation and failure in carbonate environments hinges upon a relevant constitutive modeling of carbonate rocks over a wide range of porosities. In this study, we performed a wellbore stability analysis for a lateral wellbore junction in three dimensions. The complex geometry for the wellbore junction was modeled with tetrahedral finite elements considering a rate independent elastic-plastic isotropic material that presented linear behavior during elastic strain and associated flow rule. A finite element model simulating drilling and production phases were done for field conditions from a deep water reservoir in Campos basin, offshore Brazil. In this context, several scenarios were studied considering true 3D orientation for both in situ stresses and geometry of the wellbore junction itself. We discussed the impact of constitutive modeling on the wellbore stability, based on new experimental data on two micritic porous carbonates. Series of conventional triaxial experiments were performed at room temperature in dry and wet conditions on samples of Comiso and Tavel limestones of respective porosity 17 and 16%. The wet samples were deformed in drained conditions with 10 MPa pore pressure. The initial yield stresses were identified as the critical stresses at the onset of shear-enhanced compaction, subsequent yield stresses were considered to depend on hardening given by the plastic volumetric strain. For both limestones

  12. Characterization of diagenetically altered carbonate reservoirs, South Cowden Grayburg Reservoir, West Texas

    SciTech Connect

    Lucia, F.J.; Ruppel, S.C.

    1996-12-31

    Much of the difficulty in constructing carbonate reservoir models for fluid-flow simulation results from diagenetic overprinting of depositional permeability patterns. In the South Cowden field, diagenetic effects result in (1) low porosity and permeability in the western and northern areas due to reduction of porosity by means of dolomitization and post-dolomitization compaction, (2) elimination of the petrophysical effects of depositional texture resulting from changes in particle size due to dolomitization, and (3) creation of a touching-vug pore system due to anhydrite dissolution. The extent of anhydrite alteration can be mapped to show three distinct diagenetic areas: those dominated by unaltered, altered, or dissolved anhydrite. Each alteration type has a unique acoustic-porosity transform that can be used to map the diagenetic areas and to calculate porosity when only acoustic logs are available. A single porosity-permeability transform characterizes the areas having unaltered and altered anhydrite, and the depositional stratigraphy is useful in constructing a reservoir model. A more favorable transform characterizes the area of dissolved anhydrite, and depositional stratigraphy is not useful in constructing a reservoir model because of the large effect of the diagenetic overprint.

  13. Changes in Soil Carbon and Nitrogen following Land Abandonment of Farmland on the Loess Plateau, China

    PubMed Central

    Deng, Lei; Shangguan, Zhou-Ping; Sweeney, Sandra

    2013-01-01

    The revegetation of abandoned farmland significantly influences soil organic C (SOC) and total N (TN). However, the dynamics of both soil OC and N storage following the abandonment of farmland are not well understood. To learn more about soil C and N storages dynamics 30 years after the conversion of farmland to grassland, we measured SOC and TN content in paired grassland and farmland sites in the Zhifanggou watershed on the Loess Plateau, China. The grassland sites were established on farmland abandoned for 1, 7, 13, 20, and 30 years. Top soil OC and TN were higher in older grassland, especially in the 0–5 cm soil depths; deeper soil OC and TN was lower in younger grasslands (<20 yr), and higher in older grasslands (30 yr). Soil OC and N storage (0–100 cm) was significantly lower in the younger grasslands (<20 yr), had increased in the older grasslands (30 yr), and at 30 years SOC had increased to pre-abandonment levels. For a thirty year period following abandonment the soil C/N value remained at 10. Our results indicate that soil C and TN were significantly and positively correlated, indicating that studies on the storage of soil OC and TN needs to focus on deeper soil and not be restricted to the uppermost (0–30 cm) soil levels. PMID:23940793

  14. Anisotropic rock physics models for interpreting pore structures in carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Li, Sheng-Jie; Shao, Yu; Chen, Xu-Qiang

    2016-03-01

    We developed an anisotropic effective theoretical model for modeling the elastic behavior of anisotropic carbonate reservoirs by combining the anisotropic self-consistent approximation and differential effective medium models. By analyzing the measured data from carbonate samples in the TL area, a carbonate pore-structure model for estimating the elastic parameters of carbonate rocks is proposed, which is a prerequisite in the analysis of carbonate reservoirs. A workflow for determining elastic properties of carbonate reservoirs is established in terms of the anisotropic effective theoretical model and the pore-structure model. We performed numerical experiments and compared the theoretical prediction and measured data. The result of the comparison suggests that the proposed anisotropic effective theoretical model can account for the relation between velocity and porosity in carbonate reservoirs. The model forms the basis for developing new tools for predicting and evaluating the properties of carbonate reservoirs.

  15. Improved Methodology for Estimating Recovery Factor of Carbonate Reservoirs Using Geological Parameters

    NASA Astrophysics Data System (ADS)

    Park, E.; Lee, M.; Keehm, Y.; Kwon, Y. K.

    2014-12-01

    Carbonate reservoirs are highly complicated and heterogeneous than typical sandstone reservoirs, because of their depositional and diagenetic complexity. Therefore estimating the prospectiveness in an early stage of reservoir development is not an easy task. Typically we use an empirical equation, which calculates recovery factor (RF) for this assessment. Since the equation was created with reservoir parameters (porosity, water saturation, permeability, viscosity, pressure, etc.) from sandstone reservoirs, the applicability to carbonate reservoirs is questionable. We compiled 97 carbonate reservoirs and created a database with reservoir properties, geological information, and production data. First, we applied the existing empirical equation to our data and the results were disappointing: the predicted RF's was far off from actual values and correlation was also poor. We then modified the equation by adding geological parameters, such as play type, reservoir age, reservoir type, porosity type, trap information. The new equation was modelled by determining the coefficient of each parameter using least-square minimizing scheme. The modified equation estimated the recovery factor much better and more reliably. We think that the additional geological information is essential for accurate assessment of carbonate reservoirs in early stage of development, since the carbonate reservoirs show high variability and complexity by depositional and diagenetic changes. Acknowledgements: This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Trade, Industry and Energy of Korea (GP2012-029).

  16. Carbon pool and biomass dynamics associated with deforestation, land use, and agricultural abandonment in the neotropics.

    PubMed

    Kauffman, J Boone; Hughes, R Flint; Heider, Chris

    2009-07-01

    Current rates of deforestation and the resulting C emissions in the tropics exceed those of secondary forest regrowth and C sequestration. Changing land-use strategies that would maintain standing forests may be among the least expensive of climate change mitigation options. Further, secondary tropical forests have been suggested to have great value for their potential to sequester atmospheric C. These options require an understanding of and capability to quantify C dynamics at landscape scales. Because of the diversity of physical and biotic features of tropical forests as well as approaches and intensities of land uses within the neotropics, there are tremendous differences in the capacity of different landscapes to store and sequester C. Major gaps in our current knowledge include quantification of C pools, rates and patterns of biomass loss following land-cover change, and quantification of the C storage potential of secondary forests following abandonment. In this paper we present a synthesis and further analyses from recent studies that describe C pools, patterns of C decline associated with land use, and rates of C accumulation following secondary-forest establishment--all information necessary for climate-change mitigation options. Ecosystem C pools of Neotropical primary forests minimally range from approximately 141 to 571 Mg/ha, demonstrating tremendous differences in the capacity of different forests to store C. Most of the losses in C and nutrient pools associated with conversion occur when fires are set to remove the slashed forest to prepare sites for crop or pasture establishment. Fires burning slashed primary forests have been found to result in C losses of 62-80% of prefire aboveground pools in dry (deciduous) forest landscapes and 29-57% in wet (evergreen) forest landscapes. Carbon emissions equivalent to the aboveground primary-forest pool arise from repeated fires occurring in the first 4 to 10 years following conversion. Feedbacks of climate

  17. Carbon Sequestration in Unconventional Reservoirs: Advantages and Limitations

    NASA Astrophysics Data System (ADS)

    Zakharova, N. V.; Slagle, A. L.; Goldberg, D.

    2014-12-01

    To make a significant impact on anthropogenic CO2 emissions, geologic carbon sequestration would require thousands of CO2 repositories around the world. Unconventional reservoirs, such as igneous rocks and fractured formations, may add substantial storage capacity and diversify CO2 storage options. In particular, basaltic rocks represent a promising target due to their widespread occurrence, potentially suitable reservoir structure and high reactivity with CO2, but a comprehensive evaluation of worldwide CO2 sequestration capacity in unconventional reservoirs is lacking. In this presentation we summarize available data on storage potential of basaltic rocks and fractured formations illustrated by field examples from the Columbia River Basalt, the Newark Rift Basin and IODP Site 1256, and discuss potential limiting factors, such as effective porosity and the risk of inducing earthquakes by CO2 injections. Large Igneous Provinces (LIPs), low-volume flows and intrusions, and ocean floor basalt represent three general classes of basaltic reservoirs, each characterized by different structure and storage capacity. Oceanic plateaus and LIPs are projected to have the highest CO2 storage capacity, on the order of thousands gigatons (Gt) per site, followed by continental LIPs and ocean floor basalts (hundreds to thousands Gt per site). Isolated basalt flows and intrusions are likely to offer only low- to moderate-capacity options. An important limiting factor on CO2 injection volumes and rates is the risk of inducing earthquakes by increasing pore pressure in the subsurface. On continents, available in situ stress analysis suggests that local stress perturbations at depth may create relaxed stress conditions, allowing for pore pressure increase without reactivating fractures and faults. Remote storage sites on oceanic plateaus and below the seafloor are advantageous due to low impact of potential seismic and/or leakage events. Other effects, such as thermal stresses created

  18. Carbon Reservoir History of Mars Constrained by Atmospheric Isotope Signatures

    NASA Astrophysics Data System (ADS)

    Hu, Renyu; Kass, David M.; Ehlmann, Bethany L.; Yung, Yuk

    2014-11-01

    The evolution of the atmosphere on Mars is one of the most intriguing problems in the exploration of the Solar System, and the climate of Mars may have evolved from a warmer, wetter early state to the cold, dry current state. Because CO2 is the major constituent of Mars’s atmosphere, its isotopic signatures offer a unique window to trace the evolution of climate on Mars. Here we use a box model to trace the evolution of the carbon reservoir and its iso-topic signature on Mars, with carbonate deposition and atmospheric escape as the two sinks and magmatic activity as the sole source. We derive new quantitative constraints on the amount of carbonate deposition and the atmospher-ic pressure of Mars through time, extending into the Noachian, ~3.8 Gyr before present. This determination is based on recent Mars Science Laboratory (MSL) isotopic measurements of Mars’s atmosphere, recent orbiter, lander, and rover measurements of Mars’s surface, and a newly identified mechanism (photodissociation of CO) that efficiently enriches the heavy carbon isotope. In particular, we find that escape via CO photodissociation on Mars has a frac-tionation factor of 0.6 and hence, photochemical escape processes can effectively enrich 13C in the Mars’s atmos-phere during the Amazonian. As a result, modest carbonate deposition must have occurred early in Mars’s history to compensate the enrichment effects of photochemical processes and also sputtering, even when volcanic outgassing up to 200 mbar occurred during the Hesperian. For a photochemical escape flux that scales as the square of the solar EUV flux or more, at least 0.1 bar of CO2 must have been deposited as carbonates in the Noachian and Hesperian. More carbonate deposition would be required if carbonate deposition only occurred in the Noachian or with low fractionation factors.

  19. Carbon Reservoir History of Mars Constrained by Atmospheric Isotope Signatures

    NASA Astrophysics Data System (ADS)

    Hu, R.; Kass, D. M.; Ehlmann, B. L.; Yung, Y. L.

    2014-12-01

    The evolution of the atmosphere on Mars is one of the most intriguing problems in the exploration of the Solar System, and the climate of Mars may have evolved from a warmer, wetter early state to the cold, dry current state. Because CO2 is the major constituent of Mars's atmosphere, its isotopic signatures offer a unique window to trace the evolution of climate on Mars. Here we use a box model to trace the evolution of the carbon reservoir and its isotopic signature on Mars, with carbonate deposition and atmospheric escape as the two sinks and magmatic activity as the sole source. We derive new quantitative constraints on the amount of carbonate deposition and the atmospheric pressure of Mars through time, extending into the Noachian, ~3.8 Gyr before present. This determination is based on recent Mars Science Laboratory (MSL) isotopic measurements of Mars's atmosphere, recent orbiter, lander, and rover measurements of Mars's surface, and a newly identified mechanism (photodissociation of CO) that efficiently enriches the heavy carbon isotope. In particular, we find that escape via CO photodissociation on Mars has a fractionation factor of 0.6 and hence, photochemical escape processes can effectively enrich 13C in the Mars's atmosphere during the Amazonian. As a result, modest carbonate deposition must have occurred early in Mars's history to compensate the enrichment effects of photochemical processes and also sputtering, even when volcanic outgassing up to 200 mbar occurred during the Hesperian. For a photochemical escape flux that scales as the square of the solar EUV flux or more, at least 0.1 bar of CO2 must have been deposited as carbonates in the Noachian and Hesperian. More carbonate deposition would be required if carbonate deposition only occurred in the Noachian or with low fractionation factors.

  20. New flow model for the triple media carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Nie, Renshi; Meng, Yingfeng; Yang, Zhaozhong; Guo, Jianchun; Jia, Yonglu

    2011-02-01

    A new flow model in triple media carbonate reservoir is established. There exists a triple total system including the matrix, fracture and vug subsystem, and the three subsystems are relatively independent in physical properties; in the process of oil flow, the inter-porosity flow of the vug subsystem to fracture subsystem would occur and the inter-porosity flow of the matrix subsystem to fracture subsystem would also occur and ignore the inter-porosity flow between the matrix subsystem and vug subsystem. Compared with the traditional model (the inter-porosity flow of vug to fracture is pseudo-steady), the new model considers the unsteady inter-porosity flow, based on the hypothesis that the shape of vug is spherical. The new model is illustrated and solved, and the standard type curves are drawn up, so the process and characteristics of flow are analysed thoroughly, and it is found that the new-style type curves in shape and characteristics are evidently different from the type curves of traditional model. The research would not only deepen the understanding of flow law but also enrich the theoretical models for carbonate reservoir. The research results on this new model could be applied to a real case study.

  1. Carbon sequestration in response to rising atmospheric CO2 in active and abandoned pine plantations of the southeastern US

    NASA Astrophysics Data System (ADS)

    Davis, S. C.; Drake, J. E.; Delucia, E. H.

    2010-12-01

    There is a new interest in managing pine plantations for bioenergy and carbon sequestration, but it is debated whether or not carbon storage of an aging abandoned plantation ecosystem is greater than that of an actively harvested pine plantation. Using a chronosequence of loblolly pine sites that were abandoned in different years, we compare the long term carbon budget of an aggrading forest over 115 years with the carbon budget of a repeatedly harvested loblolly pine plantation over 115 years. Using the integrated δ13C signal of wood from tree cores as well as canopy leaf gas exchange, we are able to contrast the physiological response to climate change of forests in these varied age classes. The decline in C assimilation in older forests can be explained by the ratio of internal leaf CO2 concentrations to atmospheric CO2 concentrations (Ci/Ca) using the Ca in the establishment year of a plantation forest or the Ca of the current year. Using this contrasting approach, we developed a new hypothesis for the interactive effects of age and climate on forest carbon sequestration. If canopy physiological efficiency is determined by growth conditions at an early age as our data suggest, then the photosynthetic response of a forest canopy to rising atmospheric CO2 is progressively reduced over time in newly established forest stands. We describe a new approach to scaling the effects of atmospheric CO2 concentrations with forest age. The findings of this research have important implications for land management for bioenergy and carbon sequestration under changing climatic conditions.

  2. Wellbore stability analysis in carbonate reservoir considering anisotropic behaviour

    NASA Astrophysics Data System (ADS)

    Alves, José; Guevara, Nestor; Coelho, Lucia; Baud, Patrick

    2010-05-01

    Carbonate reservoirs represent a major part of the world oil and gas reserves. In particular, recent discoveries in the pre-salt offshore Brazil place big challenges to exploration and production under high temperatures and pressures (HTHP). During production, the extraction of hydrocarbons reduces pore pressure and thus causes an increase in the effective stress and mechanical compaction in the reservoir. The compactive deformation and failure may be spatially extensive or localized to the vicinity of the wellbore, but in either case the consequences can be economically severe involving surface subsidence, well failure and various production problems. The analysis of wellbore stability and more generally of deformation and failure in carbonate environments hinges upon a relevant constitutive modeling of carbonate rocks over a wide range of porosities, in particular, observed microstructure of samples suggests anisotropic behaviour. In this study, we performed a wellbore stability analysis for a lateral wellbore junction in three dimensions. The complex geometry for the wellbore junction was modeled with tetrahedral finite elements considering a rate independent elastic-plastic isotropic material that presented linear behavior during elastic strain and associated flow rule. A finite element model simulating drilling and production phases were done for field conditions from a deep water reservoir in Campos basin, offshore Brazil. In this context, several scenarios were studied considering true 3D orientation for both in situ stresses and geometry of the wellbore junction itself. We discussed the impact of constitutive modeling, considering anisotropic ductile damage and pressure sensitiveness on the wellbore stability. Parameter values for the analysis were based based on experimental data on two micritic porous carbonates. Series of conventional triaxial experiments were performed at room temperature in dry and wet conditions on samples of Comiso and Tavel

  3. An Integrated Approach to Predicting Carbon Dioxide Storage Capacity in Carbonate Reservoirs

    NASA Astrophysics Data System (ADS)

    Smith, M. M.; Hao, Y.; Mason, H. E.; Carroll, S.

    2015-12-01

    Carbonate reservoirs are widespread globally but pose unique challenges for geologic carbon dioxide (CO2) storage due to the reactive nature of carbonate minerals and the inherently heterogeneous pore structures of these rock types. Carbonate mineral dissolution resulting from CO2-acidified fluids may actually create new storage capacity, but predicting the extent and location of enhanced storage is complicated by the presence of pore size distributions spanning orders of magnitude as well as common microfractures. To address this issue, core samples spanning a wide range of depths and predicted permeabilities were procured from wells drilled into the Weyburn-Midale reservoir from the IEA GHG's CO2 Monitoring and Storage Project, Saskatchewan, Canada; and from the Arbuckle dolomite at the Kansas Geological Survey's South-central Kansas CO2 Project. Our approach integrated non-invasive characterization, complex core-flooding experiments, and 3-D reactive transport simulations to calibrate relevant CO2 storage relationships among fluid flow, porosity, permeability, and chemical reactivity. The resulting observations from this work permit us to constrain (and place uncertainty limits on) some of the model parameters needed for estimating evolving reservoir CO2 storage capacity. The challenge remains, however, as to how to best interpret and implement these observations at the actual reservoir scale. We present our key findings from these projects and recommendations for storage capacity predictions. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  4. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Quarterly technical progress report, July--September, 1995

    SciTech Connect

    Cole, R.; Prieditis, J.; Vogt, J. Wehner, S.

    1995-10-15

    The principal objective of the Central Vacuum Unit (CVU) CO{sub 2} Huff-n-Puff (H-n-P) project is to determine the feasibility and practicality of the technology in a waterflooded shallow shelf carbonate environment. The results of parametric simulation of the CO{sub 2} H-n-P process, coupled with the CVU reservoir characterization components will determine if this process is technically and economically feasible for field implementation. The technology transfer objective of the project is to disseminate the knowledge gained through an innovative plan in support of the Department of Energy`s (DOE) objective of increasing domestic oil production and deferring the abandonment of shallow shelf carbonate (SSC) reservoirs. Tasks associated with this objective are carried out in what is considered a timely effort for near-term goals.

  5. Generation of saturation functions for simulation models of carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Huang, Qingfeng

    A rock type is the unit of rock deposited under similar conditions, which went through similar diagenetic processes, producing analogous rock fabric, with distinct set of pore types, and pore throat size distribution, having specific range of porosity and permeability. Rock typing can generally be used as a guide to assign petrophysical characteristics to different zones for detailed reservoir characterization, modeling and simulation, which provide valid frames for reservoir development. It is often assumed that conventional rock types are capable of assigning multiphase flow characteristics, such as capillary pressure and relative permeability to the cells of dynamic simulation models. However, these conventional rock types, or static reservoir rock types (SRRT) fail to capture the actual variability of capillary pressure and relative permeability, due to lack of representation of wettability difference at different elevation above the free water level (FWL) in carbonate reservoirs, especially in the highly heterogeneous reservoirs. This should be resolved through dynamic reservoir rock types (DRRT), in which wettability effect is imposed on the SRRTs to generate saturation functions for simulation models. This research studies Ghedan's comprehensive DRRT model7, and proposes a modified Ghedan's model. First, the defined static rock types are sub-divided into sub-static rock types based on porosity frequency. Second, three curve-fitting programs are coded to generate the related saturation-height functions. These are the modified Ghedan-Okuyiga equation, Cuddy function and Power Law function. Developed from Ghedan-Okuyiga function113, the recommended modified Ghedan-Okuyiga function has been proposed with saturation and implicit porosity as a function of height above FWL in the transition zone. Third, each sub-static rock type is divided into a number of DRRTs by determining the capillary pressure and relative permeability curves in the oil zone from gas

  6. Carbon implications of Virgin Lands Campaign cropland expansion and post-Soviet agricultural land abandonment in Russia and Kazakhstan

    NASA Astrophysics Data System (ADS)

    Prishchepov, A. V.; Kurganova, I.; Schierhorn, F.; Lopes de Gerenyu, V.; Müller, D.; Kuzyakov, Y.

    2015-12-01

    Political economy and institutional changes regarding land use play crucial role in shaping land cover worldwide. Among such events was the Soviet Virgin Lands Campaign, when 45.2 million ha of virgin steppes were ploughed up from 1954 to 1963 in northern Eurasia. We took opportunity to evaluate carbon (C) costs of this Campaign, particularly with the account of massive cropland abandonment in the former Campaign area after demise of the Soviet Union in 1991. Within cropland mask produced with remotely sensed data, we spatially disaggregated historical annual sown area statistics at the provincial level for Russia and Kazakhstan based on cropland suitability assessment. We also adjusted our cropland allocation model with the use of 1:3,000,000 map depicting cropland expansion in Northern Kazakhstan. We used C bookkeeping approach to assess C dynamics based on soil stratification and C field measurements. The Campaign resulted in huge C losses from soils, which accounted for 611±47 Mt C in Russia and 241±11 Mt C in Kazakhstan for upper 0-50 cm soil layer during the first 20 years of cultivation. Such C losses could be compared with C losses due to plowing up the prairies in the mid-1930s in USA. Despite the huge C losses from soils during the Campaign, the total C budget in soils of both countries at national level was positive after 1991 due to sequestered C on abandoned lands, albeit the patterns of C loss during the Campaign and C sink in post-Soviet period differed. The C sink from 1991 to 2010 on abandoned croplands in Russia (45.5Mha) comprised 976±108Mt C and Kazakhstan (12.9Mha) comprised 240±34Mt C. However, already ongoing recultivation of abandoned cropland in Kazakhstan and already planned such activities in Russia, can release stored C on abandoned lands. Our study highlights the importance of environmental evaluation of such governmental programs and their alternatives, particularly, since such programs are not rare events in modern land

  7. Integrated geologic and engineering determination of oil-reserve-growth potential in carbonate reservoirs

    SciTech Connect

    Holtz, M.H.; Rupel, S.C.; Hocott, C.R. )

    1992-11-01

    Leonardian restricted-platform carbonate reservoirs in the Permian Basin in West Texas and southeastern New Mexico exhibit abnormally low recovery efficiencies. Cumulative production form these mature reservoirs is only 18% of the original oil in place (OOIP), or about one-half the average recovery efficiency of Permian Basin carbonate reservoirs. Low recovery efficiency is directly related to high degrees of vertical and lateral facies heterogeneity caused by high-frequency, cyclic sedimentation in low-energy, carbonate platform environments and by equally complex postdepositional diagenesis. This paper reports that because of their geologic complexity, these reservoirs have high reserve-growth potential.

  8. Field Demonstration of Horizontal Infill Drilling Using Cost-effective Integrated Reservoir Modeling--Mississippian Carbonates, Central Kansas

    SciTech Connect

    Saibal Bhattacharya

    2005-08-31

    Mississippian carbonate reservoirs have produced in excess of 1 billion barrels of oil in Kansas accounting for over 16% of the state's production. With declining production from other age reservoirs, the contribution of Mississippian reservoirs to Kansas's oil production has risen to 43% as of 2004. However, solution-enhanced features such as vertical shale intervals extending from the karst erosional surface at the top introduce complexities/compartmentalizations in Mississippian carbonate reservoirs. Coupled with this, strong water drives charge many of these reservoirs resulting in limited drainage from vertical wells due to high water cuts after an initial period of low water production. Moreover, most of these fields are operated by small independent operators without access to the knowledge bank of modern research in field characterization and exploitation/development practices. Thus, despite increasing importance of Mississippian fields to Kansas production, these fields are beset with low recovery factors and high abandonment rates leaving significant resources in the ground. Worldwide, horizontal infill wells have been successful in draining compartmentalized reservoirs with limited pressure depletion. The intent of this project was to demonstrate the application of horizontal wells to successfully exploit the remaining potential in mature Mississippian fields of the mid-continent. However, it is of critical importance that for horizontal wells to be economically successful, they must be selectively targeted. This project demonstrated the application of initial and secondary screening methods, based on publicly available data, to quickly shortlist fields in a target area for detailed studies to evaluate their potential to infill horizontal well applications. Advanced decline curve analyses were used to estimate missing well-level production data and to verify if the well produced under unchanging bottom-hole conditions--two commonly occurring data

  9. Mantle carbon fluxes and reservoirs: A status update

    NASA Astrophysics Data System (ADS)

    Hirschmann, M. M.

    2015-12-01

    Carbon masses in and fluxes from the mantle are topics of intense community interest, but remain uncertain. Recent (2010-2015) estimates of ridge carbon fluxes and total mantle C concentrations each vary by a factors of 30 (0.3-8.4 X 1014 g CO2/year) and 38 (20-765 ppm C), respectively. Early estimates of C fluxes at ridges depended chiefly on C/3He ratios, but the recognition of kinetic C/He fractionation during degassing renders these estimates unsound. Methods based on CO2/Nb and CO2/Ba ratios benefit from a greatly expanded set of observations of minimally degassed MORB glasses and melt inclusions, as well as new constraints on the Nb and Ba concentrations of mean oceanic crust. Quite liberal bounds on MORB CO2/Nb and CO2/Ba of 550±250 and 125±50, combined with the ALLMORB (Gale et al. 2013) or global average MORB of Arevalo and McDonough (2010) concentrations of Nb and Ba yield fluxes of 2.1±1.3 X 1014 g CO2/year, thereby reducing the ridge flux uncertainty to a factor of 4. The C flux from oceanic islands, however, remains almost entirely unconstrained. For bulk mantle C, estimates based on He and Ar suffer from problems similar to those related to fluxes - C/He/Ar are strongly fractionated by degassing. As the upper mantle reservoir is well-constrained by sampling from MORB, uncertainty derives chiefly from the deep (OIB source) reservoir . High average mantle C (e.g. 300 or 765 ppm C; Dasgupta and Hirschmann, 2010; Marty, 2012) requires a deep C-rich reservoir that is a large fraction of the mantle (>30%), which means that it must be in part primitive (i.e. it is volatile-rich but cannot be chiefly recycled) and is too large to be "hidden", so should be sampled by OIB. Assuming source Ba and Nb concentrations similar to primitive mantle, bulk mantle with 300 or 765 ppm C require OIB sources with CO2/Ba >700-1400 and CO2/Nb>2800-5200, and would produce magmas (with appropriate Ba and Nb concentrations for OIB) with 20-40 wt.% CO2. These are far beyond any

  10. CO2 Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Annual report, January 1, 1995--December 31, 1995

    SciTech Connect

    Wehner, S.C.; Boomer, R.J.; Cole, R.; Preiditus, J.; Vogt, J.

    1996-09-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg/San Andres formation; a light oil, shallow shelf carbonate reservoir within the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico.

  11. Soil organic carbon response to land abandonment along a pluviometric gradient in Mediterranean conditions (South of Spain).

    NASA Astrophysics Data System (ADS)

    Gabarron-Galeote, Miguel A.; Trigalet, Sylvain; van Wesemael, Bas

    2014-05-01

    Land abandonment has been the most important land use change in Mediterranean region over the last decades. After this conversion, a secondary succession process begins, during which soil organic carbon (SOC) is usually assumed to increase. However, the rate of accumulation strongly depends on climatic conditions and the extent to which precipitation and temperature determine SOC dynamics is largely unknown. The objective of this study is the estimation of SOC dynamic after land abandonment along a pluviometric gradient (1085-650-350 mm y-1). Plots abandoned in different periods (chronosequence) were selected on each site. SOC was determined using a spectrometer and dry combustion, vegetation cover was described, and NDVI, used as indicator of organic matter input to soils, was calculated from LANDSAT images. SOC increased following a logistic model in the two wettest sites, with decreasing accumulation rates as SOC stock approached a plateau. Accumulation rates were proportional to precipitation, being 0.16 for the wettest and 0.03 kg C m-2 y-1 for the intermediate site until reaching the long-term state, in 8 and 49 years respectively. In the driest site no SOC accumulation was measured. SOC and NDVI followed parallel trends along the gradient, so SOC stocks were mainly driven by inputs from vegetation. In addition, on the driest extreme of the gradient, another chronosequence was sampled at high altitude and low temperature. In this case, NDVI evolved following a logistic function but values were not high enough and organic matter input to soil did not trigger SOC accumulation.

  12. Temperature-pressure conditions in coalbed methane reservoirs of the Black Warrior basin: Implications for carbon sequestration and enhanced coalbed methane recovery

    USGS Publications Warehouse

    Pashin, J.C.; McIntyre, M.R.

    2003-01-01

    equilibrate toward a normal hydrostatic pressure gradient after abandonment. Coal can hold large quantities of carbon dioxide under supercritical conditions, and supercritical isotherms indicate non-Langmiur conditions under which some carbon dioxide may remain mobile in coal or may react with formation fluids or minerals. Hence, carbon sequestration and enhanced coalbed methane recovery show great promise in subcritical reservoirs, and additional research is required to assess the behavior of carbon dioxide in coal under supercritical conditions where additional sequestration capacity may exist. ?? 2003 Elsevier Science B.V. All rights reserved.

  13. Monitoring of water and thermal transfers in the vadose zone of a carbonate reservoir formation.

    NASA Astrophysics Data System (ADS)

    Cerepi, A.; Loisy, C.; Burlot, R.

    2009-04-01

    The aim of this study is the monitoring of water and thermal transfers in vadose zone of a carbonate reservoir formation during three hydrological cycles (August 2001- November 2004). The application of the Time Domain Reflectometry (TDR) and Self-Potential (SP) methods to determine the water content of porous rock has been widely investigated. More than 285 studied point measurements of rock water content observed during three hydrological cycles and distributed among an abandoned underground quarry in Gironde, France, show a permanently undersaturated limestone (between 35% and 50 %). We also investigated the unsaturated zone in a borehole between 0 and 20 m depth until the water table. 14 TDR and SP electrodes investigate the vadose zone. For the understanding of the streaming potential and electric behaviour from the SP method of a vadose zone we performed an experimental device which allows us to quantify the measurements of electrokinetic coupling coefficient at various saturation conditions. The results show that the vadose zone is characterized by three different sub-zones which are different water dynamics. The shallow zone down to a depth of seven meters corresponds to a zone with a significant variation of water saturation related to evapotranspiration dynamic water. The second zone (so-called transition zone) between seven to sixteen meters displays a high stability. The third zone (zone of capillary fringe) between sixteen to twenty meter shows a high and constant water saturation. Experimental results show three periods of maximum water content corresponding to three occurring effective precipitations. The dephasing and the amplitude attenuation of the hydraulic and thermal waves with the depth can be modelled and explained by the physical properties of the porous medium in an unsaturated zone such as the diffusivity, the water relative permeability, the capillarity pressure versus water saturation and the effective porosity.

  14. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir, Class II

    SciTech Connect

    Hickman, T. Scott; Justice, James J.; Egg, Rebecca

    2001-08-07

    The Oxy operated Class 2 Project at West Welch Project is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO2 injection projects in lower quality Shallow Shelf Carbonate reservoirs. The research and design phase (Budget Period 1) primarily involved advanced reservoir demonstration characterization. The current demonstration phase (Budget Period 2) is the implementation of the reservoir management plan for an optimum miscible CO2 flood design based on the reservoir characterization.

  15. Links between atmospheric carbon dioxide, the land carbon reservoir and climate over the past millennium

    NASA Astrophysics Data System (ADS)

    Bauska, Thomas K.; Joos, Fortunat; Mix, Alan C.; Roth, Raphael; Ahn, Jinho; Brook, Edward J.

    2015-05-01

    The stability of terrestrial carbon reservoirs is thought to be closely linked to variations in climate, but the magnitude of carbon-climate feedbacks has proved difficult to constrain for both modern and millennial timescales. Reconstructions of atmospheric CO2 concentrations for the past thousand years have shown fluctuations on multidecadal to centennial timescales, but the causes of these fluctuations are unclear. Here we report high-resolution carbon isotope measurements of CO2 trapped within the ice of the West Antarctic Ice Sheet Divide ice core for the past 1,000 years. We use a deconvolution approach to show that changes in terrestrial organic carbon stores best explain the observed multidecadal variations in the δ13C of CO2 and in CO2 concentrations from 755 to 1850 CE. If significant long-term carbon emissions came from pre-industrial anthropogenic land-use changes over this interval, the emissions must have been offset by a natural terrestrial sink for 13C-depleted carbon, such as peatlands. We find that on multidecadal timescales, carbon cycle changes seem to vary with reconstructed regional climate changes. We conclude that climate variability could be an important control of fluctuations in land carbon storage on these timescales.

  16. Enhancement of Terrestrial Carbon Sinks throught the Reclamation of Abandoned Mined Lands

    SciTech Connect

    Gary Kronrad

    2006-06-30

    This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.

  17. Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

    SciTech Connect

    Gary Kronrad

    2006-01-31

    This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.

  18. Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

    SciTech Connect

    Gary Kronrad

    2004-10-31

    This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.

  19. Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

    SciTech Connect

    Gary Kronrad

    2005-04-30

    This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.

  20. Flood-related, organic-carbon anomalies as possible temporal markers in reservoir bottom sediments

    USGS Publications Warehouse

    Juracek, K.E.

    2004-01-01

    Results of a study of sediment cores from four reservoirs in the upper Mississippi River Basin, USA, indicated that anomalous organic carbon concentrations associated with flood deposits may provide detectable temporal markers in reservoir bottom sediments. Temporal markers are needed for reservoir sediment studies to date sediment layers deposited between the 1963-64 cesium-137 peak and the present. For two of four reservoirs studied, anomalously low organic carbon concentrations were measured for a sample interval in the upper part of a sediment core. The anomalous interval was interpreted to have been deposited during the July 1993 flood that affected a large area of the upper Mississippi River Basin. Potentially, the July 1993 flood deposit may be used as a temporal marker in reservoir bottom sediments in parts of the basin affected by the flood. Several uncertainties remain regarding the viability of organic carbon as a temporal marker including the combination of flood, basin, and reservoir characteristics required to produce a recognizable organic carbon marker in the bottom sediment and the optimal sampling strategy needed to detect the marker in a sediment core. It is proposed that flood duration and basin size may be important factors as to whether or not an anomalous and detectable organic carbon layer is deposited in a reservoir. ?? Copyright by the North American Lake Management Society 2004.

  1. CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Kovar, Mark; Wehner, Scott

    1998-01-13

    The application of cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital-intensive miscible projects. Texaco Exploration & Production Inc. and the U. S. Department of Energy have teamed up in an attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected sites for this demonstration project are the Central Vacuum Unit waterflood in Lea County, New Mexico and the Sundown Slaughter Field in Hockley County, Texas. Miscible CO2 flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin's daily production. There are significant probable reserves associated with future miscible CO2 projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response, which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO2 Huff-n-Puff process is being investigated as a near

  2. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Rebecca Egg

    2002-09-30

    The OXY-operated Class 2 Project at West Welch is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO{sub 2} injection projects in lower quality Shallow Shelf Carbonate reservoirs. The research and design phase (Budget Period 1) primarily involved advanced reservoir characterization. The current demonstration phase (Budget Period 2) is the implementation of the reservoir management plan for an optimum miscible CO{sub 2} flood design based on the reservoir characterization. Although Budget Period 1 for the Project officially ended 12/31/96, reservoir characterization and simulation work continued during the Budget Period 2. During the fifth and sixth annual reporting periods (8/3/98-8/2/00) covered by this report, work continued on interpretation of the cross well seismic data to create porosity and permeability profiles which were distributed into the reservoir geostatistically. The initial interwell seismic CO{sub 2} monitor survey was conducted, the acquired data processed and interpretation started. Only limited well work and facility construction was conducted in the project area. The CO{sub 2} injection initiated in October 1997 was continued, although the operator had to modify the operating plan in response to low injection rates, well performance and changes in CO{sub 2} supply. CO{sub 2} injection was focused in a smaller area to increase the reservoir processing rate. By the end of the reporting period three producers had shown sustained oil rate increases and ten wells had experienced gas (CO{sub 2}) breakthrough.

  3. On calculating the transfer of carbon-13 in reservoir models of the carbon cycle

    SciTech Connect

    TANS, PIETER P.

    1980-10-01

    An approach to calculating the transfer of isotopic tracers in reservoir models is outlined that takes into account the effects of isotopic fractionation at phase boundaries without any significant approximations. Simultaneous variations in both the rare isotopic tracer and the total elemental (the sum of its isotopes) concentration are considered. The proposed procedure is applicable to most models of the carbon cycle and a four-box model example is discussed. Although the exact differential equations are non-linear, a simple linear approximation exists that gives insight into the nature of the solution. The treatment will be in terms of isotopic ratios which are the directly measured quantities.

  4. Carbon Dioxide Emissions from Reservoirs in the Lower Jordan Watershed

    PubMed Central

    Alshboul, Zeyad; Lorke, Andreas

    2015-01-01

    We have analyzed monthly hydrological, meteorological and water quality data from three irrigation and drinking water reservoirs in the lower Jordan River basin and estimated the atmospheric emission rates of CO2. The data were collected between 2006 and 2013 and show that the reservoirs, which differ in size and age, were net sources of CO2. The estimated surface fluxes were comparable in magnitude to those reported for hydroelectric reservoirs in the tropical and sub-tropical zones. Highest emission rates were observed for a newly established reservoir, which was initially filled during the sampling period. In the two older reservoirs, CO2 partial pressures and fluxes were significantly decreasing during the observation period, which could be related to simultaneously occurring temporal trends in water residence time and chemical composition of the water. The results indicate a strong influence of water and reservoir management (e.g. water consumption) on CO2 emission rates, which is affected by the increasing anthropogenic pressure on the limited water resources in the study area. The low wind speed and relatively high pH favored chemical enhancement of the CO2 gas exchange at the reservoir surfaces, which caused on average a four-fold enhancement of the fluxes. A sensitivity analysis indicates that the uncertainty of the estimated fluxes is, besides pH, mainly affected by the poorly resolved wind speed and resulting uncertainty of the chemical enhancement factor. PMID:26588241

  5. Carbon Dioxide Emissions from Reservoirs in the Lower Jordan Watershed.

    PubMed

    Alshboul, Zeyad; Lorke, Andreas

    2015-01-01

    We have analyzed monthly hydrological, meteorological and water quality data from three irrigation and drinking water reservoirs in the lower Jordan River basin and estimated the atmospheric emission rates of CO2. The data were collected between 2006 and 2013 and show that the reservoirs, which differ in size and age, were net sources of CO2. The estimated surface fluxes were comparable in magnitude to those reported for hydroelectric reservoirs in the tropical and sub-tropical zones. Highest emission rates were observed for a newly established reservoir, which was initially filled during the sampling period. In the two older reservoirs, CO2 partial pressures and fluxes were significantly decreasing during the observation period, which could be related to simultaneously occurring temporal trends in water residence time and chemical composition of the water. The results indicate a strong influence of water and reservoir management (e.g. water consumption) on CO2 emission rates, which is affected by the increasing anthropogenic pressure on the limited water resources in the study area. The low wind speed and relatively high pH favored chemical enhancement of the CO2 gas exchange at the reservoir surfaces, which caused on average a four-fold enhancement of the fluxes. A sensitivity analysis indicates that the uncertainty of the estimated fluxes is, besides pH, mainly affected by the poorly resolved wind speed and resulting uncertainty of the chemical enhancement factor. PMID:26588241

  6. Calibration of NMR well logs from carbonate reservoirs with laboratory NMR measurements and μXRCT

    SciTech Connect

    Mason, Harris E.; Smith, Megan M.; Hao, Yue; Carroll, Susan A.

    2014-12-31

    The use of nuclear magnetic resonance (NMR) well log data has the potential to provide in-situ porosity, pore size distributions, and permeability of target carbonate CO₂ storage reservoirs. However, these methods which have been successfully applied to sandstones have yet to be completely validated for carbonate reservoirs. Here, we have taken an approach to validate NMR measurements of carbonate rock cores with independent measurements of permeability and pore surface area to volume (S/V) distributions using differential pressure measurements and micro X-ray computed tomography (μXRCT) imaging methods, respectively. We observe that using standard methods for determining permeability from NMR data incorrectly predicts these values by orders of magnitude. However, we do observe promise that NMR measurements provide reasonable estimates of pore S/V distributions, and with further independent measurements of the carbonate rock properties that universally applicable relationships between NMR measured properties may be developed for in-situ well logging applications of carbonate reservoirs.

  7. Carbon dioxide storage in unconventional reservoirs workshop: summary of recommendations

    USGS Publications Warehouse

    Jones, Kevin B.; Blondes, Madalyn S.

    2015-01-01

    The storage capacity for all unconventional reservoirs may be modeled using a volumetric equation starting with the extent of the rock unit and adjusted using these key factors and reaction terms. The ideas that were developed during this workshop can be used by USGS scientists to develop a methodology to assess the CO2 storage resource in unconventional reservoirs. This methodology could then be released for public comment and peer review. After completing this development process, the USGS could then use the methodology to assess the CO2 storage resource in unconventional reservoirs.

  8. FOREST ECOSYSTEM CARBON AND NITROGEN ACCUMULATION DURING THE FIRST CENTURY AFTER AGRICULTURAL ABANDONMENT

    EPA Science Inventory

    Forests of the northeastern U.S. are expected to serve as a substantial sink for carbon (C) and nitrogen (N) as they recover from extensive clearing and agriculture. However, questions remain concerning the rate, distribution and duration of this potential sink. We used a chron...

  9. Reservoir zonation in Silurian-Devonian carbonates of Wells field, Dawson County, Texas

    SciTech Connect

    Mazzullo, L.J. )

    1992-04-01

    Wells field in Dawson County, Texas, has produced over 7.5 million bbl since 1955 from Silurian-Devonian carbonates. Although originally classified as a Devonian field, production there actually is out of the Silurian Wristen and Fusselman formations. Wells field is an extremely complex system of structured and stratigraphic reservoirs not easily characterized by traditional subsurface mapping techniques. Detailed lithologic analyses of well cuttings from 29 wells in and around this field were done to evaluate reservoir zonation and potentials for either new field development wells, or recompletions from existing well bores. These analyses have shown that paleotopographic highs on the Fusselman unconformity across the field created optimum sites for Fusselman dolomite reservoir development, and collateral development of Wristen reservoirs. The Wristen reservoirs are in the form of porous carbonate mounds that grew adjacent to the paleotopographically high areas, or simple compactionally fractured cherty carbonates over these highs. The recognition of Fusselman paleotopography in most wells is implied by thickness and facies changes in the overlying Wristen section. A certain amount of structure and facies-induced reservoir separation has been documented. The results of this study have been used to identify several areas of the field where each of the three reservoirs could be exploited for underdeveloped reserves.

  10. The role of sequence stratigraphy in 3-D characterization of carbonate reservoirs

    SciTech Connect

    Tinker, S.W.; Brondos, M.D.; Brinton, L. )

    1996-01-01

    The product of 3-D reservoir characterization is a 3-D reservoir model. The integrity of the 3-D reservoir model is largely a function of the stratigraphic framework. Interpreting the correct stratigraphic framework for a subsurface reservoir is the most difficult and creative part of the 3-D modeling process. Sequence- and seismic-stratigraphic interpretation provide the best stratigraphic framework for 3-D reservoir modeling. Depositional sequences are comprised of many petrophysically-distinct lithofacies regions. If each lithofacies region was uniform and homogeneous, it would be reasonable to use a lithofacies ([open quote]layer-cake[close quote]) framework interpretation to distribute data in a 3-D model. However, lithofacies are typically time- transgressive, and often internally heterogeneous because geologic processes such as siliciclastic sediment deposition, sediment bypass, hardground formation, variable diagenesis, and facies shifts occur along depositional time surfaces on carbonate platforms. Therefore, a sequence stratigraphic framework interpretation, in which stratal geometries are honored, is better for controlling the distribution of petrophysical data in 3-D. The role that sequence stratigraphy plays in the 3-D characterization of carbonate reservoirs will be presented using two outcrop and four subsurface studies from the Paleozoic. The outcrop examples illustrate the important distinction between lithostratigraphic and sequence stratigraphic correlation, and the subsurface examples illustrate the process of quantification, integration, reduction, and analysis of geological, petrophysical, seismic, and engineering data. The concepts and techniques can be applied to carbonate reservoirs of any age.

  11. The role of sequence stratigraphy in 3-D characterization of carbonate reservoirs

    SciTech Connect

    Tinker, S.W.; Brondos, M.D.; Brinton, L.

    1996-12-31

    The product of 3-D reservoir characterization is a 3-D reservoir model. The integrity of the 3-D reservoir model is largely a function of the stratigraphic framework. Interpreting the correct stratigraphic framework for a subsurface reservoir is the most difficult and creative part of the 3-D modeling process. Sequence- and seismic-stratigraphic interpretation provide the best stratigraphic framework for 3-D reservoir modeling. Depositional sequences are comprised of many petrophysically-distinct lithofacies regions. If each lithofacies region was uniform and homogeneous, it would be reasonable to use a lithofacies ({open_quote}layer-cake{close_quote}) framework interpretation to distribute data in a 3-D model. However, lithofacies are typically time- transgressive, and often internally heterogeneous because geologic processes such as siliciclastic sediment deposition, sediment bypass, hardground formation, variable diagenesis, and facies shifts occur along depositional time surfaces on carbonate platforms. Therefore, a sequence stratigraphic framework interpretation, in which stratal geometries are honored, is better for controlling the distribution of petrophysical data in 3-D. The role that sequence stratigraphy plays in the 3-D characterization of carbonate reservoirs will be presented using two outcrop and four subsurface studies from the Paleozoic. The outcrop examples illustrate the important distinction between lithostratigraphic and sequence stratigraphic correlation, and the subsurface examples illustrate the process of quantification, integration, reduction, and analysis of geological, petrophysical, seismic, and engineering data. The concepts and techniques can be applied to carbonate reservoirs of any age.

  12. IMPACT OF FOREST HARVESTING ON RESERVOIRS AND LAKES: CARBON DYNAMICS AND MICROBIAL CYCLING

    NASA Astrophysics Data System (ADS)

    Ouellet, A.; Tremblay, L.; Lucotte, M. M.; Gelinas, Y.

    2009-12-01

    Boreal lakes and reservoirs are net heterotrophic systems. Differences in dissolved CO2 concentrations between man-made reservoirs and natural lakes suggest higher CO2 fluxes to the atmosphere from reservoirs than from lakes; human-induced perturbations such as deforestation also induce changes to the carbon cycle in aquatic systems. We used bulk analytical techniques to better characterize the impact of reservoir formation and deforestation on the processes controlling the cycling of organic carbon in boreal aquatic systems. The water column of natural and deforested lakes and reservoirs was analyzed for dissolved and particulate organic matter (DOM and POM, respectively), dissolved inorganic carbon (DIC), oxygen saturation and CO2. Atomic C:N ratios, δ13Corg, δ15Ntot and amino acids biomarkers analyses were also carried out on DOM and POM. Differences in carbon concentration, atomic C/N ratios and δ13Corg reflect the impact of deforestation on the quality and quantity of OM found in lakes and reservoirs. Water-column profiles of δ13C-DIC and δ13C-POM show large variability with perturbation indicating that there are differences in the biogeochemical processes that control carbon cycling in the different environments. These findings along with amino acids analyses show that inputs of terrestrial dissolved organic nitrogen and carbon better stimulates bacterial growth than algal activities, which results in increased aqueous CO2 concentrations and fluxes to the atmosphere. A statistical analysis of the biomarkers suggests contrasting DOM/POM sources and degradation pathways with wood harvesting and reservoir operation. Human-induced land use and hydrological modifications drive the carbon cycle of fresh water systems, which in turn modulates green house gas emissions to the atmosphere.

  13. IMPROVED OIL RECOVERY IN MISSISSIPPIAN CARBONATE RESERVOIRS OF KANSAS - NEAR TERM - CLASS 2

    SciTech Connect

    Timothy R. Carr; Don W. Green; G. Paul Willhite

    2000-04-30

    This annual report describes progress during the final year of the project entitled ''Improved Oil Recovery in Mississippian Carbonate Reservoirs in Kansas''. This project funded under the Department of Energy's Class 2 program targets improving the reservoir performance of mature oil fields located in shallow shelf carbonate reservoirs. The focus of the project was development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and the mid-continent. As part of the project, tools and techniques for reservoir description and management were developed, modified and demonstrated, including PfEFFER spreadsheet log analysis software. The world-wide-web was used to provide rapid and flexible dissemination of the project results through the Internet. A summary of demonstration phase at the Schaben and Ness City North sites demonstrates the effectiveness of the proposed reservoir management strategies and technologies. At the Schaben Field, a total of 22 additional locations were evaluated based on the reservoir characterization and simulation studies and resulted in a significant incremental production increase. At Ness City North Field, a horizontal infill well (Mull Ummel No.4H) was planned and drilled based on the results of reservoir characterization and simulation studies to optimize the location and length. The well produced excellent and predicted oil rates for the first two months. Unexpected presence of vertical shale intervals in the lateral resulted in loss of the hole. While the horizontal well was not economically successful, the technology was demonstrated to have potential to recover significant additional reserves in Kansas and the Midcontinent. Several low-cost approaches were developed to evaluate candidate reservoirs for potential horizontal well applications at the field scale, lease level, and well level, and enable the small independent producer to identify

  14. Jurassic carbonate reservoirs of the Amu Darya Basin, Uzbekistan and Turkmenistan

    SciTech Connect

    Shein, V.S.; Fortunatova, N.K.; Neilson, J.E.

    1995-08-01

    The Amu Darya Basin is a world class hydrocarbon province. Current reserves estimates are 220 TCF of gas and 800 MMbbl of oil and condensate, 50% of which is reservoired in Late Jurassic carbonates. Exploration opportunities still exist in large parts of the basin which are relatively undrilled. Within the 100-600m thick carbonate sequence, reservoir facies include reefs, shelf grainstones and turbidite fares. The major seal are Kimmeridgian - Tithonian evaporates which are up to 1600m thick in the basin centre. Stratigraphic trapping is common and often enhanced by structural modifications. The reservoirs are in communication with a major gas-prone Early-Middle Jurassic source rock. Oil-prone source rocks are thought to occur in basinal sediments which are coeval with the Late Jurassic reservoirs. Carbonate sedimentation commenced during the Late Jurassic with the development of a ramp complex. This evolved into a rimmed shelf with barrier and pinnacle reefs. Several cycles of relative sea-level change (largely eustatic?) influence the carbonate ramp/shelf systems and effect the distribution of reservoir facies. Numerous empirical observations by VNIGNI scientists on carbonate successions have enabled them to develop mathematically calculated indices for facies and reservoir prediction, which have been applied successfully in the Amu Darya Basin. Reservoir quality in the limestones is strongly controlled by primary facies. Reefs and shelf grainstones display the best reservoir characteristics. Whilst many facies have good total porosity, it is only the reef and grainstone belts where connected porosity (with pore throats greater than 10um) becomes effective. Burial cements are rare. Freshwater solution and cementation has often improved or preserved primary porosity.

  15. Reservoir compaction and surface subsidence in the Central Luconia gas bearing carbonates, offshore Sarawak, East Malaysia

    SciTech Connect

    vanDitzhunzen, P.J.D.; de Waai, J.A.

    1984-02-01

    In the Central Luconia area, offshore Sarawak, substantial gas reserves are present in Miocene carbonate buildups. The carbonates consist of limestones and dolomites with porosities ranging from 0 to 40 percent. From core analysis it became evident that there exists a potential problem with regard to the compaction of the carbonate reservoir matrix as a result of effective stress increase as the reservoirs are depleted. Triaxial compaction tests were carried out on core samples from several carbonte reservoirs. It was found that highly porous mouldic limestones show pore collapse at relatively low effective stresses. After pore collapse the uniaxial compressibility coefficient increases significantly. Reservoir compressibility parameters can be derived from core data, for collapsing as well as non-collapsing rocks. These can be used to calculate reservoir compaction from well logs for a particular pressure decline. An estimate of the expected surface subsidence can be made based on the theory of poro-elasticity and the nucleus of strain concept as described by Geertsma. Predicted subsidence figures have been taken into account in platform design. The gas reservoirs have large aquifers within the carbonate buildups. As these aquifers have not all been fully appraised, there exists some uncertainty concerning their actual compaction behaviour.

  16. The lower Miocene Liuhua carbonate reservoir, Pearl River Mouth basin, offshore People's Republic of China

    SciTech Connect

    Turner, N.L. )

    1990-06-01

    Since the drilling in January 1987 of the Amoco Liuhua 11-1-1A discovery well located 220 km southeast of Hong Kong, five additional wells have drilled and tested this lower Miocene Zhujiang Formation carbonate reservoir. Deposition of upper Zhujiang carbonates in the Liuhua area took place in an isolated platform environment. Major facies are (1) a platform-rim reef composed of red algae and coral boundstones, (2) a back-reef lagoon of fine-grained carbonates, (3) a large interior platform bank dominated by red algae but with a red algal-coral fringe on the south and southwest sides, (4) platform grainrocks, and (5) platform to lagoonal mud-supported carbonates. A paleo-water table surface present in every well represents a time of regional exposure. The reservoir is subdivided into five diagenetic carbonate units that are correlated across the platform and that cross facies boundaries and inferred time lines. The uppermost unit is a thin, tightly cemented carbonate formed at the time of drowning of the platform. Two thick highly leached carbonate units with porosities and permeabilities as high as 30% and several darcys comprise most of the reservoir. They are separated by a thin (7 m) tighter interval that formed by cementation below the water table of an exposure surface. The less porous unit at the base of the reservoir formed as a result of interaction between oil and water causing calcite cementation. Leaching continued in the carbonate below the reservoir and biodegradation occurred after oil had filled the structure. Further drilling and testing will determine the limits of the diagenetic units and whether the reservoir has commercial potential.

  17. Calculation of hydrocarbon-in-place in gas and gas-condensate reservoirs - Carbon dioxide sequestration

    USGS Publications Warehouse

    Verma, Mahendra K.

    2012-01-01

    The Energy Independence and Security Act of 2007 (Public Law 110-140) authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2), requiring estimation of hydrocarbon-in-place volumes and formation volume factors for all the oil, gas, and gas-condensate reservoirs within the U.S. sedimentary basins. The procedures to calculate in-place volumes for oil and gas reservoirs have already been presented by Verma and Bird (2005) to help with the USGS assessment of the undiscovered resources in the National Petroleum Reserve, Alaska, but there is no straightforward procedure available for calculating in-place volumes for gas-condensate reservoirs for the carbon sequestration project. The objective of the present study is to propose a simple procedure for calculating the hydrocarbon-in-place volume of a condensate reservoir to help estimate the hydrocarbon pore volume for potential CO2 sequestration.

  18. Seasonal Changes in Plankton Food Web Structure and Carbon Dioxide Flux from Southern California Reservoirs

    PubMed Central

    Adamczyk, Emily M.; Shurin, Jonathan B.

    2015-01-01

    Reservoirs around the world contribute to cycling of carbon dioxide (CO2) with the atmosphere, but there is little information on how ecosystem processes determine the absorption or emission of CO2. Reservoirs are the most prevalent freshwater systems in the arid southwest of North America, yet it is unclear whether they sequester or release CO2 and therefore how water impoundment impacts global carbon cycling. We sampled three reservoirs in San Diego, California, weekly for one year. We measured seasonal variation in the abundances of bacteria, phytoplankton, and zooplankton, as well as water chemistry (pH, nutrients, ions, dissolved organic carbon [DOC]), which were used to estimate partial pressure of CO2 (pCO2), and CO2 flux. We found that San Diego reservoirs are most often undersaturated with CO2 with respect to the atmosphere and are estimated to absorb on average 3.22 mmol C m-2 day-1. pCO2 was highest in the winter and lower in the summer, indicating seasonal shifts in the magnitudes of photosynthesis and respiration associated with day length, temperature and water inputs. Abundances of microbes (bacteria) peaked in the winter along with pCO2, while phytoplankton, nutrients, zooplankton and DOC were all unrelated to pCO2. Our data indicate that reservoirs of semi-arid environments may primarily function as carbon sinks, and that carbon flux varies seasonally but is unrelated to nutrient or DOC availability, or the abundances of phytoplankton or zooplankton. PMID:26473601

  19. Seasonal Changes in Plankton Food Web Structure and Carbon Dioxide Flux from Southern California Reservoirs.

    PubMed

    Adamczyk, Emily M; Shurin, Jonathan B

    2015-01-01

    Reservoirs around the world contribute to cycling of carbon dioxide (CO2) with the atmosphere, but there is little information on how ecosystem processes determine the absorption or emission of CO2. Reservoirs are the most prevalent freshwater systems in the arid southwest of North America, yet it is unclear whether they sequester or release CO2 and therefore how water impoundment impacts global carbon cycling. We sampled three reservoirs in San Diego, California, weekly for one year. We measured seasonal variation in the abundances of bacteria, phytoplankton, and zooplankton, as well as water chemistry (pH, nutrients, ions, dissolved organic carbon [DOC]), which were used to estimate partial pressure of CO2 (pCO2), and CO2 flux. We found that San Diego reservoirs are most often undersaturated with CO2 with respect to the atmosphere and are estimated to absorb on average 3.22 mmol C m(-2) day(-1). pCO2 was highest in the winter and lower in the summer, indicating seasonal shifts in the magnitudes of photosynthesis and respiration associated with day length, temperature and water inputs. Abundances of microbes (bacteria) peaked in the winter along with pCO2, while phytoplankton, nutrients, zooplankton and DOC were all unrelated to pCO2. Our data indicate that reservoirs of semi-arid environments may primarily function as carbon sinks, and that carbon flux varies seasonally but is unrelated to nutrient or DOC availability, or the abundances of phytoplankton or zooplankton. PMID:26473601

  20. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas

    SciTech Connect

    Kerans, C.

    1988-10-01

    Petroleum production from restricted shelf carbonates of the Lower Ordovician Ellenburger group is commonly considered to have been a result of a pervasive, relatively homogeneous tectonic fracture system within the reservoir rock. However, regional facies and diagenetic (paleokarst) studies of Ellenburger strata, based on cores and wireline logs, have demonstrated that significant reservoir compartmentalization was caused by karst modification in the upper part of the unit. 19 figures.

  1. IMPROVED OIL RECOVERY IN MISSISSIPPIAN CARBONATE RESERVOIRS OF KANSAS--NEAR TERM--CLASS 2

    SciTech Connect

    Timothy R. Carr; Don W. Green; G. Paul Willhite

    1999-06-01

    This annual report describes progress during the third year of the project entitled ''Improved Oil Recovery in Mississippian Carbonate Reservoirs in Kansas''. This project funded under the Department of Energy's Class 2 program targets improving the reservoir performance of mature oil fields located in shallow shelf carbonate reservoirs. The focus of this project is development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and the mid-continent. The project introduced a number of potentially useful technologies, and demonstrated these technologies in actual oil field operations. Advanced technology was tailored specifically to the scale appropriate to the operations of Kansas producers. An extensive technology transfer effort is ongoing. Traditional technology transfer methods (e.g., publications and workshops) are supplemented with a public domain relational database and an online package of project results that is available through the Internet. The goal is to provide the independent complete access to project data, project results and project technology on their desktop. Included in this report is a summary of significant project results at the demonstration site (Schaben Field, Ness County, Kansas). The value of cost-effective techniques for reservoir characterization and simulation at Schaben Field were demonstrated to independent operators. All major operators at Schaben have used results of the reservoir management strategy to locate and drill additional infill locations. At the Schaben Demonstration Site, the additional locations resulted in incremental production increases of 200 BOPD from a smaller number of wells.

  2. Improved Oil Recovery in Mississippian Carbonate Reservoirs of Kansas -- Near-Term -- Class 2

    SciTech Connect

    Carr, Timothy R.; Green, Don W.; Willhite, G. Paul

    1999-07-08

    This report describes progress during the third year of the project entitled ''Improved Oil Recovery in Mississippian Carbonate Reservoirs in Kansas''. This project funded under the Department of Energy's Class 2 program targets improving the reservoir performance of mature oil fields located in shallow shelf carbonate reservoirs. The focus of this project is development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and mid-continent. The project introduced a number of potentially useful technologies, and demonstrated these technologies in actual oil field operations. Advanced technology was tailored specifically to the scale appropriate to the operations of Kansas producers. An extensive technology transfer effort is ongoing. Traditional technology transfer methods (e.g., publications and workshops) are supplemented with a public domain relational database and an online package of project results that is available through the Internet. The goal is to provide the independent complete access to project data, project results and project technology on their desktop. Included in this report is a summary of significant project results at the demonstration site (Schaben Field, Ness County, Kansas). The value of cost-effective techniques for reservoir characterization and simulation at Schaben Field were demonstrated to independent operators. All major operators at Schaben have used results of the reservoir management strategy to locate and drill additional infill locations. At the Schaben Demonstration Site, the additional locations resulted in incremental production increases of 200 BOPD from a smaller number of wells.

  3. Can We Make Use of Abandoned Land for Carbon Management and Ecosystem Restoration?

    NASA Astrophysics Data System (ADS)

    Yamagata, Y.; Shoyama, K.

    2014-12-01

    Potential conflicts between biodiversity conservation and climate-change mitigation can result in trade-offs in multiple-use land management. This study aimed to detect possible changes in land-use patterns in response to biodiversity conservation and climate-change mitigation measures and the effects on ecosystem services across a watershed. For that purpose, we have developed a new method to combine land-use change scenarios and ecosystem service assessments. We analyzed land-cover change based on past and future scenarios in the rural Kushiro watershed in northern Japan. The analysis showed that if no conservation measures were implemented and the timber and agricultural industry remained small until 2060, supporting and provisioning services would decline due to less land management. Although biodiversity conservation measures are predicted to improve three of the ecosystem services that we studied, carbon sequestration and timber production would be improved to a greater degree by climate-change mitigation measures. The greatest land-cover changes are likely to occur in the unprotected area around the middle reaches of the Kushiro River, and such changes could affect the provision of ecosystem services throughout the entire watershed. Thus, our findings indicate that land-use decisions for the middle reaches of the watershed are particularly important for managing the integrated ecosystem services of the entire watershed for the future.

  4. Facies dimensions within carbonate reservoirs - guidelines from satellite images of modern analogs

    SciTech Connect

    Harris, P.M.; Kowalik, W.S.

    1995-08-01

    Modern analogs illustrate the distribution of carbonate facies within an overall depositional setting and can be an integral part of a subsurface geologic model in indicating the dimensions, trend, and interrelationships of facies that might be related to reservoir and non-reservoir distribution. Satellite images from several modern carbonate areas depict the geologic characteristics that can be expected in ancient shallow-water settings. Isolated carbonate platforms- the Bahamas, Caicos Platform in the British West Indies, Chinchorro Bank offshore of Yucatan, and portions of the Belize area; Ramp-style shelf-to-basin transitions - Abu Dhabi and northern Yucatan; Rimmed shelf margins - South Florida, portions of Belize, and the Great Barrier Reef of Australia; Broad, deep shelf lagoons - the Great Barrier Reef and Belize; Reef variability - South Florida, the Bahamas, Caicos, Northern Yucatan, and Abu Dhabi; Shallow lagoon/tidal flat settings - South Florida, the Bahamas, Caicos, Northern Yucatan, Shark Bay in Western Australia, Abu Dhabi; Mixed carbonate and siliciclastic depostion - South Florida, Belize, the Great Barrier Reef, Shark Bay and Abu Dhabi. The geologic framework as illustrated by these areas is important at the development scale where lateral variation of porosity and permeability, i.e. reservoir quality, is commonly tied to facies changes and facies dimensions are required as input to reservoir models. The geologic framework is essential at the exploration scale for reservoir facies prediction and stratigraphic play concepts which are related directly to depositional facies patterns.

  5. Organic carbon isotope constraints on the dissolved organic carbon (DOC) reservoir at the Cryogenian-Ediacaran transition

    NASA Astrophysics Data System (ADS)

    Jiang, Ganqing; Wang, Xinqiang; Shi, Xiaoying; Zhang, Shihong; Xiao, Shuhai; Dong, Jin

    2010-10-01

    Prominent negative carbonate carbon isotope (δ 13C carb) anomalies from some Ediacaran successions are accompanied by invariant or decoupled organic carbon isotope (δ 13C org) values and have been interpreted as resulting from the remineralization of a large dissolved organic carbon (DOC) reservoir capable of buffering carbon isotopes of organic matter. This inferred oceanic DOC reservoir was thought to have initiated with the onset of Cryogenian glaciations (ca. 720 Ma) and lasted for millions of years until the late Ediacaran Period (< 560 Ma). Carbon isotope analyses of the basal Doushantuo Formation (ca. 635 Ma) in south China reveal that (1) the cap carbonate has δ 13C org around -26‰ (VPDB) and relatively low Δδ 13C (22 ± 2‰) and (2) the overlying organic-rich black shale and shaly dolostone have more negative δ 13C org (-28‰ to -35‰) and higher Δδ 13C (28‰-30‰). Both δ 13C carb and δ 13C org show a + 6‰ shift within a 4-m-thick interval overlying the Doushantuo cap carbonate. The δ 13C org values of the cap carbonate are associated with low TOC (mostly < 0.1%); their paleoceanographic significance requires further tests in other Ediacaran basins. The co-varying positive shift in δ 13C carb and δ 13C org following cap carbonate deposition is best interpreted as resulting from a rapid increase in organic carbon burial, which may have resulted in the rise of oxygen and heralded the first appearance of animals a few meters above the Doushantuo cap carbonate. The data suggest that a large oceanic DOC reservoir did not exist in the early Ediacaran ocean. Excess oceanic DOC required to explain the Ediacaran Shuram and upper Doushantuo δ 13C excursions, if it existed, had to be developed during the Ediacaran Period after cap carbonate deposition.

  6. Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin

    SciTech Connect

    Wood, James R.; Harrison, William B.

    2000-10-24

    The main objective of this project is for a university-industry consortium to develop a comprehensive model for fracture carbonate reservoirs based on the ''data cube'' concept using the Michigan Basin as a prototype. This project combined traditional historical data with 2D and 3D seismic data as well as data from modern logging tools in a novel way to produce a new methodology for characterizing fractured reservoirs in carbonate rocks. Advanced visualization software was used to fuse the data and to image it on a variety of scales, ranging from basin-scale to well-scales.

  7. Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin

    SciTech Connect

    Wood, J.R.; Harrison, W.B.

    2001-01-22

    The main objective of this project is for a university-industry consortium to develop a comprehensive model for fracture carbonate reservoirs based on the ''data cube'' concept using the Michigan Basin as a prototype. This project combined traditional historical data with 2D and 3D seismic data as well as data from modern logging tools in a novel way to produce a new methodology for characterizing fractured reservoirs in carbonate rocks. Advanced visualization software was used to fuse the data and to image it on a variety of scales, ranging from basin-scale to well-scales.

  8. Geological and reservoir characterization of shallow-shelf carbonate fields, Southern Paradox Basin, Utah

    SciTech Connect

    Chidsey, T.C. Jr. ); Eby, D.E. )

    1996-01-01

    The Paradox basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from carbonate mounds within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to three wells with primary per field production ranging from 700 MBO to 2 MMBO at a 15-20% recovery rate. Five fields (Anasazi, Mule, Blue Hogan, Heron North, and Runway) within the Navajo Nation of southeastern Utah have been evaluated for CO[sub 2]-flood projects based upon geological characterization and reservoir modeling. Conventional cores from the five fields show that three compositional reservoir types are present: (1) phylloid algal, (2) bioclastic calcarenite, and (3) bryozoan-dominated. Phylloid algal mounds are abundant in four of the five fields, and exhibit the best overall porosity and permeability. This mound type developed where shallow water depths and low energy allowed establishment of calcareous algal colonies possibly on paleohighs. The principal reservoir rock is algal bafflestone composed mostly of the phylloid Ivanovia and occasionally dolomitized. The Heron North field is a bioclastic calcarenite reservoir. It represents high-energy conditions resulting in carbonate beaches developed over foreshore carbonate rubble. The principal reservoir rocks are grainstones and rudstones having grain-selective dissolution and complete dolomitization. Bryozoan-dominated mounds present in Runway field developed in quiet, below wave-base settings that appear to be localized along Mississippian fault blocks trends. The principal reservoir rocks are bindstone and framestone with no dolomitization. The resulting model suggests that CO[sub 2] miscible flooding of these and other small carbonate reservoirs in the Paradox basin could significantly increase ultimate recovery of oil.

  9. Geological and reservoir characterization of shallow-shelf carbonate fields, Southern Paradox Basin, Utah

    SciTech Connect

    Chidsey, T.C. Jr.; Eby, D.E.

    1996-12-31

    The Paradox basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from carbonate mounds within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to three wells with primary per field production ranging from 700 MBO to 2 MMBO at a 15-20% recovery rate. Five fields (Anasazi, Mule, Blue Hogan, Heron North, and Runway) within the Navajo Nation of southeastern Utah have been evaluated for CO{sub 2}-flood projects based upon geological characterization and reservoir modeling. Conventional cores from the five fields show that three compositional reservoir types are present: (1) phylloid algal, (2) bioclastic calcarenite, and (3) bryozoan-dominated. Phylloid algal mounds are abundant in four of the five fields, and exhibit the best overall porosity and permeability. This mound type developed where shallow water depths and low energy allowed establishment of calcareous algal colonies possibly on paleohighs. The principal reservoir rock is algal bafflestone composed mostly of the phylloid Ivanovia and occasionally dolomitized. The Heron North field is a bioclastic calcarenite reservoir. It represents high-energy conditions resulting in carbonate beaches developed over foreshore carbonate rubble. The principal reservoir rocks are grainstones and rudstones having grain-selective dissolution and complete dolomitization. Bryozoan-dominated mounds present in Runway field developed in quiet, below wave-base settings that appear to be localized along Mississippian fault blocks trends. The principal reservoir rocks are bindstone and framestone with no dolomitization. The resulting model suggests that CO{sub 2} miscible flooding of these and other small carbonate reservoirs in the Paradox basin could significantly increase ultimate recovery of oil.

  10. Rock-physics-based carbonate pore type characterization and reservoir permeability heterogeneity evaluation, Upper San Andres reservoir, Permian Basin, west Texas

    NASA Astrophysics Data System (ADS)

    Dou, Qifeng; Sun, Yuefeng; Sullivan, Charlotte

    2011-05-01

    In addition to mineral composition and pore fluid, pore type variations play an important role in affecting the complexity of velocity-porosity relationship and permeability heterogeneity of carbonate reservoirs. Without consideration of pore type diversity, most rock physics models applicable to clastic rocks for explaining the rock acoustic properties and reservoir parameters relationship may not work well for carbonate reservoirs. A frame flexibility factor ( γ) defined in a new carbonate rock physics model can quantify the effect of pore structure changes on seismic wave velocity and permeability heterogeneity in carbonate reservoirs. Our study of an Upper San Andres carbonate reservoir, Permian Basin, shows that for core samples of given porosity, the lower the frame flexibility factor ( γ), the higher the sonic wave velocity. For the studied reservoir, samples with frame flexibility factor ( γ) < 3.85 represent either visible vuggy pore space in a dolopackstone or intercrystalline pore space in dolowackstone. On the other hand, samples with frame flexibility factor ( γ) > 3.85 indicate either dominant interparticle pore space in dolopackstone or microcrack pore space in dolowackstone or dolomudstone. Using the frame flexibility factor ( γ), different porosity-impedance and porosity-permeability trends can be classified with clear geologic interpretation such as pore type and rock texture variations to improve porosity and permeability prediction accuracy. New porosity-permeability relations with γ classification help delineate permeability heterogeneity in the Upper San Andres reservoir, and could be useful for other similar carbonate reservoir studies. In addition, results from analysis of amplitude variation with offset (AVO) and impedance modeling indicate that by combining rock physics model and pre-stack seismic inversion, simultaneous estimation of porosity and frame flexibility factor ( γ) is quite feasible because of the strong influence of

  11. Seismic estimation of porosity in the Permian San Andres carbonate reservoir, Welch Field, Dawson, County, Texas

    SciTech Connect

    Watts, G.P.; Hinterlong, G.D. )

    1996-01-01

    OXY and the DOE Are partners in a advanced technology demonstration project at OXY's West Welch Unit. Production is from a low permeability San Andres reservoir of Permian age similar to many shallow shelf carbonate reservoirs in the Permian Basin. The project involves the construction of a detailed geological model for numerical simulation to design and then conduct a CO[sub 2] flood of the reservoir. Depositional textures of the reservoir rock are highly variable from diagenesis, mostly anhydritic cementing, creating a highly complex pore system. Identification of the interwell reservoir continuity and flow units present the greatest challenge to the reservoir description. A 1993 vintage 3-D seismic survey with a bin spacing of 110[prime] by 165[prime] has been used to assist with the interwell reservoir description. The structure definition at the top and base of the reservoir have been accurately mapped with respect to the well data. Core and well log measurements of porosity, permeability and water saturation were computed and summed across the seismic reservoir interval. Measurements of amplitude, frequency and phase within the 3-D volume were summed across the reservoir interval. All seismic attributes were sampled to the wells and compared through scatterplots to the well log and core measurements. Excellent correlation between three seismic attributes and porosity has been documented. A deterministic method has been used to estimate porosity values at each seismic bin location. The method uses the seismic measurements to shape the geology between the wells while maintaining agreement with the well data at the well locations.

  12. Seismic estimation of porosity in the Permian San Andres carbonate reservoir, Welch Field, Dawson, County, Texas

    SciTech Connect

    Watts, G.P.; Hinterlong, G.D.

    1996-12-31

    OXY and the DOE Are partners in a advanced technology demonstration project at OXY`s West Welch Unit. Production is from a low permeability San Andres reservoir of Permian age similar to many shallow shelf carbonate reservoirs in the Permian Basin. The project involves the construction of a detailed geological model for numerical simulation to design and then conduct a CO{sub 2} flood of the reservoir. Depositional textures of the reservoir rock are highly variable from diagenesis, mostly anhydritic cementing, creating a highly complex pore system. Identification of the interwell reservoir continuity and flow units present the greatest challenge to the reservoir description. A 1993 vintage 3-D seismic survey with a bin spacing of 110{prime} by 165{prime} has been used to assist with the interwell reservoir description. The structure definition at the top and base of the reservoir have been accurately mapped with respect to the well data. Core and well log measurements of porosity, permeability and water saturation were computed and summed across the seismic reservoir interval. Measurements of amplitude, frequency and phase within the 3-D volume were summed across the reservoir interval. All seismic attributes were sampled to the wells and compared through scatterplots to the well log and core measurements. Excellent correlation between three seismic attributes and porosity has been documented. A deterministic method has been used to estimate porosity values at each seismic bin location. The method uses the seismic measurements to shape the geology between the wells while maintaining agreement with the well data at the well locations.

  13. Seagrass meadows as a globally significant carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Mazarrasa, I.; Marbà, N.; Lovelock, C. E.; Serrano, O.; Lavery, P. S.; Fourqurean, J. W.; Kennedy, H.; Mateo, M. A.; Krause-Jensen, D.; Steven, A. D. L.; Duarte, C. M.

    2015-03-01

    There has been a growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the organic carbon (POC) stocks and accumulation rates and ignored the inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 402 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m sediments ranged between 3 and 1660 Mg PIC ha-1, with an average of 654 ± 24 Mg PIC ha-1, exceeding about 5 fold those of POC reported in previous studies. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of -8 ± 2 Mg PIC ha-1 degree-1 of latitude (GLM, p < 0.0003). Using PIC concentration and estimates of sediment accretion in seagrass meadows, mean PIC accumulation rates in seagrass sediments is 126.3 ± 0.7 g PIC m-2 y-1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top meter of sediment and accumulate between 22 and 76 Tg PIC y-1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrates the comparison of carbon (POC and POC) stocks between vegetated and adjacent un-vegetated sediments.

  14. A rock-physical modeling method for carbonate reservoirs at seismic scale

    NASA Astrophysics Data System (ADS)

    Li, Jing-Ye; Chen, Xiao-Hong

    2013-03-01

    Strong heterogeneity and complex pore systems of carbonate reservoir rock make its rock physics model building and fluid substitution difficult and complex. However, rock physics models connect reservoir parameters with seismic parameters and fluid substitution is the most effective tool for reservoir prediction and quantitative characterization. On the basis of analyzing complex carbonate reservoir pore structures and heterogeneity at seismic scale, we use the gridding method to divide carbonate rock into homogeneous blocks with independent rock parameters and calculate the elastic moduli of dry rock units step by step using different rock physics models based on pore origin and structural feature. Then, the elastic moduli of rocks saturated with different fluids are obtained using fluid substitution based on different pore connectivity. Based on the calculated elastic moduli of rock units, the Hashin-Shtrikman-Walpole elastic boundary theory is adopted to calculate the carbonate elastic parameters at seismic scale. The calculation and analysis of carbonate models with different combinations of pore types demonstrate the effects of pore type on rock elastic parameters. The simulated result is consistent with our knowledge of real data.

  15. Axial obliquity control on the greenhouse carbon budget through middle- to high-latitude reservoirs

    NASA Astrophysics Data System (ADS)

    Laurin, Jiří; Meyers, Stephen R.; Uličný, David; Jarvis, Ian; Sageman, Bradley B.

    2015-02-01

    Carbon sources and sinks are key components of the climate feedback system, yet their response to external forcing remains poorly constrained, particularly for past greenhouse climates. Carbon-isotope data indicate systematic, million-year-scale transfers of carbon between surface reservoirs during and immediately after the Late Cretaceous thermal maximum (peaking in the Cenomanian-Turonian, circa 97-91 million years, Myr, ago). Here we calibrate Albian to Campanian (108-72 Myr ago) high-resolution carbon isotope records with a refined chronology and demonstrate how net transfers between reservoirs are plausibly controlled by ~1 Myr changes in the amplitude of axial obliquity. The amplitude-modulating terms are absent from the frequency domain representation of insolation series and require a nonlinear, cumulative mechanism to become expressed in power spectra of isotope time series. Mass balance modeling suggests that the residence time of carbon in the ocean-atmosphere system is—by itself—insufficient to explain the Myr-scale variability. It is proposed that the astronomical control was imparted by a transient storage of organic matter or methane in quasi-stable reservoirs (wetlands, soils, marginal zones of marine euxinic strata, and potentially permafrost) that responded nonlinearly to obliquity-driven changes in high-latitude insolation and/or meridional insolation gradients. While these reservoirs are probably underrepresented in the geological record due to their quasi-stable character, they might have provided an important control on the dynamics and stability of the greenhouse climate.

  16. DESIGN AND IMPLEMENTATION OF A CO2 FLOOD UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL INJECTION WELLS IN A SHALLOW SHELF CARBONATE APPROACHING WATERFLOOD DEPLETION

    SciTech Connect

    K.J. Harpole; Ed G. Durrett; Susan Snow; J.S. Bles; Carlon Robertson; C.D. Caldwell; D.J. Harms; R.L. King; B.A. Baldwin; D. Wegener; M. Navarrette

    2002-09-01

    The purpose of this project was to economically design an optimum carbon dioxide (CO{sub 2}) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO{sub 2} horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields. The Unit was a mature waterflood with water cut exceeding 95%. Oil must be mobilized through the use of a miscible or near-miscible fluid to recover significant additional reserves. Also, because the unit was relatively small, it did not have the benefit of economies of scale inherent in normal larger scale projects. Thus, new and innovative methods were required to reduce investment and operating costs. Two primary methods used to accomplish improved economics were use of reservoir characterization to restrict the flood to the higher quality rock in the unit and use of horizontal injection wells to cut investment and operating costs. The project consisted of two budget phases. Budget Phase I started in June 1994 and ended late June 1996. In this phase Reservoir Analysis, Characterization Tasks and Advanced Technology Definition Tasks were completed. Completion enabled the project to be designed, evaluated, and an Authority for Expenditure (AFE) for project implementation submitted to working interest owners for approval. Budget Phase II consisted of the implementation and execution of the project in the field. Phase II was completed in July 2001. Performance monitoring, during Phase II, by mid 1998 identified the majority of producing wells which under performed their anticipated withdrawal rates. Newly drilled and re-activated wells had lower offtake rates than originally forecasted. As a result of poor offtake, higher reservoir pressure was a concern

  17. Reservoir characters of the Ypresian carbonates, Western Libyan Offshore, Central Mediterranean Sea

    SciTech Connect

    Mriheel, I.Y.

    1995-08-01

    Significant hydrocarbon accumulations have been discovered in Western Libyan offshore in the Ypresian carbonate reservoirs of Jdeir Formation and Jirani Dolomite. The discoveries of hydrocarbons are mainly in structural traps where the Jdeir nummulitic facies and Jirani dolomitic facies B have been structured by salt domes or underlying positive fault blocks. This study investigates the relationship between environments of deposition, diagenesis and reservoir characters of the two main hydrocarbon producing units of the Jdeir and Jirani formations. Petrographic and petrophysical studies indicate that porosity in the Jirani Dolomite is related to diagenesis in meteoric environments, while in the Jdeir reservoir is the result of the environment of deposition and diagenesis. Excellent reservoir porosity of Jdeir nummulitic facies and Jirani dolomitic facies B is related to diagenesis in meteoric water during exposure to subaerial conditions which is considered to be due to lowering of sea level and possibly local uplifting.

  18. Seagrass meadows as a globally significant carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Mazarrasa, I.; Marbà, N.; Lovelock, C. E.; Serrano, O.; Lavery, P. S.; Fourqurean, J. W.; Kennedy, H.; Mateo, M. A.; Krause-Jensen, D.; Steven, A. D. L.; Duarte, C. M.

    2015-08-01

    There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the particulate organic carbon (POC) stocks and accumulation rates and ignored the particulate inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 403 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m of sediment ranged between 3 and 1660 Mg PIC ha-1, with an average of 654 ± 24 Mg PIC ha-1, exceeding those of POC reported in previous studies by about a factor of 5. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of -8 ± 2 Mg PIC ha-1 per degree of latitude (general linear model, GLM; p < 0.0003). Using PIC concentrations and estimates of sediment accretion in seagrass meadows, the mean PIC accumulation rate in seagrass sediments is found to be 126.3 ± 31.05 g PIC m-2 yr-1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top metre of sediment and accumulate between 22 and 75 Tg PIC yr-1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite the fact that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrated by the comparison of carbon (PIC

  19. Dam tailwaters compound the effects of reservoirs on the longitudinal transport of organic carbon in an arid river

    NASA Astrophysics Data System (ADS)

    Ulseth, A. J.; Hall, R. O., Jr.

    2015-04-01

    Reservoirs on rivers can disrupt organic carbon (OC) transport and transformation, but less is known how downstream river reaches directly below dams contribute to OC processing than reservoirs alone. We compared how reservoirs and their associated tailwaters affected OC quantity and quality by calculating particulate (P) OC and dissolved (D) OC fluxes, and measuring composition and bioavailability of DOC. We sampled the Yampa River near Maybell, Colorado, USA and the Green River above and below Fontenelle and Flaming Gorge reservoirs, and their respective tailwaters from early snowmelt to base flow hydrological conditions. In unregulated reaches (Yampa River, Green River above Fontenelle reservoir), DOC and POC concentrations increased with snowmelt discharge. POC and DOC concentrations also increased with stream discharge below Fontenelle reservoir, but there was no relationship between DOC and stream flow below Flaming Gorge reservoir. The annual load of POC was 3-fold lower below Fontenelle Reservoir and nearly 7-fold lower below Flaming Gorge reservoir, compared to their respective upstream sampling sites. DOC exported to downstream reaches from both reservoirs was less bioavailable, as measured with bioassays, than DOC upriver of the reservoirs. Lastly, tailwater reaches below the reservoirs generated OC, exporting 1.6-2.2 g C m-2 d-1 of OC to downstream ecosystems. Changes in total fluxes from upstream to downstream of reservoirs and their tailwaters do not represent the simultaneous transformation and production of OC, which may lead to the underestimation of the quantity of OC mineralized, transformed, or retained in coupled river-reservoir-tailwater ecosystems.

  20. CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

    SciTech Connect

    Prieditis, J.; Wehner, S.

    1998-01-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

  1. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SANANDRES RESERVOIR

    SciTech Connect

    Unknown

    2003-01-15

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; (7) Mobility control agents.

  2. Active CO2 Reservoir Management for Carbon Capture, Utilization, and Sequestration: Impact on Permitting, Monitoring, and Public Acceptance

    NASA Astrophysics Data System (ADS)

    Buscheck, T. A.; Chen, M.; Sun, Y.; Hao, Y.; Court, B.; Celia, M. A.; Wolery, T.; Aines, R. D.

    2011-12-01

    CO2 capture and sequestration (CCS) integrated with geothermal energy production in deep geological formations can play an important role in reducing CO2 emissions to the atmosphere and thereby mitigate global climate change. For industrial-scale CO2 injection in saline formations, pressure buildup can limit storage capacity and security. Active CO2 Reservoir Management (ACRM) combines brine production with CO2 injection to relieve pressure buildup, increase injectivity, manipulate CO2 migration, constrain brine leakage, and enable beneficial utilization of produced brine. Therefore, ACRM can be an enabler of carbon capture, utilization, and sequestration (CCUS). Useful products may include freshwater, cooling water, make-up water for pressure support in oil, gas, and geothermal reservoir operations, and geothermal energy production. Implementation barriers to industrial-scale CCS include concerns about (1) CO2 sequestration security and assurance, (2) pore-space competition with neighboring subsurface activities, (3) CO2 capture costs, and (4) water-use demands imposed by CCS operations, which is particularly important where water resources are already scarce. CCUS, enabled by ACRM, has the potential of addressing these barriers. Pressure relief from brine production can substantially reduce the driving force for potential CO2 and brine migration, as well as minimize interference with neighboring subsurface activities. Electricity generated from geothermal energy can offset a portion of the parasitic energy and financial costs of CCS. Produced brine can be used to generate freshwater by desalination technologies, such as RO, provide a source for saltwater cooling systems or be used as make-up water for oil, gas, or geothermal reservoir operations, reducing the consumption of valuable freshwater resources. We examine the impact of brine production on reducing CO2 and brine leakage. A volumetric balance between injected and produced fluids minimizes the spatial

  3. Application of Carbonate Reservoir using waveform inversion and reverse-time migration methods

    NASA Astrophysics Data System (ADS)

    Kim, W.; Kim, H.; Min, D.; Keehm, Y.

    2011-12-01

    Recent exploration targets of oil and gas resources are deeper and more complicated subsurface structures, and carbonate reservoirs have become one of the attractive and challenging targets in seismic exploration. To increase the rate of success in oil and gas exploration, it is required to delineate detailed subsurface structures. Accordingly, migration method is more important factor in seismic data processing for the delineation. Seismic migration method has a long history, and there have been developed lots of migration techniques. Among them, reverse-time migration is promising, because it can provide reliable images for the complicated model even in the case of significant velocity contrasts in the model. The reliability of seismic migration images is dependent on the subsurface velocity models, which can be extracted in several ways. These days, geophysicists try to obtain velocity models through seismic full waveform inversion. Since Lailly (1983) and Tarantola (1984) proposed that the adjoint state of wave equations can be used in waveform inversion, the back-propagation techniques used in reverse-time migration have been used in waveform inversion, which accelerated the development of waveform inversion. In this study, we applied acoustic waveform inversion and reverse-time migration methods to carbonate reservoir models with various reservoir thicknesses to examine the feasibility of the methods in delineating carbonate reservoir models. We first extracted subsurface material properties from acoustic waveform inversion, and then applied reverse-time migration using the inverted velocities as a background model. The waveform inversion in this study used back-propagation technique, and conjugate gradient method was used in optimization. The inversion was performed using the frequency-selection strategy. Finally waveform inversion results showed that carbonate reservoir models are clearly inverted by waveform inversion and migration images based on the

  4. Dam tailwaters compound the effects of reservoirs on the longitudinal transport of organic carbon in an arid river

    NASA Astrophysics Data System (ADS)

    Ulseth, A. J.; Hall, R. O., Jr.

    2015-07-01

    Reservoirs on rivers can disrupt organic carbon (OC) transport and transformation, but less is known how river reaches directly below dams contribute to OC processing. We compared how reservoirs and their associated tailwaters affected OC quantity and quality by calculating particulate OC (POC) and dissolved OC (DOC) fluxes, and measuring composition and bioavailability of DOC. We sampled the Yampa River near Maybell, Colorado, USA, and the Green River above and below Fontenelle and Flaming Gorge reservoirs as well as their respective tailwaters from early snowmelt to base flow hydrological conditions. In unregulated reaches (Yampa River, Green River above Fontenelle reservoir), DOC and POC concentrations increased with snowmelt discharge. POC and DOC concentrations also increased with stream discharge below Fontenelle reservoir, but there was no relationship between DOC and stream flow below Flaming Gorge reservoir. The annual load of POC was 3-fold lower below Fontenelle Reservoir and nearly 7-fold lower below Flaming Gorge reservoir, compared to their respective upstream sampling sites. DOC exported to downstream reaches from both reservoirs was less bioavailable, as measured with bioassays, than DOC upriver of the reservoirs. Lastly, tailwater reaches below the reservoirs generated OC, exporting potentially 1.6-2.2 g C m-2 d-1 of OC to downstream ecosystems. Therefore, the effect of impounding rivers on C fluxes is greater than the impact of the reservoirs alone given the additive effect of tailwater reaches below dams, which may produce and export comparable amounts of likely autochthonous carbon to downstream reaches.

  5. Mesogenetic dissolution: Its role in porosity development in carbonate reservoirs

    SciTech Connect

    Mazzullo, S.J. ); Harris, P.M. )

    1992-05-01

    Models of porosity formation in carbonate rocks have stressed subaerial exposure and attendant shallow meteoric diagenesis. Porosity formation also occurs in deep-burial, or mesogenetic, settings as a result of dissolution enlargement of preexisting pores (porosity enhancement) and creation of new pore systems. Brines charged with organic acids, carbon dioxide, and/or hydrogen sulfide derived from organic matter diagenesis and thermochemical sulfate reduction are the likely fluids causing significant mesogenetic dissolution. Enhanced and newly created mesogenetic pore types can mimic pore types formed in shallow meteoric environments, and therefore, the mesogenetic origin of some porosity may go unrecognized.

  6. Methane exsolution due to carbon dioxide injection in deep saline reservoirs: Implications for geologic carbon sequestration

    NASA Astrophysics Data System (ADS)

    Oldenburg, C. M.; Doughty, C.; Spycher, N.

    2013-12-01

    Deep saline formations targeted for geologic carbon sequestration, especially in areas known for hydrocarbon production, may contain significant concentrations of dissolved CH4. As CO2 enters the formation water either in its free phase or dissolved forms, CH4 tends to exsolve from the water, potentially causing complications for geologic carbon sequestration. We have used numerical simulation with TOUGH2/EOS7C to investigate the process of CH4 exsolution caused by CO2 injection into deep formations containing water saturated with CH4. We validated the solubility model in TOUGH2/EOS7C against published measurements of solubility and corresponding Henry's Law coefficients which show that CO2 and CH4 solubilities actually increase with dissolution of the other component. Exsolution occurs because the partial pressures exerted by dissolved CO2 and CH4 in water exceed the static pressure, which can lead to the formation of a CH4-rich gas phase. We verified our results against a previously published one-dimensional test problem, and investigated the effects of numerical dispersion on the process. In 2D radial simulations of a model system, we found that highly concentrated CH4 gas regions form at the leading edge of the CO2 injection front, but the gas saturations in such regions are small. Because the gas saturations are small in the CH4-rich gas regions in the generic system studied here, (1) CH4 exsolution does not appear to be a problem for seismic monitoring of CO2 plumes, (2) reservoir pressurization due to dilution of supercritical CO2 by CH4 does not appear to be a concern, and (3) relative permeability is not strongly reduced.

  7. Calibration of NMR well logs from carbonate reservoirs with laboratory NMR measurements and μXRCT

    DOE PAGESBeta

    Mason, Harris E.; Smith, Megan M.; Hao, Yue; Carroll, Susan A.

    2014-12-31

    The use of nuclear magnetic resonance (NMR) well log data has the potential to provide in-situ porosity, pore size distributions, and permeability of target carbonate CO₂ storage reservoirs. However, these methods which have been successfully applied to sandstones have yet to be completely validated for carbonate reservoirs. Here, we have taken an approach to validate NMR measurements of carbonate rock cores with independent measurements of permeability and pore surface area to volume (S/V) distributions using differential pressure measurements and micro X-ray computed tomography (μXRCT) imaging methods, respectively. We observe that using standard methods for determining permeability from NMR data incorrectlymore » predicts these values by orders of magnitude. However, we do observe promise that NMR measurements provide reasonable estimates of pore S/V distributions, and with further independent measurements of the carbonate rock properties that universally applicable relationships between NMR measured properties may be developed for in-situ well logging applications of carbonate reservoirs.« less

  8. Tectonic control of the crustal organic carbon reservoir during the Precambrian

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.

    1994-01-01

    Carbon isotopic trends indicate that the crustal reservoir of reduced, organic carbon increased during the Proterozoic, particularly during periods of widespread continental rifting and orogeny. No long-term trends are apparent in the concentration of organic carbon in shales, cherts and carbonates. The age distribution of 261 sample site localities sampled for well-preserved sedimentary rocks revealed a 500-700-Ma periodicity which coincided with tectonic cycles. It is assumed that the numbers of sites are a proxy for mass of sediments. A substantial increase in the number of sites in the late Archean correlates with the first appearance between 2.9 and 2.5 Ga of extensive continental platforms and their associated sedimentation. It is proposed that the size of the Proterozoic crustal organic carbon reservoir has been modulated by tectonic control of the volume of sediments deposited in environments favorable for the burial and preservation of organic matter. Stepwise increases in this reservoir would have caused the oxidation state of the Proterozoic environment to increase in a stepwise fashion.

  9. Adaptive neuro fuzzy inference system for compressional wave velocity prediction in a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Zoveidavianpoor, Mansoor; Samsuri, Ariffin; Shadizadeh, Seyed Reza

    2013-02-01

    Compressional-wave (Vp) data are key information for estimation of rock physical properties and formation evaluation in hydrocarbon reservoirs. However, the absence of Vp will significantly delay the application of specific risk-assessment approaches for reservoir exploration and development procedures. Since Vp is affected by several factors such as lithology, porosity, density, and etc., it is difficult to model their non-linear relationships using conventional approaches. In addition, currently available techniques are not efficient for Vp prediction, especially in carbonates. There is a growing interest in incorporating advanced technologies for an accurate prediction of lacking data in wells. The objectives of this study, therefore, are to analyze and predict Vp as a function of some conventional well logs by two approaches; Adaptive Neuro-Fuzzy Inference System (ANFIS) and Multiple Linear Regression (MLR). Also, the significant impact of selected input parameters on response variable will be investigated. A total of 2156 data points from a giant Middle Eastern carbonate reservoir, derived from conventional well logs and Dipole Sonic Imager (DSI) log were utilized in this study. The quality of the prediction was quantified in terms of the mean squared error (MSE), correlation coefficient (R-square), and prediction efficiency error (PEE). Results show that the ANFIS outperforms MLR with MSE of 0.0552, R-square of 0.964, and PEE of 2%. It is posited that porosity has a significant impact in predicting Vp in the investigated carbonate reservoir.

  10. Magnitude and significance of carbon burial in lakes, reservoirs, and peatlands

    USGS Publications Warehouse

    Dean, W.E.; Gorham, E.

    1998-01-01

    Globally, lakes are currently accumulating organic carbon (OC) at an estimated annual rate of about 42 Tg.yr-. Most of the OC in all but the most oligotrophic of these lakes is autochthonous, produced by primary productio in the lakes. The sediments of reservoirs accumulate an additional 160 Tg annually, and peatlands contribute 96 Tg annually. These three carbon pools collectively cover less than 2% of the Earth's surface and constitute a carbon sink of about 300 Tg.yr-1. Althoughthe oceans cover 71% of the Earth's surface, they accumulate OC at a rate of only about 100 Tg.yr-.

  11. SCREENING METHODS FOR SELECTION OF SURFACTANT FORMULATIONS FOR IOR FROM FRACTURED CARBONATE RESERVOIRS

    SciTech Connect

    William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu; Seung Soon Jang

    2005-07-01

    This topical report presents details of the laboratory work performed to complete Task 1 of this project; developing rapid screening methods to assess surfactant performance for IOR (Improved Oil Recovery) from fractured carbonate reservoirs. The desired outcome is to identify surfactant formulations that increase the rate and amount of aqueous phase imbibition into oil-rich, oil-wet carbonate reservoir rock. Changing the wettability from oil-wet to water-wet is one key to enhancing this water-phase imbibition process that in turn recovers additional oil from the matrix portion of a carbonate reservoir. The common laboratory test to evaluate candidate surfactant formulations is to measure directly the aqueous imbibition rate and oil recovery from small outcrop or reservoir cores, but this procedure typically requires several weeks. Two methods are presented here for the rapid screening of candidate surfactant formulations for their potential IOR performance in carbonate reservoirs. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant performance reported in the literature.

  12. Val Verde Basin: Thrusted Strawn (Pennsylvanian) carbonate reservoirs, Pakenham Field area

    SciTech Connect

    Montgomery, S.L.

    1996-07-01

    An important target of recent exploration in the Val Verde basin of southwestern Texas has been thrusted Pennsylvanian (Desmoinesian) carbonates along the leading edge of the Ouachita front. These reservoirs produce gas and condensate at significant rates from fractured limestones, which were deposited in a variety of environments and later complexly juxtaposed during thrusting. Improvements in seismic imaging capabilities, particularly associated with the introduction of two-dimension (2-D) swath and three-dimensional (3-D) surveys, have allowed accurate mapping of the thrust front and have resulted in revised interpretations of basin structure and history. These data highlight the existence of multiple reservoirs at separate structural levels. Strawn reservoirs are discussed in relation to the Pakenham field area, northwestern Terrell County.

  13. Amplitude map analysis using forward modeling in sandstone and carbonate reservoirs

    SciTech Connect

    Neff, D.B. )

    1993-10-01

    The extent to which seismic amplitude maps can contribute to the analysis of hydrocarbon reservoirs was investigated for clastic and carbonate reservoirs worldwide. By using a petrophysical-based, forward modeling process called incremental pay thickness (IPT) modeling, five lithology types were quantitatively analyzed for the interplay of seismic amplitude versus lithology, porosity, hydrocarbon pore fluid saturation, bedding geometries, and reservoir thickness. The studies identified three common tuning curve shapes (concave, convex, and bilinear) that were primarily dependent upon the lithology model type and the average net porosity therein. While the reliability of pay and porosity predictions from amplitude maps varied for each model type, all analyses showed a limited thickness range for which amplitude data could successfully predict net porosity thickness or hydrocarbon pore volume. The investigation showed that systematic forward modeling is required before amplitude maps can be properly interpreted.

  14. Intrashelf basins: A geologic model for source-bed and reservoir facies deposition within carbonate shelves

    SciTech Connect

    Grover, G. Jr. )

    1993-09-01

    Intrashelf basins (moats, inshore basins, shelf basins, differentiated shelf, and deep-water lagoons of others) are depressions of varying sizes and shapes that occur within tectonically passive and regionally extensive carbonate shelves. Intrashelf basins grade laterally and downdip (seaward) into shallow-water carbonates of the regional shelf, are separated from the open marine basin by the shelf margin, and are largely filled by fine-grained subtidal sediments having attributes of shallow- and deeper water sedimentation. These basins are commonly fringed or overlain by carbonate sands, reefs, or buildups. These facies may mimic those that occur along the regional shelf margin, and they can have trends that are at a high angle to that of the regional shelf. Intrashelf basins are not intracratonic basins. The history of most intrashelf basins is a few million to a few tens of million of years. Examples of intrashelf basins are known throughout the Phanerozoic; the southern portion of the Holocene Belize shelf is a modern example of an intrashelf basin. Two types of intrashelf basins are recognized. Coastal basins pass updip into coastal clastics of the craton with the basin primarily filled by fine clastics. Shelf basins occur on the outer part of the shelf, are surrounded by shallow-water carbonate facies, and are filled by peloidal lime mud, pelagics, and argillaceous carbonates. Intrashelf basins are commonly the site of organic-rich, source-bed deposition, resulting in the close proximity of source beds and reservoir facies that may fringe or overlie the basin. Examples of hydrocarbon-charged reservoirs that were sourced by an intrashelf basin include the Miocene Bombay High field, offshore India; the giant Jurassic (Arab-D) and Cretaceous (Shuaiba) reservoirs of the Arabian Shelf; the Lower Cretaceous Sunniland trend, South Florida basin; and the Permian-Pennsylvanian reservoirs surrounding the Tatum basin in southeastern New Mexico.

  15. Patterns of changes in oil properties in complex constructions for carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Morozov, Vladimir P.; Plotnikova, Irina N.; Nosova, Fidania F.; Pronin, Nikita V.; Nosova, Julia G.

    2014-05-01

    The objects of this research are carbonate reservoirs with non-uniform lithology and filtration-volumetric parameters. The oil under study is heavy ( 0.924 g/cm3). Our research methods include the following: studying of filtration-volumetric parameters in rock samples, performing the thermal and geochemical studies of fluids . Thermal and geochemical studies performed on core samples and on fluids extracted from sediments of Bashkirian sub-panel of a 1985 well in Akansky field showed that oil properties (namely its group composition) are not constant and uniform throughout the deposit but depend on the structure of the pore space, on the porosity, and the size of pore channels. In particular, we found out that oil that saturates large pores and cavities contains less oil fractions and more resins and asphaltenes. The fine pores of the rock matrix are saturated with lighter petroleum hydrocarbons, which predominantly have oils while the percentage of asphaltenes decreases. These patterns can be explained by the process of chromatography (separation) of oil during its migration and filtration through some porous environments while filling up the collector and forming deposits. Assuming that petroleum is a colloidal solution where light hydrocarbons serve as solvents, and resin- asphaltene colloidal particles are the dissolved part, the process of filling the pores can be represented as follows. Under the influence of external forces and as a result of spreading in a porous environment, oil, when entering the collector, is subjected chromatography - the lightest and easily movable hydrocarbons (solvents) penetrate into finer pore channels (including the thinnest pores and micro cracks of the rock matrix), while the resinous asphaltene part dissolved in oil remains in the large pores and cavities. Thus, the distribution of oil in carbonate reservoir of Bashkirian sub-panel is as follows: rock matrix and its low porosity layers are filled with lighter oil, while heavier

  16. Characterization of facies and permeability patterns in carbonate reservoirs based on outcrop analogs. Final report

    SciTech Connect

    Kerans, C.; Lucia, F.J.; Senger, R.K.; Fogg, G.E.; Nance, H.S.; Hovorka, S.D.

    1993-07-01

    The primary objective of this research is to develop methods for better describing the three-dimensional geometry of carbonate reservoir flow units as related to conventional or enhanced recovery of oil. San Andres and Grayburg reservoirs were selected for study because of the 13 Bbbl of remaining mobile oil and 17 Bbbl of residual oil in these reservoirs. The key data base is provided by detailed characterization of geologic facies and rock permeability in reservior-scale outcrops of the Permian San Andres Formation in the Guadalupe Mountains of New Mexico. Emphasis is placed on developing an outcrop analog for San Andres strata that can be used as (1) a guide to interpreting the regional and local geologic framework of the subsurface reservoirs (2) a data source illustrating the scales and patterns of variability of rock-fabric facies and petrophysical properties, particularly in lateral dimension, and on scales that cannot be studied during subsurface reservoir characterization. The research approach taken to achieve these objectives utilizes the integration of geologic description, geostatistical techniques, and reservoir flow simulation experiments. Results from this research show that the spatial distribution of facies relative to the waterflood direction can significantly affect how the reservoir produces. Bypassing of unswept oil occurs due to cross flow of injected water from high permeability zones into lower permeability zones were high permeability zones terminate. An area of unswept oil develops because of the slower advance of the water-injection front in the lower permeability zones. When the injection pattern is reversed, the cross-flow effect changes due to the different arrangements of rock-fabric flow units relative to the flow of injected water, and the sweep efficiency is significantly different. Flow across low-permeability mudstones occurs showing that these layers do not necessarily represent flow barriers.

  17. Carbon capture and storage reservoir properties from poroelastic inversion: A numerical evaluation

    NASA Astrophysics Data System (ADS)

    Lepore, Simone; Ghose, Ranajit

    2015-11-01

    We investigate the prospect of estimating carbon capture and storage (CCS) reservoir properties from P-wave intrinsic attenuation and velocity dispersion. Numerical analogues for two CCS reservoirs are examined: the Utsira saline formation at Sleipner (Norway) and the coal-bed methane basin at Atzbach-Schwanestadt (Austria). P-wave intrinsic dispersion curves in the field-seismic frequency band, obtained from theoretical studies based on simulation of oscillatory compressibility and shear tests upon representative rock samples, are considered as observed data. We carry out forward modelling using poroelasticity theories, making use of previously established empirical relations, pertinent to CCS reservoirs, to link pressure, temperature and CO2 saturation to other properties. To derive the reservoir properties, poroelastic inversions are performed through a global multiparameter optimization using simulated annealing. We find that the combination of attenuation and velocity dispersion in the error function helps significantly in eliminating the local minima and obtaining a stable result in inversion. This is because of the presence of convexity in the solution space when an integrated error function is minimized, which is governed by the underlying physics. The results show that, even in the presence of fairly large model discrepancies, the inversion provides reliable values for the reservoir properties, with the error being less than 10% for most of them. The estimated values of velocity and attenuation and their sensitivity to effective stress and CO2 saturation generally agree with the earlier experimental observation. Although developed and tested for numerical analogues of CCS reservoirs, the approach presented here can be adapted in order to predict key properties in a fluid-bearing porous reservoir, in general.

  18. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1991-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database), to increase our understanding of how geologic heterogeneity affects the recovery of oil and gas from carbonate reservoirs in the State of Alabama, and to identify resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneity on hydrocarbon production. The paper reports on the progress of several subtasks. The subjects discussed are: controls on reservoir heterogeneity in the Smackover; pore facies and Smackover reservoir heterogeneity; geological and petrophysical reservoir characterization; geologic flow modeling; and geostatistical modeling. Accomplishments this quarter are summarized and their significance to EOR research is discussed. 1 ref., 4 figs. (CK)

  19. Oil Recovery Enhancement from Fractured, Low Permeability Reservoirs. [Carbonated Water

    DOE R&D Accomplishments Database

    Poston, S. W.

    1991-01-01

    The results of the investigative efforts for this jointly funded DOE-State of Texas research project achieved during the 1990-1991 year may be summarized as follows: Geological Characterization - Detailed maps of the development and hierarchical nature the fracture system exhibited by Austin Chalk outcrops were prepared. The results of these efforts were directly applied to the development of production decline type curves applicable to a dual-fracture-matrix flow system. Analysis of production records obtained from Austin Chalk operators illustrated the utility of these type curves to determine relative fracture/matrix contributions and extent. Well-log response in Austin Chalk wells has been shown to be a reliable indicator of organic maturity. Shear-wave splitting concepts were used to estimate fracture orientations from Vertical Seismic Profile, VSP data. Several programs were written to facilitate analysis of the data. The results of these efforts indicated fractures could be detected with VSP seismic methods. Development of the EOR Imbibition Process - Laboratory displacement as well as Magnetic Resonance Imaging, MRI and Computed Tomography, CT imaging studies have shown the carbonated water-imbibition displacement process significantly accelerates and increases recovery from oil saturated, low permeability rocks. Field Tests - Two operators amenable to conducting a carbonated water flood test on an Austin Chalk well have been identified. Feasibility studies are presently underway.

  20. Oil recovery enhancement from fractured, low permeability reservoirs. [Carbonated Water

    SciTech Connect

    Poston, S.W.

    1991-01-01

    The results of the investigative efforts for this jointly funded DOE-State of Texas research project achieved during the 1990-1991 year may be summarized as follows: Geological Characterization - Detailed maps of the development and hierarchical nature the fracture system exhibited by Austin Chalk outcrops were prepared. The results of these efforts were directly applied to the development of production decline type curves applicable to a dual-fracture-matrix flow system. Analysis of production records obtained from Austin Chalk operators illustrated the utility of these type curves to determine relative fracture/matrix contributions and extent. Well-log response in Austin Chalk wells has been shown to be a reliable indicator of organic maturity. Shear-wave splitting concepts were used to estimate fracture orientations from Vertical Seismic Profile, VSP data. Several programs were written to facilitate analysis of the data. The results of these efforts indicated fractures could be detected with VSP seismic methods.Development of the EOR Imbibition Process - Laboratory displacement as well as Magnetic Resonance Imaging, MRI and Computed Tomography, CT imaging studies have shown the carbonated water-imbibition displacement process significantly accelerates and increases recovery from oil saturated, low permeability rocks.Field Tests - Two operators amenable to conducting a carbonated water flood test on an Austin Chalk well have been identified. Feasibility studies are presently underway.

  1. Differential Effects of Legume Species on the Recovery of Soil Microbial Communities, and Carbon and Nitrogen Contents, in Abandoned Fields of the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Li, Jin Hua; Jiao, Shu Mei; Gao, Rong Qing; Bardgett, Richard D.

    2012-12-01

    Plant-soil interactions are known to influence a wide range of ecosystem-level functions. Moreover, the recovery of these functions is of importance for the successful restoration of soils that have been degraded through intensive and/or inappropriate land use. Here, we assessed the effect of planting treatments commonly used to accelerate rates of grassland restoration, namely introduction of different legume species Medicago sativa, Astragalus adsurgens, Melilotus suaveolens, on the recovery of soil microbial communities and carbon and nitrogen contents in abandoned fields of the Loess Plateau, China. The results showed effects were species-specific, and either positive, neutral or negative depending on the measure and time-scale. All legumes increased basal respiration and metabolic quotient and had a positive effect on activity and functional diversity of the soil microbial community, measured using Biolog EcoPlate. However, soil under Astragalus adsurgens had the highest activity and functional diversity relative to the other treatments. Soil carbon and nitrogen content and microbial biomass were effectively restored in 3-5 years by introducing Medicago sativa and Astragalus adsurgens into early abandoned fields. Soil carbon and nitrogen content were retarded in 3-5 years and microbial biomass was retarded in the fifth year by introducing Melilotus suaveolens. Overall, the restoration practices of planting legumes can significantly affect soil carbon and nitrogen contents, and the biomass, activity, and functional diversity of soil microbial community. Therefore, we propose certain legume species could be used to accelerate ecological restoration of degraded soils, hence assist in the protection and preservation of the environment.

  2. Predicting phase behavior of mixtures of reservoir fluids with carbon dioxide

    SciTech Connect

    Grigg, R.B.; Lingane, P.J.

    1983-01-01

    The use of an equation of state to predict phase behavior during carbon dioxide flooding is well established. The characterization of the C/sub 7/ fraction and the selection of interaction parameters are the most important variables. Single-contact phase behavior is presented for mixtures of Ford Geraldine (Delaware), Maljamar (Grayburg), West Sussex (Shannon), and Reservoir D reservoir fluids, and of a synthetic oil with carbon dioxide. The phase behavior of these mixtures can be reproduced using 3 to 5 pseudo components and common interaction parameters. The critical properties of the pseudo components are calculated from detailed oil characterizations. Because the parameters are not further adjusted, this approach reduces the empiricism in fitting phase data and may result in a more accurate representation of the system as the composition of the oil changes during the approach to miscibility. 21 references.

  3. Carbonized eggshell membrane as a natural polysulfide reservoir for highly reversible Li-S batteries.

    PubMed

    Chung, Sheng-Heng; Manthiram, Arumugam

    2014-03-01

    Carbonized sucrose-coated eggshell membranes (CSEMs) consisting of natural micropores function well as a polysulfide reservoir in Li/dissolved polysulfide cells. The bottom CSEM current collector encapsulates the active material, while the upper CSEM inhibitor intercepts the migrating polysulfides. This design with CSEM allows the dissolved polysulfides to be localized and the electrochemical reactions within the cathode region to be stabilized, resulting in high discharge capacity, long-term cycle stability, and high sulfur loading. PMID:24285597

  4. Integrated core-log petrofacies analysis in the construction of a reservoir geomodel: A case study of a mature Mississippian carbonate reservoir using limited data

    USGS Publications Warehouse

    Bhattacharya, S.; Doveton, J.H.; Carr, T.R.; Guy, W.R.; Gerlach, P.M.

    2005-01-01

    Small independent operators produce most of the Mississippian carbonate fields in the United States mid-continent, where a lack of integrated characterization studies precludes maximization of hydrocarbon recovery. This study uses integrative techniques to leverage extant data in an Osagian and Meramecian (Mississippian) cherty carbonate reservoir in Kansas. Available data include petrophysical logs of varying vintages, limited number of cores, and production histories from each well. A consistent set of assumptions were used to extract well-level porosity and initial saturations, from logs of different types and vintages, to build a geomodel. Lacking regularly recorded well shut-in pressures, an iterative technique, based on material balance formulations, was used to estimate average reservoir-pressure decline that matched available drillstem test data and validated log-analysis assumptions. Core plugs representing the principal reservoir petrofacies provide critical inputs for characterization and simulation studies. However, assigning plugs among multiple reservoir petrofacies is difficult in complex (carbonate) reservoirs. In a bottom-up approach, raw capillary pressure (Pc) data were plotted on the Super-Pickett plot, and log- and core-derived saturation-height distributions were reconciled to group plugs by facies, to identify core plugs representative of the principal reservoir facies, and to discriminate facies in the logged interval. Pc data from representative core plugs were used for effective pay evaluation to estimate water cut from completions, in infill and producing wells, and guide-selective perforations for economic exploitation of mature fields. The results from this study were used to drill 22 infill wells. Techniques demonstrated here can be applied in other fields and reservoirs. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

  5. Dynamics of phosphorus fractions after land-use abandonment in relation to carbon, nitrogen, and microbial community composition

    NASA Astrophysics Data System (ADS)

    Spohn, Marie

    2014-05-01

    Former agricultural land-use has strong legacy effects on biogeochemical cycles as well as on plant and microbial community composition in secondary ecosystems. Since many forests and grasslands have previously been cultivated it is important to understand long-term effects of former arable land use on these ecosystems. We studied the temporal dimension of the impact of former agricultural land use on soil total organic C (TOC), nitrogen (N), phosphorus (P) fractions, and microbial community structure in two chronosequences of abandoned vineyards, differing in exposition and slope. We found that more TOC accumulated in soils of south- than in southwest-exposed sites, which can be attributed to the drier microclimate that decreases organic matter decomposition. TOC concentrations were significantly positive correlated with total nitrogen (TN) concentrations (R=0.99, p<0.05), indicating a close relation between TOC and TN accumulation. We showed for the first time - according to our knowledge - a very slow depletion of P from the soil organic matter (SOM) after cessation of cultivation. This suggests that SOM is an effective intermediate storage of fertilizer-derived P, which slowly releases P. In contrast, labile P concentrations decreased quickly during the first 25 years of land use-abandonment. A linear relation between microbial C and TOC (R=0.83, p<0.05) was found, suggesting that soil microorganisms were predominantly substrate limited. The ratio of arbuscular mycorrhizal fungi (AMF)/bacteria increased strongly during the first decade after land-use abandonment, indicating a quick recovery of AMF most likely due to the fast colonization of the sites by herbaceous plants. Along with an increase in the abundance of trees the ratio of arbuscular mycorrhizal fungi (AMF)/bacteria decreased again. No changes were found in the total fungi/bacteria ratio during secondary succession. In conclusion, our results suggest that SOM is an effective intermediate storage of

  6. Growth and activity of reservoir microorganisms under carbon capture and storage conditions

    NASA Astrophysics Data System (ADS)

    Rakoczy, Jana; Gniese, Claudia; Krüger, Martin

    2015-04-01

    Carbon capture and storage is a technology to decelerate global warming by reducing CO2 emissions into the atmosphere. To ensure safe long-term storage of CO2 in the underground a number of factors need to be considered. One of them is microbial activity in storage reservoirs, which can lead to the formation of acidic metabolites, H2S or carbonates which then might affect injectivity, permeability, pressure build-up and long-term operability. Our research focused on the effect of high CO2 concentrations on growth and activity of selected thermophilic fermenting and sulphate-reducing bacteria isolated from deep reservoirs. Experiments with supercritical carbon dioxide at 100 bar completely inhibited growth of freshly inoculated cultures and also caused a rapid decrease of growth of a pre-grown culture. This demonstrated that supercritical carbon dioxide had a certain sterilizing effect on cells. This effect was not observed in control cultures with 100 bar of hydrostatic pressure. However, when provided with a surface for attachment, CO2-inhibited cells restarted growth after CO2 release. The same was observed for organisms able to form spores. Further experiments will examine physiological and molecular properties of the model organism allowing for prediction of its sensitivity and/or adaptability to carbon dioxide in potential future storage sites.

  7. Kinetics of carbonate dissolution in CO2-saturated aqueous system at reservoir conditions

    NASA Astrophysics Data System (ADS)

    Peng, Cheng; Crawshaw, John P.; Maitland, Geoffrey; Trusler, J. P. Martin

    2014-05-01

    In recent years, carbon capture and storage (CCS) has emerged as a key technology for limiting anthropogenic CO2 emissions while allowing the continued utilisation of fossil fuels. The most promising geological storage sites are deep saline aquifers because the capacity, integrity and injection economics are most favourable, and the environmental impact can be minimal. Many rock-fluid chemical reactions are known to occur both during and after CO2 injection in saline aquifers. The importance of rock-fluid reactions in the (CO2 + H2O) system can be understood in terms of their impact on the integrity and stability of both the formation rocks and cap rocks. The chemical interactions between CO2-acidified brines and the reservoir minerals can influence the porosity and permeability of the formations, resulting in changes in the transport processes occurring during CO2 storage. Since carbonate minerals are abundant in sedimentary rocks, one of the requirements to safely implement CO2 storage in saline aquifers is to characterise the reactivity of carbonate minerals in aqueous solutions at reservoir conditions. In this work, we reported measurements of the intrinsic rate of carbonate dissolution in CO2-saturated water under high-temperature high-pressure reservoir conditions extending up to 373 K and 14 MPa. The rate of carbonate dissolution in CO2-free HCl(aq) was also measured at ambient pressure at temperatures up to 353 K. Various pure minerals and reservoir rocks were investigated in this study, including single-crystals of calcite and magnesite, and samples of dolomite, chalks and sandstones. A specially-designed batch reactor system, implementing the rotating disc technique, was used to obtain the intrinsic reaction rate at the solid/liquid interface, free of mass transfer effects. The effective area and mineralogy of the exposed surface was determined by a combination of surface characterisation techniques including XRD, SEM, EDX and optical microscopy. The

  8. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1989-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. These studies will be utilized to develop and test mathematical models for prediction of the effects of reservoirs heterogeneities.

  9. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that effect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, or engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production.

  10. Abandoned oil fields of Texas Gulf Coast

    SciTech Connect

    Dutton, S.P.

    1984-04-01

    One nonconventional oil target in Texas is the oil that remains in abandoned fields, defined as those fields that had no oil or gas production in 1977 and 1982. This target includes oil that has not been tapped by conventional field development because of reservoir heterogeneity and oil in reservoirs that have not been subjected to any secondary or tertiary recovery efforts. A total of 138 abandoned oil fields having individual cumulative production greater than 500,000 bbl are located in the Texas Gulf Coast (railroad Commission of Texas Districts 2, 3, and 4). These 138 onshore fields produced 276 million barrels of oil before being abandoned. Nongiant fields in the Texas Gulf Coast average about 40% ultimate recovery, so these fields probably originally contained about 700 million bbl of oil in place. Therefore, about 424 million bbl of oil remain unrecovered. Reservoirs in these abandoned fields are Tertiary sandstones. The 44 abandoned fields in the upper Texas Gulf Coast (District 3) produced from a wide range of plays; those plays with the largest number of abandoned fields are Yegua and Frio deep-seated domes, Eocene deltaic sandstone, and Frio barrier/strand-plain sandstone. The 19 abandoned fields in the middle Texas Gulf Coast (District 2) produced mainly from Wilcox and Frio fluvial/deltaic sandstones and from Frio and Jackson-Yegua barrier/strand-plain sandstones. The lower Texas Gulf Coast (District 4) contains 75 abandoned fields that produced from Frio fluvial/deltaic and barrier/strand-plain sandstones and from Jackson-Yegua barrier/strand-plain sandstones.

  11. [Preliminary research on the feature of dissolved inorganic carbon in Wulixia Reservoir in summer, Guangxi, China].

    PubMed

    Liu, Wen; Pu, Jun-Bing; Yu, Shi; Zhang, Cheng; Au, Yik-Yu; Yuan, Dao-Xian; Yang, Hui; Tang, Wei

    2014-08-01

    To gain more knowledge on the transformation process of dissolved inorganic carbon in a karst reservoir, in situ monitoring, sampling and lab experiments of water columns were carried out at various sampling sites along the flow line in Wulixia Reservoir, Guangxi, China during early July, 2013. Results showed that: (1) The hydrochemical characteristics of study areas were controlled by the carbonate equilibrium system and the hydrochemical type of all water samples was HCO3-Ca + Mg. (2) The DIC concentration decreased gradually (DIC(Average) : from 1.03 to 0.78 mmol x L(-1)) and the delta13C(DIC) increased gradually (delta13C(DIC(Average) : from -10.21per thousand to -6.62 per thousand) from the reservoir end area to dam area. Meanwhile, with the depth increase in water column, the DIC concentration increased gradually (DIC(Average) : from 0.86 to 1.05 mmol x L(-1)) and the delta13C(DIC) decreased gradually (delta13C(DIC(Average) : from -7.88 per thousand to -13.39 per thousand) from the surface to the bottom of the reservoir. Possible reasons for these research results were found as follows: (1) Dissolution-precipitation process of carbonate substance could be inhibited by other processes such as biogeochemical processes, which played little role in delta13C(DIC) variations. (2) Thermal stratification existed in the study areas which could influence the distribution of DIC and delta13C(DIC) by affecting the distribution of plankton and its orientation and strength of metabolism process, and the extent of organic matter decomposition, and so on. PMID:25338366

  12. Dual permeability flow behavior for modeling horizontal well production in fractured-vuggy carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Guo, Jian-Chun; Nie, Ren-Shi; Jia, Yong-Lu

    2012-09-01

    SummaryFractured-vuggy carbonate reservoirs are composed of by matrix, fracture, and vug systems. This paper is the first investigation into the dual permeability flow issue for horizontal well production in a fractured-vuggy carbonate reservoir. Considering dispersed vugs in carbonate reservoirs and treating media directly connected with horizontal wellbore as the matrix and fracture systems, a test analysis model of a horizontal well was created, and triple porosity and dual permeability flow behavior were modeled. Standard log-log type curves were drawn up by numerical simulation and flow behavior characteristics were thoroughly analyzed. Numerical simulations showed that type curves are dominated by external boundary conditions as well as the permeability ratio of the fracture system to the sum of fracture and matrix systems. The parameter κ is only relevant to the dual permeability model, and if κ is one, then the dual permeability model is equivalent to the single permeability model. There are seven main flow regimes with constant rate of horizontal well production and five flow regimes with constant wellbore pressure of horizontal well production; different flow regimes have different flow behavior characteristics. Early radial flow and linear flow regimes are typical characteristics of horizontal well production; duration of early radial flow regime is usually short because formation thickness is generally less than 100 m. Derivative curves are W-shaped, which is a reflection of inter-porosity flows between matrix, fracture, and vug systems. A distorted W-shape, which could be produced in certain situations, such as one involving an erroneously low time of inter-porosity flows, would handicap the recognition of a linear flow regime. A real case application was successfully implemented, and some useful reservoir parameters (e.g., permeability and inter-porosity flow factor) were obtained from well testing interpretation.

  13. Reservoir-Condition Pore-Scale Imaging of Reaction in Carbonates using Synchrotron Fast Tomography

    NASA Astrophysics Data System (ADS)

    Menke, H. P.; Andrew, M. G.; Bijeljic, B.; Blunt, M. J.

    2015-12-01

    Carbon capture and storage in carbonate reservoirs is essential for mitigating climate change. Supercritical CO2 mixed with host brine is acidic and can dissolve the surrounding pore structure and change flow dynamics. However, the type, speed, and magnitude of the dissolution are dependent on both the reactive transport properties of the pore-fluid and the intrinsic properties of the rock. Understanding how changes in the pore structure, chemistry, and flow properties affect dissolution is vital for successful predictive modelling both on the pore-scale and for up-scaled reservoir simulations. Reaction in carbonates has been studied at the pore-scale but has never been imaged dynamically in situ. We present an experimental method whereby both lab-based benchtop instruments and 'Pink Beam' synchrotron radiation are used in X-ray microtomography to investigate pore structure changes during supercritical CO2 injection at reservoir conditions. Three types of pure limestone rock with broadly varying rock topology were imaged under the same reservoir conditions. Flow-rate and brine acidity was varied in successive experiments by half an order of magnitude to gain insight into the impact of flow, transport, and physical heterogeneity. The images were binarized and the magnitude of dissolution was identified on a voxel-by-voxel basis to extract pore-by-pore dissolution data. The impact of dissolution on flow characteristics was studied by computing the evolution of the pore-scale velocity fields with a flow solver. We found that increasing rock heterogeneity increased channelized flow [Figure 1] through preferential pathways and that higher flow rate increased total dissolution. Additionally, decreasing reaction rate lowered overall reaction rate and made axial flow less uniform. Experimentally measured reaction rates in real rocks are at least an order of magnitude lower when compared to batch experiments. We provide evidence that this can be due to transport limitations

  14. EMD and Teager-Kaiser energy applied to hydrocarbon detection in a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Xue, Ya-juan; Cao, Jun-xing; Tian, Ren-fei

    2014-04-01

    Oil and gas reservoirs can cause anomalies in the energy and frequency of seismic signals. We can take advantage of these anomalies for hydrocarbon detection. Based on the Teager-Kaiser (TK) energy characteristics, a method that uses this energy in association with the Empirical Mode Decomposition (EMD) method is proposed for hydrocarbon detection in carbonate reservoirs. The EMD method, which can decompose the original seismic signals into a finite number of monocomponent intrinsic mode functions (IMFs) in the temporal domain, is used for multiband filtering. A TK energy separation algorithm is used to estimate the instantaneous frequency and amplitude of the selected IMFs from the EMD method. The proposed method can generate a joint time-frequency representation that can reflect the energy tracking of the seismic signals. The instantaneous spectrums produced by the EMD/TK method have the capability to detect hydrocarbon. The model results to the gas field, which located in the eastern Ordos Basin, China, show that the EMD/TK method can be adopted and they detect the gas-bearing reservoir efficiently. Application of the EMD/TK method in hydrocarbon detection in a gas field located in the Eastern Ordos Basin shows its effectiveness. The EMD/TK method can be used as a new analysis tool to determine the instantaneous spectral properties of a reservoir to detect hydrocarbon.

  15. Capillarity and wetting of carbon dioxide and brine during drainage in Berea sandstone at reservoir conditions

    NASA Astrophysics Data System (ADS)

    Al-Menhali, Ali; Niu, Ben; Krevor, Samuel

    2015-10-01

    The wettability of CO2-brine-rock systems will have a major impact on the management of carbon sequestration in subsurface geological formations. Recent contact angle measurement studies have reported sensitivity in wetting behavior of this system to pressure, temperature, and brine salinity. We report observations of the impact of reservoir conditions on the capillary pressure characteristic curve and relative permeability of a single Berea sandstone during drainage—CO2 displacing brine—through effects on the wetting state. Eight reservoir condition drainage capillary pressure characteristic curves were measured using CO2 and brine in a single fired Berea sandstone at pressures (5-20 MPa), temperatures (25-50°C), and ionic strengths (0-5 mol kg-1 NaCl). A ninth measurement using a N2-water system provided a benchmark for capillarity with a strongly water wet system. The capillary pressure curves from each of the tests were found to be similar to the N2-water curve when scaled by the interfacial tension. Reservoir conditions were not found to have a significant impact on the capillary strength of the CO2-brine system during drainage through a variation in the wetting state. Two steady-state relative permeability measurements with CO2 and brine and one with N2 and brine similarly show little variation between conditions, consistent with the observation that the CO2-brine-sandstone system is water wetting and multiphase flow properties invariant across a wide range of reservoir conditions.

  16. Solid hydrocarbon: a migration-of-fines problem in carbonate reservoirs

    SciTech Connect

    Lomando, A.J.

    1986-05-01

    The most familiar example of a migration-of-fines problem is authigenic kaolinite, which can detach, migrate through a pore system, and bridge pore throats, thus reducing permeability. under certain conditions, a similar problem is caused by solid hydrocarbon, independent of a mode of origin, which has precipitated in carbonate pore systems. Cores from several reservoirs in the Lower Cretaceous of east Texas were used as the data base in this study. Three morphotypes of solid hydrocarbon have been identified from thin-section and scanning electron microscope observations: droplets, peanut brittle, and carpets. Droplets are small, individual, rounded particles scattered on pore walls. Peanut brittle ranges from a continuous to discontinuous thin coating with random rounded lumps that probably have droplet precursors. Carpets are thick, continuous coatings and, at the extreme, can effectively occlude whole pores. Initially, solid hydrocarbon reduces permeability without necessarily decreasing porosity significantly. Likewise, solid hydrocarbon cannot be detected directly from wireline logs. Acidizing to enhance communication to the well bore is a common completion procedure in limestone and calcareous sandstone reservoirs. In reservoirs containing solid hydrocarbon, acid etches the substrate and releases solid hydrocarbon, which migrates in the pore system and bridges pore throats. Differential well-bore pressure also may cause solid hydrocarbon to migrate. Therefore, wettability, which controls hydrocarbon adhesion to the pore walls, and the dominant morphotype are important factors in the extent of reservoir damage.

  17. Diagenetic overprint of original depositional architecture in a shallow water carbonate reservoir, Permian Basin, Texas

    SciTech Connect

    Ruppel, S.C.; Lucia, F.J.

    1996-12-31

    Permian shallow-water carbonate reservoirs are highly heterogeneous because of complex variations in depositional facies produced by high-frequency sea level rise and fall. Accordingly, establishment of a cycle stratigraphic framework is fundamental to defining reservoir heterogeneity. Because nearly all of these reservoirs have experienced multiple episodes of dolomitization and sulfate emplacement, however, permeability is a n of diagenetic overprint. The extent to which diagenesis can affect permeability development is dramatically displayed in the Grayburg Formation (middle Permian) at South Cowden field, Weit Texas. Three scales of cyclicity contribute to original depositional facies heterogeneity in the Grayburg; high-frequency cycles, averaging 3 meters in thickness, constitute the fundamental architectural element in the main reservoir interval. Despite original depositional heterogeneity due to this cyclicity, however, permeability development is substantially the result of two diagenetic events: (1) dolomite diagenesis in vertically burrowed wackestones and packstones and (2) late alteration and removal of anhydrite. Dolomite diagenesis in vertically burrowed wackestones and packstones has produced irregular vertical zones of higher permeability in mud-dominated bases of high-frequency cycles in leeward ramp-crest highstand successions. Because dolomite diagenesis is concentrated in burrowed highstand successions, the distribution of resultant permeability trends is partly constrained by patterns of longterm accommodation and high frequency cyclicity. Anhydrite diagenesis, which is characterized by conversion to gypsum or by complete removal of sulfate, is developed along basinward margins of the field and cross cuts original depositional framework.

  18. Diagenetic overprint of original depositional architecture in a shallow water carbonate reservoir, Permian Basin, Texas

    SciTech Connect

    Ruppel, S.C.; Lucia, F.J. )

    1996-01-01

    Permian shallow-water carbonate reservoirs are highly heterogeneous because of complex variations in depositional facies produced by high-frequency sea level rise and fall. Accordingly, establishment of a cycle stratigraphic framework is fundamental to defining reservoir heterogeneity. Because nearly all of these reservoirs have experienced multiple episodes of dolomitization and sulfate emplacement, however, permeability is a n of diagenetic overprint. The extent to which diagenesis can affect permeability development is dramatically displayed in the Grayburg Formation (middle Permian) at South Cowden field, Weit Texas. Three scales of cyclicity contribute to original depositional facies heterogeneity in the Grayburg; high-frequency cycles, averaging 3 meters in thickness, constitute the fundamental architectural element in the main reservoir interval. Despite original depositional heterogeneity due to this cyclicity, however, permeability development is substantially the result of two diagenetic events: (1) dolomite diagenesis in vertically burrowed wackestones and packstones and (2) late alteration and removal of anhydrite. Dolomite diagenesis in vertically burrowed wackestones and packstones has produced irregular vertical zones of higher permeability in mud-dominated bases of high-frequency cycles in leeward ramp-crest highstand successions. Because dolomite diagenesis is concentrated in burrowed highstand successions, the distribution of resultant permeability trends is partly constrained by patterns of longterm accommodation and high frequency cyclicity. Anhydrite diagenesis, which is characterized by conversion to gypsum or by complete removal of sulfate, is developed along basinward margins of the field and cross cuts original depositional framework.

  19. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman

    2003-01-17

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  20. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-06-16

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  1. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    Raj Kumar; Keith Brown; T. Scott Hickman; James J. Justice

    2000-04-27

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  2. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-12-11

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  3. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-08-10

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  4. Viral Regulation of Prokaryotic Carbon Metabolism in a Hypereutrophic Freshwater Reservoir Ecosystem (Villerest, France)

    PubMed Central

    Pradeep Ram, Angia Sriram; Colombet, Jonathan; Perriere, Fanny; Thouvenot, Antoine; Sime-Ngando, Télesphore

    2016-01-01

    The current consensus concerning the viral regulation of prokaryotic carbon metabolism is less well-studied, compared to substrate availability. We explored the seasonal and vertical distribution of viruses and its relative influence on prokaryotic carbon metabolism in a hypereutrophic reservoir, Lake Villerest (France). Flow cytometry and transmission electron microscopy (TEM) analyses to determine viral abundance (VA; range = 6.1–63.5 × 107 ml-1) and viral infection rates of prokaryotes (range = 5.3–32%) respectively suggested that both the parameters varied more significantly with depths than with seasons. Prokaryotic growth efficiency (PGE, considered as a proxy of prokaryotic carbon metabolism) calculated from prokaryotic production and respiration measurements (PGE = prokaryotic production/[prokaryotic production + prokaryotic respiration] × 100) varied from 14 to 80% across seasons and depths. Viruses through selective lyses had antagonistic impacts on PGE by regulating key prokaryotic metabolic processes (i.e., production and respiration). Higher viral lysis accompanied by higher respiration rates and lower PGE in the summer (mean = 22.9 ± 10.3%) than other seasons (mean = 59.1 ± 18.6%), led to significant loss of carbon through bacterial-viral loop and shifted the reservoir system to net heterotrophy. Our data therefore suggests that the putative adverse impact of viruses on the growth efficiency of the prokaryotic community can have strong implications on nutrient flux patterns and on the overall ecosystem metabolism in anthropogenic dominated aquatic systems such as Lake Villerest. PMID:26903963

  5. Viral Regulation of Prokaryotic Carbon Metabolism in a Hypereutrophic Freshwater Reservoir Ecosystem (Villerest, France).

    PubMed

    Pradeep Ram, Angia Sriram; Colombet, Jonathan; Perriere, Fanny; Thouvenot, Antoine; Sime-Ngando, Télesphore

    2016-01-01

    The current consensus concerning the viral regulation of prokaryotic carbon metabolism is less well-studied, compared to substrate availability. We explored the seasonal and vertical distribution of viruses and its relative influence on prokaryotic carbon metabolism in a hypereutrophic reservoir, Lake Villerest (France). Flow cytometry and transmission electron microscopy (TEM) analyses to determine viral abundance (VA; range = 6.1-63.5 × 10(7) ml(-1)) and viral infection rates of prokaryotes (range = 5.3-32%) respectively suggested that both the parameters varied more significantly with depths than with seasons. Prokaryotic growth efficiency (PGE, considered as a proxy of prokaryotic carbon metabolism) calculated from prokaryotic production and respiration measurements (PGE = prokaryotic production/[prokaryotic production + prokaryotic respiration] × 100) varied from 14 to 80% across seasons and depths. Viruses through selective lyses had antagonistic impacts on PGE by regulating key prokaryotic metabolic processes (i.e., production and respiration). Higher viral lysis accompanied by higher respiration rates and lower PGE in the summer (mean = 22.9 ± 10.3%) than other seasons (mean = 59.1 ± 18.6%), led to significant loss of carbon through bacterial-viral loop and shifted the reservoir system to net heterotrophy. Our data therefore suggests that the putative adverse impact of viruses on the growth efficiency of the prokaryotic community can have strong implications on nutrient flux patterns and on the overall ecosystem metabolism in anthropogenic dominated aquatic systems such as Lake Villerest. PMID:26903963

  6. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARDIAN-AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    SciTech Connect

    F. Jerry Lucia

    2002-01-31

    This is the final report of the project ''Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonardian-Age) Reservoirs, West Texas and New Mexico'', Department of Energy contract no. DE-AC26-98BC15105 and is the third in a series of similar projects funded jointly by the U.S. Department of Energy and The University of Texas at Austin, Bureau of Economic Geology, Reservoir Characterization Research Laboratory for Carbonates. All three projects focus on the integration of outcrop and subsurface data for the purpose of developing improved methods for modeling petrophysical properties in the interwell environment. The first project, funded by contract no. DE-AC22-89BC14470, was a study of San Andres outcrops in the Algerita Escarpment, Guadalupe Mountains, Texas and New Mexico, and the Seminole San Andres reservoir, Permian Basin. This study established the basic concepts for constructing a reservoir model using sequence-stratigraphic principles and rock-fabric, petrophysical relationships. The second project, funded by contract no. DE-AC22-93BC14895, was a study of Grayburg outcrops in the Brokeoff Mountains, New Mexico, and the South Cowden Grayburg reservoir, Permian Basin. This study developed a sequence-stratigraphic succession for the Grayburg and improved methods for locating remaining hydrocarbons in carbonate ramp reservoirs. The current study is of the Clear Fork Group in Apache Canyon, Sierra Diablo Mountains, West Texas, and the South Wasson Clear Fork reservoir, Permian Basin. The focus was on scales of heterogeneity, imaging high- and low-permeability layers, and the impact of fractures on reservoir performance. In this study (1) the Clear Fork cycle stratigraphy is defined, (2) important scales of petrophysical variability are confirmed, (3) a unique rock-fabric, petrophysical relationship is defined, (4) a porosity method for correlating high-frequency cycles and defining rock-fabric flow layers

  7. [Dissolved inorganic carbon and its carbon isotope composition in cascade reservoir of the Maotiao River during summer and autumn].

    PubMed

    Li, Gan-rong; Liu, Cong-qiang; Chen, Chuan; Wang, Bao-li; Li, Jun; Li, Si-liang; Liu, Xiao-long; Wang, Fu-shun

    2009-10-15

    Water samples along water column in the front of dams and samples at 0.5 m below surface water from tributary rivers were collected in July and October, 2007. The water chemistry, concentrations of dissolve inorganic carbon and its carbon isotopic compositions were determined, in order to investigate the geochemical behavior of carbon in the Maotiao River. This study aimed to understand the variations of the concentrations of dissolved inorganic carbon (DIC) and delta13 C(DIC) during its transport along the cascade reservoirs and river system. The results showed that DIC concentrations in summer were lower than that in autumn. In summer, the DIC concentrations were 1.35-2.84 mmol/L, with an average value of 2.12 mmol/L; and in autumn they fell into 2.03-3.98 mmol/L, with an average value of 2.67 mmol/L. The delta13 CD1 in surface water along Maotiao River ranged from -10.3% per hundred to -5.1% per hundred in summer, with a value of -8.6% per hundred in average, and in autumn, delta3 C(DIC) became more negative, and had a range from -13.0% per hundred to -6.9% per hundred, with an average value of -9.0% per hundred. Generally, DIC in surface water showed a trend to decrease from the upper reaches to lower reaches along Maotiao River, and t3 Cc1 gradually becam me more negative downstream. On the water column, DIC concentrations were higher in hypolimnion, while a delta13 C(DIC) had a reverse trend with higher values occurred in epilimnion. The results indicated that the hydrochemistry of river could be significantly changed by river damming processes. As for carbon, reservoir should be an important place for the transformation among the different carbon species. PMID:19968103

  8. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Discussion

    SciTech Connect

    Mazzullo, S.J. )

    1990-07-01

    A discussion is presented on a paper by Charles Kerans (AAPG Bull. 1988). The paper dealt with karst-associated porosity and hydrocarbon reservoir heterogenity in Ellengurger (Lower Ordovician) carbonates in the Permian basin of west Texas. The purpose of this paper is not to dispute the model presented by Kerans, but instead to present some alternative models of reservoir occurrence that are not considered in his paper and that are also widely applicable to the Ellenburger and correlative strata in the Mid-Continent. The discussion is based on regional lithostratigraphy and subsurface mapping studies of the Ellenburger in the southern Midland basin, specifically in Irion, Reagan, Crockett, Schleicher, and Sterling counties (Texas).

  9. CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

    1999-02-24

    The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

  10. The stability of chalk during flooding of carbonated sea water at reservoir in-situ conditions

    NASA Astrophysics Data System (ADS)

    Nermoen, Anders; Korsnes, Reidar I.; Madland, Merete V.

    2014-05-01

    Injection of CO2 into carbonate oil reservoirs has been proposed as a possible utilization of the captured CO2 due to its capability to enhance the oil recovery. For offshore reservoirs such as Ekofisk and Valhall it has been discussed to alternate the CO2 and sea water injection (WAG) to reduce costs and keep the beneficial effects of both sea water (SSW) and gas injection. Water and CO2 mix to form carbonic acids that enhance the solubility of carbonates, thus a serious concern has been raised upon the potential de-stabilization of the reservoirs during CO2 injection. In this study we focus on how carbonated sea water alters the mechanical integrity of carbonate rocks both to evaluate safety of carbon storage sites and in the planning of production strategies in producing oil fields since enhanced compaction may have both detrimental and beneficial effects. Here we will present results from long term experiments (approx. half year each) performed on Kansas outcrop chalk (38-41% porosity), which serves as model material to understand the physical and chemical interplaying processes taking place in chalk reservoirs. All tests are performed at uni-axial strain conditions, meaning that the confining radial stresses are automatically adjusted to ensure zero radial strain. The tests are performed at in-situ conditions and run through a series of stages that mimic the reservoir history at both Ekofisk and Valhall fields. We observe the strain response caused by the injected brine. The experimental stages are: (a) axial stress build-up by pore pressure depletion to stresses above yield with NaCl-brine which is inert to the chalk; (b) uni-axial creep at constant axial stresses with NaCl-brine; (c) sea water injection; and (d) injection of carbonated water (SSW+CO2) at various mixture concentrations. Two test series were performed in which the pore pressure was increased (re-pressurized) before stage (c) to explore the stress dependency of the fluid induced strain

  11. A light carbon reservoir recorded in zircon-hosted diamond from the Jack Hills.

    PubMed

    Nemchin, Alexander A; Whitehouse, Martin J; Menneken, Martina; Geisler, Thorsten; Pidgeon, Robert T; Wilde, Simon A

    2008-07-01

    The recent discovery of diamond-graphite inclusions in the Earth's oldest zircon grains (formed up to 4,252 Myr ago) from the Jack Hills metasediments in Western Australia provides a unique opportunity to investigate Earth's earliest known carbon reservoir. Here we report ion microprobe analyses of the carbon isotope composition of these diamond-graphite inclusions. The observed delta(13)C(PDB) values (expressed using the PeeDee Belemnite standard) range between -5 per mil and -58 per mil with a median of -31 per mil. This extends beyond typical mantle values of around -6 per mil to values observed in metamorphic and some eclogitic diamonds that are interpreted to reflect deep subduction of low-delta(13)C(PDB) biogenic surface carbon. Low delta(13)C(PDB) values may also be produced by inorganic chemical reactions, and therefore are not unambiguous evidence for life on Earth as early as 4,250 Myr ago. Regardless, our results suggest that a low-delta(13)C(PDB) reservoir may have existed on the early Earth. PMID:18596808

  12. Capillary Trapping of CO2 in Oil Reservoirs: Observations in a Mixed-Wet Carbonate Rock.

    PubMed

    Al-Menhali, Ali S; Krevor, Samuel

    2016-03-01

    Early deployment of carbon dioxide storage is likely to focus on injection into mature oil reservoirs, most of which occur in carbonate rock units. Observations and modeling have shown how capillary trapping leads to the immobilization of CO2 in saline aquifers, enhancing the security and capacity of storage. There are, however, no observations of trapping in rocks with a mixed-wet-state characteristic of hydrocarbon-bearing carbonate reservoirs. Here, we found that residual trapping of supercritical CO2 in a limestone altered to a mixed-wet state with oil was significantly less than trapping in the unaltered rock. In unaltered samples, the trapping of CO2 and N2 were indistinguishable, with a maximum residual saturation of 24%. After the alteration of the wetting state, the trapping of N2 was reduced, with a maximum residual saturation of 19%. The trapping of CO2 was reduced even further, with a maximum residual saturation of 15%. Best-fit Land-model constants shifted from C = 1.73 in the water-wet rock to C = 2.82 for N2 and C = 4.11 for the CO2 in the mixed-wet rock. The results indicate that plume migration will be less constrained by capillary trapping for CO2 storage projects using oil fields compared with those for saline aquifers. PMID:26812184

  13. Enhancing Caprock Integrity of Carbon Sequestration Reservoirs Using Colloidal Silica Gel

    NASA Astrophysics Data System (ADS)

    Roberts, S. K.; Ezzedine, S. M.; Bourcier, W.; Hunt, J. D.

    2013-12-01

    Silica gels are abundant in various subsurface applications. For example, it has been used in a) oil and gas industries as permeability reducer, b) geotechnical industry as a stabilizer and c) environmental industry as an isolator, and more recently in d) enhanced geothermal systems as a diverter agent; yet silica gels have not been evaluated for geological carbon sequestration. In the latter, several leakage pathways can compromise the integrity of the reservoir, thus the containment of the injected supercritical carbon dioxide. On one hand, interfacial dislocations around the injection well can lead leakage pathways compromising the well stability and integrity, and on the other, undetected preexisting fracture in the caprock can compromise the containment of the injected carbon dioxide. We propose to use silica gels as a sealing agent to seal fast pathways, minimize any leakages and enhance the overall integrity of the reservoir. Diverting and blocking agents currently used in the industry are often organic polymers that raise environmental concerns; whereas silicas are inorganic and environmentally friendly which underscore their suitability. In the current study we have developed a numerical model to simulate the flow mass and heat transport of silica gel in supercritical CO2 sequestration reservoirs. We illustrate the application of the model for minimizing CO2 leakages to the caprock by using the gel as sealing agent. Several 2D and 3D examples in porous and fractured network will be presented and design criteria for both applications will be discussed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  14. FMS/FMI borehole imaging of carbonate gas reservoirs, Central Luconia Province, offshore Sarawak, Malaysia

    SciTech Connect

    Singh, U.; Van der Baan, D. )

    1994-07-01

    The Central Luconia Province, offshore Sarawak, is a significant gas province characterized by extensive development of late Miocene carbonate buildups. Some 200 carbonate structures have been seismically mapped of which 70 have been drilled. FMS/FMI borehole images were obtained from three appraisal wells drilled in the [open quotes]M[close quotes] cluster gas fields situated in the northwestern part of the province. The [open quotes]M[close quotes] cluster fields are currently part of an upstream gas development project to supply liquefied natural gas. Log facies recognition within these carbonate gas reservoirs is problematic due mainly to the large gas effect. This problem is being addressed by (1) application of neural network techniques and (2) using borehole imaging tools. Cores obtained from the M1, M3, and M4 gas fields were calibrated with the FMS/FMI images. Reservoir characterization was obtained at two different scales. The larger scale (i.e., 1:40 and 1:200) involved static normalized images where the vertical stacking pattern was observed based on recognition of bed boundaries. In addition, the greater vertical resolution of the FMS/FMI images allowed recognition of thin beds. For recognition of specific lithofacies, dynamically normalized images were used to highlight lithofacies-specific sedimentary features, e.g., clay seams/stylolites, vugs, and breccia zones. In general, the FMS/FMI images allowed (1) easier recognition of reservoir features, e.g., bed boundaries, and (2) distinction between lithofacies that are difficult to characterize on conventional wireline logs.

  15. A Constrained Differential Evolution Algorithm for Reservoir Management: Optimal Placement and Control of Wells for Geological Carbon Storage with Uncertainty in Reservoir Properties

    NASA Astrophysics Data System (ADS)

    Cihan, A.; Birkholzer, J. T.; Bianchi, M.

    2014-12-01

    Injection of large volume of CO2 into deep geological reservoirs for geologic carbon sequestration (GCS) is expected to cause significant pressure perturbations in subsurface. Large-scale pressure increases in injection reservoirs during GCS operations, if not controlled properly, may limit dynamic storage capacity and increase risk of environmental impacts. The high pressure may impact caprock integrity, induce fault slippage, and cause leakage of brine and/or CO2 into shallow fresh groundwater resources. Thus, monitoring and controlling pressure buildup are critically important for environmentally safe implementation of GCS projects. Extraction of native brine during GCS operations is a pressure management approach to reduce significant pressure buildup. Extracted brine can be transferred to the surface for utilization or re-injected into overlying/underlying saline aquifers. However, pumping, transportation, treatment and disposal of extracted brine can be challenging and costly. Therefore, minimizing volume of extracted brine, while maximizing CO2 storage, is an essential objective of the pressure management with brine extraction schemes. Selection of optimal well locations and extraction rates are critical for maximizing storage and minimizing brine extraction during GCS. However, placing of injection and extraction wells is not intuitive because of heterogeneity in reservoir properties and complex reservoir geometry. Efficient computerized algorithms combining reservoir models and optimization methods are needed to make proper decisions on well locations and control parameters. This study presents a global optimization methodology for pressure management during geologic CO2 sequestration. A constrained differential evolution (CDE) algorithm is introduced for solving optimization problems involving well placement and injection/extraction control. The CDE methodology is tested and applied for realistic CO2 storage scenarios with the presence of uncertainty in

  16. Methane hydrate - A major reservoir of carbon in the shallow geosphere?

    USGS Publications Warehouse

    Kvenvolden, K.A.

    1988-01-01

    Methane hydrates are solids composed of rigid cages of water molecules that enclose methane. Sediment containing methane hydrates is found within specific pressure-temperature conditions that occur in regions of permafrost and beneath the sea in outer continental margins. Because methane hydrates are globally widespread and concentrate methane within the gas-hydrate structure, the potential amount of methane present in the shallow geosphere at subsurface depths of < ???2000 m is very large. However, estimates of the amount are speculative and range over about three orders of magnitude, from 2 ?? 103 to 4 ?? 106 Gt (gigatons = 1015 g) of carbon, depending on the assumptions made. The estimate I favor is ??? 1 ?? 104 Gt of carbon. The estimated amount of organic carbon in the methane-hydrate reservoir greatly exceeds that in many other reservoirs of the global carbon cycle - for example, the atmosphere (3.6 Gt); terrestrial biota (830 Gt); terrestrial soil, detritus and peat (1960 Gt); marine biota (3 Gt); and marine dissolved materials (980 Gt). In fact, the amount of carbon may exceed that in all fossil fuel deposits (5 ?? 103 Gt). Because methane hydrates contain so much methane and occur in the shallow geosphere, they are of interest as a potential resource of natural gas and as a possible source of atmospheric methane released by global warming. As a potential resource, methane hydrates pose both engineering and production problems. As a contributor to a changing global climate, destabilized methane hydrates, particularly those in shallow, nearshore regions of the Arctic Ocean, may have some effect, but this effect will probably be minimal, at least during the next 100 years. ?? 1988.

  17. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objectives of this project are to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. These objectives will be achieved through detailed geological, engineering, and geostatistical characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Work to date has focused on the completion of Subtasks 1, 2, and 3. Subtask 1 included the survey and tabulation of available reservoir engineering and geological data relevant to the Smackover reservoir in southwestern Alabama. Subtask 2 comprises the geological and engineering characterization of Smackover reservoir lithofacies. This has been accomplished through detailed examination and analysis of geophysical well logs, core material, well cuttings, and well-test data from wells penetrating Smackover reservoirs in southwestern Alabama. From these data, reservoir heterogeneities, such as lateral and vertical changes in lithology, porosity, permeability, and diagenetic overprint, have been recognized and used to produce maps, cross sections, graphs, and other graphic representations to aid in interpretation of the geologic parameters that affect these reservoirs. Subtask 3 includes the geologic modeling of reservoir heterogeneities for Smackover reservoirs. This research has been based primarily on the evaluation of key geologic and engineering data from selected Smackover fields. 1 fig.

  18. From the pore scale to reservoir scale: Lithohydraulic flow unit characterization of a shallow shelf carbonate reservoir, North Robertson Unit, West Texas

    SciTech Connect

    Vessell, R.K.; Davies, D.K.

    1996-12-31

    This paper presents the results of integrated geological-petrophysical reservoir characterization performed as part of the US Department of Energy Class II reservoir program. Petrographic image analysis, using a specially equipped SEM, allowed for the identification of 8 petrophysical rock types at the North Robertson Unit. Detailed log analysis resulted in the development of algorithms for the log-based identification of these rock types in 109 wells. Porosity was related to permeability for each Rock Type: thus permeability is determined from well log data. Evaluation of porosity, permeability, Sw and HPV distribution has allowed for the identification of 12 lithohydraulic flow units. These flow units have been mapped across the unit. The technique allows for the development of log-based reservoir models that are simulator-ready. The results of this study have application to all heterogeneous, shallow shelf carbonate reservoirs, they demonstrate that large fields can be successfully characterized using few cores and emphasize the importance of integrated geological-engineering analysis in reservoir characterization.

  19. From the pore scale to reservoir scale: Lithohydraulic flow unit characterization of a shallow shelf carbonate reservoir, North Robertson Unit, West Texas

    SciTech Connect

    Vessell, R.K.; Davies, D.K. )

    1996-01-01

    This paper presents the results of integrated geological-petrophysical reservoir characterization performed as part of the US Department of Energy Class II reservoir program. Petrographic image analysis, using a specially equipped SEM, allowed for the identification of 8 petrophysical rock types at the North Robertson Unit. Detailed log analysis resulted in the development of algorithms for the log-based identification of these rock types in 109 wells. Porosity was related to permeability for each Rock Type: thus permeability is determined from well log data. Evaluation of porosity, permeability, Sw and HPV distribution has allowed for the identification of 12 lithohydraulic flow units. These flow units have been mapped across the unit. The technique allows for the development of log-based reservoir models that are simulator-ready. The results of this study have application to all heterogeneous, shallow shelf carbonate reservoirs, they demonstrate that large fields can be successfully characterized using few cores and emphasize the importance of integrated geological-engineering analysis in reservoir characterization.

  20. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Geological research this quarter has focused on descriptions of core material and petrographic thin sections from reservoirs producing from the Smackover Formation in southwestern Alabama, computer entry of pertinent data, and generation of maps and cross-sections.

  1. Role of sediments for dissolved organic carbon (DOC) in lakes and reservoirs

    NASA Astrophysics Data System (ADS)

    Dadi, Tallent; Wendt-Potthoff, Katrin; Friese, Kurt; Koschorreck, Matthias

    2016-04-01

    Increasing dissolved organic carbon (DOC) concentrations have been observed in many surface waters and the increasing trend is expected to continue in the future. This leads to higher water treatment costs to remove the DOC, and to potential formation of toxic, carcinogenic disinfection by-products like trihalomethanes. Ecological status can also be affected since DOC will alter the under water light regime. The sediment water interface is a potential hot spot of DOC turnover in aquatic systems. We investigated benthic DOC exchange for a complete year in two similar reservoirs (Hassel and Rappbode pre-dams, Germany) located in catchments with different land use patterns. We quantified seasonal DOC and other solute fluxes in both the riverine and lacustrine zones of the reservoirs by sediment incubation at in situ conditions. This allowed us to assess the effect of redox conditions and temperature on benthic matter fluxes. Redox conditions appeared to be the primary regulator of DOC exchange, with uptake of DOC under oxic conditions and release of DOC under anoxic conditions. Temperature effects were appararent by the increased DOC fluxes in summer, in the lacustrine zones. The benthic flux of DOC was closely linked to the fluxes of iron and phosphorus, suggesting that adsorption of DOC to Fe mineral surfaces was the major regulating mechanism behind the observed results. The DOC fluxes seem not to be influenced by the trophic state of the reservoirs which indicates that land use differences in the catchments have minimal effects on benthic DOC turnover.

  2. Stratigraphic sections showing coal correlations within the lower coal zone of the Paleocene Fort Union Formation, Fillmore Ranch and Seaverson Reservoir quadrangles, Carbon County, Wyoming

    SciTech Connect

    Honey, J.G.; Hettinger, R.D.

    1989-01-01

    Stratigraphic sections showing coal correlations within the lower coal zone of the Paleocene Fort Union Formation, Fillmore Ranch and Seaverson Reservoir quadrangles, Carbon County, Wyoming are presented.

  3. Hydrothermal simulation of a fractured carbonate reservoir in southern Italy and automated detections of optimal positions for geothermal doublet installations

    NASA Astrophysics Data System (ADS)

    Niederau, Jan; Gomez, Sergio; Ebigbo, Anozie; Inversi, Barbara; Marquart, Gabriele; Scrocca, Davide

    2015-04-01

    In this work, we present the results of hydrothermal simulations for assessing the geothermal potential of a fractured carbonate reservoir in Campania (Guardia Lombardi). Local surface heat flows of up to 90 mW/m² suggest that this area is a potential medium-enthalpy geothermal reservoir. The targeted reservoir rocks are fractured shallow-water carbonates (Jurassic to Cretaceous) of the Apulia Platform. During the Apennine orogeny, those carbonates were affected by at least two tectonic phases: Thrust-related folding of the carbonate platform due to compression followed by extension which caused major normal faulting. Based on seismic interpretation, a discretized structural model is set up, comprising the reservoir unit and the overlying sedimentary cover. The model comprises an area of 42 km × 28 km and extends to a depth of about six kilometers. Results of calibrated hydrothermal reservoir simulations suggest that free convection occurs in some parts of the reservoir. For assessing optimal locations for potential hydrothermal doublet systems, a tool was developed which uses the results of the reservoir simulationsin combination with predefined constraints. Those constraints or minimum requirements consider: a) minimum temperature for operating the doublet system, b) minimum matrix permeability allowing for a pumping rate of 40 L/s, and c) social constraints (location of cities or conservation areas, where the construction of a potential geothermal energy plant would be problematic). The optimization tool ranks possible doublet system locations by evaluating an objective function for the minimum requirements. Those locations are further used to extract smaller models from the big reservoir model and simulate the operation of a hypothetical geothermal doublet system. By assessing the optimized results, an optimal location of a geothermal energy plant would produce water with a temperature of 163 °C from a depth of almost 4 km.

  4. The impact of reservoir conditions on the residual trapping of carbon dioxide in Berea sandstone

    NASA Astrophysics Data System (ADS)

    Niu, Ben; Al-Menhali, Ali; Krevor, Samuel C.

    2015-04-01

    The storage of carbon dioxide in deep brine-filled permeable rocks is an important tool for CO2 emissions mitigation on industrial scales. Residual trapping of CO2 through capillary forces within the pore space of the reservoir is one of the most significant mechanisms for storage security and is also a factor determining the ultimate extent of CO2 migration within the reservoir. In this study we have evaluated the impact of reservoir conditions of pressure, temperature, and brine salinity on the residual trapping characteristic curve of a fired Berea sandstone rock. The observations demonstrate that the initial-residual characteristic trapping curve is invariant across a wide range of pressure, temperature, and brine salinities and is also the same for CO2-brine systems as a N2-water system. The observations were made using a reservoir condition core-flooding laboratory that included high-precision pumps, temperature control, the ability to recirculate fluids for weeks at a time, and an X-ray CT scanner. Experimental conditions covered pressures of 5-20 MPa, temperatures of 25-50°C, and 0-5 mol/kg NaCl brine salinity. A novel coreflooding approach was developed, making use of the capillary end effect to create a large range in initial CO2 saturation (0.15-0.6) in a single coreflood. Upon subsequent flooding with CO2-equilibriated brine, the observation of residual saturation corresponded to the wide range of initial saturations before flooding resulting in a rapid construction of the initial-residual curve. For each condition we report the initial-residual curve and the resulting parameterization of the Land hysteresis models.

  5. Controls on reservoir development in a shelf carbonate: Upper Jurassic smackover formation of Alabama

    SciTech Connect

    Kopaska-Merkel, D.C.; Mann, S.D.; Schmoker, J.W.

    1994-06-01

    Hydrocarbon reservoirs of the Upper Jurassic Smackover Formation in Alabama are predominately oolitic and pelletal dolostone. Pore systems are dominated by moldic and secondary intraparticle pores, intercrystalline pores, or mixtures of these pore types. All Smackover reservoirs in Alabama have been strongly affected by early cementation, dissolution of calcium-carbonate allochems, and dolomitization. Dolomitization of the Smackover in Alabama included penecontemporaneous, early burial, and late (deep) burial episodes. Fabric-selective dolomitization yielded reservoirs strongly influenced by both depositional fabric and diagenesis. Nonselective dolomitization yielded reservoirs with intercrystalline pore systems shaped primarily by diagenesis. Thermal exposure is inversely related to porosity, but the relationship is weak (r{sup 2} < 0.5). Fabric-selective dolostone is slightly more porous than nonselective dolostone when averaged over the entire study area (averages of 18.1% and 15.1%, respectively; p = 0.0001), but nonselective dolostone is more porous at a given level of equivalent vitrinite reflectance. Smackover fields on the north flank of the Wiggins arch are unusually porous given their level of thermal maturity, and are unusual in other ways as well. Local porosity variation was controlled by depositional fabric, early cementation, dissolution, and burial compaction and cementation. Regional permeability variation cannot be explained using existing data. Permeability is locally controlled by pore-throat size, the effects of dolomite crystal-size distribution, early cementation, fracturing, and burial compaction and cementation. Pore-throat size exhibits the strongest overall correlation with permeability (r{sup 2} = 0.54). Permeability and porosity are strongly correlated locally, but the regional correlation is weak.

  6. Reservoir uncertainty, Precambrian topography, and carbon sequestration in the Mt. Simon Sandstone, Illinois Basin

    USGS Publications Warehouse

    Leetaru, H.E.; McBride, J.H.

    2009-01-01

    Sequestration sites are evaluated by studying the local geological structure and confirming the presence of both a reservoir facies and an impermeable seal not breached by significant faulting. The Cambrian Mt. Simon Sandstone is a blanket sandstone that underlies large parts of Midwest United States and is this region's most significant carbon sequestration reservoir. An assessment of the geological structure of any Mt. Simon sequestration site must also include knowledge of the paleotopography prior to deposition. Understanding Precambrian paleotopography is critical in estimating reservoir thickness and quality. Regional outcrop and borehole mapping of the Mt. Simon in conjunction with mapping seismic reflection data can facilitate the prediction of basement highs. Any potential site must, at the minimum, have seismic reflection data, calibrated with drill-hole information, to evaluate the presence of Precambrian topography and alleviate some of the uncertainty surrounding the thickness or possible absence of the Mt. Simon at a particular sequestration site. The Mt. Simon is thought to commonly overlie Precambrian basement granitic or rhyolitic rocks. In places, at least about 549 m (1800 ft) of topographic relief on the top of the basement surface prior to Mt. Simon deposition was observed. The Mt. Simon reservoir sandstone is thin or not present where basement is topographically high, whereas the low areas can have thick Mt. Simon. The paleotopography on the basement and its correlation to Mt. Simon thickness have been observed at both outcrops and in the subsurface from the states of Illinois, Ohio, Wisconsin, and Missouri. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  7. Mobilization and Transport of Organic Compounds from Reservoir Rock and Caprock in Geological Carbon Sequestration Sites

    SciTech Connect

    Zhong, Lirong; Cantrell, Kirk J.; Mitroshkov, Alexandre V.; Shewell, Jesse L.

    2014-05-06

    Supercritical CO2 (scCO2) is an excellent solvent for organic compounds, including benzene, toluene, ethyl-benzene, and xylene (BTEX), phenols, and polycyclic aromatic hydrocarbons (PAHs). Monitoring results from geological carbon sequestration (GCS) field tests has shown that organic compounds are mobilized following CO2 injection. Such results have raised concerns regarding the potential for groundwater contamination by toxic organic compounds mobilized during GCS. Knowledge of the mobilization mechanism of organic compounds and their transport and fate in the subsurface is essential for assessing risks associated with GCS. Extraction tests using scCO2 and methylene chloride (CH2Cl2) were conducted to study the mobilization of volatile organic compounds (VOCs, including BTEX), the PAH naphthalene, and n-alkanes (n-C20 – n-C30) by scCO2 from representative reservoir rock and caprock obtained from depleted oil reservoirs and coal from an enhanced coal-bed methane recovery site. More VOCs and naphthalene were extractable by scCO2 compared to the CH2Cl2 extractions, while scCO2 extractable alkane concentrations were much lower than concentrations extractable by CH2Cl2. In addition, dry scCO2 was found to extract more VOCs than water saturated scCO2, but water saturated scCO2 mobilized more naphthalene than dry scCO2. In sand column experiments, moisture content was found to have an important influence on the transport of the organic compounds. In dry sand columns the majority of the compounds were retained in the column except benzene and toluene. In wet sand columns the mobility of the BTEX was much higher than that of naphthalene. Based upon results determined for the reservoir rock, caprock, and coal samples studied here, the risk to aquifers from contamination by organic compounds appears to be relatively low; however, further work is necessary to fully evaluate risks from depleted oil reservoirs.

  8. Use of ``rock-typing`` to characterize carbonate reservoir heterogeneity. Final report

    SciTech Connect

    Ikwuakor, K.C.

    1994-03-01

    The objective of the project was to apply techniques of ``rock-typing`` and quantitative formation evaluation to borehole measurements in order to identify reservoir and non-reservoir rock-types and their properties within the ``C`` zone of the Ordovician Red River carbonates in the northeast Montana and northwest North Dakota areas of the Williston Basin. Rock-typing discriminates rock units according to their pore-size distribution. Formation evaluation estimates porosities and pore fluid saturation. Rock-types were discriminated using crossplots involving three rock-typing criteria: (1) linear relationship between bulk density and porosity, (2) linear relationship between acoustic interval transit-time and porosity, and (3) linear relationship between acoustic interval transit-time and bulk density. Each rock-type was quantitatively characterized by the slopes and intercepts established for different crossplots involving the above variables, as well as porosities and fluid saturations associated with the rock-types. All the existing production was confirmed through quantitative formation evaluation. Highly porous dolomites and anhydritic dolomites contribute most of the production, and constitute the best reservoir rock-types. The results of this study can be applied in field development and in-fill drilling. Potential targets would be areas of porosity pinchouts and those areas where highly porous zones are downdip from non-porous and tight dolomites. Such areas are abundant. In order to model reservoirs for enhanced oil recovery (EOR) operations, a more localized (e.g. field scale) study, expanded to involve other rock-typing criteria, is necessary.

  9. The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE): Results from 2011 Engineering Test Flights

    NASA Astrophysics Data System (ADS)

    Miller, C. E.; Dinardo, S. J.

    2011-12-01

    The carbon balance of Arctic ecosystems is not known with confidence since fundamental elements of the complex Arctic biological-climatologic-hydrologic system are poorly quantified. CARVE - The Carbon in Arctic Reservoirs Vulnerability Experiment - will address this key gap in science knowledge by: 1) Directly testing hypotheses attributing the mobilization of vulnerable Arctic carbon reservoirs to climate warming; 2) Delivering the first direct measurements and detailed maps of CO2 and CH4 sources on regional scales in the critical Arctic ecozone; and 3) Demonstrating new remote sensing and modeling capabilities to quantify feedbacks between carbon fluxes and carbon cycle-climate processes in the Arctic. CARVE measurements and integrated science data will provide unprecedented experimental insights into Arctic carbon cycling and its response to climate change. CARVE employs a robust, flexible strategy to reconcile Arctic carbon fluxes estimated from atmospheric concentrations of CO2 and CH4 (top-down approach) with carbon fluxes estimated from coincident measurements of surface state controls (bottom-up approach). The CARVE Science Operations involve deployments in Alaska during the spring, summer, and fall each year from 2012-2014. CARVE flight plans sample multiple permafrost domains and ecosystems, and deliver detailed observations over ground-based measurement sites, fires, and burn-recovery chronosequences. CARVE flies aboard the De Havilland DHC-6 Twin Otter. The science payload consists of: JPL's Passive Active L-band System (PALS) to deliver the measurements of soil moisture, freeze/thaw state, inundation state, and surface temperature; an airborne Fourier Transform Spectrometer (FTS) to deliver total atmospheric column measurements of CO2 and CH4, and CO; and (3) an In Situ Gas Analyzer (ISGA) to deliver continuous measurements of CO2 and CH4, and CO, calibration standards, and whole air flask samples for point measurements of over 50 trace gases

  10. High Primary Production Contrasts with Intense Carbon Emission in a Eutrophic Tropical Reservoir

    PubMed Central

    Almeida, Rafael M.; Nóbrega, Gabriel N.; Junger, Pedro C.; Figueiredo, Aline V.; Andrade, Anízio S.; de Moura, Caroline G. B.; Tonetta, Denise; Oliveira, Ernandes S.; Araújo, Fabiana; Rust, Felipe; Piñeiro-Guerra, Juan M.; Mendonça, Jurandir R.; Medeiros, Leonardo R.; Pinheiro, Lorena; Miranda, Marcela; Costa, Mariana R. A.; Melo, Michaela L.; Nobre, Regina L. G.; Benevides, Thiago; Roland, Fábio; de Klein, Jeroen; Barros, Nathan O.; Mendonça, Raquel; Becker, Vanessa; Huszar, Vera L. M.; Kosten, Sarian

    2016-01-01

    Recent studies from temperate lakes indicate that eutrophic systems tend to emit less carbon dioxide (CO2) and bury more organic carbon (OC) than oligotrophic ones, rendering them CO2 sinks in some cases. However, the scarcity of data from tropical systems is critical for a complete understanding of the interplay between eutrophication and aquatic carbon (C) fluxes in warm waters. We test the hypothesis that a warm eutrophic system is a source of both CO2 and CH4 to the atmosphere, and that atmospheric emissions are larger than the burial of OC in sediments. This hypothesis was based on the following assumptions: (i) OC mineralization rates are high in warm water systems, so that water column CO2 production overrides the high C uptake by primary producers, and (ii) increasing trophic status creates favorable conditions for CH4 production. We measured water-air and sediment-water CO2 fluxes, CH4 diffusion, ebullition and oxidation, net ecosystem production (NEP) and sediment OC burial during the dry season in a eutrophic reservoir in the semiarid northeastern Brazil. The reservoir was stratified during daytime and mixed during nighttime. In spite of the high rates of primary production (4858 ± 934 mg C m-2 d-1), net heterotrophy was prevalent due to high ecosystem respiration (5209 ± 992 mg C m-2 d-1). Consequently, the reservoir was a source of atmospheric CO2 (518 ± 182 mg C m-2 d-1). In addition, the reservoir was a source of ebullitive (17 ± 10 mg C m-2 d-1) and diffusive CH4 (11 ± 6 mg C m-2 d-1). OC sedimentation was high (1162 mg C m-2 d-1), but our results suggest that the majority of it is mineralized to CO2 (722 ± 182 mg C m-2 d-1) rather than buried as OC (440 mg C m-2 d-1). Although temporally resolved data would render our findings more conclusive, our results suggest that despite being a primary production and OC burial hotspot, the tropical eutrophic system studied here was a stronger CO2 and CH4 source than a C sink, mainly because of high

  11. High Primary Production Contrasts with Intense Carbon Emission in a Eutrophic Tropical Reservoir.

    PubMed

    Almeida, Rafael M; Nóbrega, Gabriel N; Junger, Pedro C; Figueiredo, Aline V; Andrade, Anízio S; de Moura, Caroline G B; Tonetta, Denise; Oliveira, Ernandes S; Araújo, Fabiana; Rust, Felipe; Piñeiro-Guerra, Juan M; Mendonça, Jurandir R; Medeiros, Leonardo R; Pinheiro, Lorena; Miranda, Marcela; Costa, Mariana R A; Melo, Michaela L; Nobre, Regina L G; Benevides, Thiago; Roland, Fábio; de Klein, Jeroen; Barros, Nathan O; Mendonça, Raquel; Becker, Vanessa; Huszar, Vera L M; Kosten, Sarian

    2016-01-01

    Recent studies from temperate lakes indicate that eutrophic systems tend to emit less carbon dioxide (CO2) and bury more organic carbon (OC) than oligotrophic ones, rendering them CO2 sinks in some cases. However, the scarcity of data from tropical systems is critical for a complete understanding of the interplay between eutrophication and aquatic carbon (C) fluxes in warm waters. We test the hypothesis that a warm eutrophic system is a source of both CO2 and CH4 to the atmosphere, and that atmospheric emissions are larger than the burial of OC in sediments. This hypothesis was based on the following assumptions: (i) OC mineralization rates are high in warm water systems, so that water column CO2 production overrides the high C uptake by primary producers, and (ii) increasing trophic status creates favorable conditions for CH4 production. We measured water-air and sediment-water CO2 fluxes, CH4 diffusion, ebullition and oxidation, net ecosystem production (NEP) and sediment OC burial during the dry season in a eutrophic reservoir in the semiarid northeastern Brazil. The reservoir was stratified during daytime and mixed during nighttime. In spite of the high rates of primary production (4858 ± 934 mg C m(-2) d(-1)), net heterotrophy was prevalent due to high ecosystem respiration (5209 ± 992 mg C m(-2) d(-1)). Consequently, the reservoir was a source of atmospheric CO2 (518 ± 182 mg C m(-2) d(-1)). In addition, the reservoir was a source of ebullitive (17 ± 10 mg C m(-2) d(-1)) and diffusive CH4 (11 ± 6 mg C m(-2) d(-1)). OC sedimentation was high (1162 mg C m(-2) d(-1)), but our results suggest that the majority of it is mineralized to CO2 (722 ± 182 mg C m(-2) d(-1)) rather than buried as OC (440 mg C m(-2) d(-1)). Although temporally resolved data would render our findings more conclusive, our results suggest that despite being a primary production and OC burial hotspot, the tropical eutrophic system studied here was a stronger CO2 and CH4 source than a C

  12. Global carbon burial in lakes, reservoirs and ponds; an alternative approach

    NASA Astrophysics Data System (ADS)

    Boyle, John; Hoffmann, Thomas

    2013-04-01

    It is widely stated that approximately 0.6 Pg of carbon are annually sequestered by lake, reservoir and pond sediments. The study from which this figure arises, Tranvik et al (2009), accepts: previously published values for natural lakes (0.03 to 0.07 Pg), rather higher than previously thought values for reservoirs (0.4 Pg C yr-1, based on 400,000 km2 at 1000 g C m-2, up from 0.16-0.20 Pg previously estimated), and and a previously omitted large contribution from "small eutrophic impoundments" (0.15 Pg yr-1, based on 75,000 km2 at 2000 g C m-2). As these estimates depend heavily on C burial data from 25 artificial water bodies in Iowa, we have undertaken a wider analysis to assess their global applicability. Reference: Tranvik, L.J., Downing, J.A., Cotner, J.B., Loiselle, S.A., Striegl, R.G., Ballatore, T.J., Dillon, P., Finlay, K., Fortino, K., Knoll, L.B., Kortelainen, P.L., Kutser, T., Larsen, S., Laurion, I., Leech, D.M., McCallister, S.L., McKnight, D.M., Melack, J.M., Overholt, E., Porter, J.A., Prairie, Y., Renwick, W.H., Roland, F., Sherman, B.S., Schindler, D.W., Sobek, S., Tremblay, A., Vanni, M.J., Verschoor, A.M., von Wachenfeldt, E. and Weyhenmeyer, G.A., 2009. Lakes and reservoirs as regulators of carbon cycling and climate. Limnology and Oceanography, 54(6): 2298-2314.

  13. Predicting phase behavior of mixtures of reservoir fluids with carbon dioxide

    SciTech Connect

    Grigg, R.B.; Lingane, P.J.

    1983-10-01

    The use of an equation of state to predict phase behavior during carbon dioxide flooding is well established. There is consensus that the characterization of the C fraction, the grouping of this fraction into ''pseudo components'', and the selection of interaction parameters are the most important variables. However, the literature is vague as to how to best select the pseudo components, especially when aiming for a few-component representation as for a field scale compositional simulation. Single-contact phase behavior is presented for mixtures of Ford Geraldine (Delaware), Maljamar (Grayburg), West Sussex (Shannon), and Reservoir D reservoir fluids, and of a synthetic oil C/C/C, with carbon dioxide. One can reproduce the phase behavior of these mixtures using 3-5 pseudo components and common interaction parameters. The critical properties of the pseudo components are calculated from detailed oil characterizations. Because the parameters are not further adjusted, this approach reduces the empiricism in fitting phase data and may result in a more accurate representation of the system as the composition of the oil changes during the approach to miscibility.

  14. Holocene siliciclastic-carbonate facies mosaics, Northern Belize: Exploration analog to some midcontinent Pennsylvanian (Morrowan) reservoirs

    SciTech Connect

    Lowe, D.B.; Mazzullo, S.J.

    1995-09-01

    Midwinter Lagoon is a large, shallow coastal lagoon, bordered on its seaward side by a barrier, along the mainland coast of northern Belize. As much as 19 ft of Holocene sediments, deposited on karsted Tertiary limestones during the Flandrian transgression, consist of a complex mosaic of mixed siliciclastic and carbonate facies. Basal transgressive marine, intra-lagoonal facies are variously siliciclastic-rich carbonates to carbonate-rich siliciclastics, locally with layers of shoreline mangrove peat. These facies shallow-upward to either siliciclastic or carbonate-dominated sands or muds. Lagoonal facies were deposited within a broad topographic low, locally punctuated by bedrock highs, on the underlying limestone. The seaward edge of the barrier bar complex, which was deposited on a linear topographic high, consists mostly of quartz sands, whereas the lagoonal side is a mixture of quartzose and carbonate sediments (sands and muds). The barrier bar appears to have accreted southward in response to southerly longshore drift as a tidal inlet-spit complex; quartz sands are being transported into the lagoon from its seaward side. In terms of geometry, modern and buried, intra-lagoonal carbonate sands occur as lobes deposited proximal to extant and older tidal inlets. Either carbonate or siliciclastic sands variously occur as erratically distributed, anastomosing beach deposits around small mangrove islands and along the irregular mainland coast. In contrast, siliciclastic sands on the seaward side of the barrier define a narrow but areally persistent linear trend. Similar complex facies associations and geometries are typical of many Pennsylvanian (Morrowan) reservoirs in the midcontinent US.

  15. Carbonate reactions in a natural CO2 Reservoir, Green River, Utah, USA

    NASA Astrophysics Data System (ADS)

    Chapman, H.; Bickle, M. J.; Kampman, N.; Maskell, A.; Busch, A.; Evans, J. P.

    2013-12-01

    Understanding the geochemical interaction of CO2 with minerals within a rock reservoir is vitally important to assess the long-term suitability of underground storage of anthropogenic carbon dioxide. This study investigates the complexities of changes in mineralogy, porosity and flow within a series of porous aquifers and caprocks within Jurassic sedimentary sequences flooded by natural CO2 at Green River in Utah. This study of a natural analogue will inform the processes to quantify the risk of leakage and evolution of stored CO2 over a range of time scales in a sequence of stacked aquifers separated by less permeable rock layers. A 325m well (CO2W55 diamond drilled by DOSECC in 2012) gave excellent recovery of 282m of core from two major CO2 reservoirs in the Entrada and Navajo Sandstones and from the intervening Carmel Formation caprock. Fluid samples were also taken at pressure downhole. Element and isotope geochemistry were used to constrain fluid sources, mixing and fluid-rock reactions. Comparisons were made with the geochemistry of an adjacent cold water CO2-geyser to investigate the upward leakage and horizontal flow from the Little Grand Wash normal Fault that both the geyser and borehole intersect. Here we report the geochemical and isotopic compositions of the various carbonate and silicate components of the CO2 reacted rocks to constrain fluid-mineral reactions. A series of leaching experiments investigating reagents and reaction times allowed measurement of cation and strontium isotopic compositions of the major components within this sedimentary sequence. Strontium isotopes offer a powerful constraint in the study of subsurface fluid-rock reactions as they can be measured to high precision and are not affected by mass dependent fractionations during reaction and fluid transport. Analysis of major cations (especially Ca, Mg and Fe), Sr and 87Sr/86Sr of leachates from sequential leaching experiments allows estimation of the chemical and Sr

  16. Play-level distributions of estimates of recovery factors for a miscible carbon dioxide enhanced oil recovery method used in oil reservoirs in the conterminous United States

    USGS Publications Warehouse

    Attanasi, E.D.; Freeman, P.A.

    2016-01-01

    The retention factor is the percentage of injected CO2 that is naturally retained in the reservoir. Retention factors were also estimated in this study. For clastic reservoirs, 90 percent of the estimated retention factors were between 21.7 and 32.1 percent, and for carbonate reservoirs, 90 percent were between 23.7 and 38.2 percent. The respective median values were 22.9 for clastic reservoirs and 26.1 for carbonate reservoirs. Both distributions were right skewed. The recovery and retention factors that were calculated are consistent with the corresponding factors reported in the literature.

  17. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico - petrophysical characterization of the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Lucia, F.J.

    1997-06-01

    Reservoir performance of the South Cowden Grayburg field suggests that only 21 percent of the original oil in place has been recovered. The purpose of this study is to construct a realistic reservoir model to be used to predict the location of the remaining mobile oil. Construction of reservoir models for fluid-flow simulation of carbonate reservoirs is difficult because they typically have complicated and unpredictable permeability patterns. Much of the difficulty results from the degree to which diagenetic overprinting masks depositional textures and patterns. For example, the task of constructing a reservoir model of a limestone reservoir that has undergone only cementation and compaction is easier than constructing a model of a karsted reservoir that has undergone cavern formation and collapse as well as cementation and compaction. The Permian-age carbonate-ramp reservoirs in the Permian Basin, West Texas and New Mexico, are typically anhydritic dolomitized limestone. Because the dolomitization occurred soon after deposition, depositional fabrics and patterns are often retained, and a reservoir model can be constructed using depositional concepts. Recent studies of the San Andres outcrop in the Guadalupe Mountains and the Seminole San Andres reservoir in the Permian Basin illustrate how depositional fabrics and patterns can be used to construct a reservoir model when depositional features are retained.

  18. Analytical solution of geological carbon sequestration under constant pressure injection into a horizontal radial reservoir

    NASA Astrophysics Data System (ADS)

    Jhang, R.; Liou, T.

    2013-12-01

    Carbon capture and sequestration (CCS) is believed to be an economically feasible technology to mitigate global warming by capturing carbon dioxide (CO2), the major component of greenhouse gases, from the atmosphere and injecting it into deep geological formations.Several mechanisms can help trap CO2 in the pore space of a geological reservoir, stratigraphic and structural trapping, hydrodynamic trapping, and geochemical trapping.Besides these trapping mechanisms, another important issue that deserves careful attention is the risk of CO2 leakage. The common ';constant injection rate' scenario may induce high pressure buildup that will endanger the mechanical integrity as well as the sealing capability of the cap rock. Instead of injecting CO2 at a constant mass rate, CO2 can be injected into the reservoir by fixing the pressure (usually the bottom-hole pressure) in the injection borehole. By doing so, the inevitable pressure buildup associated with the constant injection scheme can be completely eliminated in the constant pressure injection scheme. In this paper, a semi-analytical solution for CO2 injection with constant pressure was developed. For simplicity, structural and geochemical trapping mechanisms were not considered. Therefore, a horizontal reservoir with infinite radial extent was considered. Prior to injection, the reservoir is fully saturated with the formation brine. It is assumed that CO2 does not mix with brine such that a sharp interface is formed once CO2 invades the brine-saturated pores. Because of the density difference between CO2 and brine, CO2 resides above the interface. Additional assumptions were also made when building up the brine and CO2 mass balance equations: (1) both of the fluids and the geological formations are incompressible, (2) capillary pressure is neglected, (3)there is no fluid flow in the vertical direction, and the horizontal flow satisfies the Darcy's law.In order to solve for the height of brine-CO2 interface, the two

  19. Acoustic and reservoir properties of microporous carbonate rocks: Implication of micrite particle size and morphology

    NASA Astrophysics Data System (ADS)

    Regnet, J. B.; Robion, P.; David, C.; Fortin, J.; Brigaud, B.; Yven, B.

    2015-02-01

    This integrated study provides significant insight into parameters controlling the acoustic and reservoir properties of microporous limestones, improving the knowledge of the relationships among petrophysic and microstructural content. Petrophysical properties measured from laboratory and logging tools (porosity, permeability, electrical conductivity, and acoustic properties) have been coupled with thin section and scanning electron microscope observations on the EST205 borehole from the Oxfordian limestone aquifer of the eastern part of the Paris Basin. A major achievement is the establishment of the link between micrite microtexture types (particle morphology and nature of intercrystal contacts) and the physical response, introducing a new effective and interesting rock-typing approach for microporous reservoirs. Fluid-flow properties are enhanced by the progressive augmentation of intercrystalline microporosity and associated pore throat diameter, as the coalescence of micrite particles decreases. Concerning acoustic properties, the slow increase of P wave velocity can be seen as a reflection of crystal size and growing contact cementation leading to a more cohesive and stiffer micrite microtexture. By applying poroelasticity theory on our samples, we show that velocity dispersion can be a very useful tool for data discrimination in carbonates. This dispersion analysis highlights the presence of microcracks in the rocks, and their overall effect on acoustic and transport properties. The presence of microcracks is also confirmed with observations and permeability measurements under high confining pressure. Finally, a possible origin of high porous levels in neritic limestones is a mineralogical transformation of carbonates through freshwater-related diagenesis during subaerial exposure time. Finally, by applying poroelasticity theory on our samples, we show that velocity dispersion can be a very useful tool for data discrimination in carbonates.

  20. Predicting the natural state of fractured carbonate reservoirs: An Andector Field, West Texas test of a 3-D RTM simulator

    SciTech Connect

    Tuncay, K.; Romer, S.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    The power of the reaction, transport, mechanical (RTM) modeling approach is that it directly uses the laws of geochemistry and geophysics to extrapolate fracture and other characteristics from the borehole or surface to the reservoir interior. The objectives of this facet of the project were to refine and test the viability of the basin/reservoir forward modeling approach to address fractured reservoir in E and P problems. The study attempts to resolve the following issues: role of fracturing and timing on present day location and characteristics; clarifying the roles and interplay of flexure dynamics, changing rock rheological properties, fluid pressuring and tectonic/thermal histories on present day reservoir location and characteristics; and test the integrated RTM modeling/geological data approach on a carbonate reservoir. Sedimentary, thermal and tectonic data from Andector Field, West Texas, were used as input to the RTM basin/reservoir simulator to predict its preproduction state. The results were compared with data from producing reservoirs to test the RTM modeling approach. The effects of production on the state of the field are discussed in a companion report. The authors draw the following conclusions: RTM modeling is an important new tool in fractured reservoir E and P analysis; the strong coupling of RTM processes and the geometric and tensorial complexity of fluid flow and stresses require the type of fully coupled, 3-D RTM model for fracture analysis as pioneered in this project; flexure analysis cannot predict key aspects of fractured reservoir location and characteristics; fracture history over the lifetime of a basin is required to understand the timing of petroleum expulsion and migration and the retention properties of putative reservoirs.

  1. Cretaceous tide-dominated carbonate ramp: Comparison of reservoir hetergeneity in tide-versus wave-dominated carbonate ramp systems

    SciTech Connect

    Kerans, C.

    1995-08-01

    Cretaceous (upper Albian) carbonate ramp strata, Pecos River Canyon, Texas, provide a uniquely continuous exposure of a tide-dominated ramp reservoir analog. The continuous 100-km shelf-to-basin outcrop begins in inner ramp mud-rich facies that record both high-frequency (20-100 ky) and intermediate frequency (>200 ky) cyclicity. The ramp-crest is up to 40 km across depositional dip. Intermediate-scale cycles in the ramp crest include basal oyster and toucasid wackestones, chondrodontid-rudist packstones, rudist-skeletal grainstones, and caprinid biostromes. Ramp-crest grainstones are 4-23 m in thickness and extend more than 20 km in a shelf to basin direction. Rudist biostromes are 3-7 m in thickness and are up to several kilometers in dip continuity except in deeper outer ramp settings where 100-200 m wide mounds are more common. The ramp crest is dominated by grain-rich facies with moderate to high permeability. Toucasid wackestones and oyster marls are 1-5 m in thickness and extend tens of kilometers in a dip direction, representing potential fluid flow barriers. Wave-dominated ramp systems of the Permian of West Texas provide a contrast to the Cretaceous tide-dominated setting. Low-permeability high-frequency cycle base mudstones and high-permeability cycle-top grainstones are preserved in both inner ramp and ramp crest settings. Fluid-flow modeling of these Permian wave-dominated reservoir strata illustrates that the intercalation of thin high- and low-permeability layers result in crossflow trapping and thief zones controlling the position and amount of remaining oil saturation. The depositional homogeneity of the Cretaceous tide-dominated ramp indicates that diagenetic heterogeneities and gravitational effects are potentially dominant controls on reservoir performance for these strata.

  2. Permanent storage of carbon dioxide in geological reservoirs by mineral carbonation

    NASA Astrophysics Data System (ADS)

    Matter, Jürg M.; Kelemen, Peter B.

    2009-12-01

    Anthropogenic greenhouse-gas emissions continue to increase rapidly despite efforts aimed at curbing the release of such gases. One potentially long-term solution for offsetting these emissions is the capture and storage of carbon dioxide. In principle, fluid or gaseous carbon dioxide can be injected into the Earth's crust and locked up as carbonate minerals through chemical reactions with calcium and magnesium ions supplied by silicate minerals. This process can lead to near-permanent and secure sequestration, but its feasibility depends on the ease and vigour of the reactions. Laboratory studies as well as natural analogues indicate that the rate of carbonate mineral formation is much higher in host rocks that are rich in magnesium- and calcium-bearing minerals. Such rocks include, for example, basalts and magnesium-rich mantle rocks that have been emplaced on the continents. Carbonate mineral precipitation could quickly clog up existing voids, presenting a challenge to this approach. However, field and laboratory observations suggest that the stress induced by rapid precipitation may lead to fracturing and subsequent increase in pore space. Future work should rigorously test the feasibility of this approach by addressing reaction kinetics, the evolution of permeability and field-scale injection methods.

  3. Carbon Reservoir History of Mars Constrained by Atmospheric Isotopic Measurements and Carbonate Remote Sensing

    NASA Astrophysics Data System (ADS)

    Hu, R.; Kass, D. M.; Ehlmann, B. L.; Yung, Y. L.

    2015-12-01

    The evolution of the atmosphere on Mars is one of the most intriguing problems in the exploration of the Solar System, and the climate of Mars may have evolved from a warmer, wetter early state to the cold, dry current state. Because CO2 is the major constituent of Mars's atmosphere, its isotopic signatures offer a unique window to trace the evolution of climate on Mars. We derive new quantitative constraints on the amount of carbonate deposition and the atmospheric pressure of Mars through time, extending into the Noachian, ~3.8 Gyr before present. This determination is based on recent Mars Science Laboratory (MSL) isotopic measurements of Mars's atmosphere, recent orbiter, lander, and rover measurements of Mars's surface, and a newly identified mechanism (photodissociation of CO) that efficiently enriches the heavy carbon isotope. In particular, we find that escape via CO photodissociation on Mars has a fractionation factor of 0.6 and hence, photochemical escape processes can effectively enrich 13C in the Mars's atmosphere during the Amazonian. This enrichment is partially compensated by moderate carbonate precipitation during the late Noachian and/or Hesperian. The current atmospheric 13C/12C and rock and soil carbonate measurements indicate an early atmosphere with a surface pressure less than 1 bar. Only scenarios with large amounts of carbonate formation in open lakes permit higher values up to 1.8 bars. The evolutionary scenarios are fully testable with data from the MAVEN mission and further studies of the isotopic composition of carbonate in the Martian rock record through time.

  4. Seismic prediction of prolific oil zones in carbonate reservoirs with extremely low porosity and permeability under salt

    NASA Astrophysics Data System (ADS)

    Zheng, Xiaodong; Xu, Anna; Yang, Zhifang; Li, Yonggen; Liu, Ying; Zhang, Xin

    2005-06-01

    The Carboniferous reservoir in KJ oilfield is a carbonate reservoir with extremely low porosity and permeability and high-pressure. The reservoir has severe heterogeneity, is deeply buried, has complex master control factors, is covered with thick salt, all of which result in the serious distortion of reflection time and amplitudes under the salt, the poor seismic imaging, and the low S/N ratio and resolution. The key to developing this kind of reservoir is to correctly predict the distribution of highly profitable oil zones. In this paper we start by analyzing the master control factors, perform seismic-log calibration, optimize the seismic attributes indicating the lithofacies, karst, petrophysical properties, and fractures, and combine these results with the seismic, geology, log, oil reservoir engineering, and well data. We decompose the seismic prediction into six key areas: structural interpretation, prediction of lithofacies, karst, petrophysical properties, fractures, and then perform an integrated assessment. First, based on building the models of faults and fractures, sedimentary facies, and karst, we predict the distribution of the most favorable reservoir zones qualitatively. Then, using multi-parameter inversion and integrated multi-attribute analysis, we predict the favorable reservoir distribution quantitatively and setni-quantitatively to clarify the distribution of high-yield zones. We finally have a reliable basis for optimal selection of exploration and development targets.

  5. Computerized texture analysis of borehole electrical images from Middle East carbonate reservoirs: A contribution to porosity characterization

    SciTech Connect

    Delhomme, J.P. ); Nurmi, R. )

    1991-03-01

    Porosity heterogeneities have been found to be common in carbonate reservoirs and are a major factor affecting fluid flow and recovery efficiency. A review of Middle East and Indian reservoirs reveals that there are four types of heterogeneous fabrics: layered porosity, interwoven porosity, isolated porosity, and isolated nonporous within reservoir zones. Their presence can adversely affect the interpretation, testing, and completion of a well. Electrical imagery is a key to defining the spatial arrangement and orientation of the porosity distribution, or porosity fabric. To assist in the interpretation and quantification of heterogeneous porosity, specialized image analysis techniques have been developed. Although mathematical morphology concepts developed for medical imagery are used, geological imagery has necessitated the development of some original approaches. The initial focus of the computer image analysis is of isolated porosity and also thin porosity layers alternating with nonporous carbonate rock. The 'porosity typing' summary log of the textural analysis of reservoir porosity has a variety of applications, but it is an immediate input for well testing and well completion design. Moreover, as carbonate image fabrics are generally related to depositional and or diagenetic facies, a fabric summary and zonation is also valuable for well-to-well correlation in either reservoir or exploration studies.

  6. Prospecting and developing carbonate reservoirs under excessive pressures in fields of preCaspian depression taken as an example

    SciTech Connect

    Leonard, R.; Perepelichenko, V.; Shilin, A.

    1996-08-01

    All large sub-salt hydrocarbon fields of the PreCaspian depression are connected with carbonate reservoirs and are characterized by abnormally high reservoir pressures of different origin. Exploratory drilling in fields under excessive pressures is very much complicated. To reduce the probability of disastrous absorptions and blowouts there has been developed special drilling-in technology with constant bottom-hole pressure control. To avoid fractures healing, to provide hydrocarbon phase state control, and to achieve maximum oil recovery there has been worked out a new technology of oil field development. According to this technology oil should be recovered first from the lower peripheral parts of the pool. This technology (taking into account the abnormally high reservoir pressures) provides gradual decreasing of reservoir pressure in the process of field development.

  7. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Czirr, K.L.; Gaddis, M.P.; Moshell, M.K.

    2002-02-21

    The principle objective of this project is to demonstrate the economic viability and widespread applicability of an innovative reservoir management and carbon dioxide (CO2) flood project development approach for improving CO2 flood project economics in shallow shelf carbonate (SSC) reservoirs.

  8. Abandoned Channel Fill Sequences in Tidal Estuaries

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Goni, M. A.; Watson, E. B.

    2014-12-01

    This study proposes a modification of the current model for abandoned channel fill stratigraphy produced in unidirectional flow river reaches to incorporate seasonal tidal deposition. Evidence supporting this concept came from a study of two consecutive channel abandonment sequences in Ropers Slough of the lower Eel River Estuary in northern California. Aerial photographs showed that Ropers Slough was abandoned around 1943, reoccupied after the 1964 flood, and abandoned again in 1974 with fill continuing to the present. Planform geomorphic characteristics derived from these images were used in conjunction with sub-cm resolution stratigraphic analyses to describe the depositional environment processes and their resultant sedimentary deposits. Results showed that both abandonment sequences recorded quasi-annual scale fluvial/tidal deposition couplets. In both cases tidal deposits contained very little sand, and were higher in organic and inorganic carbon content than the sandier fluvial through-flow deposits. However, the two abandonment fills differed significantly in terms of the temporal progression of channel narrowing and fluvial sediment deposition characteristics. The first abandonment sequence led to a more rapid narrowing of Ropers Slough and produced deposits with a positive relationship between grain size/deposit thickness and discharge. The second abandonment resulted in a much slower narrowing of Ropers Slough and generally thinner fluvial deposits with no clear relationship between grain size/deposit thickness and discharge. The δ13C values and organic nitrogen to organic carbon ratios of deposits from the first phase overlapped with Eel River suspended sediment characteristics found for low flows (1-5 times mean discharge), while those of the second phase were consistent suspended sediment from higher flows (7-10 times mean discharge). The abandoned channel fill sequences appeared to differ due to the topographic steering of bed sediment transport and

  9. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARADIAN AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    SciTech Connect

    James W. Jennings, Jr.; F. Jerry Lucia

    2001-10-01

    Petrophysical heterogeneity in the South Wasson Clear Fork (SWCF) reservoir and other shallow-water platform carbonates in the Permian Basin and elsewhere is composed of a large-scale stratigraphically controlled component and a small-scale poorly correlated component. The large-scale variability exists as a flow-unit scale petrophysical layering that is laterally persistent at interwell scales and produces highly stratified reservoir behavior. Capturing the rate-enhancing effect of the small-scale variability requires carefully controlled averaging procedures at four levels of scaleup. Porosity can be easily scaled using arithmetic averaging procedures. Permeability, however, requires carefully controlled power-averaging procedures. Effective permeability is increased at every scaleup level.

  10. Experiments and modeling of variably permeable carbonate reservoir samples in contact with CO₂-acidified brines

    SciTech Connect

    Smith, Megan M.; Hao, Yue; Mason, Harris E.; Carroll, Susan A.

    2014-12-31

    Reactive experiments were performed to expose sample cores from the Arbuckle carbonate reservoir to CO₂-acidified brine under reservoir temperature and pressure conditions. The samples consisted of dolomite with varying quantities of calcite and silica/chert. The timescales of monitored pressure decline across each sample in response to CO₂ exposure, as well as the amount of and nature of dissolution features, varied widely among these three experiments. For all samples cores, the experimentally measured initial permeability was at least one order of magnitude or more lower than the values estimated from downhole methods. Nondestructive X-ray computed tomography (XRCT) imaging revealed dissolution features including “wormholes,” removal of fracture-filling crystals, and widening of pre-existing pore spaces. In the injection zone sample, multiple fractures may have contributed to the high initial permeability of this core and restricted the distribution of CO₂-induced mineral dissolution. In contrast, the pre-existing porosity of the baffle zone sample was much lower and less connected, leading to a lower initial permeability and contributing to the development of a single dissolution channel. While calcite may make up only a small percentage of the overall sample composition, its location and the effects of its dissolution have an outsized effect on permeability responses to CO₂ exposure. The XRCT data presented here are informative for building the model domain for numerical simulations of these experiments but require calibration by higher resolution means to confidently evaluate different porosity-permeability relationships.

  11. Construction of efficient-sensitive factor for complex carbonate reservoirs and its applications

    NASA Astrophysics Data System (ADS)

    Liu, Lifeng; Zandong Sun, Sam; Tian, Jun; Cao, Guoyi; Yue, Xingtong; Hou, Xinye

    2015-10-01

    Currently, increasing the proportion of highly efficient wells is of great significance for enhancing both the reservation and production of the carbonate reservoirs in the Tarim Basin. Research has shown that the relationship between P-wave velocity and gas saturation is mostly nonlinear, which implies that velocity information or velocity-related parameters are not available for highly efficient well identification. Based on the differences between highly efficient wells and the others, a new type of efficient-sensitive factor is established by summarizing the pre-stack elastic information of the highly efficient ones, which takes into account the combination of density and porosity. Then, the effectiveness of this factor is verified by practical production in the Tazhong area, which demonstrates that the constructed factor is remarkably sensitive to highly efficient wells, while low efficiency wells, water wells and mud filled wells always fail. Furthermore, an approximate linear relationship is achieved between cumulative production and the efficient-sensitive factor, which can be used as an important indicator for commercial reservoir evaluation and highly efficient well optimization.

  12. Seasonal patterns in carbon dioxide in 15 mid-continent (USA) reservoirs

    USGS Publications Warehouse

    Jones, John R.; Obrecht, Daniel V.; Graham, Jennifer; Balmer, Michelle B.; Filstrup, Christopher T.; Downing, John A.

    2016-01-01

    Evidence suggests that lakes are important sites for atmospheric CO2 exchange and so play a substantial role in the global carbon budget. Previous research has 2 weaknesses: (1) most data have been collected only during the open-water or summer seasons, and (2) data are concentrated principally on natural lakes in northern latitudes. Here, we report on the full annual cycle of atmospheric CO2 exchanges of 15 oligotrophic to eutrophic reservoirs in the Glacial Till Plains of the United States. With one exception, these reservoirs showed an overall loss of CO2 during the year, with most values within the lower range reported for temperate lakes. There was a strong cross-system seasonal pattern: an average of 70% of total annual CO2 efflux occurred by the end of spring mixis; some 20% of annual flux was reabsorbed during summer stratification; and the remaining 50% of efflux was lost during autumnal mixing. Net annual flux was negatively correlated with depth and positively correlated with both water residence time and DOC, with the smallest annual CO2 efflux measured in shallow fertile impoundments. Strong correlations yield relationships allowing regional up-scaling of CO2 evasion. Understanding lacustrine CO2 uptake and evasion requires seasonal analyses across the full range of lake trophic states and morphometric attributes.

  13. Development of a combined isotopic and mass-balance approach to determine dissolved organic carbon sources in eutrophic reservoirs.

    PubMed

    Pierson-Wickmann, Anne-Catherine; Gruau, Gérard; Jardé, Emilie; Gaury, Nicolas; Brient, Luc; Lengronne, Marion; Crocq, André; Helle, Daniel; Lambert, Thibault

    2011-04-01

    A combined mass-balance and stable isotope approach was set up to identify and quantify dissolved organic carbon (DOC) sources in a DOC-rich (9mgL(-1)) eutrophic reservoir located in Western France and used for drinking water supply (so-called Rophemel reservoir). The mass-balance approach consisted in measuring the flux of allochthonous DOC on a daily basis, and in comparing it with the effective (measured) DOC concentration of the reservoir. The isotopic approach consisted, for its part, in measuring the carbon isotope ratios (δ(13)C values) of both allochthonous and autochthonous DOC sources, and comparing these values with the δ(13)C values of the reservoir DOC. Results from both approaches were consistent pointing out for a DOC of 100% allochthonous origin. In particular, the δ(13)C values of the DOC recovered in the reservoir (-28.5±0.2‰; n=22) during the algal bloom season (May-September) showed no trace of an autochthonous contribution (δ(13)C in algae=-30.1±0.3‰; n=2) being indistinguishable from the δ(13)C values of allochthonous DOC from inflowing rivers (-28.6±0.1‰; n=8). These results demonstrate that eutrophication is not responsible for the high DOC concentrations observed in the Rophemel reservoir and that limiting eutrophication of this reservoir will not reduce the potential formation of disinfection by-products during water treatment. The methodology developed in this study based on a complementary isotopic and mass-balance approach provides a powerful tool, suitable to identify and quantify DOC sources in eutrophic, DOC-contaminated reservoirs. PMID:21190712

  14. Carbon dioxide-brine-rock interactions in a carbonate reservoir capped by shale: Experimental insights regarding the evolution of trace metals

    NASA Astrophysics Data System (ADS)

    Marcon, Virginia; Kaszuba, John P.

    2015-11-01

    Trace metal behavior provides important information regarding fluid-rock interactions in CO2-charged water-rock systems and constrains potential environmental impacts. Hydrothermal experiments evaluated mechanisms of release, evolution, and subsequent scavenging of trace metals at 160 °C and 25 MPa. Experiments were designed to simulate two theoretical locations within a CO2-charged reservoir: (1) at the contact between a shale caprock and carbonate reservoir and (2) deeper within a carbonate reservoir, away from the shale. CO2 injection into brine (ionic strength = 3.3 mol/kg) decreased the pH by 1-2 units; concomitant mineral dissolution elevated Ba, Co, Cu, Pb, and V concentrations in the brine at both simulated locations within the reservoir. Additionally, Fe, Ni, and Zn concentrations increased in the mixed shale-carbonate experiment; Ba and Cd concentrations increased in the carbonate-only experiment. However, concentrations of Fe, Ba, Cr, and Pb in the mixed shale-carbonate experiment and Cr, Pb, V, and Zn within the carbonate-only experiment subsequently decreased as a result of precipitation of sulfides (Fe and Co sulfides), oxides, and clays. At the conclusion of the experiments, Fe, Pb, and Cr exceeded U.S. Environmental Protection Agency maximum contaminant limits in both experiments. In addition, zinc exceeded the limits at the simulated shale-carbonate contact and Ba, Cu, and Cd exceeded the limits in the simulated carbonate reservoir. Experimentally observed trends of decreasing Fe and Pb concentrations suggest these trace metals become less of an environmental concern as CO2-water-rock reactions evolve with time. The shale caprock plays an active role in trace metal evolution. The shale is a large source of metals, but also provides metal sinks such as primary clays, secondary smectites, and other silicates that are not found deeper within the carbonate reservoir, away from the shale. This potential mechanism of self-healing mitigates, but does not

  15. Organic Carbon Burial in Lakes and Reservoirs of the Conterminous United States.

    PubMed

    Clow, David W; Stackpoole, Sarah M; Verdin, Kristine L; Butman, David E; Zhu, Zhiliang; Krabbenhoft, David P; Striegl, Robert G

    2015-07-01

    Organic carbon (OC) burial in lacustrine sediments represents an important sink in the global carbon cycle; however, large-scale OC burial rates are poorly constrained, primarily because of the sparseness of available data sets. Here we present an analysis of OC burial rates in water bodies of the conterminous U.S. (CONUS) that takes advantage of recently developed national-scale data sets on reservoir sedimentation rates, sediment OC concentrations, lake OC burial rates, and water body distributions. We relate these data to basin characteristics and land use in a geostatistical analysis to develop an empirical model of OC burial in water bodies of the CONUS. Our results indicate that CONUS water bodies sequester 20.8 (95% CI: 9.4-65.8) Tg C yr(-1), and spatial patterns in OC burial are strongly influenced by water body type, size, and abundance; land use; and soil and vegetation characteristics in surrounding areas. Carbon burial is greatest in the central and southeastern regions of the CONUS, where cultivation and an abundance of small water bodies enhance accumulation of sediment and OC in aquatic environments. PMID:26061185

  16. Total Organic Carbon prediction in shale gas reservoirs using fuzzy logic

    NASA Astrophysics Data System (ADS)

    Ouadfeul, Sid-Ali; Aliouane, Leila

    2015-04-01

    Here, we suggest the use the fuzzy logic approach for the prediction of the Total Organic Carbon (TOC) from well-logs data in shale gas reservoirs, two models are used for the estimation of the TOC from well-logs data; the first one is called the Schmoker's model while the second one is called the Passey's model. Scmocker's model requires the continuous measurement of the Bulk density, in case of absence of the bulk density measurement the Schmoker's model is not able to predict the TOC. In this case we suggest the use fuzzy logic system able to predict the total organic carbon in shale gas formations. The input of the fuzzy system is the four raw well-logs data measurements corresponding to the natural gamma ray, the neutron porosity, the slowness of the primary and shear waves. The desired output is the calculated TOC using the Schmoker's model. Application to well-logs data of two horizontal wells drilled in the lower Barnett shale clearly shows the ability of the fuzzy logic approach to suggest values of the total organic carbon in case of no bulk density measurement. Keywords TOC, Schmoker's model, Fuzzy logic, shale gas, Barnett shale, prediction.

  17. Enhanced carbonate reservoir model for an old reservoir utilizing new techniques: The Schaben Field (Mississippian), Ness County, Kansas

    SciTech Connect

    Carr, T.P.; Guy, W.J.; Franseen, E.K.; Bhattacharya, S. )

    1996-01-01

    The Pennsylvanian-Mississippian unconformity is a major stratigraphic event in Kansas that truncates rocks ranging from Precambrian to Mississippian. Many of the 6,000 fields in Kansas are located immediately beneath this unconformity. One example, Schaben Field located in Ness County, Kansas, has produced approximately 9 million barrels since it was discovered in 1963. Production is from the Mississippian (Osagian) cherty dolomites beneath the inconformity. The field was initially developed on a regular forty-acre spacing, but recent drilling has demonstrated the potential for additional targeted infill drilling. To develop an enhanced reservoir model for the Schabin field modern core, log, and well data were integrated with the existing data. New techniques such as [open quotes]Pseudoseismic[close quotes] and the [open quotes]Super[close quotes] Pickett plot were used to leverage the existing data and provide tools for analysis and 3D visualization. The pseudoseismic approach uses well-logs within a standard 3D seismic visualization system to provide a detailed macroscale view of karst patterns. The petrophysical analyses using the [open quotes]Super[close quotes] Pickett plot were used to recognize subtle trends and patterns for each of multiple reservoir intervals. Visual and petrographic examination of core from the field confirms karst development and indicates multiple stages of fracturing, brecciation, and dissolution features that were important in controlling and modifying development of reservoirs. The understanding of the reservoir heterogeneities resulting from the paleokarst model at Schaben field emphasizes the importance of integrating available data with new techniques to provide a predictive tool for discovery of additional pay within existing subunconformity fields in Kansas.

  18. Enhanced carbonate reservoir model for an old reservoir utilizing new techniques: The Schaben Field (Mississippian), Ness County, Kansas

    SciTech Connect

    Carr, T.P.; Guy, W.J.; Franseen, E.K.; Bhattacharya, S.

    1996-12-31

    The Pennsylvanian-Mississippian unconformity is a major stratigraphic event in Kansas that truncates rocks ranging from Precambrian to Mississippian. Many of the 6,000 fields in Kansas are located immediately beneath this unconformity. One example, Schaben Field located in Ness County, Kansas, has produced approximately 9 million barrels since it was discovered in 1963. Production is from the Mississippian (Osagian) cherty dolomites beneath the inconformity. The field was initially developed on a regular forty-acre spacing, but recent drilling has demonstrated the potential for additional targeted infill drilling. To develop an enhanced reservoir model for the Schabin field modern core, log, and well data were integrated with the existing data. New techniques such as {open_quotes}Pseudoseismic{close_quotes} and the {open_quotes}Super{close_quotes} Pickett plot were used to leverage the existing data and provide tools for analysis and 3D visualization. The pseudoseismic approach uses well-logs within a standard 3D seismic visualization system to provide a detailed macroscale view of karst patterns. The petrophysical analyses using the {open_quotes}Super{close_quotes} Pickett plot were used to recognize subtle trends and patterns for each of multiple reservoir intervals. Visual and petrographic examination of core from the field confirms karst development and indicates multiple stages of fracturing, brecciation, and dissolution features that were important in controlling and modifying development of reservoirs. The understanding of the reservoir heterogeneities resulting from the paleokarst model at Schaben field emphasizes the importance of integrating available data with new techniques to provide a predictive tool for discovery of additional pay within existing subunconformity fields in Kansas.

  19. Differential Hydrocarbon Migration and Entrapment in the Karstified Carbonate Reservoir: A Case Study of the Well TZ83 Block of the Central Tarim Uplift Zone

    NASA Astrophysics Data System (ADS)

    Xiang, Caifu; Wang, Jianzhong; Pang, Xiongqi; Zhou, Changqian; Jiang, Zhenxue; Liu, Luofu

    The hydrocarbon migration and entrapment mechanism in the lower overlapped basins, occurring in the complex carbonate pore-fissure-fracture reservoirs, is one of the key problems that have to be solved for effective hydrocarbon exploration. The production, gas/oil ratio, and the composition of crude oils and natural gas in the TZ83 Well block are high at the intersection point of the NE and NW-strike faults and decrease gradually along the ridge of the structure. A basic model of the pore-fissure-fracture system is built according to the achievements in the research on carbonate karstification. Processes of hydrocarbon migration and entrapment in this system are analyzed, which indicate that an understanding of the complexness of differential hydrocarbon migration is the key to interpreting this phenomenon. The hydrocarbon must charge the nearest compartment before migrating further away to charge other compartments in its pathway in the complex pore-fissure-fracture system. As a result, the following two phenomena appear: (1) Gas is enriched near the hydrocarbon injection point and drives away the oil, which is enriched in the compartments farther from the injection point. (2) The complex gas-oil-water relationship is controlled by the lateral connecting networks. Based on this, this article shows that the fault intersection point is the injection point of the oil and gas, and the main pathway system is distributed along the ridge of the structure. The theory of deferential hydrocarbon migration in the pore-fissure-fracture system can be presented from two aspects: (1) In hydrocarbon exploration, the structure of the fissure-fracture system should be described first, and then the special distribution of gas-oil-water can be predicted according to the main charging point and the main pathway system. (2) Exploration should be confined to the hydrocarbon charging point and the main pathway systems. An explored area should not be abandoned merely due to failures in

  20. Chemical and physical characteristics of water and sediment in Scofield Reservoir, Carbon County, Utah

    USGS Publications Warehouse

    Waddell, Kidd M.; Darby, D.W.; Theobald, S.M.

    1985-01-01

    Evaluations based on the nutrient content of the inflow, outflow, water in storage, and the dissolved-oxygen depletion during the summer indicate that the trophic state of Scofield Reservoir is borderline between mesotrophic and eutrophic and may become highly eutrophic unless corrective measures are taken to limit nutrient inflow. Sediment deposition in Scofield Reservoir during 1943-79 is estimated to be 3,000 acre-feet, and has decreased the original storage capacity of the reservoir by 4 percent. The sediment contains some coal, and age dating of those sediments (based on the radioisotope lead-210) indicates that most of the coal was deposited prior to about 1950. Scofield Reservoir is dimictic, with turnovers occurring in the spring and autumn. Water in the reservoir circulates completely to the bottom during turnovers. The concentration of dissolved oxygen decreases with depth except during parts of the turnover periods. Below an altitude of about 7,590 feet, where 20 percent of the water is stored, the concentration of dissolved oxygen was less than 2 milligrams per liter during most of the year. During the summer stratification period, the depletion of dissolved oxygen in the deeper layers is coincident with supersaturated conditions in the shallow layers; this is attributed to plant photosynthesis and bacterial respiration in the reservoir. During October 1,1979-August 31, 1980, the discharge-weighted average concentrations of dissolved solids was 195 milligrams per liter in the combined inflow from Fish, Pondtown, and Mud Creeks, and was 175 milligrams per liter in the outflow (and to the Price River). The smaller concentration in the outflow was due primarily to precipitation of calcium carbonate in the reservoir--about 80 percent of the decrease can be accounted for through loss as calcium carbonate. The estimated discharge-weighted average concentration of total nitrogen (dissolved plus suspended) in the combined inflow of Fish, Pondtown, and Mud

  1. the COS-Dwarfs survey: the carbon reservoir around sub-L* galaxies

    SciTech Connect

    Bordoloi, Rongmon; Tumlinson, Jason; Peeples, Molly S.; Fox, Andrew J.; Thom, Christopher; Werk, Jessica K.; Prochaska, J. Xavier; Tripp, Todd M.; Katz, Neal; Burchett, Joseph N.; Davé, Romeel; Ford, Amanda Brady; Weinberg, David H.; Kollmeier, Juna A.

    2014-12-01

    We report new observations of circumgalactic gas from the COS-Dwarfs survey, a systematic investigation of the gaseous halos around 43 low-mass z ≤ 0.1 galaxies using background QSOs observed with the Cosmic Origins Spectrograph. From the projected one-dimensional and two-dimensional distribution of C IV absorption, we find that C IV is detected out to ≈100 kpc (corresponding roughly to ≈0.5 R {sub vir}) of the host galaxies. The C IV absorption strength falls off radially as a power law, and beyond ≈0.5 R {sub vir}, no C IV absorption is detected above our sensitivity limit of ≈50-100 mÅ. We find a tentative correlation between detected C IV absorption strength and star formation, paralleling the strong correlation seen in highly ionized oxygen for L ∼ L* galaxies by the COS-Halos survey. The data imply a large carbon reservoir in the circumgalactic medium (CGM) of these galaxies, corresponding to a minimum carbon mass of ≳ 1.2 × 10{sup 6} M {sub ☉} out to ∼110 kpc. This mass is comparable to the carbon mass in the interstellar medium and exceeds the carbon mass currently in the stars of these galaxies. The C IV absorption seen around these sub-L* galaxies can account for almost two-thirds of all W{sub r} ≥ 100 mÅ C IV absorption detected at low z. Comparing the C IV covering fraction with hydrodynamical simulations, we find that an energy-driven wind model is consistent with the observations whereas a wind model of constant velocity fails to reproduce the CGM or the galaxy properties.

  2. What is below the support layer affects carbon nanotube growth: an iron catalyst reservoir yields taller nanotube carpets.

    PubMed

    Shawat, E; Mor, V; Oakes, L; Fleger, Y; Pint, C L; Nessim, G D

    2014-01-01

    Here we demonstrate an approach to enhance the growth of vertically aligned carbon nanotubes (CNTs) by including a catalyst reservoir underneath the thin-film alumina catalyst underlayer. This reservoir led to enhanced CNT growth due to the migration of catalytic material from below the underlayer up to the surface through alumina pinholes during processing. This led to the formation of large Fe particles, which in turn influenced the morphology evolution of the catalytic iron surface layer through Ostwald ripening. With inclusion of this catalyst reservoir, we observed CNT growth up to 100% taller than that observed without the catalyst reservoir consistently across a wide range of annealing and growth durations. Imaging studies of catalyst layers both for different annealing times and for different alumina support layer thicknesses demonstrate that the surface exposure of metal from the reservoir leads to an active population of smaller catalyst particles upon annealing as opposed to a bimodal catalyst size distribution that appears without inclusion of a reservoir. Overall, the mechanism for growth enhancement we present here demonstrates a new route to engineering efficient catalyst structures to overcome the limitations of CNT growth processes. PMID:24323364

  3. Geochemical analysis of atlantic rim water, carbon county, wyoming: New applications for characterizing coalbed natural gas reservoirs

    USGS Publications Warehouse

    McLaughlin, J.F.; Frost, C.D.; Sharma, S.

    2011-01-01

    Coalbed natural gas (CBNG) production typically requires the extraction of large volumes of water from target formations, thereby influencing any associated reservoir systems. We describe isotopic tracers that provide immediate data on the presence or absence of biogenic natural gas and the identify methane-containing reservoirs are hydrologically confined. Isotopes of dissolved inorganic carbon and strontium, along with water quality data, were used to characterize the CBNG reservoirs and hydrogeologic systems of Wyoming's Atlantic Rim. Water was analyzed from a stream, springs, and CBNG wells. Strontium isotopic composition and major ion geochemistry identify two groups of surface water samples. Muddy Creek and Mesaverde Group spring samples are Ca-Mg-S04-type water with higher 87Sr/86Sr, reflecting relatively young groundwater recharged from precipitation in the Sierra Madre. Groundwaters emitted from the Lewis Shale springs are Na-HCO3-type waters with lower 87Sr/86Sr, reflecting sulfate reduction and more extensive water-rock interaction. To distinguish coalbed waters, methanogenically enriched ??13CDIC wasused from other natural waters. Enriched ??13CDIC, between -3.6 and +13.3???, identified spring water that likely originates from Mesaverde coalbed reservoirs. Strongly positive ??13CDIC, between +12.6 and +22.8???, identified those coalbed reservoirs that are confined, whereas lower ??13CDIC, between +0.0 and +9.9???, identified wells within unconfined reservoir systems. Copyright ?? 2011. The American Association of Petroleum Geologists. All rights reserved.

  4. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  5. Dynamic three-dimensional pore-scale imaging of reaction in a carbonate at reservoir conditions.

    PubMed

    Menke, Hannah P; Bijeljic, Branko; Andrew, Matthew G; Blunt, Martin J

    2015-04-01

    Quantifying CO2 transport and average effective reaction rates in the subsurface is essential to assess the risks associated with underground carbon capture and storage. We use X-ray microtomography to investigate dynamic pore structure evolution in situ at temperatures and pressures representative of underground reservoirs and aquifers. A 4 mm diameter Ketton carbonate core is injected with CO2-saturated brine at 50 °C and 10 MPa while tomographic images are taken at 15 min intervals with a 3.8 μm spatial resolution over a period of 2(1/2) h. An approximate doubling of porosity with only a 3.6% increase in surface area to volume ratio is measured from the images. Pore-scale direct simulation and network modeling on the images quantify an order of magnitude increase in permeability and an appreciable alteration of the velocity field. We study the uniform reaction regime, with dissolution throughout the core. However, at the pore scale, we see variations in the degree of dissolution with an overall reaction rate which is approximately 14 times lower than estimated from batch measurements. This work implies that in heterogeneous rocks, pore-scale transport of reactants limits dissolution and can reduce the average effective reaction rate by an order of magnitude. PMID:25738415

  6. The effects of land abandonment and long-term afforestation practices on the organic carbon and lignin content of a Mediteranean soil

    NASA Astrophysics Data System (ADS)

    Stijsiger, Romy; Nadal-Romero, Estela; Campo, Julian; Cammeraat, Erik

    2016-04-01

    Afforestation is an important strategy that can decrease atmospheric carbon in sequestering it in biomass and soils (Pérez-Crusado et al., 2014). In Spain an active afforestation program was adopted in the 1950s, when after wide spread land abandonment the soils were severely eroded (FAO, 2015). In this research the organic carbon and lignin content of the soils in the Araguás catchment area in the Spanish Pyrenees were examined. This research is part of a larger research examining the effect of afforestation over time (Med Afforest Project, PIEF-GA-2013-624974). The research area was afforested with both the P. sylvestris (Scotts Pine) and the P.nigra (Black Pine). Both sites were compared to bare soil (representing severely eroded soil), natural secondary succession (re-vegetation) and meadows. The method used to assess the lignin content is Curie-point pyrolysis with tetramethylammonium hydroxide (TMAH). The results showed a reducing trend for the soil organic carbon (SOC) content with depth. The highest SOC and lignin contents in the topsoil were found under P.nigra and secondary succession. This decline in lignin content corresponds with a high degradation rate (Ad/Al) in the top soil and lower degradation rates in depths of >20 cm. Meadows showed an increased SOC content in deeper horizons, which corresponds to high lignin content as well. In which the meadows showed an increase in lignin content for the soil depths of >20 cm that was unusual and could not be explained by the S/G and P/G ratios and the degradation ratio (Ad/Al). According to the results, P. nigra was the best afforestation practice for increasing the SOC and lignin contents in the soil. The P. sylvestris was considered but proved to be less successful than natural secondary succession. Acknowledgements This research was supported by a Marie Curie Intra-European Fellowship in the project "MED-AFFOREST" (PIEF-GA-2013-624974). JC also acknowledges the VALi+d postdoctoral contract (APOSTD/2014

  7. Improved Oil Recovery in Mississippian Carbonate Reservoirs of Kansas - Near-Term, Class II

    SciTech Connect

    Carr, Timothy R.; Green, Don W.; Willhite, G. Paul

    2001-10-30

    The focus of this project was development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and the mid-continent.

  8. Experiments and modeling of variably permeable carbonate reservoir samples in contact with CO₂-acidified brines

    DOE PAGESBeta

    Smith, Megan M.; Hao, Yue; Mason, Harris E.; Carroll, Susan A.

    2014-12-31

    Reactive experiments were performed to expose sample cores from the Arbuckle carbonate reservoir to CO₂-acidified brine under reservoir temperature and pressure conditions. The samples consisted of dolomite with varying quantities of calcite and silica/chert. The timescales of monitored pressure decline across each sample in response to CO₂ exposure, as well as the amount of and nature of dissolution features, varied widely among these three experiments. For all samples cores, the experimentally measured initial permeability was at least one order of magnitude or more lower than the values estimated from downhole methods. Nondestructive X-ray computed tomography (XRCT) imaging revealed dissolution featuresmore » including “wormholes,” removal of fracture-filling crystals, and widening of pre-existing pore spaces. In the injection zone sample, multiple fractures may have contributed to the high initial permeability of this core and restricted the distribution of CO₂-induced mineral dissolution. In contrast, the pre-existing porosity of the baffle zone sample was much lower and less connected, leading to a lower initial permeability and contributing to the development of a single dissolution channel. While calcite may make up only a small percentage of the overall sample composition, its location and the effects of its dissolution have an outsized effect on permeability responses to CO₂ exposure. The XRCT data presented here are informative for building the model domain for numerical simulations of these experiments but require calibration by higher resolution means to confidently evaluate different porosity-permeability relationships.« less

  9. Hydrology of the Valley-fill and carbonate-rock reservoirs, Pahrump Valley, Nevada-California

    USGS Publications Warehouse

    Malmberg, Glenn T.

    1967-01-01

    This is the second appraisal of the water supply of Pahrump Valley, made 15 years after the first cooperative study. In the first report the average recharge was estimated to be 23,000 acre-feet per year, only 1,000 acre-feet more than the estimate made in this report. All this recharge was considered to be available for development. Because of the difficulty in salvaging the subsurface outflow from the deep carbonate-rock reservoir, this report concludes that the perennial yield may be only 25,000 acre-feet. In 1875, Bennetts and Manse Springs reportedly discharged a total of nearly 10,000 acre-feet of water from the valley-fill reservoir. After the construction of several flowing wells in 1910, the spring discharge began to decline. In the mid-1940's many irrigation wells were drilled, and large-capacity pumps were installed. During the 4-year period of this study (1959-62), the net pumping draft averaged about 25,000 acre-feet per year, or about twice the estimated yield. In 1962 Bennetts Spring was dry, and the discharge from Marse Spring was only 1,400 acre-feet. During the period February 1959-February 1962, pumping caused an estimated storage depletion of 45,000 acre-feet, or 15,000 acre-feet per year. If the overdraft is maintained, depletion of stored water will continue and pumping costs will increase. Water levels in the vicinity of the Pahrump, Manse, and Fowler Ranches declined more than ]0 feet in response to the pumping during this period, and they can be expected to continue to decline at ,the projected rate of more than 3 feet per year. The chemical quality of the pumped water has been satisfactory for irrigation and domestic use. Recycling of water pumped or irrigation, however, could result in deterioration of the water quality with time.

  10. The Influence of Seal Properties on Pressure Buildup and Leakage of Carbon Dioxide from Sequestration Reservoirs (Invited)

    NASA Astrophysics Data System (ADS)

    Benson, S. M.; Chabora, E.

    2009-12-01

    The transport properties of seals, namely permeability, relative permeability, and capillary pressure control both migration of carbon dioxide and brine through the seal. Only recently has the the importance of brine migration emerged as key issue in the environmental performance of carbon dioxide sequestration projects. In this study we use numerical simulation to show that brine migration through the seal can be either advantageous or deleterious to the environmental performance of a carbon dioxide sequestration project. Brine migration through the seal can lower the pressure buildup in the storage reservoir, thereby reducing the risk of leakage or geomechanical stresses on the seal. On the other hand, if the seal is penetrated by a permeable fault it can lead to focused flow up a fault, which could lead to brine migration into drinking water aquifers. We also show that as the carbon dioxide plume grows, brine flow undergoes a complex evolution from upward flow to downward flows driven by countercurrent migration of carbon dioxide and brine in the seal and capillary pressure gradients at the base of the seal. Finally, we discuss desirable attributes seals, taking into account both carbon dioxide and brine migration through the seal. In particular, identifying seals that provide an effective capillary barrier to block the flow of carbon dioxide while allowing some brine migration through the seal can help to control pressure buildup and allow more efficient utilization of a sequestration reservoir. This could be particularly important in those settings that may be limited by the maximum allowable pressure buildup.

  11. Abandoned Texas oil fields

    SciTech Connect

    Not Available

    1980-12-01

    Data for Texas abandoned oil fields were primarily derived from two sources: (1) Texas Railroad Commission (TRRC), and (2) Dwight's ENERGYDATA. For purposes of this report, abandoned oil fields are defined as those fields that had no production during 1977. The TRRC OILMASTER computer tapes were used to identify these abandoned oil fields. The tapes also provided data on formation depth, gravity of oil production, location (both district and county), discovery date, and the cumulative production of the field since its discovery. In all, the computer tapes identified 9211 abandoned fields, most of which had less than 250,000 barrel cumulative production. This report focuses on the 676 abandoned onshore Texas oil fields that had cumulative production of over 250,000 barrels. The Dwight's ENERGYDATA computer tapes provided production histories for approximately two-thirds of the larger fields abandoned in 1966 and thereafter. Fields which ceased production prior to 1966 will show no production history nor abandonment date in this report. The Department of Energy hopes the general availability of these data will catalyze the private sector recovery of this unproduced resource.

  12. Soil organic carbon in Apolobamba (Bolivia): Quantity and quality of the reservoir

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Á.; Faz, A.

    2009-04-01

    soluble organic carbon (WSOC) were messure. In addition, 13C MNR technique was used in surface samples in each plot in order to determine the main carbonide groups: alkyl, O-alkyl, aromatic and carboxilic. Results were discussing through statistical analyses. Soil profile datas exhibited very low TOC in Ulla-Ulla zone including the surface horizon. Sampling plot results showed maximum TOC contents in Wakampata and Puyo-Puyo surface samples; on the other hand, Sucondori, Caballchiñuni and Ulla-Ulla presented minimum contents. Generally speaking, low and medium WSOC inputs were determined in surface and subsurface samples, respectively, in studied areas. Moreover, Wakampata and Japu zones presented high O-alkyl percentages; it could be related to highest polysacharide concentrations and the easiest SOM degradation, taking into account alkyl/O-alkyl ratios. On the contrary, Ulla-Ulla and Caballchiñuni exhibited highest carboxilic percentages pointing out a SOM oxidation increase. In conclusion, Apolobamba soils presented different SOC conditions. There were some zones which could be characterized as excellent carbon reservoirs due to high SOM quantity and quality; however, in other census places could be identify a certain soil exhaustion degree, as a consequence to the soil overexploitation due to the cattle camelid concentrations both the natural wind erosion in these zones. It should be carried out conservation actions in order to improve the carbon sink and to preserve the soil and the biodiversity in Apolobamba.

  13. Regional-scale porosity and permeability variations in Upper Devonian Leduc buildups: Implications for reservoir development and prediction in carbonates

    SciTech Connect

    Amthor, J.E.; Mountjoy, E.W.; Machel, H.G.

    1994-10-01

    Upper Devonian carbonate rocks of the Rimbey-Meadowbrook reef trend in the subsurface of central Alberta are characterized by a wide range of porosity and permeability values. Dolostones show the highest values of absolute and average horizontal and vertical permeability. For all rock types, horizontal permeability averages tens of times to several hundred times the vertical permeability. If considered irrespective of burial depth, limestones and dolomitic limestones are more porous than dolostones. There is an overall decrease of porosity and permeability in Leduc Formation carbonates with increasing burial depth and thermal maturity along the reef trend. At relatively shallow burial depths (<2000 m), limestone and dolomitized buildups have comparable porosity values and distributions. Dolomitization has resulted mainly in redistribution of primary limestone porosity to secondary dolomite porosity types with a concomitant minor increase in permeability. At greater burial depths (>2000 m), dolostones are significantly more porous and permeable than limestones. The better porosity and permeability of dolostones relative to limestones at greater depths is of economic significance for exploration in Upper Devonian carbonates of the deep Alberta basin (and probably other carbonate areas), where reservoirs are mostly found in dolostones and where limestones have a low reservoir potential and pose a considerable exploration risk. The best reservoir potential in the Leduc Formation of the deep Alberta basin occurs in dolomitized buildups that were connected to a regional conduit system.

  14. Effects of depositional facies and diagenesis on calculating petrophysical properties for wireline logs in Permian carbonate reservoirs of west Texas

    SciTech Connect

    Holtz, M.H.; Major, R.P. )

    1994-03-01

    The complex interplay between depositional facies and diagenesis in carbonate rocks presents numerous problems for calculating petrophysical properties from wireline logs. If carbonate reservoirs are divided into flow units of similar depositional and diagenetic textures, empirical equations that apply specifically to that geologically identified flow unit can be developed to accurately measure porosity and water saturation. In Guadalupian and Leonardian reservoirs, carbonate mudstones deposited in subtidal marine settings are predominantly dolomite, although they contain some shale. The shale in these rocks can be detected with gamma-ray logs and empirical equations for calculation of porosity from log must include a gamma-ray component to compensate for the presence of shale. Because porosity in these rocks is dominantly intercrystalline, capillary pressure characteristics are predictable and saturations can be calculated with the Archie equation. Subtidal carbonate packstones and grainstones are composed of dolomite, anhydrite, and gypsum. The matrix acoustic transit times of these three minerals are similar, and acoustic logs are the best tool for measuring porosity. Neutron logs are the least accurate porosity tools if gypsum is present. Photo-electric density logs can distinguish gypsum from anhydrite. Because porosity in these rocks is dominantly interparticle and/or moldic, dual porosity cementation exponent corrections are needed to calculate saturations with the Archie equation, and capillary pressure saturation relationships are variable. Carbonates deposited in tidal-flat environments are generally composed of dolomite, sulfate minerals, and quartz silt, requiring a full suite of open-hole logs to make reliable porosity measurements. Diagenesis influences reservoir mineralogy and pore types. A common style of burial diagenesis in Guadalupian and Leonardian reservoirs is hydration of anhydrite to gypsum and leaching of sulfate cement and dolomite matrix.

  15. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    SciTech Connect

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores

  16. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    DOE PAGESBeta

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could resultmore » from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores are the most likely

  17. Carbonate mound reservoirs in the paradox formation: An outcrop analogue along the San Juan River, Southeastern Utah

    SciTech Connect

    Chidsey, T. C. Jr.; Morgan, C.D.; Eby, D.E.

    1996-06-01

    Carbonate mound reservoirs within the Pennsylvanian (Desmoinesian) Paradox Formation are major producers of oil and gas in the Paradox basin of Utah, Colorado, and Arizona. Outcrops of the Paradox Formation along the San Juan River of southeastern Utah provide small-scale analogues of reservoir heterogeneity, flow barriers and baffles, lithofacies, and geometry. These characteristics can be used in reservoir simulation models for secondary/tertiary recovery of oil from small fields in the basin. Exposures of the Paradox Formation Ismay zone in the Wild Horse Canyon area display lateral facies changes from phylloid algal mounds to off-mound detrital wedges or fans bounded at the top by a flooding surface. The phylloid mounds are composed of bafflestone, skeletal grainstone, packstone, and cementstone. Algal plates, brachiopods, bryozoans, and rugose corals are commonly found in the phylloid mounds. The mound wall is composed of rudstone, lumpstone, and cementstone. The detrital fan consists of transported algal material, grainstone, and mudstone with open-marine fossils. Within the mound complex is an inter-mound trough tentatively interpreted to be a tidal channel. The geometry and composition of the rocks in the trough significantly add to the overall heterogeneity of the mound. Reservoir models are being developed for possible water- and carbon-dioxide floods of small Paradox basin fields to determine the most effective secondary/tertiary recovery method. The models will include lithologic fabrics, flooding surfaces, and inter-mound troughs, based on the mound complex exposed at Wild Horse Canyon. This project may also provide reservoir information for simulation models in small Paleozoic carbonate mound fields in other basins worldwide.

  18. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir

    SciTech Connect

    1998-06-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations, a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. The goals of the project are the development of guidelines for cost-effective selection of candidate reservoirs and wells, along with estimating recovery potential. This project has two defined budget periods. The first budget period primarily involves tasks associated with reservoir analysis and characterization, characterizing existing producibility problems, and reservoir simulation of the proposed technology. The final budget period covers the actual field demonstration of the proposed technology. Technology transfer spans the entire course of the project. This report covers the concluding tasks performed under the second budget period.

  19. Determining Carbon and Oxygen Stable Isotope Systematics in Brines at Elevated p/T Conditions to Enhance Monitoring of CO2 Induced Processes in Carbon Storage Reservoirs

    NASA Astrophysics Data System (ADS)

    Becker, V.; Myrttinen, A.; Mayer, B.; Barth, J. A.

    2012-12-01

    Stable carbon isotope ratios (δ13C) are a powerful tool for inferring carbon sources and mixing ratios of injected and baseline CO2 in storage reservoirs. Furthermore, CO2 releasing and consuming processes can be deduced if the isotopic compositions of end-members are known. At low CO2 pressures (pCO2), oxygen isotope ratios (δ18O) of CO2 usually assume the δ18O of the water plus a temperature-dependent isotope fractionation factor. However, at very high CO2 pressures as they occur in CO2 storage reservoirs, the δ18O of the injected CO2 may in fact change the δ18O of the reservoir brine. Hence, changing δ18O of brine constitutes an additional tracer for reservoir-internal carbon dynamics and allows the determination of the amount of free phase CO2 present in the reservoir (Johnson et al. 2011). Further systematic research to quantify carbon and oxygen isotope fractionation between the involved inorganic carbon species (CO2, H2CO3, HCO3-, CO32-, carbonate minerals) and kinetic and equilibrium isotope effects during gas-water-rock interactions is necessary because p/T conditions and salinities in CO2 storage reservoirs may exceed the boundary conditions of typical environmental isotope applications, thereby limiting the accuracy of stable isotope monitoring approaches in deep saline formations (Becker et al. 2011). In doing so, it is crucial to compare isotopic patterns observed in laboratory experiments with artificial brines to similar experiments with original fluids from representative field sites to account for reactions of dissolved inorganic carbon (DIC) with minor brine components. In the CO2ISO-LABEL project, funded by the German Ministry for Education and Research, multiple series of laboratory experiments are conducted to determine the influence of pressure, temperature and brine composition on the δ13C of DIC and the δ18O of brines in water-CO2-rock reactions with special focus placed on kinetics and stable oxygen and carbon isotope fractionation

  20. Using Biosurfactants Produced from Agriculture Process Waste Streams to Improve Oil Recovery in Fractured Carbonate Reservoirs

    SciTech Connect

    Stephen Johnson; Mehdi Salehi; Karl Eisert; Sandra Fox

    2009-01-07

    This report describes the progress of our research during the first 30 months (10/01/2004 to 03/31/2007) of the original three-year project cycle. The project was terminated early due to DOE budget cuts. This was a joint project between the Tertiary Oil Recovery Project (TORP) at the University of Kansas and the Idaho National Laboratory (INL). The objective was to evaluate the use of low-cost biosurfactants produced from agriculture process waste streams to improve oil recovery in fractured carbonate reservoirs through wettability mediation. Biosurfactant for this project was produced using Bacillus subtilis 21332 and purified potato starch as the growth medium. The INL team produced the biosurfactant and characterized it as surfactin. INL supplied surfactin as required for the tests at KU as well as providing other microbiological services. Interfacial tension (IFT) between Soltrol 130 and both potential benchmark chemical surfactants and crude surfactin was measured over a range of concentrations. The performance of the crude surfactin preparation in reducing IFT was greater than any of the synthetic compounds throughout the concentration range studied but at low concentrations, sodium laureth sulfate (SLS) was closest to the surfactin, and was used as the benchmark in subsequent studies. Core characterization was carried out using both traditional flooding techniques to find porosity and permeability; and NMR/MRI to image cores and identify pore architecture and degree of heterogeneity. A cleaning regime was identified and developed to remove organic materials from cores and crushed carbonate rock. This allowed cores to be fully characterized and returned to a reproducible wettability state when coupled with a crude-oil aging regime. Rapid wettability assessments for crushed matrix material were developed, and used to inform slower Amott wettability tests. Initial static absorption experiments exposed limitations in the use of HPLC and TOC to determine

  1. Transport of Organic Contaminants Mobilized from Coal through Sandstone Overlying a Geological Carbon Sequestration Reservoir

    SciTech Connect

    Zhong, Lirong; Cantrell, Kirk J.; Bacon, Diana H.; Shewell, Jesse L.

    2014-02-01

    Column experiments were conducted using a wetted sandstone rock installed in a tri-axial core holder to study the flow and transport of organic compounds mobilized by scCO2 under simulated geologic carbon storage (GCS) conditions. The sandstone rock was collected from a formation overlying a deep saline reservoir at a GCS demonstration site. Rock core effluent pressures were set at 0, 500, or 1000 psig and the core temperature was set at 20 or 50°C to simulate the transport to different subsurface depths. The concentrations of the organic compounds in the column effluent and their distribution within the sandstone core were monitored. Results indicate that the mobility though the core sample was much higher for BTEX compounds than for naphthalene. Retention of organic compounds from the vapor phase to the core appeared to be primarily controlled by partitioning from the vapor phase to the aqueous phase. Adsorption to the surfaces of the wetted sandstone was also significant for naphthalene. Reduced temperature and elevated pressure resulted in greater partitioning of the mobilized organic contaminants into the water phase.

  2. Determination of porosity and facies trends in a complex carbonate reservoir, by using 3-D seismic, borehole tools, and outcrop geology

    SciTech Connect

    Zacharakis, T.G. Jr.; Comet, J.N.; Murillo, A.A.

    1996-08-01

    Mesozoic carbonate reservoirs are found in the Mediterranean Sea, off the east coast of Spain. A wide variation of porosities are found in the core samples and logs: vuggy, breccia, fractures, and cavern porosity. In addition, complex Tertiary carbonate geometries include olistostromes, breccia bodies, and reef buildups, which are found on top of Mesozoic carbonates. Predicting the porosity trends within these oil productive reservoirs requires an understanding of how primary porosity was further enhanced by secondary processes, including fractures, karstification, and dolomitization in burial conditions. Through an extensive investigation of field histories, outcrop geology, and seismic data, a series of basic reservoir styles have been identified and characterized by well log signature and seismic response. The distribution pattern of the different reservoirs styles is highly heterogeneous, but by integrating subsurface data and outcrop analogs, it is possible to distinguish field-scale and local patterns of both vertical and local variations in reservoir properties. Finally, it is important to quantify these reservoir properties through the study of seismic attributes, such as amplitude variations, and log responses at the reservoir interval. By incorporating 3-D seismic data, through the use of seismic inversion, it is possible to predict porosity trends. Further, the use of geostatistics can lead to the prediction of reservoir development within the carbonate facies.

  3. Abandoning wells working group

    SciTech Connect

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  4. Carbon dioxide emissions from Tucuruí reservoir (Amazon biome): New findings based on three-dimensional ecological model simulations.

    PubMed

    Curtarelli, Marcelo Pedroso; Ogashawara, Igor; de Araújo, Carlos Alberto Sampaio; Lorenzzetti, João Antônio; Leão, Joaquim Antônio Dionísio; Alcântara, Enner; Stech, José Luiz

    2016-05-01

    We used a three-dimensional model to assess the dynamics of diffusive carbon dioxide flux (F(CO2)) from a hydroelectric reservoir located at Amazon rainforest. Our results showed that for the studied periods (2013 summer/wet and winter/dry seasons) the surface averaged F(CO2) presented similar behaviors, with regular emissions peaks. The mean daily surface averaged F(CO2) showed no significant difference between the seasons (p>0.01), with values around -1338mg Cm-2day-1 (summer/wet) and -1395mg Cm-2day-1 (winter/dry). At diel scale, the F(CO2) was large during the night and morning and low during the afternoon in both seasons. Regarding its spatial distribution, the F(CO2) showed to be more heterogeneous during the summer/wet than during the winter/dry season. The highest F(CO2) were observed at transition zone (-300mg Cm-2h-1) during summer and at littoral zone (-55mg Cm-2h-1) during the winter. The total CO2 emitted by the reservoir along 2013 year was estimated to be 1.1Tg C year-1. By extrapolating our results we found that the total carbon emitted by all Amazonian reservoirs can be around 7Tg C year-1, which is 22% lower than the previous published estimate. This significant difference should not be neglected in the carbon inventories since the carbon emission is a key factor when comparing the environmental impacts of different sources of electricity generation and can influences decision makers in the selection of the more appropriate source of electricity and, in case of hydroelectricity, the geographical position of the reservoirs. PMID:26914722

  5. Geochemical relationships of petroleum in Mesozoic reservoirs to carbonate source rocks of Jurassic Smackover Formation, southwestern Alabama

    SciTech Connect

    Claypool, G.E.; Mancini, E.A.

    1989-07-01

    Algal carbonate mudstones of the Jurassic Smackover Formation are the main source rocks for oil and condensate in Mesozoic reservoir rocks in southwestern Alabama. This interpretation is based on geochemical analyses of oils, condensates, and organic matter in selected samples of shale (Norphlet Formation, Haynesville Formation, Trinity Group, Tuscaloosa Group) and carbonate (Smackover Formation) rocks. Potential and probable oil source rocks are present in the Tuscaloosa Group and Smackover Formation, respectively. Extractable organic matter from Smackover carbonates has molecular and isotopic similarities to Jurassic oil. Although the Jurassic oils and condensates in southwestern Alabama have genetic similarities, they show significant compositional variations due to differences in thermal maturity and organic facies/lithofacies. Organic facies reflect different depositional conditions for source rocks in the various basins. The Mississippi Interior Salt basin was characterized by more continuous marine to hypersaline conditions, whereas the Manila and Conecuh embayments periodically had lower salnity and greater input of clastic debris and terrestrial organic matter. Petroleum and organic matter in Jurassic rocks of southwestern Alabama show a range of thermal transformations. The gas content of hydrocarbons in reservoirs increases with increasing depth and temperature. In some reservoirs where the temperature is above 266/degrees/F(130/degrees/C), gas-condensate is enriched in isotopically heavy sulfur, apparently derived from thermochemical reduction of Jurassic evaporite sulfate. This process also resulted in increase H/sub 2/S and CO in the gas, and depletion of saturated hydrocarbons in the condensate liquids.

  6. Carbon dioxide and helium emissions from a reservoir of magmatic gas beneath Mammoth Mountain, California

    USGS Publications Warehouse

    Sorey, M.L.; Evans, William C.; Kennedy, B.M.; Farrar, C.D.; Hainsworth, L.J.; Hausback, B.

    1998-01-01

    Carbon dioxide and helium with isotopic compositions indicative of a magmatic source (??13C = -4.5 to -5???, 3He/4He = 4.5 to 6.7 RA) are discharging at anomalous rates from Mammoth Mountain, on the southwestern rim of the Long Valley caldera in eastern California. The gas is released mainly as diffuse emissions from normal-temperature soils, but some gas issues from steam vents or leaves the mountain dissolved in cold groundwater. The rate of gas discharge increased significantly in 1989 following a 6-month period of persistent earthquake swarms and associated strain and ground deformation that has been attributed to dike emplacement beneath the mountain. An increase in the magmatic component of helium discharging in a steam vent on the north side of Mammoth Mountain, which also began in 1989, has persisted until the present time. Anomalous CO2 discharge from soils first occurred during the winter of 1990 and was followed by observations of several areas of tree kill and/or heavier than normal needlecast the following summer. Subsequent measurements have confirmed that the tree kills are associated with CO2 concentrations of 30-90% in soil gas and gas flow rates of up to 31,000 g m-2 d-1 at the soil surface. Each of the tree-kill areas and one area of CO2 discharge above tree line occurs in close proximity to one or more normal faults, which may provide conduits for gas flow from depth. We estimate that the total diffuse CO2 flux from the mountain is approximately 520 t/d, and that 30-50 t/d of CO2 are dissolved in cold groundwater flowing off the flanks of the mountain. Isotopic and chemical analyses of soil and fumarolic gas demonstrate a remarkable homogeneity in composition, suggesting that the CO2 and associated helium and excess nitrogen may be derived from a common gas reservoir whose source is associated with some combination of magmatic degassing and thermal metamorphism of metasedimentary rocks. Furthermore, N2/Ar ratios and nitrogen isotopic values

  7. Modeling and optimizing the design of matrix treatments in carbonate reservoirs with self-diverting acid systems

    NASA Astrophysics Data System (ADS)

    Bulgakova, G. T.; Kharisov, R. Ya; Sharifullin, A. R.; Pestrikov, A. V.

    2015-01-01

    Application of a self-diverting-acid based on viscoelastic surfactant (SDVA) is a promising technology for improving the efficacy of acid treatment in oil and gas-bearing carbonate reservoirs. In this study, we present a mathematical model for assessing SDVA flow and reaction with carbonate rock using the SDVA rheological characteristics. The model calculates the technological parameters for acidizing operations and the prediction of well productivity after acid treatment, in addition to technical and economic optimization of the acidizing process by modeling different acid treatment options with varying volumes, injection rates, process fluids stages and initial economic scenarios.

  8. Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs to an Unconfined Oxidizing Carbonate Aquifer

    SciTech Connect

    Wang, Guohui; Qafoku, Nikolla; Lawter, Amanda R.; Bowden, Mark E.; Harvey, Omar; Sullivan, E. C.; Brown, Christopher F.

    2015-07-15

    A series of batch and column experiments combined with solid phase characterization studies (i.e., quantitative x-ray diffraction and wet chemical extractions) were conducted to address a variety of scientific issues and evaluate the impacts of the potential leakage of carbon dioxide (CO2) from deep subsurface storage reservoirs. The main objective was to gain an understanding of how CO2 gas influences: 1) the aqueous phase pH; and 2) mobilization of major, minor, and trace elements from minerals present in an aquifer overlying potential CO2 sequestration subsurface repositories. Rocks and slightly weathered rocks representative of an unconfined, oxidizing carbonate aquifer within the continental US, i.e., the Edwards aquifer in Texas, were used in these studies. These materials were exposed to a CO2 gas stream or were leached with a CO2-saturated influent solution to simulate different CO2 gas leakage scenarios, and changes in aqueous phase pH and chemical composition were measured in the liquid samples collected at pre-determined experimental times (batch experiments) or continuously (column experiments). The results from the strong acid extraction tests confirmed that in addition to the usual elements present in most soils, rocks, and sediments, the Edward aquifer samples contain As, Cd, Pb, Cu, and occasionally Zn, which may potentially be mobilized from the solid to the aqueous phase during or after exposure to CO2. The results from the batch and column experiments confirmed the release of major chemical elements into the contacting aqueous phase (such as Ca, Mg, Ba, Sr, Si, Na, and K); the mobilization and possible rapid immobilization of minor elements (such as Fe, Al, and Mn), which are able to form highly reactive secondary phases; and sporadic mobilization of only low concentrations of trace elements (such as As, Cd, Pb, Cu, Zn, Mo, etc.). The results from this experimental research effort will help in developing a systematic understanding of how CO2

  9. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1996-12-31

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  10. Characterization of nanometer-scale porosity in reservoir carbonate rock by focused ion beam-scanning electron microscopy.

    PubMed

    Bera, Bijoyendra; Gunda, Naga Siva Kumar; Mitra, Sushanta K; Vick, Douglas

    2012-02-01

    Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam-scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50-300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2-5 μm) that were observed to further link with bulk pores outside the matrix. PMID:22214656

  11. Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs

    SciTech Connect

    William A. Goddard; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu

    2007-09-30

    This report summarizes work during the 30 month time period of this project. This was planned originally for 3-years duration, but due to its financial limitations, DOE halted funding after 2 years. The California Institute of Technology continued working on this project for an additional 6 months based on a no-cost extension granted by DOE. The objective of this project is to improve the performance of aqueous phase formulations that are designed to increase oil recovery from fractured, oil-wet carbonate reservoir rock. This process works by increasing the rate and extent of aqueous phase imbibition into the matrix blocks in the reservoir and thereby displacing crude oil normally not recovered in a conventional waterflood operation. The project had three major components: (1) developing methods for the rapid screening of surfactant formulations towards identifying candidates suitable for more detailed evaluation, (2) more fundamental studies to relate the chemical structure of acid components of an oil and surfactants in aqueous solution as relates to their tendency to wet a carbonate surface by oil or water, and (3) a more applied study where aqueous solutions of different commercial surfactants are examined for their ability to recover a West Texas crude oil from a limestone core via an imbibition process. The first item, regarding rapid screening methods for suitable surfactants has been summarized as a Topical Report. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the surface of these chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite

  12. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Reply

    SciTech Connect

    Kerans, C. )

    1990-07-01

    A reply to a comment made on Kerans' paper (AAGP Bull. 1988) by S.J. Mazzullo is presented. The author takes exception that Mazzullo's contention that he left out important types of hydrocarbon reservoirs in the Permian basin of west Texas and points out that his original intention was to model karst-controlled reservoir rocks only.

  13. Co-assessment of biomass and soil organic carbon stocks in a future reservoir area located in Southeast Asia.

    PubMed

    Descloux, Stéphane; Chanudet, Vincent; Poilvé, Hervé; Grégoire, Alain

    2011-02-01

    An assessment of the organic carbon stock present in living or dead vegetation and in the soil on the 450 km2 of the future Nam Theun 2 hydroelectric reservoir in Lao People's Democratic Republic was made. Nine land cover types were defined on the studied area: dense, medium, light, degraded, and riparian forests; agricultural soil; swamps; water; and others (roads, construction sites, and so on). Their geographical distribution was assessed by remote sensing using two 2008 SPOT 5 images. The area is mainly covered by dense and light forests (59%), while agricultural soil and swamps account for 11% and 2%, respectively. For each of these cover types, except water, organic carbon density was measured in the five pools defined by the Intergovernmental Panel on Climate Change: aboveground biomass, litter, deadwood, belowground biomass, and soil organic carbon. The area-weighted mean carbon densities for these pools were estimated at 45.4, 2.0, 2.2, 3.4, and 62.2 tC/ha, respectively, i.e., a total of about 115±15 tC/ha for a soil thickness of 30 cm, corresponding to a total flooded organic carbon stock of 5.1±0.7 MtC. This value is much lower than the carbon density for some South American reservoirs for example where total organic carbon stocks range from 251 to 326 tC/ha. It can be mainly explained by (1) the higher biomass density of South American tropical primary rainforest than of forests in this study and (2) the high proportion of areas with low carbon density, such as agricultural or slash-and-burn zones, in the studied area. PMID:20364314

  14. Subtask 1.17 - Measurement of Hydrocarbon Evolution from Coal and Petroleum Reservoirs Under Carbon Dioxide Floods

    SciTech Connect

    Steven B. Hawthorne

    2006-12-31

    The project developed, built, and tested three apparatuses for studying different interactions of carbon dioxide with geologic materials. In Year 1, an online instrument was constructed by coupling a high-pressure carbon dioxide extraction system with a flame ionization detector that can yield a real-time profile and quantitative measurements of hydrocarbons removed from materials such as coal and petroleum reservoir rock. In Years 2 and 3, one instrument was built to measure the excess sorption of carbon dioxide in geologic materials such as coal and showed that measurable uptake of carbon dioxide into the coal matrix is rapid. The final apparatus was built to expose geologic materials to carbon dioxide for long periods of time (weeks to months) under the range of pressures and temperatures relevant to carbon dioxide sequestration. The apparatus allows as many as twenty gram-sized samples of geologic materials to be exposed simultaneously and can also include exposures with geologic brines. The system was used to demonstrate complete conversion of magnesium silicate to magnesium carbonate in less than 4 weeks when exposed to clean water or brine, compared to no measurable conversion of dry magnesium carbonate.

  15. Atmospheric transport simulations in support of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE)

    NASA Astrophysics Data System (ADS)

    Henderson, J. M.; Eluszkiewicz, J.; Mountain, M. E.; Nehrkorn, T.; Chang, R. Y.-W.; Karion, A.; Miller, J. B.; Sweeney, C.; Steiner, N.; Wofsy, S. C.; Miller, C. E.

    2015-04-01

    This paper describes the atmospheric modeling that underlies the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) science analysis, including its meteorological and atmospheric transport components (polar variant of the Weather Research and Forecasting (WRF) and Stochastic Time Inverted Lagrangian Transport (STILT) models), and provides WRF validation for May-October 2012 and March-November 2013 - the first 2 years of the aircraft field campaign. A triply nested computational domain for WRF was chosen so that the innermost domain with 3.3 km grid spacing encompasses the entire mainland of Alaska and enables the substantial orography of the state to be represented by the underlying high-resolution topographic input field. Summary statistics of the WRF model performance on the 3.3 km grid indicate good overall agreement with quality-controlled surface and radiosonde observations. Two-meter temperatures are generally too cold by approximately 1.4 K in 2012 and 1.1 K in 2013, while 2 m dewpoint temperatures are too low (dry) by 0.2 K in 2012 and too high (moist) by 0.6 K in 2013. Wind speeds are biased too low by 0.2 m s-1 in 2012 and 0.3 m s-1 in 2013. Model representation of upper level variables is very good. These measures are comparable to model performance metrics of similar model configurations found in the literature. The high quality of these fine-resolution WRF meteorological fields inspires confidence in their use to drive STILT for the purpose of computing surface influences ("footprints") at commensurably increased resolution. Indeed, footprints generated on a 0.1° grid show increased spatial detail compared with those on the more common 0.5° grid, better allowing for convolution with flux models for carbon dioxide and methane across the heterogeneous Alaskan landscape. Ozone deposition rates computed using STILT footprints indicate good agreement with observations and exhibit realistic seasonal variability, further indicating that WRF

  16. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2002-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 2 of the project has been reservoir characterization, 3-D modeling and technology transfer. This effort has included six tasks: (1) the study of rockfluid interactions, (2) petrophysical and engineering characterization, (3) data integration, (4) 3-D geologic modeling, (5) 3-D reservoir simulation and (6) technology transfer. This work was scheduled for completion in Year 2. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions is near completion. Observations regarding the diagenetic processes influencing pore system development and

  17. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2001-09-14

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been

  18. Improved oil recovery in Mississippian carbonate reservoirs of Kansas near term Class 2. Annual report, September 18, 1994--March 15, 1997

    SciTech Connect

    Carr, T.R.; Green, D.W.; Willhite, G.P.

    1998-04-01

    This annual report describes progress during the second year of the project entitled {open_quotes}Improved Oil Recovery in Mississippian Carbonate Reservoirs in Kansas{close_quotes}. This project funded under the Department of Energy`s Class 2 program targets improving the reservoir performance of mature oil fields located in shallow shelf carbonate reservoirs. The focus of this project is development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and the mid-continent. As part of the project, several tools and techniques for reservoir description and management were developed, modified and demonstrated. These include: (1) a new approach to subsurface visualization using electric logs ({open_quotes}Pseudoseismic{open_quotes}); (2) a low-cost easy-to-use spreadsheet log analysis software (PfEFFER); and (3) an extension of the BOAST-3 computer program for full field reservoir simulation. The world-wide-web was used to provide rapid and flexible dissemination of the project results through the Internet. Included in this report is a summary of significant project results at the demonstration site (Schaben Field, Ness County, Kansas). These results include an outline of the reservoir description based on available and newly acquired data and reservoir simulation results. Detailed information is available on-line through the Internet. Based on the reservoir simulation, three infill wells will be drilled to validate the reservoir description and demonstrate the effectiveness of the proposed reservoir management strategies. The demonstration phase of the project has just begun and will be presented in the next annual report.

  19. Long eccentricity cycle in Pliocene oceanic carbon reservoir: A comparison between the Mediterranean and the South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Jianru; Wang, Pinxian

    2015-12-01

    As quantitative paleoclimate time series extend deeper into the geological past, growing evidence indicates the extensive occurrence of the 400-kyr long eccentricity cycle in geological records. The long cycles are best manifested in the marine carbon isotope as a series of δ13Cmax, which correspond to the long eccentricity's minima; however, it remains unclear how eccentricity affects the oceanic carbon reservoir. To determine what processes are involved in generating the 400-kyr cycles, one long eccentricity cycle in the Late Pliocene from 3.2 Myr to 2.8 Myr was examined in two sections, respectively, from the Mediterranean and the South China Sea. The results indicate that the Mediterranean section displays distinct precession cycles in all of the studied proxy time series, and their amplitudes are modulated by eccentricity, whereas the precession cycles and the eccentricity modulation are much weaker in the proxy sequences from the South China Sea. The difference is attributed to the fact that African monsoon was overwhelmingly dominated by precessional forcing, and the Mediterranean basin was isolated from glacial-induced reorganizations of the global ocean, whereas totally different conditions existed in the South China Sea. It may be inferred from the comparison that the δ13Cmax originated largely from the global ocean and was unlikely caused by local basin factors. At the long-eccentricity maximum, summer insolation reached a maximum at low latitudes, and the intensified global monsoon changed the ocean carbon reservoir and the δ13C value. Because of the long residence time of carbon in the ocean, δ13C changes in the global oceanic reservoir primarily occur on a 105-yr time scale with a smoothing effect in the lower frequencies. The 400-kyr long eccentricity was pervasive at least in the Cenozoic Ocean, but its expression was subject to spatio-temporal variations, particularly under the influence of the ice-sheet development.

  20. Ranking of Texas reservoirs for application of carbon dioxide miscible displacement

    SciTech Connect

    Ham, J

    1996-04-01

    Of the 431 reservoirs screened, 211 projected revenue that exceeded cost, ie, were profitable. Only the top 154 reservoirs, however, showed a profit greater than 30%. The top 10 reservoirs predicted a profit of at least 80%. Six of the top ten were Gulf Coast sandstones. The reservoirs are representative of the most productive discoveries in Texas; they account for about 72% of the recorded 52 billion barrels oil production in the State. Preliminary evaluation in this study implied that potential production from CO{sub 2}-EOR could be as much as 4 billion barrels. In order to enhance the chances of achieving this, DOE should consider a targeted outreach program to the specific independent operators controlling the leases. Development of ownership/technical potential maps and an outreach program should be initiated to aid this identification.

  1. Carbonate-platform scale correlation of stacked high-frequency sequences in the Arab-D reservoir, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Al-Awwad, Saad F.; Collins, Lindsay B.

    2013-08-01

    The Late Jurassic Arab Formation contains a number of hydrocarbon-bearing carbonates, the most important of which is the lowermost Arab-D reservoir. The reservoir lithofacies in Khurais Field are: couplets of 1) lime mud and 2) intraclastic lithofacies representing basinal turbidites; 3) pelletal lithofacies representing lower shoreface sands and silts; 4) stromatoporoid lithofacies representing a reef; 5) Cladocoropsis and 6) dasyclad lithofacies representing a lagoon; 7) peloidal and 8) oolitic lithofacies representing shore-attached sand sheets; 9) cryptomicrobial lithofacies representing supratidal flats; 10) anhydrites representing sabkha followed by salina deposits; and 11) stratigraphically reoccurring dolomite. These are arranged in two, partially preserved, third-order sequences, the upper of which represents the Arab-D Member and the lower of which represents the upper Jubaila Formation. Within these sequences lie six fourth-order high frequency sequences, composed of fifth-order parasequences and parasequence-scale cycles. The preserved upward shallowing trend of the Arab-D reservoir is manifested laterally by a regional eastward thickening interpreted to be the result of an eastward progradation across the shallow Late Jurassic epeiric shelf and into the relatively deep Arabian intrashelf basin. This study presents a correlation model that explains the drastic thickening and downward climb of the reservoir lithofacies that is observed between the outcrops south of Riyadh and the subsurface in Ghawar Field. This model is different from the one currently used and predicts an eastward porosity improvement in the upper part of the reservoir accompanied by a porosity reduction in the lower part, assuming a null diagenetic modification effect.

  2. Carbon dioxide and helium emissions from a reservoir of magmatic gas beneath Mammoth Mountain, California

    SciTech Connect

    Sorey, M.L.; Evans, W.C. Kennedy, B.M. Farrar, C.D. Hainsworth, L.J. Hausback, B.

    1998-07-01

    Carbon dioxide and helium with isotopic compositions indicative of a magmatic source ({delta}thinsp{sup 13}C={minus}4.5 to {minus}5{per_thousand}, {sup 3}He/{sup 4}He=4.5 to 6.7 R{sub A}) are discharging at anomalous rates from Mammoth Mountain, on the southwestern rim of the Long Valley caldera in eastern California. The gas is released mainly as diffuse emissions from normal-temperature soils, but some gas issues from steam vents or leaves the mountain dissolved in cold groundwater. The rate of gas discharge increased significantly in 1989 following a 6-month period of persistent earthquake swarms and associated strain and ground deformation that has been attributed to dike emplacement beneath the mountain. An increase in the magmatic component of helium discharging in a steam vent on the north side of Mammoth Mountain, which also began in 1989, has persisted until the present time. Anomalous CO{sub 2} discharge from soils first occurred during the winter of 1990 and was followed by observations of several areas of tree kill and/or heavier than normal needlecast the following summer. Subsequent measurements have confirmed that the tree kills arc associated with CO{sub 2} concentrations of 30{endash}90{percent} in soil gas and gas flow rates of up to 31,000 gthinspm{sup {minus}2}thinspd{sup {minus}1} at the soil surface. Each of the tree-kill areas and one area of CO{sub 2} discharge above tree line occurs in close proximity to one or more normal faults, which may provide conduits for gas flow from depth. We estimate that the total diffuse CO{sub 2} flux from the mountain is approximately 520 t/d, and that 30{endash}50 t/d of CO{sub 2} are dissolved in cold groundwater flowing off the flanks of the mountain. Isotopic and chemical analyses of soil and fumarolic gas demonstrate a remarkable homogeneity in composition, suggesting that the CO{sub 2} and associated helium and excess nitrogen may be derived from a common gas reservoir whose source is associated with

  3. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    SciTech Connect

    Stephen C. Ruppel

    2004-07-20

    Our analysis and imaging of reservoir properties at the Fullerton Clear Fork field (Figure 1) is in its final stages. Major accomplishments during the past 6 months include: (1) characterization of facies and cyclicity in cores, (2) correlation of cycles and sequences using core-calibrated wireline logs, (3) calculation and modeling of wireline porosity, (4) analysis of new cores for conventional and special core analysis data, (5) construction of full-field reservoir model, and (6) revision of 3D seismic inversion of reservoir porosity and permeability. One activity has been eliminated from the originally proposed tasks. Task 3 (Characterization and Modeling of Rock Mechanics and Fractures) has been deleted because we have determined that fractures are not significant contributing in the reservoir under study. A second project extension has been asked for to extend the project until 7/31/04. Remaining project activities are: (1) interpretation and synthesis of fieldwide data, (2) preparation of 3D virtual reality demonstrations of reservoir model and attributes, (3) transfer of working data sets to the operator for reservoir implementation and decision-making, and (4) preparation and distribution of final reports.

  4. Carbon Solubility in Core Melts in Shallow Magma Ocean Environment and its bearing on Distribution of Carbon between Deep Earth Reservoirs

    NASA Astrophysics Data System (ADS)

    Dasgupta, R.; Walker, D.

    2007-12-01

    pressure, this may indicate the presence of a hidden carbon- rich mantle reservoir untapped by oceanic volcanism. For the entire range of possible bulk Earth carbon content from chondritic to subchondritic and for the mantle carbon content of 50-1000 ppm, DC of 10-4- 100 are derived. But for 1000 ppm bulk Earth carbon, DC is 10-2-100. Using the complete range of possible DC for a magma ocean at ~2200 °C, we predict maximum carbon content of the Earth's core to be 6-7 wt.% and a preferred value of 0.25 ± 0.15 wt.% carbon for a bulk Earth carbon concentration of 1000 ppm. Based on our estimate, the core is likely one of the most enriched terrestrial reservoirs of carbon with concentration as high as 0.4 wt.%, which likely is at least an order of magnitude higher than that of the average mantle. The higher carbon content of OIBs compared to MORBs thus may derive in part from core contributions to mantle plumes.[1] Dasgupta, R. and Hirschmann, M.M. 2006, Nature 440, 659- 662. [2] Wood, B.J. 1993, Earth Planet Sci Lett 117, 593-607.

  5. Carbonate reservoir characterization using seismic velocity and amplitude variation with offset analysis: Hardeman basin, Texas, test case

    SciTech Connect

    Pigott, J.D.; Shrestha, R.K. ); Warwick, R.A. )

    1991-03-01

    Mississippian bioherms in the Hardeman basin, Texas, produce from dolomitized mud cores with porosities that can vary from 10 to 40%. These carbonate buildups, though often similar in seismic reflector boundary configuration, can vary remarkably in reservoir quality (e.g., porosity) owing to diagenesis. However, imaging these lateral variations of porosity and determining the reservoir pressure is possible with detailed seismic velocity control and amplitude variation with offset (AVO) analysis. The investigated 24-fold seismic profile was acquired by four Vibroseis trucks in the Hardeman basin across two bioherms, one oil-productive and other tight and water-filled. Detailed stacking velocity analyses on the relative amplitude processed line directly delineate areas of increasing and decreasing gross porosity and dramatically differentiate the two mounds. Moreover, the detailed velocity analyses help provide a more accurate stacked section with resultant better definition of the external mound configuration. Analysis of available laboratory compressional and shear wave velocity data for carbonate rocks reveal that Young's modulus in carbonates is a function of porosity and differential pressure. Comparison of the derived Young's modulus from an inversion of the AVO data for the unstacked line with the experimental laboratory data yield porosity and differential pressure estimates over the productive bioherm which are within 18% and 15%, respectively, of those observed in the borehole.

  6. Magnitude and Significance of Carbon Burial in Lakes, Reservoirs, and Northern Peatlands

    USGS Publications Warehouse

    U.S. Geological Survey

    1999-01-01

    It is estimated that freshwater lakes in the world have a total area of about 1.5x1012 m2 (Shiklomanov, 1993; table 1). Including saline inland seas in this total would add another 1x1012 m2. The 28 largest (area of each > 5,000 km2) freshwater lakes in the world have a total area of 1.18x1012 m2 or about 79 percent of the total area of all freshwater lakes. If the 28 large lakes bury organic carbon (OC), on average, at the same rate as Lake Michigan (5 g/m2/yr), then the annual rate of OC burial in these 28 lakes is about 6 Tg/yr (6 terragrams per year or 6x1012 g/yr; table 1). If the smaller lakes bury OC, on average, at the same rate as an average Minnesota lake (72 g/m2/yr), then the annual rate of OC accumulation in these smaller lakes is about 23 Tg/yr (23x1012 g/yr; table 1). If saline inland seas bury OC at the Lake Michigan rate, this would be an additional 5 Tg/yr, for a total of 34 Tg/yr for all freshwater lakes and saline inland seas (table 1). Mulholland and Elwood (1982) estimated the OC burial in all lakes and inland seas (excluding the Black Sea) to be 60 Tg/yr today (table 1) and an average of 20 Tg/yr for the last 10,000 years. Stallard (1998) modeled terrestrial sedimentation as a series of 864 scenarios. For lake area, he used 1.54x1012 m2, the area of the 250 largest lakes in the world. This is close to the total of large and small lakes given in table 1. Again, including inland seas to this total would add an additional 1x1012 m2. Results of scenarios for lakes and reservoirs were divided into two components, those with clastic sediments and those with organic sediments. The results of OC burial in the most likely of Stallard's scenarios for lakes range from 48 to 72 Tg/yr (table 1), the average of which is close to the 60 Tg/yr estimated by Mulholland and Elwood (1982). We will use an average of 54 Tg/yr (table 1). The closeness of these estimates, calculated by different methods, suggests that this value is not in error by more than a factor

  7. Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    1997-08-01

    The objective is to utilize reservoir characteristics and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. Also the project seeks to demonstrate the performance and economic viability of the project in the field.

  8. Integration of Well & Core Data of Carbonate Reservoirs with Surface Seismic in Garraf Oil Field, Southern Iraq

    NASA Astrophysics Data System (ADS)

    Mhuder, J. J.; Muhlhl, A. A.; Basra Geologiests

    2013-05-01

    The Garraf Field is situated in Southern Iraq in Nasiriya area, is located in Mesopotamian basin. The carbonate facies are dominant in main reservoirs in Garraf field (Mishrif and Yammama Formations) which is Cretaceous in age. The structure of the reservoir in this field are low relief gentle anticlinal structure aligned in NW to SE direction, and No fault were observed and interpreted in 3D seismic section. 3D seismic survey by Iraqi Oil Exploration Company No 2 was successfully conducted on the Garraf field at 2008-2009 using recording system SERCEL 408UL and Vibrators Nomad 65. Bin size: 25*25, Fold: 36, SP Interval: 50m, Lines Interval: 300m, 3 wells were drilled Ga (1, 2, 3) and it used for seismic to well tie in Petrel. Data analysis was conducted for each reservoirs for Lithological and sedimentological studies were based on core and well data .The study showed That the Mishrif Formation deposited in a broad carbonate platform with shallowing upward regressive succession and The depositional environment is extending from outer marine to shallow middle-inner shelf settings with restricted lagoons as supported by the present of Miliolid fossils. The fragmented rudist biostromes accumulated in the middle shelf. No rudist reef is presence in the studied cores. While the Major sequences are micritic limestone of lagoonal and oolitic/peloidal grainstone sandy shoal separated by mudstone of Yamama formation. Sedimentation feature are seen on seismic attributes and it is help for understanding of sedimentation environment and suitable structure interpretation. There is good relationship between Acustic Impedance and porosity, Acustic Impedance reflects porosity or facies change of carbonate rather than fluid content. Data input used for 3D Modeling include 3D seismic and AI data, petrophysical analysis, core and thin section description. 3D structure modeling were created base on the geophysical data interpretation and Al analysis. Data analysis for Al data were

  9. [Effects of biological regulated measures on active organic carbon and erosion-resistance in the Three Gorges Reservoir region soil].

    PubMed

    Huang, Ru; Huang, Lin; He, Bing-Hui; Zhou, Li-Jiang; Yu, Chuan; Wang, Feng

    2013-07-01

    To gain a better knowledge of characteristics of soils and provide a scientific basis for soil erosion control in the Three Gorges Reservoir Area, contents of aggregates and total soil organic carbon (SOC), as well as soil active organic carbon fractions including particulate organic carbon (POC), readily oxidized organic carbon (ROC), dissolved organic carbon (DOC), microbial biomass carbon (MBC) in the 0-30 cm soil layer under seven different biological regulated measures were studied by the field investigation combined with the laboratory analysis. Results showed that the content of the SOC and active organic carbon fractions decreased with the increasing soil depth; the content of the SOC and active organic carbon fractions in 0-10 cm was significantly higher than that in 20-30 cm. The stability of soil aggregates were also significantly influenced by biological regulated measures, the content of > 0.25 mm water-stable aggregates in seven types of biological regulated measures was in the order of Koelreuteria bipinnata + Cassia suffruticasa > hedgerows > closed forest > natural restoration > economic forest > traditional planting > control plot, moreover, the content of 0.25 mm water-stable aggregates correlated positively with the content of SOC. Soils under different biological regulated measures all demonstrated fractal features, and soil under the measure of Koelreuteria bipinnata + Cassia suffruticasa was found to have the lowest value of fractal dimension and soil erodiable K, indicating a relatively strong structure stability and erosion-resistant capacity. Negative correlation was observed when compared the content of active organic carbon fractions with the soil erodiable K. It can be concluded that properties of soil can be managed through biological regulated measures; thence had an influence on the soil erosion-resistant capacity. PMID:24028016

  10. Integrated sequence stratigraphic concepts and carbonate depositional models as a predictive tool for reservoir heterogeneity: Alabama Ferry Field (Albian), Texas

    SciTech Connect

    Kupecz, J.A.; Tompson, P.

    1995-08-01

    Alabama Ferry Field, Leon County, Texas, produces oil and gas from carbonate grainstones of the Albian Glen Rose {open_quotes}D{close_quotes} interval. The field extends over approximately 40,000 acres, and has estimated reserves of 100 million barrels of oil and 250 bcf of gas. It is notable for its shelf-interior position, approximately 40 km (25 miles) NW of the Glen Rose shelf edge. The field is representative of those producing from thin, areally restricted grainstones which accumulated on a low-relief carbonate shelf. The reservoir is interpreted to represent highstand systems tract deposits, which consist of a series of stacked grainstones bounded by deeper marine shales. The productive grainstones are directly beneath a regional, seismic-scale sequence boundary. Reservoir compartmentalization is the result of internal, facies- and diagenetically-controlled heterogeneity within the grainstones, as well as from shales and carbonate mudstones that act as inter-shoal permeability barriers. Facies within the grainstones are variably affected by marine and meteoric diagenesis. Controls on diagenesis include mineralogy of allochems, energy of depositional setting, grain packing, presence/absence of off-shoal algal coating, and degree of early cementation. Micropaleontological analysis of shales and carbonate mudstones reveal two depositional styles within the field. The first represents lateral facies change coeval to grainstone buildups, which suggest permeability barriers with limited lateral extent. In contrast, the second style represents deposition during marine flooding; these barriers are interpreted to have laterally extensive distribution. Therefore, the integration of carbonate depositional systems, micropaleontology, diagenesis, and sequence stratigraphy has implications for the ultimate development of this and similar fields.

  11. Improved oil recovery in Mississippian carbonate reservoirs of Kansas: Near term, Class 2. [Annual report], September 18, 1994--October 1, 1995. Draft.

    SciTech Connect

    Carr, T.R.; Green, D.W.; Willhite, G.P.

    1996-01-01

    This report represents a summary of the progress during the first year of Budget period 1 of the near term Class 2 project entitled ``Improved Oil Recovery in Mississippian Carbonate Reservoirs of Kansas``. Two examples of advanced technologies developed as part of this project are highlighted along with the use of the Internet to transfer these technologies. The two advanced technologies are a spread-sheet petrophysical analysis and reservoir evaluation (PfEFFER), and a petrophysical/seismic approach to well logs (pseudoseismic). Work continues on multi-disciplinary reservoir characterization at the demonstration site. The potential for incremental primary recovery is being evaluated using the improved reservoir characterization to target infill drilling and evaluate the potential of a horizontal well. The impact of successful incremental primary recovery from sub-Pennsylvanian unconformity Mississippian reservoirs such as are present at the Schaben demonstration site would be significant for Kansas and the US.

  12. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-19

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  13. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  14. Keys to evaluating {open_quotes}paleokarst{close_quotes} reservoirs - guidelines from Quaternary carbonates and enhanced petrography

    SciTech Connect

    Dravis, J.J.

    1996-12-31

    Paleokarst is often invoked to explain reservoir development in ancient brecciated carbonates. However, the paleokarst model is valid only when fabrics seen in Quaternary cave systems are present and petrography of the non-brecciated zones supports subaerial exposure. Quaternary caves typically exhibit early fractures, microscopic to cavernous secondary porosity, solution collapse and brecciation, cave cements, and reddish-brown cave fill. Inter-cavern rocks show fabric-selective dissolution, porosity inversion, precompaction cements, and capping laminated soil crusts. In brecciated Ellenburger and Upper Elk Point (Devonian, W. Canada) reservoirs, major discrepancies exist between what the paleokarst model predicts and what is actually observed. Reddish calcretes, cavernous porosity and cave cements are absent. Enhanced petrography reveals relict sutured grains, implying burial dolomitization. These same dolomites are brecciated and breccia clasts contain stylolites rotated at different angles to each other and the horizon, implying burial brecciation. Fractures cutting these burial dolomites and stylolites are burial in origin. Preserved secondary porosity is unrelated to brecciated zones and facies controlled. Therefore, brecciation and reservoir quality in both sequences were created by burial dissolution of replacement dolomites and not by subaerial karstification. Brecciation alone does not prove the unconformity-related paleokarst model or the timing of porosity development.

  15. Keys to evaluating [open quotes]paleokarst[close quotes] reservoirs - guidelines from Quaternary carbonates and enhanced petrography

    SciTech Connect

    Dravis, J.J. )

    1996-01-01

    Paleokarst is often invoked to explain reservoir development in ancient brecciated carbonates. However, the paleokarst model is valid only when fabrics seen in Quaternary cave systems are present and petrography of the non-brecciated zones supports subaerial exposure. Quaternary caves typically exhibit early fractures, microscopic to cavernous secondary porosity, solution collapse and brecciation, cave cements, and reddish-brown cave fill. Inter-cavern rocks show fabric-selective dissolution, porosity inversion, precompaction cements, and capping laminated soil crusts. In brecciated Ellenburger and Upper Elk Point (Devonian, W. Canada) reservoirs, major discrepancies exist between what the paleokarst model predicts and what is actually observed. Reddish calcretes, cavernous porosity and cave cements are absent. Enhanced petrography reveals relict sutured grains, implying burial dolomitization. These same dolomites are brecciated and breccia clasts contain stylolites rotated at different angles to each other and the horizon, implying burial brecciation. Fractures cutting these burial dolomites and stylolites are burial in origin. Preserved secondary porosity is unrelated to brecciated zones and facies controlled. Therefore, brecciation and reservoir quality in both sequences were created by burial dissolution of replacement dolomites and not by subaerial karstification. Brecciation alone does not prove the unconformity-related paleokarst model or the timing of porosity development.

  16. 3-D seismic evidence of the effects of carbonate karst collapse on overlying clastic stratigraphy and reservoir compartmentalization

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Simmons, J.L. Jr.; Jons, R.A.; Lancaster, D.E.; Elphick, R.Y.; Pendleton, V.M.

    1996-09-01

    A multidisciplinary team, composed of stratigraphers, petrophysicists, reservoir engineers, and geophysicists, studied a portion of Boonsville gas field in the Fort Worth Basin of north-central Texas to determine how modern techniques can be combined to understand the mechanisms by which fluvio-deltaic depositional processes create reservoir compartmentalization in a low- to moderate-accommodation basin. An extensive database involving well logs, cores, production, and pressure data from more than 200 wells, 26 mi{sup 2} of 3-D seismic data, vertical seismic profiles, and checkshots was assembled to support this investigation. The authors found the most important geologic influence on stratigraphy and reservoir compartmentalization in this basin to be the existence of numerous karst collapse chimneys over the area covered. These near-vertical karst collapses originated in, or near, the deep Ordovician-age Ellenburger carbonate section and created vertical chimneys extending as high as 2,500 ft above their point of origin, causing significant disruptions in the overlying clastic strata.

  17. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    SciTech Connect

    Stephen C. Ruppel

    2003-07-01

    Excellent progress continues to be made on most objectives and goals. Primary focus during the past 6 months has been (1) simulation of reservoir performance using the reservoir model constructed for the Phase 1 study area, (2) extension of core and log characterization activities to the Phase 2 study area, (3) development of an initial velocity-based inversion model from the 3-D seismic volume for porosity characterization, (4) continuation of quality-control analysis of wireline logs. Preliminary results of the study were presented at a technology-transfer workshop in May 2003 in Midland/Odessa Texas.

  18. Dry Stream Reaches in Carbonate Terranes: Surface Indicators of Ground-Water Reservoirs

    USGS Publications Warehouse

    Brahana, J.V.; Hollyday, E.F.

    1988-01-01

    In areas where dry stream reaches occur, subsurface drainage successfully competes with surface drainage, and sheet-like dissolution openings have developed parallel to bedding creating the ground-water reservoir. Union Hollow in south-central Tennessee is the setting for a case study that illustrates the application of the dry stream reach technique. In this technique, dry stream reach identification is based on two types of readily acquired information: remotely sensed black and white infrared aerial photography; and surface reconnaissance of stream channel characteristics. Test drilling in Union Hollow subsequent to identification of the dry reach proved that a localized ground-water reservoir was present.

  19. Impact of a large tropical reservoir on riverine transport of sediment, carbon, and nutrients to downstream wetlands

    NASA Astrophysics Data System (ADS)

    Kunz, Manuel J.; Wüest, Alfred; Wehrli, Bernhard; Landert, Jan; Senn, David B.

    2011-12-01

    Large dams can have major ecological and biogeochemical impacts on downstream ecosystems such as wetlands and riparian habitats. We examined sediment removal and carbon (C), nitrogen (N), and phosphorus (P) cycling in Itezhi-Tezhi Reservoir (ITT; area = 364 km2, hydraulic residence time = 0.7 yr), which is located directly upstream of a high ecological value floodplain ecosystem (Kafue Flats) in the Zambezi River Basin. Field investigations (sediment cores, sediment traps, water column samples), mass balance estimates, and a numerical biogeochemical reservoir model were combined to estimate N, P, C, and sediment removal, organic C mineralization, primary production, and N fixation. Since dam completion in 1978, 330 × 103 tons (t) of sediment and 16 × 103, 1.5 × 103, 200 t of C, N, and P, respectively, have accumulated annually in ITT sediments. Approximately 50% of N inputs and 60% of P inputs are removed by the reservoir, illustrating its potential in decreasing nutrients to the downstream Kafue Flats floodplain. The biogeochemical model predicted substantial primary production in ITT (˜280 g C m-2 yr-1), and significant N-fixation (˜30% for the total primary production) was required to support primary production due to marginal inputs of inorganic N. Model simulations indicate that future hydropower development in the reservoir, involving the installation of turbines driven by hypolimnetic water, will likely result in the delivery of low-oxygen waters to downstream ecosystems and increased outputs of dissolved inorganic N and P by a factor of ˜4 and ˜2 compared to current dam management, respectively.

  20. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. 1994 Annual report

    SciTech Connect

    Wehner, S.C.

    1995-05-01

    It is anticipated that this project will show that the application of the CO{sub 2} Huff-n-Puff process in shallow shelf carbonates can be economically implemented to recover appreciable volumes of light oil. The goals of the project are the development of guidelines for cost-effective selection of candidate reservoirs and wells, along with estimating recovery potential. The selected site for the demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Work is nearing completion on the reservoir characterization components of the project. The near-term emphasis is to, (1) provide an accurate distribution of original oil-in-place on a waterflood pattern entity level, (2) evaluate past recovery efficiencies, (3) perform parametric simulations, and (4) forecast performance for a site specific field demonstration of the proposed technology. Macro zonation now exists throughout the study area and cross-sections are available. The Oil-Water Contact has been defined. Laboratory capillary pressure data was used to define the initial water saturations within the pay horizon. The reservoir`s porosity distribution has been enhanced with the assistance of geostatistical software. Three-Dimensional kriging created the spatial distributions of porosity at interwell locations. Artificial intelligence software was utilized to relate core permeability to core porosity, which in turn was applied to the 3-D geostatistical porosity gridding. An Equation-of-State has been developed and refined for upcoming compositional simulation exercises. Options for local grid-refinement in the model are under consideration. These tasks will be completed by mid-1995, prior to initiating the field demonstrations in the second budget period.

  1. Carbon isotope fractionation between Fe-carbide and diamond; a light C isotope reservoir in the deep Earth and Core?

    NASA Astrophysics Data System (ADS)

    Mikhail, S.; Jones, A. P.; Hunt, S. A.; Guillermier, C.; Dobson, D. P.; Tomlinson, E.; Dan, H.; Milledge, H.; Franchi, I.; Wood, I.; Beard, A.; Verchovsky, S.

    2010-12-01

    The largest accessible reservoir for terrestrial carbon is the mantle; however the core may yield even more. Carbon is commonly proposed as the light element (or one of) to make up the observed density deficit in the earth’s metallic core (NAKAJIMA et al., 2009). The potential isotopic effects of carbon incorporation into the core have not yet been investigated. In-situ ion probe (nanoSIMS) mapping and imaging of carbon isotope variations across rare sub-mm-scale Fe-rich carbide inclusions in mantle diamond (from Jagersfontein, South Africa) show the carbide to be significantly depleted in 13C relative to their diamond host. Distinctive textures suggest metallic liquid precipitates similar in geometry to (giant) nitrogen platelets, controlled by the octahedral symmetry of diamond, which we interpret as syngenic formation. The difference in δ13C values between the two natural phases for diamond-Fe carbide, gives an isotopic fractionation factor (ΔC) which agrees well with HPHT multi-anvil experiments (5-9 GPa and >1400°C). Our measured ΔC between Fe-carbide and diamond may only have local significance, but the measured isotopic values represent characterization of the highest PT carbide known (i.e. > minimum depth of the diamond stability field ≈ 150 km). The direction and magnitude of ΔC agrees with observations of the ΔC between cohenite-graphite in iron meteorites (DEINES and WICKMAN, 1975) and both agree with HPHT experiments, thus suggesting that carbon in the deep Earth, and particularly in the core, may be similarly fractionated (i.e. depleted in the 13C). Since metallic liquid drained from the silicate mantle to form the core during the early Earth, we can use our values as a proxy to constrain evolution of deep carbon reservoirs such as the core and bulk silicate Earth. For example, we can test the suggestion of Grady et al (2004) that the upper mantle value of δ13C ≈ -5 ‰ may not be representative of the bulk Earth, since solar system

  2. Investigating Protostellar Carbon Reservoirs with High-Resolution Spectroscopy Toward Massive Young Stellar Objects

    NASA Astrophysics Data System (ADS)

    Smith, R. L.; Blake, G. A.; Boogert, A. C. A.; Pontoppidan, K. M.; Lockwood, A. C.

    2014-09-01

    High-resolution CO spectra toward massive YSOs reveal less dispersion in [12C16O]/[13C16O] gas compared to low-mass YSOs, while these ratios may be similarly affected by CO ice. Our new data suggest that CO2 may not originate from a CO reservoir.

  3. Impact of stylolitization on diagenesis of a Lower Cretaceous carbonate reservoir from a giant oilfield, Abu Dhabi, United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Paganoni, Matteo; Al Harthi, Amena; Morad, Daniel; Morad, Sadoon; Ceriani, Andrea; Mansurbeg, Howri; Al Suwaidi, Aisha; Al-Aasm, Ihsan S.; Ehrenberg, Stephen N.; Sirat, Manhal

    2016-04-01

    Bed-parallel stylolites are a widespread diagenetic feature in Lower Cretaceous limestone reservoirs, Abu Dhabi, United Arab Emirates (UAE). Diagenetic calcite, dolomite, kaolin and small amounts of pyrite, fluorite, anhydrite and sphalerite occur along and in the vicinity of the stylolites. Petrographic observations, negative δ18OVPDB, fluid inclusion microthermometry, and enrichment in 87Sr suggest that these cements have precipitated from hot basinal brines, which migrated along the stylolites and genetically related microfractures (tension gashes). Fluid migration was presumably related to lateral tectonic compression events related to the foreland basin formation. The low solubility of Al3 + in formation waters suggests that kaolin precipitation was linked to derivation of organic acids during organic matter maturation, probably in siliciclastic source rocks. The mass released from stylolitization was presumably re-precipitated as macro- and microcrystalline calcite cement in the host limestones. The flanks of the oilfield (water zone) display more frequent presence and higher amplitude of stylolites, lower porosity and permeability, higher homogenization temperatures and more radiogenic composition of carbonates compared to the crest (oil zone). This indicates that oil emplacement retards diagenesis. This study demonstrates that stylolitization plays a crucial role in fluid flow and diagenesis of carbonate reservoirs during basin evolution.

  4. Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity. [Jurassic Smackover Formation

    SciTech Connect

    Mancini, E.A.

    1990-01-01

    The objective of this project is to augment the National Reservoir Database (TORIS database), to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama, and to identify resources that are producible at moderate cost. This objective will be achieved through detailed geological, geostatistical, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon, and engineering characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the state of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Work to date has focused on completion of Subtasks 1, 2, and 3 of this project. Work on Subtask 4 began in this quarter, and substantial additional work has been accomplished on Subtask 2. Subtask 1 included the survey and tabulation of available reservoir engineering and geological data. Subtask 2 comprises the geologic and engineering characterization of smackover reservoir lithofacies. Subtask 3 includes the geologic modeling of reservoir heterogeneities. Subtask 4 includes the development of reservoir exploitation methodologies for strategic infill drilling. 1 fig.

  5. Carbonate/clay-mineral relationships and the origin of protodolomite in L-2 and L-3 carbonate reservoir rocks of the Bombay high field, India

    NASA Astrophysics Data System (ADS)

    Gundu Rao, C.

    1981-07-01

    This paper consists of two parts. The first deals with carbonate/clay-mineral relationships and the second with the origin of protodolomite in L-2 and L-3 carbonate reservoir rocks of the Bombay High Oil Field, India. Six carbonate/clay-mineral assemblages, viz. (1) calcite-protodolomite-chlorite-kaolinite, (2) calcite-protodolomite-montmorillonite-kaolinite, (3) calcite-montmorillonite-kaolinite, (4) calcite-protodolomite-montmorillonite, (5) calcite-protodolomite-vermiculite, and (6) calcite-montmorillonite-chlorite-kaolinite are recognized among the L-2 and L-3 carbonate reservoir rocks of the offshore Bombay High Oil Field, India. These form disequilibrium assemblages on a Al 2O 3 (kaolinite), CaO (calcite) and MgO (magnesite) facies diagram. Therefore, the clay minerals are terrigenous in origin and have at least contributed the magnesium needed for the formation of protodolomite. The protodolomite seen in L-2 and L-3 rocks is limpid, water-clear, non-zoned, and inclusion-free with an average grain diameter of 7-10 μm and on the X-ray chart shows a consistent (104) peak between 2.93 Å to 2.90 Å ' d' spacing, reading 30-40 mole% MgCO 3 solid solution in calcite. By comparison with other types of dolomite, viz (1) replacement, (2) evaporite, (3) sabkha, and (4) schizohaline, the present protodolomite seems to be of biogenic origin and in all probability appears to be a new form of dolomite to be reported from an ancient subsurface carbonate formation.

  6. Response surfaces for CO2 leakage from geologic storage along abandoned wellbores

    NASA Astrophysics Data System (ADS)

    Jordan, A.; Carey, J. W.; Pawar, R. J.; Stauffer, P. H.

    2011-12-01

    The storage of carbon dioxide (CO2) in geologic reservoirs that have previously been drilled for oil and gas exploration is under investigation worldwide as an option for reducing the amount of anthropogenic carbon introduced to the atmosphere. Reservoirs that have already been tapped for hydrocarbon production have several benefits over development of new sites: they tend to be geologically well-understood, with existing wellbore data to help further characterize the local geologic framework; are known to be conducive to trapping buoyant or pressurized fluids; may have infrastructure in place; and are likely to be already impacted ecologically as compared to pristine sites. One downside to using depleted hydrocarbon reservoirs is the potential for CO2 leakage along pre-existing wellbores that were either not designed for CO2 sequestration or have been improperly plugged and abandoned. The primary goal of this study is to develop estimates of possible wellbore leakage rates of CO2 from storage reservoirs to the surface and/or into overlaying aquifers, as a function of wellbore properties and the surrounding geologic framework. The Finite Element Heat and Mass transfer code (FEHM) was used to perform Monte Carlo simulations of multiphase flow along wellbores across a wide range of geologic and wellbore parameters. Several wellbore scenarios were studied, including a simple wellbore between the CO2 storage reservoir and the surface; a wellbore intersecting a saline aquifer ("thief zone"); and a wellbore intersecting both a thief zone and a freshwater aquifer. The Problem Solving environment for Uncertainty Analysis and Design Exploration (PSUADE) software was used to analyze results and produce response surfaces for the estimation of wellbore flow rate as a function of the primary factors that influence leakage. These results will be used to develop abstractions for leakage rates to be incorporated in performance assessments of geologic CO2 storage, which will help

  7. Heavy oil reservoirs recoverable by thermal technology. Annual report

    SciTech Connect

    Kujawa, P.

    1981-02-01

    The purpose of this study was to compile data on reservoirs that contain heavy oil in the 8 to 25/sup 0/ API gravity range, contain at least ten million barrels of oil currently in place, and are non-carbonate in lithology. The reservoirs within these constraints were then analyzed in light of applicable recovery technology, either steam-drive or in situ combustion, and then ranked hierarchically as candidate reservoirs. The study is presented in three volumes. Volume I presents the project background and approach, the screening analysis, ranking criteria, and listing of candidate reservoirs. The economic and environmental aspects of heavy oil recovery are included in appendices to this volume. This study provides an extensive basis for heavy oil development, but should be extended to include carbonate reservoirs and tar sands. It is imperative to look at heavy oil reservoirs and projects on an individual basis; it was discovered that operators, and industrial and government analysts will lump heavy oil reservoirs as poor producers, however, it was found that upon detailed analysis, a large number, so categorized, were producing very well. A study also should be conducted on abandoned reservoirs. To utilize heavy oil, refiners will have to add various unit operations to their processes, such as hydrotreaters and hydrodesulfurizers and will require, in most cases, a lighter blending stock. A big problem in producing heavy oil is that of regulation; specifically, it was found that the regulatory constraints are so fluid and changing that one cannot settle on a favorable recovery and production plan with enough confidence in the regulatory requirements to commit capital to the project.

  8. The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE): Examining the complex Arctic biological-climatologic-hydrologic system

    NASA Astrophysics Data System (ADS)

    McDonald, K. C.; Podest, E.; Miller, C. E.; Dinardo, S. J.

    2012-12-01

    Fundamental aspects of the complex Arctic biological-climatologic-hydrologic system remain poorly quantified. As a result, significant uncertainties exist in the carbon budget of the Arctic ecosystem. NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is a currently-operational Earth Venture 1 (EV-1) mission that is examining correlations between atmospheric and surface state variables for the Alaskan terrestrial ecosystems. CARVE is conducted through a series of intensive seasonal aircraft campaigns, ground-based observations, and analysis sustained over a 5-year mission timeframe. CARVE employs a C-23 Sherpa aircraft to fly an innovative airborne remote sensing payload. This payload includes an L-band radiometer/radar system and a nadir-viewing spectrometer to deliver simultaneous measurements of land surface state variables that control gas emissions (i.e., soil moisture and inundation, freeze/thaw state, surface temperature) and total atmospheric columns of carbon dioxide, methane, and carbon monoxide. The aircraft payload also includes a gas analyzer that links greenhouse gas measurements directly to World Meteorological Organization standards and provide vertical profile information. CARVE measurement campaigns are scheduled regularly throughout the growing season each year to capture the seasonal variability in Arctic system carbon fluxes associated with the spring thaw, the summer drawdown, and the fall refreeze. Continuous ground-based measurements provide temporal and regional context as well as calibration for CARVE airborne measurements. CARVE bridges critical gaps in our knowledge and understanding of Arctic ecosystems, linkages between the Arctic hydrologic and terrestrial carbon cycles, and the feedbacks from fires and thawing permafrost. Ultimately, CARVE will provide an integrated set of data that will provide unprecedented experimental insights into Arctic carbon cycling. Portions of this work were carried out at the Jet

  9. Strontium isotope quantification of siderite, brine and acid mine drainage contributions to abandoned gas well discharges in the Appalachian Plateau

    SciTech Connect

    Chapman, Elizabeth C.; Capo, Rosemary C.; Stewart, Brian W.; Hedin, Robert S.; Weaver, Theodore J.; Edenborn, Harry M.

    2013-04-01

    Unplugged abandoned oil and gas wells in the Appalachian region can serve as conduits for the movement of waters impacted by fossil fuel extraction. Strontium isotope and geochemical analysis indicate that artesian discharges of water with high total dissolved solids (TDS) from a series of gas wells in western Pennsylvania result from the infiltration of acidic, low Fe (Fe < 10 mg/L) coal mine drainage (AMD) into shallow, siderite (iron carbonate)-cemented sandstone aquifers. The acidity from the AMD promotes dissolution of the carbonate, and metal- and sulfate-contaminated waters rise to the surface through compromised abandoned gas well casings. Strontium isotope mixing models suggest that neither upward migration of oil and gas brines from Devonian reservoirs associated with the wells nor dissolution of abundant nodular siderite present in the mine spoil through which recharge water percolates contribute significantly to the artesian gas well discharges. Natural Sr isotope composition can be a sensitive tool in the characterization of complex groundwater interactions and can be used to distinguish between inputs from deep and shallow contamination sources, as well as between groundwater and mineralogically similar but stratigraphically distinct rock units. This is of particular relevance to regions such as the Appalachian Basin, where a legacy of coal, oil and gas exploration is coupled with ongoing and future natural gas drilling into deep reservoirs.

  10. High Resolution Chemostratigraphy of Khartam Member of the Permo-Triassic Khuff Carbonate : Outcrop Reservoir Analog Approach from Central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Abdullatif, Osman; Adam, Ammar

    2013-04-01

    The Permo- Triassic carbonate Khuff reservoir (and equivalents) in the Middle East are estimated to contain about 15-20 % of the world's gas reserves. Excellently exposed Permian-Triassic outcropping strata in central Saudi Arabia provide good outcrop analog to the subsurface Khuff reservoir. The outcrop analog can allow examining and evaluating the stratigraphical and sedimentological heterogeneity which has important impact or reservoir quality and architecture. This chemostratigraphic study is part of an integrated outcrop analog study utilizing both field and laboratory stratigraphical and sedimentological data. The study objective is to characterize the chemostratigraphic properties and signatures related to depositional facies, diagenetic overprint, cyclicity and stratigraphic hierarchy. The Chemostratigraphic outcrop analog study is intended to provide a database and to enhance understanding and prediction of the Khuff carbonate reservoir rocks heterogeneity and quality. The field work included detailed sedimentological and stratigraphical description and analysis, gamma-ray logging and bed-by-bed sampling of outcrop sections of the Khartam Member. Lithofacies varies from mudstone, wackestone, packstone to grainstone and several meter to less than meter scale cyclicity were determined. For all samples collected chemical analysis was carried out for major, trace and rare earth elements. The chemostratigraphic signatures, based on major, trace and rare earth elements, and observed at the outcrop sections is capable of capturing stratigraphic and sedimentologic features observed at the outcrop scale and related to lithofacies, cyclicity, stacking pattern and surfaces. Reservoir and non reservoir facies were also identified and correlated. The high resolution chemostratigraphic approach used in this study may help to refine of stratigraphic hierarchy and reservoir models based on subsurface data. Consequently, this might contribute to better understanding of

  11. Uncovering the Minor Contribution of Land-Cover Change in Upland Forests to the Net Carbon Footprint of a Boreal Hydroelectric Reservoir.

    PubMed

    Dessureault, Pierre-Luc; Boucher, Jean-François; Tremblay, Pascal; Bouchard, Sylvie; Villeneuve, Claude

    2015-07-01

    Hydropower in boreal conditions is generally considered the energy source emitting the least greenhouse gas per kilowatt-hour during its life cycle. The purpose of this study was to assess the relative contribution of the land-use change on the modification of the carbon sinks and sources following the flooding of upland forested territories to create the Eastmain-1 hydroelectric reservoir in Quebec's boreal forest using Carbon Budget Model of the Canadian Forest Sector. Results suggest a carbon sink loss after 100 yr of 300,000 ± 100,000 Mg CO equivalents (COe). A wildfire sensitivity analysis revealed that the ecosystem would have acted as a carbon sink as long as <75% of the territory had burned over the 100-yr-long period. Our long-term net carbon flux estimate resulted in emissions of 4 ± 2 g COe kWh as a contribution to the carbon footprint calculation, one-eighth what was obtained in a recent study that used less precise and less sensitive estimates. Consequently, this study significantly reduces the reported net carbon footprint of this reservoir and reveals how negligible the relative contribution of the land-use change in upland forests to the total net carbon footprint of a hydroelectric reservoir in the boreal zone can be. PMID:26437092

  12. Laboratory measurements of large-scale carbon sequestration flows in saline reservoirs

    SciTech Connect

    Backhaus, Scott N

    2010-01-01

    Brine saturated with CO{sub 2} is slightly denser than the original brine causing it to sink to the bottom of a saline reservoir where the CO{sub 2} is safely sequestered. However, the buoyancy of pure CO{sub 2} relative to brine drives it to the top of the reservoir where it collects underneath the cap rock as a separate phase of supercritical fluid. Without additional processes to mix the brine and CO{sub 2}, diffusion in this geometry is slow and would require an unacceptably long time to consume the pure CO{sub 2}. However, gravity and diffusion-driven convective instabilities have been hypothesized that generate enhanced CO{sub 2}-brine mixing promoting dissolution of CO{sub 2} into the brine on time scale of a hundred years. These flows involve a class of hydrodynamic problems that are notoriously difficult to simulate; the simultaneous flow of mUltiple fluids (CO{sub 2} and brine) in porous media (rock or sediment). The hope for direct experimental confirmation of simulations is dim due to the difficulty of obtaining high resolution data from the subsurface and the high pressures ({approx}100 bar), long length scales ({approx}100 meters), and long time scales ({approx}100 years) that are characteristic of these flows. We have performed imaging and mass transfer measurements in similitude-scaled laboratory experiments that provide benchmarks to test reservoir simulation codes and enhance their predictive power.

  13. Dolomite reservoirs: Porosity evolution and reservoir characteristics

    SciTech Connect

    Sun, S.Q.

    1995-02-01

    Systematic analyses of the published record of dolomite reservoirs worldwide reveal that the majority of hydrocarbon-producing dolomite reservoirs occurs in (1) peritidal-dominated carbonate, (2) subtidal carbonate associated with evaporitic tidal flat/lagoon, (3) subtidal carbonate associated with basinal evaporite, and (4) nonevaporitic carbonate sequence associated with topographic high/unconformity, platform-margin buildup or fault/fracture. Reservoir characteristics vary greatly from one dolomite type to another depending upon the original sediment fabric, the mechanism by which dolomite was formed, and the extent to which early formed dolomite was modified by post-dolomitization diagenetic processes (e.g., karstification, fracturing, and burial corrosion). This paper discusses the origin of dolomite porosity and demonstrates the porosity evolution and reservoir characteristics of different dolomite types.

  14. An Evaluation of the Carbon Sequestration Potential of the Cambro-Ordovician Strata of the Illinois and Michigan Basins. Part 1. Evaluation of Phase 2 CO2 Injection Testing in the Deep Saline Gunter Sandstone Reservoir (Cambro-Ordovician Knox Group), Marvin Blan No. 1 Hancock County, Kentucky Part 2. Time-lapse Three-Dimensional Vertical Seismic Profile (3D-VSP) of Sequestration Target Interval with Injected Fluids

    SciTech Connect

    Bowersox, Richard; Hickman, John; Leetaru, Hannes

    2012-12-20

    Part 1 of this report focuses on results of the western Kentucky carbon storage test, and provides a basis for evaluating injection and storage of supercritical CO2 in Cambro-Ordovician carbonate reservoirs throughout the U.S. Midcontinent. This test demonstrated that the Cambro- Ordovician Knox Group, including the Beekmantown Dolomite, Gunter Sandstone, and Copper Ridge Dolomite in stratigraphic succession from shallowest to deepest, had reservoir properties suitable for supercritical CO2 storage in a deep saline reservoir hosted in carbonate rocks, and that strata with properties sufficient for long-term confinement of supercritical CO2 were present in the deep subsurface. Injection testing with brine and CO2 was completed in two phases. The first phase, a joint project by the Kentucky Geological Survey and the Western Kentucky Carbon Storage Foundation, drilled the Marvin Blan No. 1 carbon storage research well and tested the entire Knox Group section in the open borehole – including the Beekmantown Dolomite, Gunter Sandstone, and Copper Ridge Dolomite – at 1152–2255 m, below casing cemented at 1116 m. During Phase 1 injection testing, most of the 297 tonnes of supercritical CO2 was displaced into porous and permeable sections of the lowermost Beekmantown below 1463 m and Gunter. The wellbore was then temporarily abandoned with a retrievable bridge plug in casing at 1105 m and two downhole pressure-temperature monitoring gauges below the bridge plug pending subsequent testing. Pressure and temperature data were recorded every minute for slightly more than a year, providing a unique record of subsurface reservoir conditions in the Knox. In contrast, Phase 2 testing, this study, tested a mechanically-isolated dolomitic-sandstone interval in the Gunter.

  15. Elevated carbon dioxide flux at the Dixie Valley geothermal field, Nevada; relations between surface phenomena and the geothermal reservoir

    USGS Publications Warehouse

    Bergfeld, D.; Goff, F.; Janik, C.J.

    2001-01-01

    In the later part of the 1990s, a large die-off of desert shrubs occurred over an approximately 1 km2 area in the northwestern section of the Dixie Valley (DV) geothermal field. This paper reports results from accumulation-chamber measurements of soil CO2 flux from locations in the dead zone and stable isotope and chemical data on fluids from fumaroles, shallow wells, and geothermal production wells within and adjacent to the dead zone. A cumulative probability plot shows three types of flux sites within the dead zone: Locations with a normal background CO2 flux (7 g m-2 day-1); moderate flux sites displaying "excess" geothermal flux; and high flux sites near young vents and fumaroles. A maximum CO2 flux of 570 g m-2 day-1 was measured at a location adjacent to a fumarole. Using statistical methods appropriate for lognormally distributed populations of data, estimates of the geothermal flux range from 7.5 t day-1 from a 0.14-km2 site near the Stillwater Fault to 0.1 t day-1 from a 0.01 -km2 location of steaming ground on the valley floor. Anomalous CO2 flux is positively correlated with shallow temperature anomalies. The anomalous flux associated with the entire dead zone area declined about 35% over a 6-month period. The decline was most notable at a hot zone located on an alluvial fan and in the SG located on the valley floor. Gas geochemistry indicates that older established fumaroles along the Stillwater Fault and a 2-year-old vent in the lower section of the dead zone discharge a mixture of geothermal gases and air or gases from air-saturated meteoric water (ASMW). Stable isotope data indicate that steam from the smaller fumaroles is produced by ??? 100??C boiling of these mixed fluids and reservoir fluid. Steam from the Senator fumarole (SF) and from shallow wells penetrating the dead zone are probably derived by 140??C to 160??C boiling of reservoir fluid. Carbon-13 isotope data suggest that the reservoir CO2 is produced mainly by thermal decarbonation of

  16. Sediment accumulation and carbon, nitrogen, and phosphorus deposition in the large tropical reservoir Lake Kariba (Zambia/Zimbabwe)

    NASA Astrophysics Data System (ADS)

    Kunz, Manuel J.; Anselmetti, Flavio S.; Wüest, Alfred; Wehrli, Bernhard; Vollenweider, Adrian; Thüring, Silvan; Senn, David B.

    2011-09-01

    Large dams affect the aquatic continuum from land to ocean by accumulating particles and nutrients in their reservoirs. We examined sediment cores to quantify sediment, organic carbon (OC), nitrogen (N), and phosphorous (P) accumulation, and to examine historic changes and spatial variability in the sedimentation pattern in Lake Kariba, the largest hydropower reservoir in the Zambezi River Basin (ZRB). Sediment characteristics (concentrations of OC, N, P; δ13C and δ15N; wet bulk density) showed large variability both with sediment depth and between cores. While organic matter (OM) in river deltas was primarily allochthonous in origin, OM characteristics (δ13C, C:N) in lacustrine sediments suggest that autochthonous sources account for >45% of the OM that accumulates over large areas of the lake. At the same time, the relative contribution of allochthonous material within individual layers of lacustrine cores varied considerably with depth due to discrete flood deposits. The overall sediment accumulation rate in Lake Kariba is on the order of 4 × 106 t yr-1, and the estimated OC accumulation of 120 × 103 t C yr-1 accounts for ˜1‰ of globally buried OC in reservoirs. In addition, mass balance calculations revealed that approximately 70% and 90% of incoming total N and P, respectively, are eliminated from the water column by sedimentation (N, P) and denitrification (N). Since Lake Kariba attenuates flow from ˜50% of the ZRB, these OC, N, and P removals represent a drastic reduction in nutrient loadings to downstream riparian ecosystems and to the coastal Indian Ocean.

  17. Geomechanical characterization and reservoir simulation of a carbon dioxide sequestration project in a mature oil field, Teapot Dome, WY

    NASA Astrophysics Data System (ADS)

    Chiaramonte, Laura

    In this dissertation, I present my contribution towards the understanding and prediction of the risk of CO2 leakage through natural pathways (i.e. faults and fractures). The main portion of this dissertation deals with geomechanical aspects of CO2 Sequestration in Teapot Dome, WY, a mature oil field. The last study investigates the use of induce microseismicity to enhance permeability and injectivity in tight reservoirs and to monitor carbon sequestration projects. In the first three projects, the Tensleep Formation, a Pennsylvanian age eolian fractured sandstone, is evaluated as the target horizon for a pilot CO2 EOR-carbon storage experiment, in a three-way closure trap against a bounding fault, termed the S1 fault. In the first study, a geomechanical model of the Tensleep Fm. has been developed to evaluate the potential for CO2 injection inducing slip on the S1 fault and thus threatening seal integrity. The geomechanical analysis demonstrated that CO2 sequestration will not induce slip on the reservoir-bounding fault, nor is cracking the cap rock a concern. In the second study, a 3D reservoir model and fluid flow simulation of the Tensleep Fm., under these geomechanical constraints, was developed to model the migration of the injected CO2 as well as to obtain limits on the rates and volumes of CO2 that can be injected without compromising seal integrity. The results of the numerical simulations corroborate the analytical results of the geomechanical analysis that seal integrity will not be compromised by the pilot injection. In the third study, we test an Amplitude Versus Angle and Azimuth (AVAZ) analysis to identify the presence of fractures using wide-azimuth 3D seismic data. The objective of the project was to obtain a 3D characterization of the fracture network on both the reservoir and the caprock that will allow for a more accurate assessment of the impact of these features in reservoir permeability and in the risk of CO2 leakage. The AVAZ results were

  18. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2003-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling that utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 3 of the project has been reservoir characterization, 3-D modeling, testing of the geologic-engineering model, and technology transfer. This effort has included six tasks: (1) the study of seismic attributes, (2) petrophysical characterization, (3) data integration, (4) the building of the geologic-engineering model, (5) the testing of the geologic-engineering model and (6) technology transfer. This work was scheduled for completion in Year 3. Progress on the project is as follows: geoscientific reservoir characterization is completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been completed. Observations regarding the diagenetic

  19. LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model

    NASA Astrophysics Data System (ADS)

    Zeebe, R. E.

    2011-06-01

    The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO3 dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO2 sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com.

  20. Carboniferous-Lower Permian carbonate reservoirs of the Timan-Pechora Basin

    SciTech Connect

    Zhemchugova, V.A.; Schamel, S.

    1994-01-01

    The Carboniferous-Lower Permian carbonate succession of the Timan-Pechora basin is a major hydrocarbon-bearing complex, hosting about half of the oil and nearly a third of the gas reserves of the basin. The succession represents the last episode of carbonate deposition on the northeastern margin of the Russian platform before the closure of the Ural seaway in the mid-Permian. The lower part of the succession (upper Visean-Moscovian) contains three major transgressive-regressive sequences. Depositional facies ranged from nearshore carbonate-shale-evaporite through shallow shelf detrital carbonates to outer-shelf carbonate-siliceous shale. The most pronounced regression during this interval occurred during the Serpukhovian, when marine sabkhas covered vast portions of the carbonate platform. Late Carboniferous-Early Permian sedimentation was complicated by the onset of Uralian tectonism. Flysch from the encroaching orogen accumulated initially in the east, advanced westward across the passive margin, and finally covered the carbonate platform in Artinskian-Kungurian time. Simultaneously, structural inversion along the Pechora-Kolva aulacogen and elsewhere provided sites for bioherm growth, in addition to exposing parts of the lower succession to erosion and karstification. Overall polarity of the basin switched as the eastern margin was elevated in the frontal thrusts of the Urals. The carbonate succession was terminated by increased clastic input from the advancing Ural orogen. 6 refs., 9 figs.

  1. Prediction of compressional wave velocity by an artificial neural network using some conventional well logs in a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Zoveidavianpoor, Mansoor; Samsuri, Ariffin; Shadizadeh, Seyed Reza

    2013-08-01

    As vital records for the upstream petroleum industry, compressional-wave (Vp) data provide important information for reservoir exploration and development activities. Due to the different nature and behaviour of the influencing parameters, more complex nonlinearity exists for Vp modelling purposes. Therefore, formulating a prediction tool that can accurately estimate the lacking log data, such as Vp, is of prime importance. Therefore, an attempt has been made to develop a prediction model for Vp as a function of some conventional well logs by using an artificial neural network (ANN). The obtained results are compared to those of multiple linear regression (MLR) models. A total of 2156 data points from a giant Middle Eastern carbonate reservoir, derived from a conventional wire line and a dipole sonic imager log were used in this study. The efficiency of the employed approach, quantified in terms of the mean squared error correlation coefficient (R-square), and prediction efficiency error, is evaluated through simulation and the results are presented. The result showed that an ANN outperforms MLRs and was found to be more robust and reliable.

  2. Reactive Transport Modeling of Supercritical Carbon Dioxide Injection Into Mafic Rock Reservoirs

    NASA Astrophysics Data System (ADS)

    Podgorney, R.; Hull, L.; Huang, H.; McLing, T.

    2007-12-01

    Technologies to reduce emissions of greenhouse gases and increase the sequestration of CO2 have received increasing attention since the development of the Kyoto protocol. One promising technology is the sequestration of CO2 in geologic formations. The suitability of a fractured basalt reservoir for CO2 sequestration is constrained by three broad categories of issues, which we refer to as physical, technical, and economic constraints. Physical constraints are beyond human control; thus, it is a requirement that a systematic method be developed by which a particular target reservoir may be evaluated to determine if it lies within the bounds required for safe and effective disposal. Technical constraints, on the other hand, are challenges to the ability to design, construct, and/or monitor a sequestration project as a result of limitations on our ability to determine the distribution of properties in the subsurface, our knowledge of the behavior of CO2 in the deep subsurface, and the current state of computational science and subsurface monitoring. Equally important are the heterogeneity of economic costs associated with sequestering CO2 at different sites and within different formations. The work presented here focuses on the technical aspects of CO2 injection, specifically examining reactive transport of CO2 in the subsurface in the vicinity of the injection well using the simulation code TOUGHREACT. Pressure distribution and propagation, kinetics of the geochemical reactions, and resultant changes in permeability/porosity are examined in order to evaluate injection scenarios that maximize the longevity of the injection well and sustainability of the reservoir.

  3. 4D seismic to image a thin carbonate reservoir during a miscible C02 flood: Hall-Gurney Field, Kansas, USA

    USGS Publications Warehouse

    Raef, A.E.; Miller, R.D.; Franseen, E.K.; Byrnes, A.P.; Watney, W.L.; Harrison, W.E.

    2005-01-01

    The movement of miscible CO2 injected into a shallow (900 m) thin (3.6-6m) carbonate reservoir was monitored using the high-resolution parallel progressive blanking (PPB) approach. The approach concentrated on repeatability during acquisition and processing, and use of amplitude envelope 4D horizon attributes. Comparison of production data and reservoir simulations to seismic images provided a measure of the effectiveness of time-lapse (TL) to detect weak anomalies associated with changes in fluid concentration. Specifically, the method aided in the analysis of high-resolution data to distinguish subtle seismic characteristics and associated trends related to depositional lithofacies and geometries and structural elements of this carbonate reservoir that impact fluid character and EOR efforts.

  4. Characterization of carbonate reservoir property changes due to dissolution for far-field conditions of CO2 storage

    NASA Astrophysics Data System (ADS)

    Mangane, P. O.; Gouze, P.; Luquot, L.

    2012-12-01

    Geological storage of CO2 in reservoir pore fluid (e.g. deep saline aquifers), is one of the diverse technologies being explored for deacreasing atmospheric CO2 concentration. After injecting the CO2 as a supercritical fluid at depth, it will slowly dissolve into the pore water producing low pH fluids with a high capacity for dissolving carbonates and consequently changing irreversibly the hydrodynamical properties of the reservoir. Characterizing these changes is essential for modelling flow and CO2 transport during and after the CO2 injection. Here we report experimental results from the injection of the CO2-saturated brine into two distinct limestone cores (a bioclastic carbonate and an oolitic carbonate) of 9 mm diameter, 18 mm length. 3D high-resolution X-ray microtomography (XRMT) of the rock sample have been performed before and after the experiments. The experiments were performed using in-situ sequestration conditions (P = 12MPa and T = 100°C), and notably, under chemical conditions given at the position far away from the well injection site (i.e area where the volume of dissolved CO2 into the brine is low, due to CO2 consumption by the dissolution processes occured during its transport from the well injection site). Permeability k is calculated from the pressure drop across the sample and porosity Φ is deduced from chemical concentration of the outlet fluid. The change of the pore structure is analysed in terms of connectivity, tortuosity and fluid-rock interface from processing the XRMT images. These experiments show that far from the well injection site, dissolution processes are characterized by slow mass tranfer including, in the case of carbonate rock, transport of fine particles, which locally clog the porous space. Then, that leads to the damage of the carbonate reservoir both in terms of connectivity of the porous space and CO2 hydrodynamical storage capacity. In fact, the results of the two experiments show that the porosity decreased locally

  5. Q estimation using modified S transform based on pre-stack gathers and its applications on carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Zandong Sun, Sam; Sun, Xuekai; Wang, Yonggang; Xie, Huiwen

    2015-10-01

    Pre-stack seismic data is acknowledged to be more favorable in estimating Q values since it carries much more valuable information in traveltime and amplitude than post-stack data. However, the spectrum of reflectors can be strongly altered by nearby reflector or side lobes of the wavelet, which thereby degrades the accuracy of Q estimation based on the pre-stack spectral ratio method. To solve this problem, we propose a method based on the modified S-transform (MST) for estimating Q values from pre-stack gathers, in which Q values can be obtained with regression analysis based on the relationship between spectral ratio slope and the square of offset. Through tests on a numerical model, we first prove advantages of this pre-stack spectral ratio method compared to the traditional post-stack method. Besides, it is also shown that application of MST would lead to a much more focused intercept, which is the kernel for the pre-stack method. Therefore, the accuracy of Q estimation using MST is further improved when compared with that of conventional S-transform (ST). Based on this Q estimation method, we apply relevant processing methods (e.g. inverse Q filtering and dynamic Q migration) in practice, in order to improve imaging resolution and gathering quality with better amplitude and phase relationships. Applications on a carbonate reservoir witness remarkable enhancements of the imaging result, in which features of faults and deep strata are more clearly revealed. Moreover, pre-stack common-reflection-point (CRP) gathers obtained by dynamic Q migration well compensate the amplitude loss and correct the phase. Its ultimate pre-stack elastic inversion result better characterizes the geologic rules of complex carbonate reservoir predominated by secondary-storage-space.

  6. Dynamic Pore-Scale Imaging of Reactive Transport in Heterogeneous Carbonates at Reservoir Conditions Across Multiple Dissolution Regimes

    NASA Astrophysics Data System (ADS)

    Menke, H. P.; Bijeljic, B.; Andrew, M. G.; Blunt, M. J.

    2014-12-01

    Sequestering carbon in deep geologic formations is one way of reducing anthropogenic CO2 emissions. When supercritical CO2 mixes with brine in a reservoir, the acid generated has the potential to dissolve the surrounding pore structure. However, the magnitude and type of dissolution are condition dependent. Understanding how small changes in the pore structure, chemistry, and flow properties affect dissolution is paramount for successful predictive modelling. Both 'Pink Beam' synchrotron radiation and a Micro-CT lab source are used in dynamic X-ray microtomography to investigate the pore structure changes during supercritical CO2 injection in carbonate rocks of varying heterogeneity at high temperatures and pressures and various flow-rates. Three carbonate rock types were studied, one with a homogeneous pore structure and two heterogeneous carbonates. All samples are practically pure calcium carbonate, but have widely varying rock structures. Flow-rate was varied in three successive experiments by over an order of magnitude whlie keeping all other experimental conditions constant. A 4-mm carbonate core was injected with CO2-saturated brine at 10 MPa and 50oC. Tomographic images were taken at 30-second to 20-minute time-resolutions during a 2 to 4-hour injection period. A pore network was extracted using a topological analysis of the pore space and pore-scale flow modelling was performed directly on the binarized images with connected pathways and used to track the altering velocity distributions. Significant differences in dissolution type and magnitude were found for each rock type and flowrate. At the highest flow-rates, the homogeneous carbonate was seen to have predominately uniform dissolution with minor dissolution rate differences between the pores and pore throats. Alternatively, the heterogeneous carbonates which formed wormholes at high flow rates. At low flow rates the homogeneous rock developed wormholes, while the heterogeneous samples showed evidence

  7. Design and Implementation of a CO(2) Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    Harpole, K.J.; Dollens, K.B.; Durrett, E.G.; Bles, J.S

    1997-10-31

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. All work this quarter falls within the demonstration project.

  8. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    Czirr, Kirk

    1999-10-28

    The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the fourth quarter falls within the demonstration project.

  9. Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Carbonate Approaching Waterflood Depletion

    SciTech Connect

    J. Scott Bles; Kimberly B. Dollens

    1998-04-28

    The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the fourth quarter falls within the demonstration project.

  10. Amplitude-versus-angle analysis and wide-angle-inversion of crosswell seismic data in a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Ibrahim, Mohamed S.

    pronounced for thinner reservoirs, particularly those beyond the vertical resolution of the seismic. For any interface imaged from above and from beneath, the results AVA characters must result from identical contrasts in elastic properties in the two sets of images, albeit in reverse order. An inversion approach to handle both datasets simultaneously, at pre-critical angles, is demonstrated in this work. The main exploration problem for carbonate reefs is determining the porosity distribution. Images of elastic properties, obtained from deterministic and geostatistical simultaneous inversion of a high-resolution crosswell seismic survey were used to obtain the internal structure and reservoir properties (porosity) of Niagaran Michigan reef. The images obtained are the best of any Niagaran pinnacle reef to date.

  11. Field-wide Pressure Response of Three Mid-Cenozoic Sandstone Reservoirs to Fluid Production: a Reverse Analog to Carbon Storage

    NASA Astrophysics Data System (ADS)

    Gillespie, J.; Jordan, P. D.; Chehal, S.; Gonzales, G.; goodell, J. A.; Wilson, J.

    2013-12-01

    Potential carbon storage reservoirs exist in mature oilfields of the southern San Joaquin Valley, California. Data regarding fluid extraction and injection and reservoir pressure exist for the three main oil reservoirs with carbon storage potential: the Monterey (Stevens sandstone member), Vedder and Temblor formations. The pressure response of these reservoirs to fluid volume changes over time provides information regarding how carbon storage may affect the pressure gradients in the adjacent saline aquifers outside the fields where less data exist. This project may provide a template for analysis of other potential carbon storage reservoirs that are contiguous with oilfields. A field-scale version of the productivity index (PI, defined as the average net fluid production rate divided by the average pressure drop over the time period) was calculated for fields with substantial production from depths suitable for carbon storage. The PI determines the reservoir's pressure response to fluid production and is related to the effective CO2 storage capacity. The variance of the 2005 pressure values within each reservoir provides a measure of reservoir continuity. The highest PI values (113,000 and 88,410 m3/yr/MPa) are in the Vedder Formation. The lowest PI values occur in the Temblor Formation and range from 3734 to 16,460 m3/yr/MPa. This indicates the Vedder reservoirs have more pressure support from the aquifer beyond the field than do the Temblor reservoirs. The pressure variance of 3.2 MPa within the Vedder Formation in the Greeley Field is the lowest. The greatest variance (8.5 MPa) occurs within the Temblor Formation in the Carneros unit of the Railroad Gap field. This indicates greater uniformity in the Vedder and more compartmentalization of the Temblor. Pressure response in the Stevens is more varied within the two fields examined in this study: North and South Coles Levee. In North Coles Levee, water injection was employed throughout the field resulting in a

  12. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-02-25

    The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite lithofacies have higher reservoir quality than the shoal lithofacies due to overall higher permeabilities and greater interconnectivity. Thrombolite dolostone flow units, which are dominated by dolomite intercrystalline and vuggy pores, are characterized by a pore system comprised of a higher percentage of large-sized pores and larger pore throats. Rock-fluid interactions (diagenesis) studies have shown that although the primary control on

  13. Key Factors for Determining Risk of Groundwater Impacts Due to Leakage from Geologic Carbon Sequestration Reservoirs

    SciTech Connect

    Carroll, Susan; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-01-06

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow underwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models,l referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which "no impact" to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur.

  14. The reservoir potential of the Zechstein-3 carbonate member (Platten), offshore Netherlands

    SciTech Connect

    Baird, A.; Kelly, J.; Symonds, R. )

    1993-09-01

    The Platten has been examined from 31 released and nonreleased wells, dominantly from northern P and Q quadrants, Dutch North Sea, and including a limited number of adjacent onshore wells. Wireline log interpretations have been allied with available core log, sidewall core, and ditch sample data. This has allowed a division into four broad facies associations: lower ramp, shoal shoreface, lagoonal, and the dominantly siliciclastic peritidal. Primary porosity is concentrated in ooid grainstones of the shoal/shoreface facies association. Diagenesis has also been examined. While the Platten has been broadly affected by early dolomitization, which generally occluded porosity, later diagenesis was more selective and had a significant control on porosity creation more selective and has a significant control on porosity creation as well as occlusion. Location of Platten reservoir potential is shown by facies association, diagenetic texture, and percentage porosity maps. The best reservoir conditions in the Platten exist where the shoal/shoreface facies association coincides with faults and with diagenesis associated with fluid movements through fractures. Low-temperature hydrothermal fluids are shown in this study to be the most important control on the hydrocarbon potential of the Platten in much of the P and Q quadrants.

  15. Organic matter turnover in reservoirs of the Harz Mountains (Germany): evidence from 13C/12C changes in dissolved inorganic carbon

    NASA Astrophysics Data System (ADS)

    Barth, Johannes A. C.; Nenning, Franziska; van Geldern, Robert; Mader, Michael; Friese, Kurt

    2014-05-01

    The Harz Mountains in Germany host several reservoirs for drinking water and electricity supply, the largest of which is the Rappbode System with its two pre-reservoirs. They are the Hassel and the Rappbode pre-reservoirs that have about the same size. These pre-reservoirs were investigated in a comparative study in order to quantify turnover of dissolved organic carbon (DOC) as a representative for organic matter. The objective was to find out how organic matter turnover in these reservoirs may affect dissolved inorganic carbon (DIC) and related CO2 dynamics. Depth profiles of dissolved organic and inorganic carbon (DOC and DIC) were established together with their carbon stable isotope distributions (expressed as δ13CDIC and δ13CDOC). Our results showed up to 104 % increase of DIC contents by organic matter turnover when calculated via isotope mass balances. This contrasted observations of DIC concentration differences between waters collected at the surface and at 12 m depth. These concentration comparisons showed much less DIC increases, and in some cases even decreases, between surface and bottom waters. Such discrepancies could be explained by formation of CO2 at depths below the photic zone that reached calculated values above 7000 ppmV. Such high CO2 concentrations may have reduced the DIC pool by upwards migration. Despite such a concentration decrease, turnover of organic matter has likely incorporated its isotope signal into the DIC pool. While not all DOC present was transposed to DIC, other forms of organic matter from sediments may also have transferred their isotope ratio on the DIC pool. However, with its stable isotope ratio of -28.5 permille the measured DOC was representative of C3 plants and can be assumed as a proxy for other forms of sedimentary carbon including carbon from pore waters and particulate organic matter. Other carbon turnover, including DOC leaching, increased import to the reservoirs after precipitation events and

  16. The Abandonment of Social Studies?

    ERIC Educational Resources Information Center

    Griffith, Bryant

    1991-01-01

    Addresses the question of whether the social studies should be abandoned. Discusses Kieran Egan's analysis of the importance of storytelling and Egan's proposal to abandon the social studies curriculum in favor of a pedagogy more consistent with the way children think. Critiques Egan's view and examines implications for educators. (SG)

  17. Modes and timing of fracture network development in poly-deformed carbonate reservoir analogues, Mt. Chianello, southern Italy

    NASA Astrophysics Data System (ADS)

    Vitale, Stefano; Dati, Francesco; Mazzoli, Stefano; Ciarcia, Sabatino; Guerriero, Vincenzo; Iannace, Alessandro

    2012-04-01

    Structural and paleostress analyses carried out on a kilometre-sized outcrop of allochthonous shallow-water carbonate units of the southern Apennines allowed us to unravel a superposed deformation pattern associated with plate convergence. The reconstructed tectonic evolution involves: (i) early extensional faulting and fracturing associated with bending of the foreland lithosphere during forebulge and foredeep stages (including the development of both 'tangential' and 'radial' normal fault and tensile fractures; Early-Middle Miocene); (ii) large-scale thrusting and folding (Late Miocene); (iii) transcurrent faulting (including two distinct sub-stages characterized by different remote stress fields; Pliocene-Early Pleistocene), and (iv) extensional faulting (late Quaternary). Stage (i) normal faults - generally occurring as conjugate sets - and related fractures and veins are variably deformed and overprinted by later horizontal shortening. Despite having experienced such a long and complex structural history, the studied carbonates are characterized by a 'background' fracture network - including two joint/vein sets orthogonal to each other and to bedding - that appears to be associated with the early fault sets that formed during the first (foredeep/forebulge-related) deformation stage. Therefore, away from younger (Late Miocene to Quaternary) fault zones, the permeability structure of the studied carbonates appears to be essentially controlled by the early, inherited fracture network. As a similar fracture network is likely to characterize also the buried Apulian Platform carbonates, representing the reservoir units for major oil fields in southern Italy, our results also bear possible implications for a better understanding of fluid flow in the subsurface and related hydrocarbon production.

  18. Capillary pressure-saturation relations for supercritical CO2 and brine in limestone/dolomite sands: implications for geologic carbon sequestration in carbonate reservoirs.

    PubMed

    Wang, Shibo; Tokunaga, Tetsu K

    2015-06-16

    In geologic carbon sequestration, capillary pressure (Pc)-saturation (Sw) relations are needed to predict reservoir processes. Capillarity and its hysteresis have been extensively studied in oil-water and gas-water systems, but few measurements have been reported for supercritical (sc) CO2-water. Here, Pc-Sw relations of scCO2 displacing brine (drainage), and brine rewetting (imbibition) were studied to understand CO2 transport and trapping behavior under reservoir conditions. Hysteretic drainage and imbibition Pc-Sw curves were measured in limestone sands at 45 °C under elevated pressures (8.5 and 12.0 MPa) for scCO2-brine, and in limestone and dolomite sands at 23 °C (0.1 MPa) for air-brine using a new computer programmed porous plate apparatus. scCO2-brine drainage and imbibition curves shifted to lower Pc relative to predictions based on interfacial tension, and therefore deviated from capillary scaling predictions for hydrophilic interactions. Fitting universal scaled drainage and imbibition curves show that wettability alteration resulted from scCO2 exposure over the course of months-long experiments. Residual trapping of the nonwetting phases was determined at Pc = 0 during imbibition. Amounts of trapped scCO2 were significantly larger than for those for air, and increased with pressure (depth), initial scCO2 saturation, and time. These results have important implications for scCO2 distribution, trapping, and leakage potential. PMID:25945400

  19. Microbial Methane Formation from Coal and Wood in Abandoned Coal Mines - Analogues for biogenic methane formation in Black Shales

    NASA Astrophysics Data System (ADS)

    Krüger, M.; Beckmann, S.; Engelen, B.; Cypionka, H.

    2009-04-01

    About seven percent of the global annual methane emissions originate from coal mining. Also, mine gas has come into focus of the power industry and is being used increasingly for heat and power production. In many coal deposits worldwide, stable carbon and hydrogen isotopic signatures of methane indicate a mixed thermogenic and biogenic origin. In this study, we have measured in an abandoned coal mine methane fluxes and isotopic signatures of methane and carbon dioxide, and collected samples for microbiological and phylogenetic investigations. Mine timber and hard coal showed an in-situ production of methane with isotopic signatures similar to those of the methane in the mine atmosphere. Enrichment cultures amended with mine timber or hard coal as sole carbon sources formed methane over a period of nine months. Predominantly, acetoclastic methanogenesis was stimulated in enrichments containing acetate or hydrogen/carbon dioxide. Molecular techniques revealed that the archaeal community in enrichment cultures and unamended samples was dominated by members of the Methanosarcinales. The combined geochemical and microbiological investigations identify microbial methanogenesis as a recent source of methane in abandoned coal mines. Overall, our new results support the assumption that abandoned coal reservoirs have a potential to supply methane gas for energy production over extended time scales. The worldwide increased mining activity will go along with an increased coal weathering and the formation of biogenic methane. Currently, our research is focussing on the question to which extent and for how long recent biogenic methane production is contributing to shale gas formation as another important future energy resource.

  20. Interpretation of a carbonate reservoir using P-P and P-SV seismic data

    SciTech Connect

    Miller, S.L.M.; Stewart, R.R.; Lawton, D.C.; Harrison, M.P.; Szata, K.J.

    1994-12-31

    Two orthogonal three-component seismic lines were acquired by Unocal Canada Ltd., in January, 1987, over the Nisku Lousana Field in central Alberta. The purpose of the survey was to investigate a Late Devonian Nisku patch reef though to be separated from the Nisku shelf to the east by an anhydrite basin. The data are of good quality and major events were correlated between P-P and P-SV sections of both lines using offset synthetic seismograms. Interpretation of P-P and P-SV sections show time interval, V{sub p}/V{sub s}, and amplitude variations in the zone of interest. A change in lithology from anhydrite to dolomite, increased porosity, and small quantities of gas could be contributing to the observed decrease in V{sub p}/V{sub s} in an interval containing the reservoir.

  1. Aneth oil field carbonate mound reservoir - Organic-rich mudbank origin

    SciTech Connect

    Peterson, J.A. )

    1989-09-01

    The Aneth oil field (approximately 400 million bbl ultimate recovery) occurs within an isolated southeast-northwest-trending Pennsylvanian (Desmoinesian) algal carbonate bank buildup located approximately 25 mi (40 km) basinward of the main carbonate shelf of the Paradox basin in Utah. Desmoinesian deposition was strongly cyclic, with as many as 30 main evaporite-carbonate cycles recognized. The Aneth algal bank is part of the Desert Creek cycle, which is the first cycle above that of the most widespread salt-bearing cycle. The Desert Creek carbonate facies grades basinward to increasingly prevalent evaporite facies, dominated by thick salt beds in the basin center. Within the isolated algal-mound facies, the Desert Creek cycle is characterized by a vertical succession that includes (1) basal black, organic-rich, dolomitic, silty shale, and (2) overlying dark chalky, finely crystalline dolomite which grades upward into (3) the main carbonate mound facies dominated by accumulations of calcareous, leafy green algae with associated brachiopods, fusulinids, small foraminifera, ostracods, and, rarely, corals. Mound buildups are overlain by a relatively thin, black, organic-rich shale unit, the basal bed of the succeeding mound-bearing Ismay cycle. This upper shale unit thickens markedly on the flanks of the Desert Creek and other mounds.

  2. Simulation study to determine the feasibility of injecting hydrogen sulfide, carbon dioxide and nitrogen gas injection to improve gas and oil recovery oil-rim reservoir

    NASA Astrophysics Data System (ADS)

    Eid, Mohamed El Gohary

    This study is combining two important and complicated processes; Enhanced Oil Recovery, EOR, from the oil rim and Enhanced Gas Recovery, EGR from the gas cap using nonhydrocarbon injection gases. EOR is proven technology that is continuously evolving to meet increased demand and oil production and desire to augment oil reserves. On the other hand, the rapid growth of the industrial and urban development has generated an unprecedented power demand, particularly during summer months. The required gas supplies to meet this demand are being stretched. To free up gas supply, alternative injectants to hydrocarbon gas are being reviewed to support reservoir pressure and maximize oil and gas recovery in oil rim reservoirs. In this study, a multi layered heterogeneous gas reservoir with an oil rim was selected to identify the most optimized development plan for maximum oil and gas recovery. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked. The development scheme is identified, in which the pattern and completion of the wells are optimized to best adapt to the heterogeneity of the reservoir. Lateral and maximum block contact holes will be investigated. The non-hydrocarbon gases considered for this study are hydrogen sulphide, carbon dioxide and nitrogen, utilized to investigate miscible and immiscible EOR processes. In November 2010, re-vaporization study, was completed successfully, the first in the UAE, with an ultimate objective is to examine the gas and condensate production in gas reservoir using non hydrocarbon gases. Field development options and proces schemes as well as reservoir management and long term business plans including phases of implementation will be identified and assured. The development option that maximizes the ultimate recovery factor will be evaluated and selected. The study achieved satisfactory results in integrating gas and oil

  3. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2007-06-30

    The objective of this research project was to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in the hopes of observing changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE No.DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data. Attribute analysis was a very useful tool in enhancing changes in seismic character present, but difficult to interpret on time amplitude slices. Lessons learned from and tools/techniques developed during this project will allow high-resolution seismic imaging to be routinely applied to many CO{sub 2} injection programs in a large percentage of shallow carbonate oil fields in the midcontinent.

  4. Sedimentological cross section of Cambro-Ordovician carbonate shelf (Knox group, Conassauga Formation) in central Alabama: facies, diagenesis, potential reservoirs

    SciTech Connect

    Sternbach, L.R.

    1984-04-01

    Cambro-Ordovician thrust-imbricated carbonates in central Alabama are the focus of renewed exploration interest. Samples from east-west-trending core holes within the surface-most thrust plates reconstruct the carbonate shelf and shelf-edge facies before deformation. The Upper Cambrian shelf margin now is in the subsurface of Talledega County; coeval dolostones in the western part of the state represent the former shelf interior. Rock analogs to former environments include the following. (1) Barrier shoals (Conasauga Formation) - dark colored, partially dolomitized ooid and skeletal grainstones. (2) Submerged back-barrier and offshelf dolomitized sediments (lower Knox Group) - western belt: finely crystalline algal thrombolites, fenestral dolopelmicrites, rippled beds; eastern belt: finely laminated dolostones, slope-derived pebbles and graded beds. (3) Tidal flats (upper Knox Group) - light-colored, crystalline dolostones, dolomitized pellet grainstones, algal laminites, pseudomorphs after sulfates and early diagenetic chertification. (4) Former emergent shelf -(Knox unconformity)-pelmicrite, skeletal wackestones, erosional chert pebble conglomerate. Multiple possibilities for hydrocarbon reservoirs appear throughout the sequence. Vuggy and intercrystalline dolostone porosity is primarily in the lower Knox formations. Primary interparticle pores are retained in lower Knox algal buildups. Breccia porosity occurs in the strata below the Knox unconformity through solution of the underlying Knox Group. Fractures in the subsurface are believed to enhance permeability in all porosity types.

  5. Sedimentological cross section of Cambro-Ordovician carbonate shelf (Knox group, Conasauga Formation) in central Alabama: facies, diagenesis, potential reservoirs

    SciTech Connect

    Sternbach, L.R.

    1984-04-01

    Cambro-Ordovician thrust-imbricated carbonates in central Alabama are the focus of renewed exploration interest. Samples from east-west-trending core holes within the surface-most thrust plates reconstruct the carbonate shelf and shelf-edge facies before deformation. The Upper Cambrian shelf margin now is in the subsurface of Talledega County; coeval dolostones in the western part of the state represent the former shelf interior. Rock analogs to former environments include the following. (1) Barrier shoals (Conasauga Formation) - dark colored, partially dolomitized ooid and skeletal grainstones. (2) Submerged back-barrier and offshelf dolomitized sediments (lower Knox Group) - western belt: finely crystalline algal thrombolites, fenestral dolopelmicrites, rippled beds; eastern belt: finely laminated dolostones, slope-derived pebbles and graded beds. (3) Tidal flats (upper Knox Group) - light-colored, crystalline dolostones, dolomitized pellet grainstones, algal laminites, pseudomorphs after sulfates and early diagenetic chertification. (4) Former emergent shelf -(Knox unconformity)-pelmicrite, skeletal wackestones, erosional chert pebble conglomerate. Multiple possibilities for hydrocarbon reservoirs appear throughout the sequence. Vuggy and intercrystalline dolostone porosity is primarily in the lower Knox formations. Primary interparticle pores are retained in lower Knox algal buildups. Breccia porosity occurs in the strata below the Knox unconformity through solution of the underlying Knox Group. Fractures in the subsurface are believed to enhance permeability in all porosity types.

  6. Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonaradian Age) Reservoirs, West Texas and New Mexico

    SciTech Connect

    Lucia, F. Jerry; Jennings, Jr., James W.

    2001-05-08

    A preliminary reservoir model was constructed for the Lower Clear Fork of the South Wasson Clear Fork reservoir. The model was constructed by calibrating high-frequency cycles observed in cores to the porosity log. The rock fabrics mostly fall in petrophysical class 1, and cross plots of porosity and water saturation could not be used to identify rock fabrics. Data from two limestone fields and one dolostone field were presented to support the contention that grain-dominated fabrics have higher porosity than mud-dominated fabrics do and that this difference is retained when the limestone is dolomitized.

  7. Investigating Protoplanetary Carbon Reservoirs and Molecular Inheritance Along a Galactic Gradient

    NASA Astrophysics Data System (ADS)

    Smith, R. L.; Blake, G. A.; Boogert, A. C. A.; Pontoppidan, K. M.; Lockwood, A. C.

    2015-07-01

    Our large suite of high-resolution observations toward massive YSOs along a Galactic gradient suggest that CO2 may not originate from CO, and that massive YSOs may follow different evolutionary paths for carbon than their low-mass counterparts.

  8. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    SciTech Connect

    James R. Wood; William B. Harrison

    2002-12-01

    The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration. Plotting and examination of these data show that contrary to most depictions, the Michigan Basin is in fact extensively faulted and fractured, particularly in the central portion of the basin. This is in contrast to most of the existing work on the Michigan Basin, which tends to show relatively simple structure with few or minor faults. It also appears that these fractures and faults control the Paleozoic sediment deposition, the subsequent hydrocarbon traps and very likely the regional dolomitization patterns. Recent work has revealed that a detailed fracture pattern exists in the interior of the Central Michigan Basin, which is related to the mid-continent gravity high. The inference is that early Precambrian, ({approx}1 Ga) rifting events presumed by many to account for the gravity anomaly subsequently controlled Paleozoic sedimentation and later hydrocarbon accumulation. There is a systematic relationship between the faults and a number of gas and oil reservoirs: major hydrocarbon accumulations consistently occur in small anticlines on the upthrown side of the faults. The main tools used in this study to map the fault/fracture patterns are detailed, close-interval (CI = 10 feet) contouring of the formation top picks accompanied by a new way of visualizing the data using a special color spectrum to bring out the third dimension. In addition, recent improvements in visualization and contouring software were instrumental in the study. Dolomitization is common in the

  9. Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Reservoirs

    SciTech Connect

    L.A. Davis; A.L. Graham; H.W. Parker; J.R. Abbott; M.S. Ingber; A.A. Mammoli; L.A. Mondy; Quanxin Guo; Ahmed Abou-Sayed

    2005-12-07

    Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Formations The U.S. and other countries may enter into an agreement that will require a significant reduction in CO2 emissions in the medium to long term. In order to achieve such goals without drastic reductions in fossil fuel usage, CO2 must be removed from the atmosphere and be stored in acceptable reservoirs. The research outlined in this proposal deals with developing a methodology to determine the suitability of a particular geologic formation for the long-term storage of CO2 and technologies for the economical transfer and storage of CO2 in these formations. A novel well-logging technique using nuclear-magnetic resonance (NMR) will be developed to characterize the geologic formation including the integrity and quality of the reservoir seal (cap rock). Well-logging using NMR does not require coring, and hence, can be performed much more quickly and efficiently. The key element in the economical transfer and storage of the CO2 is hydraulic fracturing the formation to achieve greater lateral spreads and higher throughputs of CO2. Transport, compression, and drilling represent the main costs in CO2 sequestration. The combination of well-logging and hydraulic fracturing has the potential of minimizing these costs. It is possible through hydraulic fracturing to reduce the number of injection wells by an order of magnitude. Many issues will be addressed as part of the proposed research to maximize the storage rate and capacity and insure the environmental integrity of CO2 sequestration in geological formations. First, correlations between formation properties and NMR relaxation times will be firmly established. A detailed experimental program will be conducted to determine these correlations. Second, improved hydraulic fracturing models will be developed which are suitable for CO2 sequestration as opposed to enhanced oil recovery (EOR

  10. The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) FTS: Results From the 2012/13 Alaska Campaigns

    NASA Astrophysics Data System (ADS)

    Kurosu, Thomas P.; Miller, Charles E.; Dinardo, Stephen J.

    2014-05-01

    The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is an aircraft-based Earth Venture 1 mission to study the carbon balance of the Alaskan Arctic ecosystem, with a particular focus on carbon release from melting permafrost. Operating from its base in Fairbanks, AK, the CARVE aircraft covers a range of principle flight paths in the Alaskan interior, the Yukon River valley, and the northern Alaska coast around Barrow and Dead Horse. Flight paths are chosen to maximize ecosystem variability and cover burn-recovery/regrowth sequences. CARVE observations cover the Arctic Spring/Summer/Fall seasons, with multiple flights per season and principle flight path. Science operations started in May 2012 and are currently envisaged to continue until 2015. The CARVE suite of instruments includes flask measurements, in situ gas analyzers for CO2, CH4 and CO observations, and a three-band polarizing Fourier Transform Spectrometer (FTS) for column measurements of CO2, CH4, CO, their interfering species (e.g., H2O), and O2. The FTS covers the spectral regions of 4,200-4,900 cm-1, 5,800-6,400 cm-1, and 12,900-13,200 cm-1, with a spectral resolution of 0.2 cm-1. Aircraft-based FTS science observations in Alaska have been performed since 23-05-2012. First-version data products from all CARVE instruments derived from observations during the 2012 campaign were publicly released earlier in 2013. The FTS has performed well during flight conditions, particularly with respect to vibration damping. Outstanding challenges include the need for improved spectral and radiometric calibration, as well as compensating for low signal-to-noise spectra acquired under Alaskan flight conditions. We present results from FTS column observations of CO2, CH4, and CO, observed during the 2012 and 2013 campaigns, including preliminary comparisons of CARVE FTS measurements with satellite observations of CO2 from TANSO/GOSAT and CO from MOPITT.

  11. TSR versus non-TSR processes and their impact on gas geochemistry and carbon stable isotopes in Carboniferous, Permian and Lower Triassic marine carbonate gas reservoirs in the Eastern Sichuan Basin, China

    NASA Astrophysics Data System (ADS)

    Liu, Q. Y.; Worden, R. H.; Jin, Z. J.; Liu, W. H.; Li, J.; Gao, B.; Zhang, D. W.; Hu, A. P.; Yang, C.

    2013-01-01

    The Palaeozoic and lowermost Mesozoic marine carbonate reservoirs of the Sichuan Basin in China contain variably sour and very dry gas. The source of the gas in the Carboniferous, Permian and Lower Triassic reservoirs is not known for certain and it has proved difficult to discriminate and differentiate the effects of thermal cracking- and TSR-related processes for these gases. Sixty-three gas samples were collected and analysed for their composition and carbon stable isotope values. The gases are all typically very dry (alkane gases being >97.5% methane), with low (<1%) nitrogen and highly variable H2S and CO2. Carboniferous gas is negligibly sour while the Lower Triassic gas tends to be most sour. The elevated H2S (up to 62%) is due to thermochemical sulphate reduction with the most sour Triassic and Permian reservoirs being deeper than 4800 m. The non-TSR affected Carboniferous gas is a secondary gas that was derived from the cracking of sapropelic kerogen-derived oil and primary gas and is highly mature. Carboniferous (and non-sour Triassic and Permian) gas has unusual carbon isotopes with methane and propane being isotopically heavier than ethane (a reversal of typical low- to moderate-maturity patterns). The gas in the non-sour Triassic and Permian reservoirs has the same geochemical and isotopic characteristics (and therefore the same source) as the Carboniferous gas. TSR in the deepest Triassic reservoirs altered the gas composition reaching 100% dryness in the deepest, most sour reservoirs showing that ethane and propane react faster than methane during TSR. Ethane evolves to heavier carbon isotope values than methane during TSR leading to removal of the reversed alkane gas isotope trend found in the Carboniferous and non-sour Triassic and Permian reservoirs. However, methane was directly involved in TSR as shown by the progressive increase in its carbon isotope ratio as gas souring proceeded. CO2 increased in concentration as gas souring proceeded, but

  12. Stable isotope composition of suspended particulate organic matter in twenty reservoirs from Guangdong, southern China: implications for pelagic carbon and nitrogen cycling.

    PubMed

    Hou, Wei; Gu, Binhe; Lin, Qiuqi; Gu, Jiguang; Han, Bo-Ping

    2013-07-01

    We studied seasonal variations in the carbon and nitrogen stable isotopes (δ(13)C and δ(15)N) of particulate organic matter (POM) in the surface water of 20 man-made reservoirs in southern China during March, August and December 2010. These reservoirs are located from subtropical to tropical region, varied in trophic states and were influenced by several types of human activities. The geomorphometric and biogeochemical gradients in tropical/subtropical regions are complicated and poorly understood because of low variation in temperature and high variation in hydrological processes. The POM samples were collected from all the reservoirs to assess the seasonal variation patterns of δ(13)CPOM and δ(15)NPOM. Variation in δ(13)CPOM followed seasonal thermal and hydrological cycles. By contrast, δ(15)NPOM did not seasonally differ, which may have been complicated by phytoplankton assimilation of N originating in agricultural waste entering the reservoirs and of atmospheric nitrogen during the wet season as well as an increased relative contribution of animal waste in the reservoirs in the dry season. Within each sampling period, nutrient availability is more important than thermal and solar radiation inputs in the summer, and these physical drivers are more important during the dry and cold winter month in controlling δ(13)CPOM and δ(15)NPOM. On an annual basis, trophic states (total P, total N and chlorophyll a) are the primary drivers for the changes in both δ(13)CPOM and δ(15)NPOM across reservoirs. When the seasonal effect is removed using annual averages from each reservoir, we found that latitude, trophic states, pH, rainfall, water temperature, reservoir age, catchment area to reservoir area (CA:RA) ratio and together explained about 80% of the variance in both δ(13)CPOM and δ(15)NPOM. Our findings also suggest that the trend of δ(15)NPOM is less predictable than δ(13)CPOM. The consistent (15)N depletion and enrichment of POM in different reservoirs

  13. Drake passage and central american seaway controls on the distribution of the oceanic carbon reservoir

    DOE PAGESBeta

    Fyke, Jeremy G.; D'Orgeville, Marc; Weaver, Andrew J.

    2015-05-01

    A coupled carbon/climate model is used to explore the impact of Drake Passage opening and Central American Seaway closure on the distribution of carbon in the global oceans. We find that gateway evolution likely played an important role in setting the modern day distribution of oceanic dissolved inorganic carbon (DIC), which is currently characterized by relatively low concentrations in the Atlantic ocean, and high concentrations in the Southern, Indian, and Pacific oceans. In agreement with previous studies, we find a closed Drake Passage in the presence of an open Central American Seaway results in suppressed Atlantic meridional overturning and enhancedmore » southern hemispheric deep convection. Opening of the Drake Passage triggers Antarctic Circumpolar Current flow and a weak Atlantic meridional overturning circulation (AMOC). Subsequent Central American Seaway closure reinforces the AMOC while also stagnating equatorial Pacific subsurface waters. These gateway-derived oceanographic changes are reflected in large shifts to the global distribution of DIC. An initially closed Drake Passage results in high DIC concentrations in the Atlantic and Arctic oceans, and lower DIC concentrations in the Pacific/Indian/Southern oceans. Opening Drake Passage reverses this gradient by lowering mid-depth Atlantic and Arctic DIC concentrations and raising deep Pacific/Indian/Southern Ocean DIC concentrations. Central American Seaway closure further reinforces this trend through additional Atlantic mid-depth DIC decreases, as well as Pacific mid-depth DIC concentration increases, with the net effect being a transition to a modern distribution of oceanic DIC.« less

  14. Drake passage and central american seaway controls on the distribution of the oceanic carbon reservoir

    SciTech Connect

    Fyke, Jeremy G.; D'Orgeville, Marc; Weaver, Andrew J.

    2015-05-01

    A coupled carbon/climate model is used to explore the impact of Drake Passage opening and Central American Seaway closure on the distribution of carbon in the global oceans. We find that gateway evolution likely played an important role in setting the modern day distribution of oceanic dissolved inorganic carbon (DIC), which is currently characterized by relatively low concentrations in the Atlantic ocean, and high concentrations in the Southern, Indian, and Pacific oceans. In agreement with previous studies, we find a closed Drake Passage in the presence of an open Central American Seaway results in suppressed Atlantic meridional overturning and enhanced southern hemispheric deep convection. Opening of the Drake Passage triggers Antarctic Circumpolar Current flow and a weak Atlantic meridional overturning circulation (AMOC). Subsequent Central American Seaway closure reinforces the AMOC while also stagnating equatorial Pacific subsurface waters. These gateway-derived oceanographic changes are reflected in large shifts to the global distribution of DIC. An initially closed Drake Passage results in high DIC concentrations in the Atlantic and Arctic oceans, and lower DIC concentrations in the Pacific/Indian/Southern oceans. Opening Drake Passage reverses this gradient by lowering mid-depth Atlantic and Arctic DIC concentrations and raising deep Pacific/Indian/Southern Ocean DIC concentrations. Central American Seaway closure further reinforces this trend through additional Atlantic mid-depth DIC decreases, as well as Pacific mid-depth DIC concentration increases, with the net effect being a transition to a modern distribution of oceanic DIC.

  15. Ordovician carbonate buildups: Potential gas reservoirs in the Ordos basin, central China

    SciTech Connect

    Huaida Hsu )

    1991-03-01

    The Ordos basin of central China covers an area of about 25,000 km{sup 2}. A series of eastward moving overthrusts developed along its western flank, but most of the basin consists of a stable slope that dips westward less than one degree. The basin contains sediments from Sinian to Middle Ordovician and from the Middle Carboniferous to Cretaceous. Its evolutionary history is similar to that of the Alberta basin. Recently drilled wildcat wells have produced commercial gas flows that are closely associated with Ordovician carbonate buildups and a weathered surface between the Ordovician and Carboniferous. Most of the buildups consist of agal mounds; however, some Middle Ordovician reefs developed in the western portion and along the southern margin of the Ordos basin. More than 200 buildups were delineated using seismic stratigraphic techniques. They can be divided into four distinct types. The growth and distribution of buildups were controlled by sea-level fluctuations. The interpretations made in this study were based on the integration of results from a variety of analyses including vertical profiling, differential interformational velocity analysis, amplitude versus offset comparisons, G-log analysis, seismic modeling techniques, and high-precision gravity surveys. The best gas prospects are the Ordovician carbonate buildups distributed around the basin's central uplift. The delineation of carbonate buildups and the demonstration that they are associated with commercial gas flows open the gate for future gas exploration in this area.

  16. The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE): Five Years of Insights into the High Latitude Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Miller, C. E.

    2015-12-01

    CARVE is a NASA Earth Ventures (EV-1) investigation designed to quantify correlations between atmospheric and surface state variables for the Alaskan terrestrial ecosystems through intensive seasonal aircraft campaigns, ground-based observations, and analysis. In 2015 CARVE completed its 5-year mission. CARVE campaigns across the 2012-2015 growing seasons have established a baseline for monthly, regional scale estimates for surface-atmosphere fluxes of carbon dioxide (CO2) and methane (CH4), and begun to elucidate their environmental and biogeochemical controls. We find that large interannual variability in biogenic CH4 and CO2 fluxes, fire, and significant cold season fluxes complicate attempts to estimate accurate annual C budgets or C balance trends for high latitude ecosystems. We discuss our current estimates for seasonal to interannual CH4 and CO2 fluxes as well as lessons learned from CARVE to guide future investigations of carbon cycling and ecosystem vulnerability in the Arctic-Boreal region with particular emphasis on NGEE-Arctic and ABoVE.

  17. Pore facies analysis: incorporation of rock properties into pore geometry based classes in a Permo-Triassic carbonate reservoir in the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Rahimpour-Bonab, H.; Aliakbardoust, E.

    2014-06-01

    Pore facies analysis is a useful method for the classification of reservoir rocks according to pore geometry characteristics. The importance of this method is related to the dependence of the dynamic behaviour of the reservoir rock on the pore geometry. In this study, pore facies analysis was performed by the quantification and classification of the mercury injection capillary pressure (MICP) curves applying the multi-resolution graph-based clustering (MRGC) method. Each pore facies includes a limited variety of rock samples with different depositional fabrics and diagenetic histories, which are representative of one type of pore geometry. The present pore geometry is the result of the interaction between the primary rock fabric and its diagenetic overprint. Thus the variations in petrographic properties can be correlated with the pore geometry characteristics. Accordingly, the controlling parameters in the pore geometry characteristics were revealed by detailed petrographic analysis in each pore facies. The reservoir rock samples were then classified using the determined petrographic properties which control the pore system quality. This method is proposed for the classification of reservoir rocks in complicated carbonate reservoirs, in order to reduce the incompatibility of traditional facies analysis with pore system characteristics. The method is applicable where enough capillary pressure data is not available.

  18. Carbon dioxide emission from surface water in cascade reservoirs-river system on the Maotiao River, southwest of China

    NASA Astrophysics Data System (ADS)

    Wang, Fushun; Wang, Baoli; Liu, Cong-Qiang; Wang, Yuchun; Guan, Jin; Liu, Xiaolong; Yu, Yuanxiu

    2011-07-01

    Recently, controversies about whether hydropower is still a clean energy have been arisen up with the studies about high CO 2 emission flux from hydroelectric reservoirs in boreal and tropical regions. In this study, four subtropical reservoirs and their related reaches, draining on karstic area in southwest of China, were investigated to understand their CO 2 emission, with monthly sampling strategy from July 2007 to June 2008. pCO 2 values in the surface water of these reservoirs ranged from 38 to 3300 μ atm, indicating that reservoir surface could be not only source but also sink to atmosphere CO 2 in different seasons. In Hongfeng reservoir, the flux of CO 2 from surface water varied from -9 to 70 mmol m -2 d -2 with an average of 15 mmol m -2 d -2, and in Baihua reservoir, it had a range from -8 to 77 mmol m -2 d -2 with an average of 24 mmol m -2 d -2. Hongyan reservoir had similar average flux of CO 2 to Baihua reservoir. Xiuwen had the highest average flux of CO 2 with a value of 47 mmol m -2 d -2 among the studied reservoirs. Downstream the dams discharged by hydropower generation from these reservoirs generally had quite high flux of CO 2, with an average of 489 ± 297 mmol m -2 d -2, which is close to those from tropical rivers. This means that water releasing from these reservoirs would be an important way for CO 2 emission into atmosphere. The results showed that dam construction has significant impacts on the river water chemistry, with abrupt changes in pCO 2, DO, T, pH and SIc in surface water and their outlets. In addition, with the development of thermal gradient in warm seasons, water chemistry along the water column of reservoirs also showed seasonal variations, except in Xiuwen reservoir which only has daily storage capacity.

  19. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF... SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall be abandoned on the sites. Property abandoned in violation of the regulations in this part may be...

  20. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  1. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  2. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  3. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  4. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  5. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2006-08-31

    The objective of this research project is to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in an attempt to observe changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data.

  6. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2005-09-01

    The objective of this research project is to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data to observe changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 18 months of seismic monitoring, one baseline and six monitor surveys clearly imaged changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators.

  7. The dolomitized{open_quotes}O{close_quotes} Limestone in the Barinas basin: A hydrocarbon reservoir in carbonate rocks

    SciTech Connect

    Aquino, R.; Boujana, M.

    1996-08-01

    The {open_quotes}O{close_quotes} Limestone Member, top of Escandalosa Formation of a Lower to Upper Cretaceous age, is an interval of about 70 feet thick. It represents a coastal facies of caitonate platform; dominated by carbonates of calcarenitic lithologies intercalated with some sandy, glauconitic, calcareous bodies and thin bioturbated shaly intervals. Detailed studies carried out in five cores yield to a new approach and subdivision within this interval based on diagnostic erosive surfaces that may be interpreted as sequence boundaries. Based on sedimentology, trace fossil assemblages and diagenetic events, the milieu of sedimentation varies from foreshore to offshore. Porous dolomite levels occur within the {open_quotes}O{close_quotes} Limestone. This porosity is of intergranular, moldic and vuggy types. Some microfractures are also observed. Subaerial karstification is an alternative hypothesis that can explain the origin of the localized dolomitized vuggy reservoirs. The following sequence of events is suggested: (1) Sedimentation followed by bioturbation, then lithification with a probable replacement of aragonite by calcite, (2) Early dolomitization undergoing the {open_quotes}mixing{close_quote} or {open_quotes}Dorag {close_quotes} Model, (3) Dedolomitization and dissolution generating a moldic porosity enhanced the vuggy forms. This stage may have been influenced by karst processes, (4) Burial diagenesis accompanied by stylolitization and fracturation with pressure-solution effects, and (5) Some levels increase their porosity because of partial dolomitization; in others the vuggy porosity is totally infilled with sparry calcite.

  8. Assessing spatial uncertainty in reservoir characterization for carbon sequestration planning using public well-log data: A case study

    USGS Publications Warehouse

    Venteris, E.R.; Carter, K.M.

    2009-01-01

    Mapping and characterization of potential geologic reservoirs are key components in planning carbon dioxide (CO2) injection projects. The geometry of target and confining layers is vital to ensure that the injected CO2 remains in a supercritical state and is confined to the target layer. Also, maps of injection volume (porosity) are necessary to estimate sequestration capacity at undrilled locations. Our study uses publicly filed geophysical logs and geostatistical modeling methods to investigate the reliability of spatial prediction for oil and gas plays in the Medina Group (sandstone and shale facies) in northwestern Pennsylvania. Specifically, the modeling focused on two targets: the Grimsby Formation and Whirlpool Sandstone. For each layer, thousands of data points were available to model structure and thickness but only hundreds were available to support volumetric modeling because of the rarity of density-porosity logs in the public records. Geostatistical analysis based on this data resulted in accurate structure models, less accurate isopach models, and inconsistent models of pore volume. Of the two layers studied, only the Whirlpool Sandstone data provided for a useful spatial model of pore volume. Where reliable models for spatial prediction are absent, the best predictor available for unsampled locations is the mean value of the data, and potential sequestration sites should be planned as close as possible to existing wells with volumetric data. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  9. Sulfide formation in reservoir carbonates of the Devonian Nisku Formation, Alberta, Canada: An ion microprobe study

    SciTech Connect

    Riciputi, L.R.; Cole, D.R.; Machel, H.G.

    1996-01-01

    The processes affecting sulfur during diagenesis in carbonates have been investigated by ion microprobe analysis of {sigma} {sup 34}S values of pyrite, marcasite, and anhydrite from the Devonian Nisku Formation in the Western Canada Sedimentary Basin. Pyrite and marcasite from three Nisku wells have {sigma}{sup 34}S ranging between -35 and +20{per_thousand}. The {sigma}{sup 34}S values increase b6y up to 50{per_thousand} with increasing well depth in two different Nisku wells, and {sigma}{sup 34}S also increases by up to 15{per_thousand} as grain size increases form 40 to over 100 {mu}m in individual samples. The appearance of native sulfur is accompanied by an increase of up to 30{per_thousand} in pyrite {sigma}{sup 34}S values. Bulk and ion probe analyses of anhydrite are relatively uniform ({sigma}{sup 34}S = +22 to +30{per_thousand} CDT). The predominately low {sigma}{sup 34}S values of Nisku sulfides indicate bacterial sulfate reduction. Textural relations indicate that Fe-sulfide formation in Nisku carbonates may have occurred by two different mechanisms. Much of the sulfide has {sigma}{sup 34}S values that suggest that it was associated with bacterial sulfate reduction, although most Fe-sulfides did not form until after pervasive matrix dolomitization (depths of 300-1000 m). Other sulfide may have formed later, during deep ({approximately}4km) burial via thermochemical sulfate reduction. The range in {sigma}{sup 34}S values in a single thin section and correlations between pyrite morphology and isotopic values suggest that sulfate reduction was a very localized process, and that the sulfate reduction environment varied considerably on a small scale. 61 refs., 10 figs., 1 tab.

  10. Improved oil recovery in Mississippian carbonate reservoirs of Kansas -- near term -- Class 2. Quarterly report, April 1--June 30, 1995

    SciTech Connect

    Carr, T.; Green, D.W.; Willhite, G.P.; Schoeling, L.; Reynolds, R.

    1995-07-01

    The objective of this project is to demonstrate incremental reserves from Osagian and Meramecian (Mississippian) dolomite reservoirs in western Kansas through application of reservoir characterization to identify areas of unrecovered mobile oil. The project addresses producibility problems in two fields: specific reservoirs target the Schaben Field in Ness County, Kansas, and the Bindley Field in Hodgeman County, Kansas. The producibility problems to be addressed include inadequate reservoir characterization, drilling and completion design problems, non-optimum recovery efficiency. The results of this project will be disseminated through various technology transfer activities. General overview--progress is reported for the period from 1 April 1995 to 30 June 1995. Work in this quarter has concentrated on reservoir characterization with the initiation of technology transfer. Difficulties still remain in the drilling of the final two wells. Some preliminary work on reservoir characterization has been completed, and related technology transfer has been initiated.

  11. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    SciTech Connect

    James R. Wood; William B. Harrison

    2001-04-01

    Among the accomplishments of this past reporting period are obtaining a complete landgrid for the State of Michigan and the digital processing of the high and medium resolution DEM files. We can now extract lineations from the DEMs automatically using machine algorithms. One tentative result that may be very significant is that we may be seeing manifestations of buried structures in the DEM data. We are looking at a set of extracted lineations in the northern lower peninsula that appear to follow the trend of the pinnacle reefs (Silurian) which had relief approaching 300 feet but are now buried to greater than 3000 feet. We have also extracted the dolomite alteration data from all fields and can show that this is mainly confined to the basin center. It may be related to the paleo-rift suggested by the paleomagnetic and gravity data. As reported last time, the acquisition of a 3D seismic dataset over Stoney Point Field from Marathon Oil Company, is complete and attention is being devoted to incorporating the data into the project database and utilizing it. The surface lineation study is focusing on Stoney Point Field using the high-resolution DEM data and plotting of subsurface formation top data for the main reservoir, the Trenton (Ordovician) Formation. The fault pattern at Stoney Point is well documented by Marathon and we are looking for any manifestations on the surface. The main project database is now about as complete as it will be for this project. The main goals have been met, although the scanning of the paper records will have to continue beyond the scheduled end of the project due to the sheer number of records and the increased donations of data from companies as word spread of the project. One of the unanticipated benefits of the project has been the cooperation of gas and oil companies that are or were active in the Michigan Basin in donating material to the project. Both Michigan Tech and Western Michigan continue to receive donations at an

  12. Source Term Modeling for Evaluating the Potential Impacts to Groundwater of Fluids Escaping from a Depleted Oil Reservoir Used for Carbon Sequestration

    SciTech Connect

    Cantrell, Kirk J.; Brown, Christopher F.

    2014-06-13

    In recent years depleted oil reservoirs have received special interest as carbon storage reservoirs because of their potential to offset costs through collaboration with enhanced oil recovery projects. Modeling is currently being conducted to evaluate potential risks to groundwater associated with leakage of fluids from depleted oil reservoirs used for storage of CO2. Modeling results reported here focused on understanding how toxic organic compounds found in oil will distribute between the various phases within a storage reservoir after introduction of CO2, understanding the migration potential of these compounds, and assessing potential groundwater impacts should leakage occur. Two model scenarios were conducted to evaluate how organic components in oil will distribute among the phases of interest (oil, CO2, and brine). The first case consisted of 50 wt.% oil and 50 wt.% water; the second case was 90 wt.% CO2 and 10 wt.% oil. Several key organic compounds were selected for special attention in this study based upon their occurrence in oil at significant concentrations, relative toxicity, or because they can serve as surrogate compounds for other more highly toxic compounds for which required input data are not available. The organic contaminants of interest (COI) selected for this study were benzene, toluene, naphthalene, phenanthrene, and anthracene. Partitioning of organic compounds between crude oil and supercritical CO2 was modeled using the Peng-Robinson equation of state over temperature and pressure conditions that represent the entire subsurface system (from those relevant to deep geologic carbon storage environments to near surface conditions). Results indicate that for a typical set of oil reservoir conditions (75°C, and 21,520 kPa) negligible amounts of the COI dissolve into the aqueous phase. When CO2 is introduced into the reservoir such that the final composition of the reservoir is 90 wt.% CO2 and 10 wt.% oil, a significant fraction of the oil

  13. In-filled reservoirs serving as sediment archives to analyse soil organic carbon erosion - Taking a closer look at the Karoo rangelands

    NASA Astrophysics Data System (ADS)

    Krenz, Juliane; Greenwood, Philip; Kuhn, Brigitte; Heckrath, Goswin; Foster, Ian; Boardman, John; Meadows, Michael; Kuhn, Nikolaus

    2016-04-01

    The semi-arid rangelands of the Great Karoo region in South Africa, which are nowadays characterized by badlands on the foot slopes of upland areas and complex gully systems in valley bottoms, have experienced a number of environmental changes. With the settlement of European farmers in the late 18th century agricultural activities increased, leading to overgrazing which probably acted as a trigger to land degradation. As a consequence of higher water demands and shifting rainfall patterns, many dams and small reservoirs have been constructed to provide drinking water for cattle or to facilitate irrigation during dry periods. Most of these dams are now filled with sediment and many have become breached, revealing sediment archives that can be used to analyse land use changes as well as carbon erosion and deposition during the last ca. 100 years. In this ongoing project, a combination of analytical methods that include drone imagery, landscape mapping, erosion modelling and sediment analysis have been employed to trace back the sediment origin and redistribution within the catchment, setting a special focus on the carbon history. Sediment deposits from a silted-up reservoir were analysed for varying physicochemical parameters, in order to analyse erosional and depositional patterns. A sharp decrease in total carbon content with decreasing depth suggests that land degradation during and after the post-European settlement most likely triggered erosion of the relatively fertile surface soils which presumably in-filled the reservoirs. It is assumed that the carbon-rich bottom layers of the dam deposits originate from these eroded surface soils. A combination of erosion modelling and sediment analysis will be used to determine the source areas of the depositional material and might clarify the question if land degradation in the Karoo has resulted in its return from being a net sink of carbon into a net source of carbon.

  14. Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality shallow shelf carbonate reservoir. End of budget period report, August 3, 1994--December 31, 1996

    SciTech Connect

    Taylor, A.R.; Hinterlong, G.; Watts, G.; Justice, J.; Brown, K.; Hickman, T.S.

    1997-12-01

    The Oxy West Welch project is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO{sub 2} injection projects in a lower quality shallow shelf carbonate reservoir. The research and design phase primarily involves advanced reservoir characterization and accelerating the production response. The demonstration phase will implement the reservoir management plan based on an optimum miscible CO{sub 2} flood as designed in the initial phase. During Budget Period 1, work was completed on the CO{sub 2} stimulation treatments and the hydraulic fracture design. Analysis of the CO{sub 2} stimulation treatment provided a methodology for predicting results. The hydraulic fracture treatment proved up both the fracture design approach a and the use of passive seismic for mapping the fracture wing orientation. Although the 3-D seismic interpretation is still being integrated into the geologic model and interpretation of borehole seismic is still underway, the simulator has been enhanced to the point of giving good waterflood history matches. The simulator-forecasted results for an optimal designed miscible CO{sub 2} flood in the demonstration area gave sufficient economics to justify continuation of the project into Budget Period 2.

  15. Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality shallow shelf carbonate reservoir. Quarterly report, April 1 - June 30, 1996

    SciTech Connect

    Taylor, A.R.

    1996-07-01

    West Welch Unit is one of four large waterflood units in the Welch Field located in the Northwestern portion of Dawson County, Texas. The Welch Field was discovered in the early 1940`s and produces oil under a solution gas drive mechanism from the San Andres formation at approximately 4800 ft. The field has been under waterflood for 30 years and a significant portion has been infill drilled on 20-ac density. A 1982-86 Pilot CO{sub 2} injection project in the offsetting South Welch Unit yielded positive results. The recent installation of a CO{sub 2} pipeline near the field allowed the phased development of a miscible CO{sub 2} injection project at the South Welch Unit. The reservoir quality is poorer at the West Welch Unit due to its relative position to sea level during deposition. Because of the proximity of a CO{sub 2} source and the CO{sub 2} operating experience that would be available from the South Welch Unit, West Welch Unit is an ideal location for demonstrating methods for enhancing economics of IOR projects in lower quality SSC reservoirs. This Class 2 project concentrates on the efficient design of a miscible CO{sub 2} project based on detailed reservoir characterization from advanced petrophysics, 3-D seismic interpretations and cross wellbore tomography interpretations. During the quarter, work continued on the simulation history match using only the base geologic model generated from available wellbore data. Tomography processing methods were further refined and 3-D surface seismic data was 1115 reprocessed to increase the frequency and decrease the bin size.

  16. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    SciTech Connect

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  17. Elastic softening in Fe7C3 with implications for Earth's deep carbon reservoirs

    NASA Astrophysics Data System (ADS)

    Liu, Jiachao; Li, Jie; Ikuta, Daijo

    2016-03-01

    Iron carbide Fe7C3 has recently emerged as a potential host of reduced carbon in Earth's mantle and a candidate component of the inner core, but the equation of state of Fe7C3 is still uncertain, partly because the nature of pressure-induced magnetic transitions in Fe7C3 and their elastic effects remain controversial. Here we report the compression curve of hexagonal Fe7C3 in neon medium with dense pressure sampling and in comparison with pure iron in the same loading. The results revealed elastic softening between 7 GPa and 20 GPa, which can be attributed to noncollinear alignment of spin moments in a state between the ferromagnetic and paramagnetic phases, as expected for Invar-type alloys. The volume reduction associated with the softening would enhance the stability of Fe7C3 in the deeper part of the upper mantle and transition zone. As a result of subsequent spin crossover at higher pressures, Fe7C3 at inner core conditions likely occurs as the nonmagnetic phase, which remains a candidate for the major component of the Earth's central sphere.

  18. The Robustness of Clumped Isotope Temperatures to Bond Reordering: Evidence from Deeply Buried Carbonate Reservoirs

    NASA Astrophysics Data System (ADS)

    MacDonald, J.; John, C. M.; Girard, J. P.

    2014-12-01

    Numerous studies have shown that clumped isotope thermometry records the temperature of precipitation for carbonate minerals in surface and near-surface environments. However, the ability of a mineral to retain its clumped isotope signature at deeper, hotter burial conditions is still debated. Dolomite has been shown to be more robust to clumped isotope bond reordering than calcite. In this contribution we measure clumped isotopes in calcite veins from Southern Europe that have been buried to up to 7 km to test the robustness of calcite and dolomite to bond reordering. First, we analysed finely crystalline dolostone matrix samples collected in industry wells from Southwest France and buried to between 2 and 5.5 km, Results indicated a temperatures of ~40-60 °C, interpreted to represent formation in an early burial environment. By contrast, coarser dolomite crystals that are petrographically distinct from the fine-grained dolomite record higher temperatures and are interpreted to reflect a deeper, hotter phase of dolomite formation. Preliminary analysis of a calcite vein from a Cretaceous dolostone in Southern Europe buried to 6.3 km records a temperature of 41±3 °C; the calcite matrix around this records a similarly low temperature. This is well below the present-day well temperature of 130-140 °C. Our results indicate that both calcite and dolomite are not affected by bond reordering at the range of depths and temperatures investigated here. Furthermore, this suggests that clumped isotope thermometry can be applied to deeply-buried samples (i.e. >5km).

  19. HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

    2003-12-10

    The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration will being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the U.S.

  20. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico. Quarterly report, January 1--April 30, 1996

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1996-04-30

    The objective of this project is to investigate styles of reservoir heterogeneity found in low-permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  1. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico. Quarterly technical progress report, April 1, 1995--June 1, 1995

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1995-09-01

    The objective of this project is to investigate styles of reservoir heterogeneity that occur in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Technical progress is reported for outcrop activities and subsurface activities.

  2. Brazilian inland water bio-optical dataset to support carbon budget studies in reservoirs as well as anthropogenic impacts in Amazon floodplain lakes: Preliminary results

    NASA Astrophysics Data System (ADS)

    Barbosa, C.; Novo, E.; Ferreira, R.; Carvalho, L.; Cairo, C.; Lopes, F.; Stech, J.; Alcantara, E.

    2015-04-01

    This work presents ongoing efforts and preliminary results for building a dataset that represents the first and most comprehensive bio-optical information available on Brazilian inland waters to support the development of remote sensing algorithms for monitoring aquatic systems. From 2012 to 2014 optical and limnological data was gathered along thirteen field campaigns in five Brazilian reservoirs, in an irrigation and domestic water supply reservoir located in semi-arid northeast of the country and in Amazonian floodplain lakes, thus covering the diversity of Brazilian inland waters. At each site 20 stations, on average, were sampled to acquire profiles of the following optical variables: absorption, attenuation, scattering, and backscattering coefficients and radiances/irradiances spectra above and in-water. Alongside these measurements, water samples were collected for determining concentrations of chlorophyll-a (Chl-a), Total Suspended Solid (TSS), Total Dissolved Carbon (TDC) and its organic/inorganic fractions, CDOM absorption, phytoplankton specific absorption [aph*] and Non-Algal Particles absorption [aNAP*]. Preliminary results show that Chl-a concentrations ranged from 0.6 to 243μg/L in reservoirs and 0.90 to 92μg/L in Amazonian lakes, while TSS concentrations ranged from 0.3 to 31mg/L in reservoirs and 0.5 to 162mg/L in Amazonian lakes. In situ beam attenuation coefficients ranged from 1.4 to 16m-1 in reservoirs and 12.5 to 38m-1 in Amazonian lakes, while diffuse attenuation coefficients of downwelling irradiance over the Photosynthetically Active Radiation (Kd(PAR)) extended from 0.35 to 4.5m-1 in reservoirs and 1.69 to 13.30m-1 in Amazonian lakes. Our research group is building this dataset anticipating future demands for algorithm validation regarding OLI/Landsat8 data and ESA Sentinel missions to be launched as of 2015.

  3. Use of 3D Seismic Azimuthal Iso-Frequency Volumes for the Detection and Characterization of High Porosity/Permeability Zones in Carbonate Reservoirs

    NASA Astrophysics Data System (ADS)

    Toelle, Brian E.

    Among the most important properties controlling the production from conventional oil and gas reservoirs is the distribution of porosity and permeability within the producing geologic formation. The geometry of the pore space within these reservoirs, and the permeability associated with this pore space geometry, impacts not only where production can occur and at what flow rates but can also have significant influence on many other rock properties. Zones of high matrix porosity can result in an isotropic response for certain reservoir properties whereas aligned porosity/permeability, such as open, natural fracture trends, have been shown to result in reservoirs being anisotropic in many properties. The ability to identify zones within a subsurface reservoir where porosity/permeability is significantly higher and to characterize them according to their geometries would be of great significance when planning where new boreholes, particularly horizontal boreholes, should be drilled. The detection and characterization of these high porosity/permeability zones using their isotropic and anisotropic responses may be possible through the analysis of azimuthal (also referred to as azimuth-limited) 3D seismic volumes. During this study the porosity/permeability systems of a carbonate, pinnacle reef within the northern Michigan Basin undergoing enhanced oil recovery were investigated using selected seismic attributes extracted from azimuthal 3D seismic volumes. Based on the response of these seismic attributes an interpretation of the geometry of the porosity/permeability system within the reef was made. This interpretation was supported by well data that had been obtained during the primary production phase of the field. Additionally, 4D seismic data, obtained as part of the CO2 based EOR project, supported reservoir simulation results that were based on the porosity/permeability interpretation.

  4. Application of reservoir characterization and advanced technologies to improve recovery and economics in a lower quality shallow shelf Sand Andreas Reservoir: Quarterly technical report, January 1, 1997--March 31, 1997

    SciTech Connect

    Taylor, A.R., Hickman, T.S., Justice, J.J.

    1997-04-30

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: l.Advanced petrophysics 1547 2.Three-dimensional (3-D) seismic 3.Cross-well bore tomography 4.Advanced reservoir simulation 5.Carbon dioxide (CO{sub 2}) stimulation treatments 6.Hydraulic fracturing design and monitoring 7. Mobility control agents SUMMARY OF TECHNICAL PROGRESS West Welch Unit is one of four large waterflood units in the Welch Field in the northwestern portion of Dawson County, Texas. The Welch Field was discovered in the early 1940`s and produces oil under a solution gas drive mechanism from the San Andres formation at approximately 4800 ft. The field has been under waterflood for 30 years and a significant portion has been infill-drilled on 20-ac density. A 1982- 86 Pilot C0{sub 2} injection project in the offsetting South Welch Unit yielded positive results. Recent installation of a C0{sub 2} pipeline near the field allowed the phased development of a miscible CO injection project at the South Welch Unit.

  5. High-resolution sequence stratigraphy of Late Mississippian carbonates in the Appalachian basin, implications for compartmentalization of reservoir facies

    SciTech Connect

    Al-Tawil, A.; Read, J.F. )

    1996-01-01

    The Late Mississippian Newman/Greenbrier carbonates were deposited in the Appalachian foreland basin whose depocenter lay to the south and east of Kentucky, West Virginia and Virginia. Over 50 closely spaced detailed measured sections along with numerous wireline logs, biostratigraphic data, and lithologic markers are used to construct detailed facies cross-sections. In the Newman limestone along the Cincinnati Arch, four sequences bounded by regional unconformities can be recognized. The lower three sequences contain one to eight oolite bearing disconformity bounded parasequences. Parasequences within sequences one to three, progressively onlap the Waverly and Cincinnati arches. These are dominated by shoal water ooid grainstone and lagoonal skeletal wackestone/mudstone facies, while eolianite quartzose peloidal grainstone facies are restricted to the lower two sequences. Sequence four is thicker and capped by a disconformity, but is internally conformable. It contains thick oolite units in the lower part (up to 10 m), open ramp skeletal packstone and shale (2nd order maximum flooding of the studied interval). In the much thicker foreland basin sections in West Virginia, four sequences also can be defined. The lowstand deposits are characterized by red beds up-dip, locally thickened tidal flat facies down-dip, and thin grainstone tongues extending into the slope/basin facies. Within the sequences, parasequences lack bounding disconformities, and are dominated by open ramp skeletal packstone and shoal water ooid grainstone facies. Eolianite facies are common in landward parts of the lower two sequences. The complex regional distribution and vertical compartmentalization of these multilateral oolitic reservoirs in both areas on this tropical ramp reflect tidal bar morphologies, differential regional subsidence patterns, coupled with 4th order moderate amplitude eustacy.

  6. High-resolution sequence stratigraphy of Late Mississippian carbonates in the Appalachian basin, implications for compartmentalization of reservoir facies

    SciTech Connect

    Al-Tawil, A.; Read, J.F.

    1996-12-31

    The Late Mississippian Newman/Greenbrier carbonates were deposited in the Appalachian foreland basin whose depocenter lay to the south and east of Kentucky, West Virginia and Virginia. Over 50 closely spaced detailed measured sections along with numerous wireline logs, biostratigraphic data, and lithologic markers are used to construct detailed facies cross-sections. In the Newman limestone along the Cincinnati Arch, four sequences bounded by regional unconformities can be recognized. The lower three sequences contain one to eight oolite bearing disconformity bounded parasequences. Parasequences within sequences one to three, progressively onlap the Waverly and Cincinnati arches. These are dominated by shoal water ooid grainstone and lagoonal skeletal wackestone/mudstone facies, while eolianite quartzose peloidal grainstone facies are restricted to the lower two sequences. Sequence four is thicker and capped by a disconformity, but is internally conformable. It contains thick oolite units in the lower part (up to 10 m), open ramp skeletal packstone and shale (2nd order maximum flooding of the studied interval). In the much thicker foreland basin sections in West Virginia, four sequences also can be defined. The lowstand deposits are characterized by red beds up-dip, locally thickened tidal flat facies down-dip, and thin grainstone tongues extending into the slope/basin facies. Within the sequences, parasequences lack bounding disconformities, and are dominated by open ramp skeletal packstone and shoal water ooid grainstone facies. Eolianite facies are common in landward parts of the lower two sequences. The complex regional distribution and vertical compartmentalization of these multilateral oolitic reservoirs in both areas on this tropical ramp reflect tidal bar morphologies, differential regional subsidence patterns, coupled with 4th order moderate amplitude eustacy.

  7. Burial dolomitisation in a non-tropical carbonate petroleum reservoir: the Oligocene Tikorangi Formation, Taranaki Basin, New Zealand

    NASA Astrophysics Data System (ADS)

    Hood, Steven D.; Nelson, Campbell S.; Kamp, Peter J. J.

    2004-11-01

    The Oligocene Tikorangi Formation is a subsurface, non-tropical, limestone-rich, fracture-producing oil reservoir in Taranaki Basin, New Zealand. The formation is distinct from uplifted and exposed age-equivalent New Zealand limestones due to partial dolomitisation by modest quantities of silt-sized, scattered, inclusion-rich, euhedral dolomite rhombs, occasionally displaying idiotopic fabrics. Rhombs commonly have dull luminescent Fe-rich cores, and oscillatory bright and dull concentric outers. The dolomites are non-stoichiometric, high calcian and highly ferroan varieties. Dolomite 18O and 13C values are moderately depleted, while associated precursor calcite phases are less depleted. Petrographic, geochemical and geohistory evidence suggest that the dolomite formed during and following the later stages of pressure-dissolution cementation in a relatively closed, moderately deep burial environment (ca. 0.85-1.9 km burial depth, ca. 33-65 °C) in the early Miocene (ca. 24-18 Ma) from warm, saline-enriched pore fluids by mainly mimic fabric-selective replacement of interparticle, and rarely intraparticle, micrite/matrix. Dolomitisation did not affect skeletal grains or calcite cements or develop any secondary porosity. Mg supply was restricted and was likely sourced internally from micritic inter- and intraparticle precursor material, and from the pressure-dissolution of calcitic skeletons. Importantly, dolomitisation occurred prior to compression-related brittle fracturing of the carbonates, responsible for creating extensive hydrocarbon-bearing fracture networks. Because of the greater susceptibility of the dolomitised limestones to brittle fracturing, their location and distribution may have important implications for hydrocarbon prospectivity and production within the Tikorangi Formation.

  8. High resolution reservoir architecture of late Jurassic Haynesville ramp carbonates in the Gladewater field, East Texas Salt Basin

    SciTech Connect

    Goldhammer, R.K.

    1996-12-31

    The East Texas Salt Basin contains numerous gas fields within Upper Jurassic Haynesville ramp-complex reservoirs. A sequenced-keyed, high-resolution zonation scheme was developed for the Haynesville Formation in Gladewater field by integrating core description, well-log, seismic, porosity and permeability data. The Haynesville at Gladewater represents a high-energy ramp system, localized on paleotopographic highs induced by diapirism of Callovian Age Salt (Louann). Ramp crest grainstones serve as reservoirs. We have mapped the distribution of reservoir facies within a hierarchy of upward-shallowing parasequences grouped into low-frequency sequences. The vertical stacking patterns of parasequences and sequences reflect the interplay of eustasy, sediment accumulation patterns, and local subsidence (including salt movement and compaction). In this study we draw on regional relations from analogous, Jurassic systems in Mexico to constrain the stratigraphic architecture, age model, and facies model. Additionally, salt-cored Holocene, grain-rich shoals from the Persian Gulf provide excellent facies analogs. The result is a new high-resolution analysis of reservoir architecture at a parasequence scale that links reservoir facies to depositional facies. The new stratigraphy scheme demonstrates that different geographic portions of the field have markedly distinct reservoir intervals, both in terms of total pay and the sequence-stratigraphic interval within which it occurs. Results from this study are used to evaluate infill drill well potential, in well planning, for updating reservoir models, and in refining field reserve estimates.

  9. High resolution reservoir architecture of late Jurassic Haynesville ramp carbonates in the Gladewater field, East Texas Salt Basin

    SciTech Connect

    Goldhammer, R.K. )

    1996-01-01

    The East Texas Salt Basin contains numerous gas fields within Upper Jurassic Haynesville ramp-complex reservoirs. A sequenced-keyed, high-resolution zonation scheme was developed for the Haynesville Formation in Gladewater field by integrating core description, well-log, seismic, porosity and permeability data. The Haynesville at Gladewater represents a high-energy ramp system, localized on paleotopographic highs induced by diapirism of Callovian Age Salt (Louann). Ramp crest grainstones serve as reservoirs. We have mapped the distribution of reservoir facies within a hierarchy of upward-shallowing parasequences grouped into low-frequency sequences. The vertical stacking patterns of parasequences and sequences reflect the interplay of eustasy, sediment accumulation patterns, and local subsidence (including salt movement and compaction). In this study we draw on regional relations from analogous, Jurassic systems in Mexico to constrain the stratigraphic architecture, age model, and facies model. Additionally, salt-cored Holocene, grain-rich shoals from the Persian Gulf provide excellent facies analogs. The result is a new high-resolution analysis of reservoir architecture at a parasequence scale that links reservoir facies to depositional facies. The new stratigraphy scheme demonstrates that different geographic portions of the field have markedly distinct reservoir intervals, both in terms of total pay and the sequence-stratigraphic interval within which it occurs. Results from this study are used to evaluate infill drill well potential, in well planning, for updating reservoir models, and in refining field reserve estimates.

  10. Well-based stable carbon isotope leakage monitoring of an aquifer overlying the CO2 storage reservoir at the Ketzin pilot site, Germany

    NASA Astrophysics Data System (ADS)

    Nowak, Martin; Myrttinen, Anssi; Zimmer, Martin; van Geldern, Robert; Barth, Johannes A. C.

    2014-05-01

    At the pilot site for CO2 storage in Ketzin, a new well-based leakage-monitoring concept was established, comprising geochemical and hydraulic observations of the aquifer directly above the CO2 reservoir (Wiese et al., 2013, Nowak et al. 2013). Its purpose was to allow early detection of un-trapped CO2. Within this monitoring concept, we established a stable carbon isotope monitoring of dissolved inorganic carbon (DIC). If baseline isotope values of aquifer DIC (δ13CDIC) and reservoir CO2 (δ13CCO2) are known and distinct from each other, the δ13CDIC has the potential to serve as an an early indicator for an impact of leaked CO2 on the aquifer brine. The observation well of the overlying aquifer was equipped with an U-tube sampling system that allowed sampling of unaltered brine. The high alkaline drilling mud that was used during well drilling masked δ13CDIC values at the beginning of the monitoring campaign. However, subsequent monitoring allowed observing on-going re-equilibration of the brine, indicated by changing δ13CDIC and other geochemical values, until values ranging around -23 ‰ were reached. The latter were close to baseline values before drilling. Baselineδ13CDIC and δ13CCO2 values were used to derive a geochemical and isotope model that predicts evolution of δ13CDIC, if CO2 from the reservoir would leak into the aquifer. The model shows that equilibrium isotope fractionation would have to be considered if CO2 dissolves in the brine. The model suggests that stable carbon isotope monitoring is a suitable tool to assess the impact of injected CO2 in overlying groundwater aquifers. However, more data are required to close gaps of knowledge about fractionation behaviour within the CO2(g) - DIC system under elevated pressures and temperatures. Nowak, M., Myrttinen, A., Zimmer, M., Wiese, B., van Geldern, R., Barth, J.A.C., 2013. Well-based, Geochemical Leakage Monitoring of an Aquifer Immediately Above a CO2 Storage Reservoir by Stable Carbon

  11. Seasonal energy storage using bioenergy production from abandoned croplands

    NASA Astrophysics Data System (ADS)

    Campbell, J. Elliott; Lobell, David B.; Genova, Robert C.; Zumkehr, Andrew; Field, Christopher B.

    2013-09-01

    Bioenergy has the unique potential to provide a dispatchable and carbon-negative component to renewable energy portfolios. However, the sustainability, spatial distribution, and capacity for bioenergy are critically dependent on highly uncertain land-use impacts of biomass agriculture. Biomass cultivation on abandoned agriculture lands is thought to reduce land-use impacts relative to biomass production on currently used croplands. While coarse global estimates of abandoned agriculture lands have been used for large-scale bioenergy assessments, more practical technological and policy applications will require regional, high-resolution information on land availability. Here, we present US county-level estimates of the magnitude and distribution of abandoned cropland and potential bioenergy production on this land using remote sensing data, agriculture inventories, and land-use modeling. These abandoned land estimates are 61% larger than previous estimates for the US, mainly due to the coarse resolution of data applied in previous studies. We apply the land availability results to consider the capacity of biomass electricity to meet the seasonal energy storage requirement in a national energy system that is dominated by wind and solar electricity production. Bioenergy from abandoned croplands can supply most of the seasonal storage needs for a range of energy production scenarios, regions, and biomass yield estimates. These data provide the basis for further down-scaling using models of spatially gridded land-use areas as well as a range of applications for the exploration of bioenergy sustainability.

  12. Life in the slow lane; biogeochemistry of biodegraded petroleum containing reservoirs and implications for energy recovery and carbon management.

    PubMed

    Head, Ian M; Gray, Neil D; Larter, Stephen R

    2014-01-01

    Our understanding of the processes underlying the formation of heavy oil has been transformed in the last decade. The process was once thought to be driven by oxygen delivered to deep petroleum reservoirs by meteoric water. This paradigm has been replaced by a view that the process is anaerobic and frequently associated with methanogenic hydrocarbon degradation. The thermal history of a reservoir exerts a fundamental control on the occurrence of biodegraded petroleum, and microbial activity is focused at the base of the oil column in the oil water transition zone, that represents a hotspot in the petroleum reservoir biome. Here we present a synthesis of new and existing microbiological, geochemical, and biogeochemical data that expands our view of the processes that regulate deep life in petroleum reservoir ecosystems and highlights interactions of a range of biotic and abiotic factors that determine whether petroleum is likely to be biodegraded in situ, with important consequences for oil exploration and production. Specifically we propose that the salinity of reservoir formation waters exerts a key control on the occurrence of biodegraded heavy oil reservoirs and introduce the concept of palaeopickling. We also evaluate the interaction between temperature and salinity to explain the occurrence of non-degraded oil in reservoirs where the temperature has not reached the 80-90°C required for palaeopasteurization. In addition we evaluate several hypotheses that might explain the occurrence of organisms conventionally considered to be aerobic, in nominally anoxic petroleum reservoir habitats. Finally we discuss the role of microbial processes for energy recovery as we make the transition from fossil fuel reliance, and how these fit within the broader socioeconomic landscape of energy futures. PMID:25426105

  13. Life in the slow lane; biogeochemistry of biodegraded petroleum containing reservoirs and implications for energy recovery and carbon management

    PubMed Central

    Head, Ian M.; Gray, Neil D.; Larter, Stephen R.

    2014-01-01

    Our understanding of the processes underlying the formation of heavy oil has been transformed in the last decade. The process was once thought to be driven by oxygen delivered to deep petroleum reservoirs by meteoric water. This paradigm has been replaced by a view that the process is anaerobic and frequently associated with methanogenic hydrocarbon degradation. The thermal history of a reservoir exerts a fundamental control on the occurrence of biodegraded petroleum, and microbial activity is focused at the base of the oil column in the oil water transition zone, that represents a hotspot in the petroleum reservoir biome. Here we present a synthesis of new and existing microbiological, geochemical, and biogeochemical data that expands our view of the processes that regulate deep life in petroleum reservoir ecosystems and highlights interactions of a range of biotic and abiotic factors that determine whether petroleum is likely to be biodegraded in situ, with important consequences for oil exploration and production. Specifically we propose that the salinity of reservoir formation waters exerts a key control on the occurrence of biodegraded heavy oil reservoirs and introduce the concept of palaeopickling. We also evaluate the interaction between temperature and salinity to explain the occurrence of non-degraded oil in reservoirs where the temperature has not reached the 80–90°C required for palaeopasteurization. In addition we evaluate several hypotheses that might explain the occurrence of organisms conventionally considered to be aerobic, in nominally anoxic petroleum reservoir habitats. Finally we discuss the role of microbial processes for energy recovery as we make the transition from fossil fuel reliance, and how these fit within the broader socioeconomic landscape of energy futures. PMID:25426105

  14. Bearing the risk of abandonment

    SciTech Connect

    Attanasio, Donna M.

    2010-05-15

    In Order Nos. 679 and 679-A, FERC adopted a policy of authorizing rate incentives for new transmission early in the development process to encourage transmission investment. The abandoned-plant cost recovery incentive creates a tension between ratepayer and investor interests, which is increasingly reflected in FERC's orders. (author)

  15. [Variations of Inorganic Carbon and its Impact Factors in Surface-Layer Waters in a Groundwater-Fed Reservoir in Karst Area, SW China].

    PubMed

    Li, Jian-hong; Pu, Jun-bing; Yuan, Dao-xian; Liu, Wen; Xiao, Qiong; Yu, Shi; Zhang Tao; Mo, Xue; Sun, Ping-an; Pan, Mou-cheng

    2015-08-01

    In order to understand the inorganic carbon cycle of the groundwater-fed reservoir in karst area, Dalongdong Reservoir, which is located at Shanglin County, Guangxi Zhuang Autonomous Region, China, was investigated from 12th to 20th July, 2014. Concentration of dissolved inorganic carbon (DIC), delta13C of DIC (delta13C(DIC)), partial CO2 pressure (pCO2) and CO2 flux across water-air interface were studied by observation in situ and high-resolution diel monitoring. Results show that: (1) DIC concentration and water pCO2 increased from upstream area to downstream area [DIC(average)): from 122.88 to 172.02 mg x L(-1), pCO2(average) : from 637.91 x 10(-6) to 1399.97 x 10(-6)], while delta13C(DIC) decreased from upstream area to downstream area [delta13C(DIC(average): from -4.34% per hundred to -6.97% per hundred] in the reservoir. (2) CO2 efflux across water-air interface varied from 7.11 to 335.54 mg x (m2 x h)(-1) with mean of 125.03 mg x (m2 x h)(-1) in Dalongdong reservoir surface-layer waters, which was the source of atmospheric CO2. CO2 effluxes across water-air interface in upstream area [mean 131.73 mg x (m2 x h)(-1)] and downstream area [mean 170.25 mg x (m2 x h)(-1)] were higher than that in middle area [mean 116.05 mg x (m2 x h))(-1)] in the reservoir. (3) Water pCO2 and CO2 efflux across water-air interface showed similar characteristics of diel variations, which decreased in daylight and increased in night and showed a negative correlation with chlorophyll a (Chla). Possible reasons of research results are found as follows: (1) DIC concentration, water pCO2 and delta13C(DIC) are influenced by biomass of phytoplankton, turbidity, conductivity, the depth of water and transparency, while CO2 efflux across water-air interface is controlled by both of biomass of phytoplankton and wind speed. (2) Photosynthesis, respiration and vertical motion of phytoplankton possibly affect diel variations of DIC cycle in the groundwater-fed reservoir in karst area. PMID

  16. Analysis of reservoir heterogeneities due to shallowing-upward cycles in carbonate rocks of the Pennsylvanian Wahoo Limestone of Northeastern Alaska. Annual report, October 1990--September 1991

    SciTech Connect

    Watts, K.

    1992-09-01

    The primary objective of this project is to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the carboniferous Pennsylvanian Wahoo Limestone. The Wahoo Limestone is the upper formation of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A principal goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo Limestone. This report presents the preliminary results of research accomplished by a team of specialists in carbonate petrology, biostratigraphy, and diagenesis during the 1990--1991 fiscal year.It includes a summary of regional geological framework studies, a discussion conodont analyses, an overview of diagenetic studies, a brief description of progress in computerized database development, and appendices containing some of the new data on petrographic analyses, conodont analyses, and locality and sample information. Our correlation scheme, which uses cyclic stratigraphy, biostratigraphy, and cement stratigraphy, will allow interpretation of the depositional history and paleogeographic evolution of the region. We have developed predictive facies models and will make paleogeographic maps to illustrate different stages in the history of the Wahoo carbonate ramp. Our detailed analyses of the Wahoo Limestone will provide a basis for interpreting correlative rocks in the adjacent subsurface of the coastal plain of ANWR, a potential hydrocarbon lease-sale area. In a broader sense, our work will provide an excellent generic example of carbonate shallowing-upward cycles which typify carbonate sediments.

  17. Analysis of reservoir heterogeneities due to shallowing-upward cycles in carbonate rocks of the Pennsylvanian Wahoo Limestone of Northeastern Alaska

    SciTech Connect

    Watts, K.

    1992-09-01

    The primary objective of this project is to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the carboniferous Pennsylvanian Wahoo Limestone. The Wahoo Limestone is the upper formation of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A principal goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo Limestone. This report presents the preliminary results of research accomplished by a team of specialists in carbonate petrology, biostratigraphy, and diagenesis during the 1990--1991 fiscal year.It includes a summary of regional geological framework studies, a discussion conodont analyses, an overview of diagenetic studies, a brief description of progress in computerized database development, and appendices containing some of the new data on petrographic analyses, conodont analyses, and locality and sample information. Our correlation scheme, which uses cyclic stratigraphy, biostratigraphy, and cement stratigraphy, will allow interpretation of the depositional history and paleogeographic evolution of the region. We have developed predictive facies models and will make paleogeographic maps to illustrate different stages in the history of the Wahoo carbonate ramp. Our detailed analyses of the Wahoo Limestone will provide a basis for interpreting correlative rocks in the adjacent subsurface of the coastal plain of ANWR, a potential hydrocarbon lease-sale area. In a broader sense, our work will provide an excellent generic example of carbonate shallowing-upward cycles which typify carbonate sediments.

  18. Application of Integrated Reservoir management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    B. Pregger; D. Davies; D. Moore; G. Freeman; J. Callard; J.W. Nevans; L. Doublet; R. Vessell; T. Blasingame

    1997-08-31

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  19. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    1998-03-12

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  20. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vehicle which has been left unattended or abandoned on a street, road, highway, parking lot, or any other... impoundment procedures. (d) Civilian vehicles left abandoned on the reservation will be towed to...

  1. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vehicle which has been left unattended or abandoned on a street, road, highway, parking lot, or any other... impoundment procedures. (d) Civilian vehicles left abandoned on the reservation will be towed to...

  2. Porous Carbon Spheres: Rational Design of Si/SiO2 @Hierarchical Porous Carbon Spheres as Efficient Polysulfide Reservoirs for High-Performance Li-S Battery (Adv. Mater. 16/2016).

    PubMed

    Rehman, Sarish; Guo, Shaojun; Hou, Yanglong

    2016-04-01

    S. Guo, Y. Hou, and S. Rehman develop a new class of silicon crosslinked with hierarchical porous carbon spheres usable as an efficient polysulfide reservoir for enhancing the performance of lithium-sulfur batteries. As described on page 3167, the developed hybrid material adsorbs negatively charged polysulfides via both chemical and physical adsorption. Remarkably, the hybrid spheres show a high specific capacity, an excellent rate capability and long cyclability. PMID:27105813

  3. Area of Interest 1, CO2 at the Interface. Nature and Dynamics of the Reservoir/Caprock Contact and Implications for Carbon Storage Performance

    SciTech Connect

    Mozley, Peter; Evans, James; Dewers, Thomas

    2014-10-31

    Formation reservoir/caprock interface in order to extend our work to a reservoir/caprock pair this is currently being assessed for long-term carbon storage. These analyses indicate that interface features similar to those observed at the Utah sites 3 were not observed. Although not directly related to our main study topic, one byproduct of our investigation is documentation of exceptionally high degrees of heterogeneity in the pore-size distribution of the Mount Simon Sandstone. This suggests that the unit has a greater-than-normal potential for residual trapping of supercritical CO2.

  4. Using Recent Advances in 2D Seismic Technology and Surface Geochemistry to Economically Redevelop a Shallow Shelf Carbonate Reservoir: Vernon Field, Isabella County, M, Class III

    SciTech Connect

    Wood, James R.; Bornhorst, T.J.; Chittick, S.D.; Harrison, William B.; Tayjor, W. Quinlan

    2001-08-07

    In this project a consortium consisting of Cronus Exploration (Traverse City, MI), Michigan Technological University (Houghton, MI) and Western Michigan University (Kalamazoo, MI) proposed to develop and execute an economical and environmentally sensitive plan for recovery of hydrocarbons from an abandoned shallow-shelf carbonate field that is typical of many fields in the U.S. Midwest. This is a 5-year project that will use surface geochemistry as a tool to reduce risk in locating and producing hydrocarbons in Class II fields. The project will develop new techniques for measuring hydrocarbon gases in the soil horizon to locate new and bypassed oil in the shallow-shelf carbonate environments typified by the Dundee and Trenton Formations of the Michigan Basin (Fisher et. al., 1988). In Phase I of the project, the consortium proposes to re-develop the Vernon Oil field located in Vernon Twp, Isabella County, Michigan and produce both bypassed hydrocarbons from the original field and to locate and produce extensions of the original field.

  5. Design and implementation of a CO{sub 2} flood utilizing advanced reservoir characterization and horizontal injection wells in a shallow shelf carbonate approaching waterflood depletion. Technical progress report

    SciTech Connect

    Chimahusky, J.S.

    1996-04-19

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a CO{sub 2} project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. This report includes work on the reservoir characterization and project design objective and the demonstration project objective.

  6. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    P. K. Pande

    1998-10-29

    Initial drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficiency

  7. Role of sea-level change in deep water deposition along a carbonate shelf margin, Early and Middle Permian, Delaware Basin: implications for reservoir characterization

    NASA Astrophysics Data System (ADS)

    Li, Shunli; Yu, Xinghe; Li, Shengli; Giles, Katherine A.

    2015-04-01

    The architecture and sedimentary characteristics of deep water deposition can reflect influences of sea-level change on depositional processes on the shelf edge, slope, and basin floor. Outcrops of the northern slope and basin floor of the Delaware Basin in west Texas are progressively exposed due to canyon incision and road cutting. The outcrops in the Delaware Basin were measured to characterize gravity flow deposits in deep water of the basin. Subsurface data from the East Ford and Red Tank fields in the central and northeastern Delaware Basin were used to study reservoir architectures and properties. Depositional models of deep water gravity flows at different stages of sea-level change were constructed on the basis of outcrop and subsurface data. In the falling-stage system tracts, sandy debris with collapses of reef carbonates are deposited on the slope, and high-density turbidites on the slope toe and basin floor. In the low-stand system tracts, deep water fans that consist of mixed sand/mud facies on the basin floor are comprised of high- to low-density turbidites. In the transgression and high-stand system tracts, channel-levee systems and elongate lobes of mud-rich calciturbidite deposits formed as a result of sea level rise and scarcity of sandy sediment supply. For the reservoir architecture, the fan-like debris and high-density turbidites show high net-to-gross ratio of 62 %, which indicates the sandiest reservoirs for hydrocarbon accumulation. Lobe-like deep water fans with net-to-gross ratio of 57 % facilitate the formation of high quality sandy reservoirs. The channel-levee systems with muddy calciturbidites have low net-to-gross ratio of 30 %.

  8. High resolution sequence stratigraphy in the upper Jurassic carbonate platform of the Paris basin: Reservoir geometries in lagoonal, protected marine and ooids shoals environments

    SciTech Connect

    Pascal, H.; Villalobos, L. Guillocheau, F.

    1995-08-01

    Reservoir geometry reconstruction within carbonate platforms has been carried out in the Upper Jurassic of the Paris Basin based on high-resolution sequence stratigraphy correlations (cores and well-logs). 18 cored wells over 25 kM{sup 2} have been correlated (Saint-Clair-sur-Epte field, Gaz de France). During lower and middle Oxfordian the Paris Basin is a carbonate platform prograding southward. This progradational trend can be subdivided into three upper order sequences (parasequences sets, mean duration: one m.y.). The lower parasequence-set is a stacking of shallowing-upward parasequences made up of tidal ooids bars surrounded laterally and backward by more protected environments (large variety of coated grains). The middle parasequence-set is recorded in lagoonal environments with numerous channels and lobes of storm washover-fans. Metric-thick sequences have been correlated over the field. They are ernersive upward (subtidal lagoonal deposits cut by storm-induced channels and lobes, covered by small karsts). The upper parasequence-set is made-up of protected-marine deposits grading into lagoonal sediments. The metric thick shallowing-upward sequences are composed by sheet-shaped, strongly bioturbated, medium to coarse-grained bioclastic limestones. Correlation levels are the deepest facies (strongly monospecifically bioturbated wackstones). Shape and size of reservoirs will be quantified.

  9. USING RECENT ADVANCES IN 2D SEISMIC TECHNOLOGY AND SURFACE GEOCHEMISTRY TO ECONOMICALLY REDEVELOP A SHALLOW SHELF CARBONATE RESERVOIR: VERNON FIELD, ISABELLA COUNTRY, MI

    SciTech Connect

    James R. Wood; A. Wylie; W. Quinlan

    2004-04-01

    The principal objective of this demonstration project is to test surface geochemical techniques for detecting trace amounts of light hydrocarbons in pore gases as a means of reducing risk in hydrocarbon exploration and production. A major part of the remaining project will focus on using surface geochemistry to delineate prospects. A Niagaran reef field geochemical survey, the Bagley Prospect area in Otsego County, Michigan is scheduled to take place this summer. Previous wells drilled in Bagley Prospect area in the early 1970's and in place in late 2002 and early 2003 resulted in discoveries and numerous hydrocarbon shows in the Brown Niagaran reservoir interval. The Bagley region is still considered an area of interest by the industry and appears ripe for a geochemical survey. Our industry partner is interested in a possible test in the Bagley prospect because subsurface geophysical and geological interpretation indicates the presence of structures. Anomalous production and pressure data further suggest the region is not yet well understood and should not be considered mature. The most recent well, the Bagley 1-22A sidetrack, was unsuccessful at locating a new reef culmination to the south of the original vertical well and did not encounter hydrocarbon shows. The sidetrack and well were plugged and abandoned. The proposed geochemical survey will concentrate on areas away from the Bagley 1-22A to the north and west but will include the entire prospect so that the existing data can be used in interpretations. Bagley appears to offer a unique combination of potential and data for a geochemical study that focuses on looking for new oil in an area that has exhausted traditional geologic and geophysical methods. The Bear Lake pinnacle reef trend in Manistee County, Michigan, is also scheduled for further geochemical work this summer. Industry interest, mostly by small companies, is picking up in this area and it is also ripe for targeted geochemical surveys for the

  10. Characterizing Microbial Diversity and Function in Natural Subsurface CO2 Reservoir Systems for Applied Use in Geologic Carbon Sequestration Environments

    NASA Astrophysics Data System (ADS)

    Freedman, A.; Thompson, J. R.

    2013-12-01

    The injection of CO2 into geological formations at quantities necessary to significantly reduce CO2 emissions will represent an environmental perturbation on a continental scale. The extent to which biological processes may play a role in the fate and transport of CO2 injected into geological formations has remained an open question due to the fact that at temperatures and pressures associated with reservoirs targeted for sequestration CO2 exists as a supercritical fluid (scCO2), which has generally been regarded as a sterilizing agent. Natural subsurface accumulations of CO2 serve as an excellent analogue for studying the long-term effects, implications and benefits of CO2 capture and storage (CCS). While several geologic formations bearing significant volumes of nearly pure scCO2 phases have been identified in the western United States, no study has attempted to characterize the microbial community present in these systems. Because the CO2 in the region is thought to have first accumulated millions of years ago, it is reasonable to assume that native microbial populations have undergone extensive and unique physiological and behavioral adaptations to adjust to the exceedingly high scCO2 content. Our study focuses on the microbial communities associated with the dolomite limestone McElmo Dome scCO2 Field in the Colorado Plateau region, approximately 1,000 m below the surface. Fluid samples were collected from 10 wells at an industrial CO2 production facility outside Cortez, CO. Subsamples preserved on site in 3.7% formaldehyde were treated in the lab with Syto 9 green-fluorescent nucleic acid stain, revealing 3.2E6 to 1.4E8 microbial cells per liter of produced fluid and 8.0E9 cells per liter of local pond water used in well drilling fluids. Extracted DNAs from sterivex 0.22 um filters containing 20 L of sample biomass were used as templates for PCR targeting the 16S rRNA gene. 16S rRNA amplicons from these samples were cloned, sequenced and subjected to microbial

  11. Secondary Forests from Agricultural Abandonment in Amazonia 2000-2009

    NASA Technical Reports Server (NTRS)

    Morton, Douglas

    2010-01-01

    Ongoing negotiations to include reducing emissions from tropical deforestation and forest degradation (REDD+) in a post-Kyoto climate agreement highlight the critical role of satellite data for accurate and transparent accounting of forest cover changes. In addition to deforestation and degradation, knowledge of secondary forest dynamics is essential for full carbon accounting under REDD+. Land abandonment to secondary forests also frames one of the key tradeoffs for agricultural production in tropical forest countries-whether to incentivize secondary forest growth (for carbon sequestration and biodiversity conservation) or low-carbon expansion of agriculture or biofuels production in areas of secondary forests. We examined patterns of land abandonment to secondary forest across the arc of deforestation in Brazil and Bolivia using time series of annual Landsat and MODIS data from 2000-2009. Rates of land abandonment to secondary forest during 2002-2006 were less than 5% of deforestation rates in these years. Small areas of new secondary forest were scattered across the entire arc of deforestation, rather than concentrated in any specific region of the basin. Taken together, our analysis of the satellite data record emphasizes the difficulties of addressing the pool of new secondary forests in the context of REDD+ in Amazonia. Due to the small total area of secondary forests, land sparing through agricultural intensification will be an important element of efforts to reduce deforestation rates under REDD+ while improving agricultural productivity in Amazonia.

  12. Stress change and fault slip in produced gas reservoirs used for storage of natural gas and carbon-dioxide

    NASA Astrophysics Data System (ADS)

    Orlic, Bogdan; Wassing, Brecht

    2013-04-01

    Gas extraction and subsequent storage of natural gas or CO2 in produced gas reservoirs will change the state of stress in a reservoir-seal system due to poro-mechanical, thermal and possibly chemical effects. Depletion- and injection-induced stresses can mechanically damage top- and side-seals, re-activate pre-existing sealing faults and create new fractures, allowing fluid migration out of the storage reservoir and causing induced seismicity. The first case study describes a field scale three-dimensional geomechanical numerical modelling of a depleted gas field in the Netherlands, which will be used for underground gas storage (UGS). The field experienced induced seismicity associated with gas production in the past and concerns were raised regarding the risk of future injection-related seismicity. The numerical modelling study aimed at investigating the potential of major faults for reactivation during UGS operations. The geomechanical model was calibrated to match the location and timing of the fault slip on the main central fault, which has most likely caused past seismic events during gas production. Simulation results showed that the part of the central fault most sensitive to slip during reservoir depletion is located at partial juxtaposition of the two main reservoir blocks across the central fault, which is in agreement with the seismological localization of the recorded seismic events. UGS operations with annual cycles of gas injection and production will largely have stabilizing effects on fault stability. The potential for fault slip on the central fault will therefore be low throughout annual operational cycles of this storage facility. The second case study describes a field scale two-dimensional geomechanical modelling of an offshore depleted gas field in the Netherlands, which is being considered for CO2 storage. The geomechanical modelling study aimed at investigating the mechanical impact of induced stress changes, resulting from past gas

  13. Development planning and management of petroleum reservoirs using tank models and nonlinear programming

    SciTech Connect

    McFarland, J.W.; Lasdon, L.; Loose, V.

    1984-04-01

    This study demonstrates the feasibility of applying generalized reduced gradient nonlinear programing methods to solve optimal control models for petroleum reservoir development planning and management. The objective of the models is to maximize present value of profits; their decision variables are how many wells to drill in each time period, the production rates, abandonment time, and platform size. The analysis uses tank-type reservoir models to describe the reservoir dynamics, and models both a gas reservoir with water drive, and a 3-phase oil reservoir. Results of several case studies on each model are presented. Extensions that consider spatial variation in the reservoir and use grid reservoir models are investigated. 40 references.

  14. Reservoir-scale stratigraphic controls on the distribution of vertical fractures: insights from a 200-m thick carbonate platform exposure (Sorrento peninsula, Italy)

    NASA Astrophysics Data System (ADS)

    Corradetti, Amerigo; Tavani, Stefano; Iannace, Alessandro; Vinci, Francesco; Pirmez, Carlos; Torrieri, Stefano; Giorgioni, Maurizio; Strauss, Christoph; Pignalosa, Antonio; Mazzoli, Stefano

    2016-04-01

    Through-going fractures cutting across numerous beds are often invoked to match large-scale permeability patterns in tight carbonate reservoirs. Despite the importance of these structures for fluid flow simulations, there are only few field analogues allowing estimating many of their parameters, including spacing and vertical extent, which are instead required to populate reservoir models. This is mostly due to the fact that the study of these reservoir-scale fractures requires very wide outcrops that for several reasons, including logistics, are rarely analysed. Nevertheless, recent improvements in the construction of digital models of outcrops can greatly help to overcome many logistic issues. In this work, we present the results obtained from combined field and remote sensing observations of a 300-meters wide and 200-meters high carbonate platform reservoir analogue in the Sorrento peninsula (Italy). The outcrop consists of a nearly vertical cliff exposing alternating gently-dipping shallow-water limestones and dolomites characterized by the presence of several vertical fractures of different size and hence with different vertical connectivity. In order to gather both stratigraphic and structural (i.e. fracture) data, we integrated field measurements and stratigraphic logs with a remote sensing study carried out on a digital model of the cliff, made by means of multi-view stereo-photogrammetry. This combined field and remote sensing study has allowed us to recognize that major bed-perpendicular through-going fractures are vertically discontinuous due to variable segmentation and fracture distribution within the country rock. In particular, we observed that large (i.e. tens of meters in height) fractures pass across medium to thick beds (bed thickness > 30 cm), while they arrest against packages made of thinly stratified layers of dolomites. In essence, through-going fractures arrest on weak levels, consisting of thinly bedded layers interposed between packages

  15. Investigation of early water breakthrough and the likely effectiveness of water shut-off treatments in heterogeneous carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Alblooshi, Younes

    Progressive percentage of total fluid produced in the oil industry is formation brine. Ever, increasing water cut will reduce oil recovery, diminish wells' productivity and increase cost of eventual artificial lift and produced water handling. This study investigates the problem of early water development in layered and heterogeneous reservoirs and determines the effect of various reservoir parameters on the development of water front movement in the presence of thief zones. A water injection in a line-staggered pattern was simulated to analyze these effects on the water breakthrough time, WBTT, and the evolution of water front in the thief zone. To achieve this, sensitivity analysis is conducted to investigate and determine the effect of some reservoir parameters that would explain the experience of having unpredicted advancement of injected water resulting in early water breakthrough and high water cut wells. These reservoir parameters included layers' horizontal permeability, Kv/Kh ratio, thickness of high permeability layers, water gravity effect, oil API gravity effect, and injection/production rate ratio (or IPR). Threshold of these parameters beyond which its effect would be constant is also determined to help operators to better estimate the water breakthrough time and hence better decision making process in waterflooding projects. Moreover, water shut-off, WSO, treatments are simulated to determine their effectiveness in delaying the water breakthrough time, and reducing water cut percentages for maximum possible time, under different thief zones' conditions. Extreme thief zone cases are selected from the first part of the study for this purpose. Also, the optimum WSO treatment thickness is identified at which a maximum delay in time is achieved which yields to best treatment practices in the fields. Finally, this study summarizes the applicability of these WSO treatment methods, and it identifies the level of effectiveness based on specific given

  16. Multiple factors drive regional agricultural abandonment.

    PubMed

    Osawa, Takeshi; Kohyama, Kazunori; Mitsuhashi, Hiromune

    2016-01-15

    An understanding of land-use change and its drivers in agroecosystems is important when developing adaptations to future environmental and socioeconomic pressures. Agricultural abandonment occurs worldwide with multiple potentially positive and negative consequences; however, the main factors causing agricultural abandonment in a country i.e., at the macro scale, have not been identified. We hypothesized that socio-environmental factors driving agricultural abandonment could be summarized comprehensively into two, namely "natural" and "social", and the relative importance of these differs among regions. To test this postulate, we analyzed the factors currently leading to agricultural abandonment considering ten natural environment variables (e.g., temperature) and five social variables (e.g., number of farmers) using the random forest machine learning method after dividing Japan into eight regions. Our results showed that agricultural abandonment was driven by various socio-environmental factors, and the main factors leading to agricultural abandonment differed among regions, especially in Hokkaido in northern Japan. Hokkaido has a relatively large area of concentrated farmland, and abandonment might have resulted from the effectiveness of cultivation under specific climate factors, whereas the other regions have relatively small areas of farmland with many elderly part-time farmers. In such regions, abandonment might have been caused by the decreasing numbers of potential farmers. Thus, two different drivers of agricultural abandonment were found: inefficient cultivation and decreasing numbers of farmers. Therefore, agricultural abandonment cannot be prevented by adopting a single method or policy. Agricultural abandonment is a significant problem not only for food production but also for several ecosystem services. Governments and decision-makers should develop effective strategies to prevent further abandonment to ensure sustainable future management of agro

  17. An integrated approach for determination of pore-type distribution in carbonate-siliciclastic Asmari Reservoir, Cheshmeh-Khosh Oilfield, SW Iran

    NASA Astrophysics Data System (ADS)

    Gharechelou, Sajjad; Amini, Abdolhossein; Kadkhodaie-Ilkhchi, Ali; Moradi, Babak

    2015-10-01

    This paper presents an integrated pore type study at microscopic (core data), mesoscopic (well logs) and megascopic scales (3D seismic data) in the mixed carbonate-siliciclastic Asmari Reservoir of the Cheshmeh-Khosh Oilfield, SW Iran. Firstly, pore types are determined in a microscopic scale based on petrographic studies of thin sections. Well logs and nuclear magnetic resonance (NMR) log data are employed for pore type determination based on a velocity deviation log (mesoscopic scale). For each pore type subclass, a suite of physical rock properties including average poroperm values, T2 distribution, capillary pressure, pore size distribution and depositional texture are calculated. For this purpose, the NMR log, mercury injection capillary pressure data and core descriptions are interpreted in an integrated approach. Capillary pressure and pore size distribution in each pore type class are determined by mercury injection capillary pressure tests and synthesis of a continuous capillary pressure log from the NMR log (pseudo Pc curves). For dynamic behavior examination of the reservoir, the pore types are analysed in the framework of hydraulic flow units. Finally, 3D post-stacked seismic data are converted to a cube of pore types based on acoustic impedance inversion and seismic attributes. The methodology of this study is accomplished by using core and log data from three key wells and a 3D post-stack seismic data from the studied field. Lastly, a map of pore type distribution is established to provide a clue on the high and low permeable zones of the field. The presented methodology signifies reservoir anatomy on micro to mega scales.

  18. Interaction Between CO2-Rich Sulfate Solutions and Carbonate Reservoir Rocks from Atmospheric to Supercritical CO2 Conditions: Experiments and Modeling

    NASA Astrophysics Data System (ADS)

    Cama, J.; Garcia-Rios, M.; Luquot, L.; Soler Matamala, J. M.

    2014-12-01

    A test site for CO2 geological storage is situated in Hontomín (Spain) with a reservoir rock that is mainly composed of limestone. During and after CO2 injection, the resulting CO2-rich acid brine gives rise to the dissolution of carbonate minerals (calcite and dolomite) and gypsum (or anhydrite at depth) may precipitate since the reservoir brine contains sulfate. Experiments using columns filled with crushed limestone or dolostone were conducted under different P-pCO2 conditions (atmospheric: 1-10-3.5 bar; subcritical: 10-10 bar; and supercritical: 150-34 bar), T (25, 40 and 60 ºC) and input solution compositions (gypsum-undersaturated and gypsum-equilibrated solutions). We evaluated the effect of these parameters on the coupled reactions of calcite/dolomite dissolution and gypsum/anhydrite precipitation. The CrunchFlow and PhreeqC (v.3) numerical codes were used to perform reactive transport simulations of the experiments. Under the P-pCO2-T conditions, the volume of precipitated gypsum was smaller than the volume of dissolved carbonate minerals, yielding an increase in porosity (Δporosity up to ≈ 4%). A decrease in T favored limestone dissolution regardless of pCO2 owing to increasing undersaturation with decreasing temperature. However, gypsum precipitation was favored at high T and under atmospheric pCO2 conditions but not at high T and under 10 bar of pCO2 conditions. The increase in limestone dissolution with pCO2 was directly attributed to pH, which was more acidic at higher pCO2. Increasing pCO2, carbonate dissolution occurred along the column whereas it was localized in the very inlet under atmospheric conditions. This was due to the buffer capacity of the carbonic acid, which maintains pH at around 5 and keeps the solution undersaturated with respect to calcite and dolomite along the column. 1D reactive transport simulations reproduced the experimental data (carbonate dissolution and gypsum precipitation for different P-pCO2-T conditions). Drawing

  19. LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model v2.0.4

    NASA Astrophysics Data System (ADS)

    Zeebe, R. E.

    2012-01-01

    The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO3 dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. LOSCAR's configuration of ocean geometry is flexible and allows for easy switching between modern and paleo-versions. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO2 sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com.

  20. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    SciTech Connect

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim; Gilbert, Bob; Lake, Larry W.; Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett; Thomas, Sunil G.; Rightley, Michael J.; Rodriguez, Adolfo; Klie, Hector; Banchs, Rafael; Nunez, Emilio J.; Jablonowski, Chris

    2006-11-01

    survivability issues. Our findings indicate that packaging represents the most significant technical challenge associated with application of sensors in the downhole environment for long periods (5+ years) of time. These issues are described in detail within the report. The impact of successful reservoir monitoring programs and coincident improved reservoir management is measured by the production of additional oil and gas volumes from existing reservoirs, revitalization of nearly depleted reservoirs, possible re-establishment of already abandoned reservoirs, and improved economics for all cases. Smart Well monitoring provides the means to understand how a reservoir process is developing and to provide active reservoir management. At the same time it also provides data for developing high-fidelity simulation models. This work has been a joint effort with Sandia National Laboratories and UT-Austin's Bureau of Economic Geology, Department of Petroleum and Geosystems Engineering, and the Institute of Computational and Engineering Mathematics.

  1. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    SciTech Connect

    Mohan Kelkar

    2002-09-30

    The main objectives of the proposed study are as follows: (1) To understand and evaluate an unusual primary oil production mechanism which results in decreasing (retrograde) oil cut (ROC) behavior as reservoir pressure declines. (2) To improve calculations of initial oil in place so as to determine the economic feasibility of completing and producing a well. (3) To optimize the location of new wells based on understanding of geological and petrophysical properties heterogeneities. (4) To evaluate various secondary recovery techniques for oil reservoirs producing from fractured formations. (5) To enhance the productivity of producing wells by using new completion techniques. These objectives are important for optimizing field performance from West Carney Field located in Lincoln County, Oklahoma. The field, which was discovered in 1980, produces from Hunton Formation in a shallow-shelf carbonate reservoir. The early development in the field was sporadic. Many of the initial wells were abandoned due to high water production and constraints in surface facilities for disposing excess produced water. The field development began in earnest in 1995 by Altex Resources. They had recognized that production from this field was only possible if large volumes of water can be disposed. Being able to dispose large amounts of water, Altex aggressively drilled several producers. With few exceptions, all these wells exhibited similar characteristics. The initial production indicated trace amount of oil and gas with mostly water as dominant phase. As the reservoir was depleted, the oil cut eventually improved, making the overall production feasible. The decreasing oil cut (ROC) behavior has not been well understood. However, the field has been subjected to intense drilling activity because of prior success of Altex Resources. In this work, we will investigate the primary production mechanism by conducting several core flood experiments. After collecting cores from representative

  2. Dissimilar properties within a carbonate-reservoir's small fault zone, and their impact on the pressurization and leakage associated with CO2 injection

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Guglielmi, Yves; Cappa, Frédéric

    2013-02-01

    This paper focuses on a small fault zone (too small to be detected by geophysical imaging) affecting a carbonate reservoir composed of porous and low-porosity layers. In a gallery located at 250 m depth, the hydraulic properties of a 20 m thick section of the reservoir affected by the studied fault are characterized by structural measurements and hydraulic injection into boreholes. We conducted electrical tomographies before and after an 18 hour-long injection, to image the fluid flow through the fault zone. Our main finding is that the damage zone displays contrasting permeability values (up to two orders of magnitude) inherited from the differential alteration of the intact rock layers. To characterize the impact of these hydraulic-property variations on the fluid flow, we carried out numerical simulations of water and supercritical CO2 injections, using the TOUGH2 code. Two damage-zone models were compared, with heterogeneous (Model 1) and homogeneous (Model 2) hydraulic properties. In Model 1, injected fluids cannot escape through the fault zone; they generate a high fluid overpressure, located in the damage-zone layers having the highest permeability and storativity. In Model 2, fluids can easily migrate; the overpressure is lower and located in the host rock along the fault zone.

  3. Carbon dioxide emission rate of Kīlauea Volcano: Implications for primary magma and the summit reservoir

    USGS Publications Warehouse

    Gerlach, T.M.; McGee, K.A.; Elias, T.; Sutton, A.J.; Doukas, M.P.

    2002-01-01

     We report a CO2 emission rate of 8500 metric tons per day (t d−1) for the summit of Kīlauea Volcano, several times larger than previous estimates. It is based on three sets of measurements over 4 years of synchronous SO2 emission rates and volcanic CO2/SO2concentration ratios for the summit correlation spectrometer (COSPEC) traverse. Volcanic CO2/SO2 for the traverse is representative of the global ratio for summit emissions. The summit CO2 emission rate is nearly constant, despite large temporal variations in summit CO2/SO2 and SO2 emission rates. Summit CO2 emissions comprise most of Kīlauea's total CO2 output (∼9000 t d−1). The bulk CO2 content of primary magma determined from CO2emission and magma supply rate data is ∼0.70 wt %. Most of the CO2 is present as exsolved vapor at summit reservoir depths, making the primary magma strongly buoyant. Turbulent mixing with resident reservoir magma, however, prevents frequent eruptions of buoyant primary magma in the summit region. CO2 emissions confirm that the magma supply enters the edifice through the summit reservoir. A persistent several hundred parts per million CO2 anomaly arises from the entry of magma into the summit reservoir beneath a square kilometer area east of Halemaumau pit crater. Since most of the CO2 in primary magma is degassed in the summit, the summit CO2 emission rate is an effective proxy for the magma supply rate. Both scrubbing of SO2 and solubility controls on CO2and S in basaltic melt cause high CO2/SO2 in summit emissions and spatially uncorrelated distributions of CO2 and SO2 in the summit plume.

  4. Design and implementation of a CO2 flood utilizing advanced reservoirs characterization and horizontal injection wells in a shallow shelf carbonate approaching water floods depletion: Technical progress report, January 1, 1997--March 31, 1997

    SciTech Connect

    Chimahusky, J.S., Casteel, J.F.

    1997-05-01

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO{sub 2}) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. All work this quarter falls within the demonstration project.

  5. Comparative modeling of fault reactivation and seismicity in geologic carbon storage and shale-gas reservoir stimulation

    NASA Astrophysics Data System (ADS)

    Rutqvist, Jonny; Rinaldi, Antonio; Cappa, Frederic

    2016-04-01

    The potential for fault reactivation and induced seismicity are issues of concern related to both geologic CO2 sequestration and stimulation of shale-gas reservoirs. It is well known that underground injection may cause induced seismicity depending on site-specific conditions, such a stress and rock properties and injection parameters. To date no sizeable seismic event that could be felt by the local population has been documented associated with CO2 sequestration activities. In the case of shale-gas fracturing, only a few cases of felt seismicity have been documented out of hundreds of thousands of hydraulic fracturing stimulation stages. In this paper we summarize and review numerical simulations of injection-induced fault reactivation and induced seismicity associated with both underground CO2 injection and hydraulic fracturing of shale-gas reservoirs. The simulations were conducted with TOUGH-FLAC, a simulator for coupled multiphase flow and geomechanical modeling. In this case we employed both 2D and 3D models with an explicit representation of a fault. A strain softening Mohr-Coulomb model was used to model a slip-weakening fault slip behavior, enabling modeling of sudden slip that was interpreted as a seismic event, with a moment magnitude evaluated using formulas from seismology. In the case of CO2 sequestration, injection rates corresponding to expected industrial scale CO2 storage operations were used, raising the reservoir pressure until the fault was reactivated. For the assumed model settings, it took a few months of continuous injection to increase the reservoir pressure sufficiently to cause the fault to reactivate. In the case of shale-gas fracturing we considered that the injection fluid during one typical 3-hour fracturing stage was channelized into a fault along with the hydraulic fracturing process. Overall, the analysis shows that while the CO2 geologic sequestration in deep sedimentary formations are capable of producing notable events (e

  6. 7 CFR 767.51 - Property abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR... 7 Agriculture 7 2010-01-01 2010-01-01 false Property abandonment. 767.51 Section 767.51... AGRICULTURE SPECIAL PROGRAMS INVENTORY PROPERTY MANAGEMENT Property Abandonment and Personal Property...

  7. 7 CFR 767.51 - Property abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR... 7 Agriculture 7 2011-01-01 2011-01-01 false Property abandonment. 767.51 Section 767.51... AGRICULTURE SPECIAL PROGRAMS INVENTORY PROPERTY MANAGEMENT Property Abandonment and Personal Property...

  8. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

  9. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

  10. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

  11. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

  12. 19 CFR 147.47 - Mandatory abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

  13. 19 CFR 147.47 - Mandatory abandonment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

  14. 19 CFR 147.47 - Mandatory abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

  15. 19 CFR 147.47 - Mandatory abandonment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

  16. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Abandoned vehicles. 636.31 Section 636.31... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.31 Abandoned vehicles. (a) Any MP or DOD police officer who finds or has knowledge of a...

  17. Evolution of abandoned underground hardrock mine closures by the Texas abandoned mine land reclamation program

    SciTech Connect

    Rhodes, M.J.

    1997-12-31

    The Texas Abandoned Mine Land (AML) Reclamation program began investigating, designing and implementing hard rock abandoned underground mine closures, after a young boy fell to his death in an abandoned mine opening in 1982. This paper discusses the evolution of abandoned hard rock mine closures in west Texas, by the Texas AML program in response to the development of abandoned underground mine resource information. Case histories are presented of the Texas AML program`s efforts in west Texas including: mine history summaries; site characterization, environmental assessment; design and construction planning considerations, and construction cost information.

  18. Crosswell Seismic Amplitude-Versus-Offset for Detailed Imaging of Facies and Fluid Distribution within Carbonate Oil Reservoirs

    SciTech Connect

    Wayne Pennington; Mohamed Ibrahim; Roger Turpening; Sean Trisch; Josh Richardson; Carol Asiala; Walid Mabrouk

    2008-09-30

    Crosswell seismic surveys were conducted at two fields in northern Michigan. One of these, Springdale, included two monitor wells that are located external to the reef, and the other, Coldspring, employed two production wells within the reef. The Springdale wells extended to much greater depths than the reef, and imaging was conducted from above and from beneath the reef. The resulting seismic images provide the best views of pinnacle Niagaran reefs obtained to date. The tops of the reservoirs can be clearly distinguished, and their lateral extent or dipping edges can be observed along the profile. Reflecting events internal to the reef are evident; some of them are fairly continuous across the reef and others are discontinuous. Inversion of the seismic data indicates which events represent zones of higher porosity and which are lower porosity or even anhydrite plugged. The full stacked image includes angles that are beyond critical for many of the interfaces, and some reflections are visible only for a small range of angles, presumably near their critical angle. Stacking these angles in provides an opportunity for these events to be seen on the stacked image, where otherwise they would have been unrecognized. For inversion, however, the complexity associated with phase changes beyond critical can lead to poor results, and elastic inversion of partial angle stacks may be best conducted with restrictions to angles less than critical. Strong apparent attenuation of signals occurs when seismic ray paths pass through the upper part of the Springdale reservoir; this may be due to intrinsic attenuation and/or scattering of events due to the locally strongly varying gas saturation and extremely low fluid pressures. Signal-to-noise limitations become evident far from the source well in the Coldspring study, probably because the raw data were strongly affected by tube-wave noise generated by flow through the perforation of the receiver well. The seismic images obtained, and

  19. Mercury (Hg) accumulation in terrestrial carbon (C) reservoirs: magnitude, spatial patterns, fate upon C losses, and implications of global change

    NASA Astrophysics Data System (ADS)

    Obrist, D.; Johnson, D. W.; Lindberg, S. E.; Luo, Y.

    2012-04-01

    Terrestrial ecosystems are strong natural reservoirs that retain the bulk of atmospheric Hg deposition. As a result, a long-term legacy of past and present Hg pollution is sequestered in surface litter and soil pools. Hg shows a particular affinity to—and hence tends to accumulate in—terrestrial organic C. We present a summary of a comprehensive five-year investigation where we quantified: (i) relationships between Hg and C across 14 forests sites to assess the affinity of Hg to C accumulation across spatial scales; (ii) the degree to which C determines net retention and spatial accumulation of Hg; (iii) the fate of Hg upon losses of C, including losses though wildfires and mineralization; (iv) the coupling of gaseous Hg losses to CO2 respiration; and (v) the potential sensitivity of climate-change induced changes in C on terrestrial Hg sequestration. Results show that continental-scale spatial distribution of Hg in soils and litter is strongly related to C, and that old terrestrial C pools (as determined by C/N ratios) are particularly prone to Hg enrichment. The correlation of Hg and C is likely responsible for increasing Hg levels (concentrations and pools of total Hg, as well as methylated Hg) with higher latitude, which we attribute to a legacy of Hg sequestration in C-rich layers of northern ecosystems. Experimental studies and field observations to address fate of Hg sequestered in organic C show that: (i) fires leads to up-to-complete Hg losses in either gaseous elemental or particulate-bound form; (ii) litter decomposition also leads to evasion losses of Hg in the range of 50% of initial Hg, but little Hg is subject to runoff as dissolved Hg; (iii) soils effectively retain Hg with only about 3% of Hg subject to volatilization upon C loss during respiration; (iv) no links between CO2 and gaseous Hg concentrations are observed in soil depth profiles in the field, indicating that fate and movement of gaseous Hg is decoupled from that of CO2. We calculate

  20. Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

    SciTech Connect

    Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

    1999-04-28

    The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

  1. A critical evaluation of a steamflood pilot in a deep heavy carbonate reservoir in Ikiztepe Field, Turkey

    SciTech Connect

    Nakamura, S.; Sarma, H.K.; Umucu, T.

    1995-12-31

    This paper presents an evaluation of a 4,430-ft deep steamflood pilot being carried out jointly by the Japan National Oil Corporation (JNOC) and Turkish Petroleum Corporation (TPAO) in collaboration with the Japan EOR Research Association (JEORA) in the Sinan heavy, oil reservoir of the Ikiztepe field, Turkey. The paper discusses pilot operations and performance highlighting the problems and the corresponding remedial measures/solutions adopted. Also presented is a discussion of results of an integrated simulation history match study. The pilot is in its final phase, and has so far yielded oil-steam ratios (OSR) of 3.42 and 0.32 during the initial cyclic steam stimulation phase and the steamflood, respectively.

  2. [Changes of plant community biomass and soil nutrients during the vegetation succession on abandoned cultivated land in desert steppe region].

    PubMed

    An, Hui; Yang, Xin-Guo; Liu, Bing-Ru; Li, Xue-Bin; He, Xiu-Zhen; Song, Nai-Ping

    2011-12-01

    By the method of substituting temporal serial with spatial serial, and taking five abandoned cultivated lands with different ages (1, 4, 9, 12, and 20 years) in desert steppe region as test objects, this paper studied the change characteristics of plant community biomass and soil nutrients during vegetation succession. With the increasing abandoned years, the plant community aboveground biomass on the abandoned lands increased after an initial decrease, whereas the total nitrogen, total phosphorus, organic carbon contents, and carbon density in 0-60 cm soil layer increased first, decreased then, and increased again, with the maximum values of soil total nitrogen and phosphorus contents appeared on the abandoned lands with the ages 4 and 20 years. During vegetation succession, the effects of soil total nitrogen and organic carbon on plant community biomass were greater than those of soil total phosphorus and soil bulk density. PMID:22384580

  3. Design and implementation of a CO{sub 2} flood utilizing advanced reservoir characterization and horizontal injection wells in a shallow shelf carbonate approaching waterflood depletion. Quarterly report, April 1, 1995--June 30, 1995

    SciTech Connect

    Wier, D.R.

    1995-09-01

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a CO{sub 2} project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. The work reported here is on the reservoir characterization and project design objective. This objective is scheduled to be completed in early 1996 at which time work on the field demonstration phase is scheduled to begin.

  4. [Eco-restoration of abandoned farmland in the Loess Plateau].

    PubMed

    Hou, Fujiang; Xiao, Jinyu; Nan, Zhibiao

    2002-08-01

    The vegetation on abandoned farmland was succeeded from Agriophyllum arenarium community to Lespedeza davurica community under cutting conditions. More plant species was recruited at the initial stage of restoration. The new plant species established earlier were annual Agriophyllum arenarium and perennial Pennisetum flaccidum which could be the dominant species or sub-dominant species. The perennial Artemisia capillaris established in early-middle stage could be the sub-dominant species, and leguminous plants appeared in late-middle stage could only be the associated species. The aboveground biomass of annual species reduced by 8.8% annually, while the perennial species increased with the similar rate. The aboveground biomass of leguminous species increased continuously. As the restoration proceeded, more underground biomass was distributed in upper soil layer. In 1-7 years of restoration of abandoned land, the clay and silt in 0-30 cm soil profile reduced, while grit increased, but the inverse trend occurred after 7 years. The water content in 0-100 cm soil profile increased continuously, especially during middle stage. Total and available nitrogen in 0-100 cm soil profile reduced in early stage, but increased in late stage. Total and available phosphorus and organic carbon in soil profile reduced continuously under cutting conditions. For the restoration of abandoned farmland to the current stable community, it would take 8-9 years for dominant population, 9-11 years for vegetative community and 11-12 years for soil system. PMID:12418248

  5. Improved oil recovery in Mississippian carbonate reservoirs of Kansas - near term -- Class 2. Quarterly progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Carr, T.; Green, D.W.; Willhite, G.P.

    1995-11-01

    The objective of this project is to demonstrate incremental reserves from Osagian and Meramecian dolomite reservoirs in western Kansas through application of reservoir characterization to identify areas of unrecovered mobile petroleum. Specific reservoirs targeted are the Schaben Field in Ness County and the Bindley Field in Hodgeman County.

  6. Reservoir Model of the Jacksonburg-Stringtown Oil Field; Northwestern West Virginia: Potential for Miscible Carbon Dioxide Enhanced Oil Recovery

    NASA Astrophysics Data System (ADS)

    Bergerud, Blake

    Located in northwestern West Virginia, the Jacksonburg-Stringtown field has produced over 22 million barrels of oil (MMBO) since its discovery in 1895. The primary producing interval within the field is the Late Devonian Gordon Stray. Log analysis shows this formation to represent an estuarine depositional system. Four subunits within the formation are defined based on depositional framework: barrier sand, central bay shale, estuarine channels, and fluvial channel subunits. RHOmaa/Umaa lithological composition plots support the conclusion of a marine-influenced estuarine depositional framework. Structural and isopach maps generated with data from 73 local wells reveal a northeast-southwest trending sand deposit of 15-35 foot thickness, which is interpreted as the depocenter for the incised valley of the Gordon Stray. Analysis of formation horizon maps shows that the reservoir is synclinal and, as a result, contains a stratigraphic trap as opposed to the more common structural traps found in the immediate area. Porosity and pore-feet distribution maps indicate high porosity regions in southern regions of the field and high pore volume in northern areas. A miscible CO2 flood model estimates that an additional 7.3 MMBO could be recovered from the high porosity regions in the southern half of the field. The Jacksonburg-Stringtown field is well-suited for enhanced oil recovery and/or geologic CO2 sequestration.

  7. The use of the terrestrial snails of the genera Megalobulimus and Thaumastus as representatives of the atmospheric carbon reservoir

    PubMed Central

    Macario, Kita D.; Alves, Eduardo Q.; Carvalho, Carla; Oliveira, Fabiana M.; Ramsey, Christopher Bronk; Chivall, David; Souza, Rosa; Simone, Luiz Ricardo L.; Cavallari, Daniel C.

    2016-01-01

    In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America. PMID:27271349

  8. The use of the terrestrial snails of the genera Megalobulimus and Thaumastus as representatives of the atmospheric carbon reservoir.

    PubMed

    Macario, Kita D; Alves, Eduardo Q; Carvalho, Carla; Oliveira, Fabiana M; Ramsey, Christopher Bronk; Chivall, David; Souza, Rosa; Simone, Luiz Ricardo L; Cavallari, Daniel C

    2016-01-01

    In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America. PMID:27271349

  9. The use of the terrestrial snails of the genera Megalobulimus and Thaumastus as representatives of the atmospheric carbon reservoir

    NASA Astrophysics Data System (ADS)

    Macario, Kita D.; Alves, Eduardo Q.; Carvalho, Carla; Oliveira, Fabiana M.; Ramsey, Christopher Bronk; Chivall, David; Souza, Rosa; Simone, Luiz Ricardo L.; Cavallari, Daniel C.

    2016-06-01

    In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America.

  10. Wettability of supercritical carbon dioxide/water/quartz systems: simultaneous measurement of contact angle and interfacial tension at reservoir conditions.

    PubMed

    Saraji, Soheil; Goual, Lamia; Piri, Mohammad; Plancher, Henry

    2013-06-11

    Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact angle between the fluids and the rock mineral surface. A thorough study of these parameters and their variations with temperature and pressure will provide a better understanding of the carbon sequestration process and thus improve predictions of the sequestration efficiency. In this study, the controversial concept of wettability alteration of quartz surfaces in the presence of supercritical carbon dioxide (sc-CO2) was investigated. A novel apparatus for measuring interfacial tension and contact angle at high temperatures and pressures based on Axisymmetric Drop Shape Analysis with no-Apex (ADSA-NA) method was developed and validated with a simple system. Densities, interfacial tensions, and dynamic contact angles of CO2/water/quartz systems were determined for a wide range of pressures and temperatures relevant to geological sequestration of CO2 in the subcritical and supercritical states. Image analysis was performed with ADSA-NA method that allows the determination of both interfacial tensions and contact angles with high accuracy. The results show that supercritical CO2 alters the wettability of quartz surface toward less water-wet conditions compared to subcritical CO2. Also we observed an increase in the water advancing contact angles with increasing temperature indicating less water-wet quartz surfaces at higher temperatures. PMID:23627310

  11. Mapping the extent of abandoned farmland in Central and Eastern Europe using MODIS time series satellite data

    NASA Astrophysics Data System (ADS)

    Alcantara, Camilo; Kuemmerle, Tobias; Baumann, Matthias; Bragina, Eugenia V.; Griffiths, Patrick; Hostert, Patrick; Knorn, Jan; Müller, Daniel; Prishchepov, Alexander V.; Schierhorn, Florian; Sieber, Anika; Radeloff, Volker C.

    2013-09-01

    The demand for agricultural products continues to grow rapidly, but further agricultural expansion entails substantial environmental costs, making recultivating currently unused farmland an interesting alternative. The collapse of the Soviet Union in 1991 led to widespread abandonment of agricultural lands, but the extent and spatial patterns of abandonment are unclear. We quantified the extent of abandoned farmland, both croplands and pastures, across the region using MODIS NDVI satellite image time series from 2004 to 2006 and support vector machine classifications. Abandoned farmland was widespread, totaling 52.5 Mha, particularly in temperate European Russia (32 Mha), northern and western Ukraine, and Belarus. Differences in abandonment rates among countries were striking, suggesting that institutional and socio-economic factors were more important in determining the amount of abandonment than biophysical conditions. Indeed, much abandoned farmland occurred in areas without major constraints for agriculture. Our map provides a basis for assessing the potential of Central and Eastern Europe’s abandoned agricultural lands to contribute to food or bioenergy production, or carbon storage, as well as the environmental trade-offs and social constraints of recultivation.

  12. Continued distress among abandoned dogs in Fukushima.

    PubMed

    Nagasawa, Miho; Mogi, Kazutaka; Kikusui, Takefumi

    2012-01-01

    In Fukushima, Japan, a prolonged refugee situation caused by a major nuclear incident after the earthquake of March 11, 2011 has led to the unintentional abandonment of many pets. We received stray or abandoned dogs from rescue centers in Fukushima Prefecture. During re-socialization training and health care, we accessed the behavioral characteristics and the urine cortisol level of each dog and compared them with those of other abandoned dogs not involved in this earthquake. The dogs from Fukushima showed significantly lower aggression toward unfamiliar people, trainability, and attachment to their caretakers; also, urine cortisol levels in the dogs from Fukushima were 5-10-fold higher than those in abandoned dogs from another area of Japan. These results suggested that the dogs from Fukushima suffered through an extremely stressful crisis. PMID:23061007

  13. Weyl's Abandonment of Unified Field Theory

    NASA Astrophysics Data System (ADS)

    Sieroka, Norman

    2015-01-01

    In 1918, Hermann Weyl proposed a generalisation of Riemannian geometry, in order to unify general relativity and electrodynamics. This paper investigates the physical, mathematical and philosophical reasons for his subsequent abandonment of any such attempt towards a unified field theory.

  14. 7 CFR 767.51 - Property abandonment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR..., manage, and operate the abandoned security property, including marketing perishable security property...

  15. The rail abandonment process: A southern perspective

    SciTech Connect

    Not Available

    1988-12-01

    One factor in evaluating the desirability of rail transport for high-level radioactive wastes or spent fuels is the frequency, or lack thereof, with which railroad and railroad lines have been, and are, abandoned. If DOE makes a decision to use the rail option and a line is subsequently abandoned, the choice results in increased cost, time delays and possibly safety problems: Information is therefore needed prior to the decision-making process to evaluate the desirability of the rail shipping option. One result of the abandonments mentioned herein, as well as other later abandonments, is the creation of a US rail system undergoing an evolutionary process in the 1980s as far-reaching as the changes that occurred when the industry was in its infancy a century and-a-half ago. The purpose of this paper is to examine the factors leading to some of these changes by tracing the historical development of the rail abandonment process, with particular emphasis on the rise of regional railroads, their problems in the modern era and current trends in rail abandonments as well as their effects on the southeastern United States.

  16. Design and implementation of a CO{sub 2} flood utilizing advanced reservoir characterization and horizontal injection wells in a shallow shelf carbonate approaching waterflood depletion. Annual report, June 3, 1994--October 31, 1995

    SciTech Connect

    Hallenbeck, L.D.; Harpole, K.J.; Gerard, M.G.

    1996-05-01

    The work reported here covers Budget Phase I of the project. The principal tasks in Budget Phase I are the Reservoir Analysis and Characterization Task and the Advanced Technology Definition Task. Completion of these tasks have enabled an optimum carbon dioxide (CO{sub 2}) flood project to be designed and evaluated from an economic and risk analysis standpoint. Field implementation of the project has been recommended to the working interest owner of the South Cowden Unit (SCU) and approval has been obtained. The current project has focused on reducing initial investment cost by utilizing horizontal injection wells and concentrating the project in the best productivity area of the field. An innovative CO{sub 2} purchase agreement (no take or pay requirements, CO{sub 2} purchase price tied to West Texas Intermediate crude oil price) and gas recycle agreements (expensing cost as opposed to large capital investments for compression) were negotiated to further improve project economics. A detailed reservoir characterization study was completed by an integrated team of geoscientists and engineers. The study consisted of detailed core description, integration of log response to core descriptions, mapping of the major flow units, evaluation of porosity and permeability relationships, geostatistical analysis of permeability trends, and direct integration of reservoir performance with the geological interpretation. The study methodology fostered iterative bidirectional feedback between the reservoir characterization team and the reservoir engineering/simulation team to allow simultaneous refinement and convergence of the geological interpretation with the reservoir model. The fundamental conclusion from the study is that South Cowden exhibits favorable enhanced oil recovery characteristics, particularly reservoir quality and continuity.

  17. Manual of carbonate sedimentology

    SciTech Connect

    Reijers, T.J.; Hsu, K.S.

    1986-01-01

    This manual, organised along encycolopaedic/lexicographic lines, summarizes information on the properties and characteristics of carbonates and their environments. Part 1 deals with the elements of carbonates; Part 2 with environments, settings, and carbonate bodies; Part 3 with carbonate diagenesis, and Part 4 with carbonate reservoirs. Contents include: Elements of carbonates; Carbonate Environments, Settings and Bodies; Carbonate diagenesis; Carbonate reservoirs; Alphabetical Indices; English, Dutch, German, Spanish, French Computer Compatible Codes; Commonly Used (Informal) abbreviations.

  18. Architectural characteristics and petrophysical properties evolution of a strike-slip fault zone in a fractured porous carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Guglielmi, Yves; Lamarche, Juliette; Cappa, Frédéric; Marié, Lionel

    2012-11-01

    This paper describes the structural, petrophysical and hydromechanical properties relationships between a small fault zone and the porous layered carbonate series which host it. In a gallery located at 250-m depth, the deformation of a 22-m thick section of layered carbonates-, affected by a strike slip-fault have been characterized by means of structural (Q-value), acoustic velocities (Vp), porosity and uniaxial compressive strength (σc) measurements conducted in situ at the meter scale, and on laboratory samples at the infra-centimeter scale. A clear influence of the layers initial properties on fault architecture and properties evolution is underlined. In the porous layers with a low σc, there is an important accommodation of the deformation by micro-mechanisms resulting in a progressive decrease in the porosity toward the fault core. In the low-porosity layers with a high σc, deformations are accommodated toward the fault core by: an increase in the fracture porosity, in the micro-cracks porosity, and by displacements along pre-existing fractures resulting from a joint roughness decrease. The fault zone appears as relatively stiff and low permeable zones intercalated with low stiffness and high fracture permeability zones that extend one to tens of meters from the fault following the initial properties contrasts and geometry of the sedimentary layers.

  19. Characterizing Microbial Diversity and Function in Natural Subsurface CO2 Reservoir Systems for Applied Use in Geologic Carbon Sequestration Environments

    NASA Astrophysics Data System (ADS)

    Freedman, A. J.; Thompson, J. R.

    2012-12-01

    The injection of CO2 into geological formations at quantities necessary to significantly reduce CO2 emissions will represent an environmental perturbation on a continental scale. The extent to which biological processes may play a role in the fate and transport of CO2 injected into geological formations has remained an open question due to the fact that at temperatures and pressures associated with reservoirs targeted for sequestration CO2 exists as a supercritical fluid (scCO2), which has generally been regarded as a sterilizing agent. Natural subsurface accumulations of CO2 serve as an excellent analogue for studying the long-term effects, implications and benefits of CO2 capture and storage (CCS). While several geologic formations bearing significant volumes of nearly pure scCO2 phases have been identified in the western United States, no study has attempted to characterize the microbial community present in these systems. Because the CO2 in the region is thought to have first accumulated millions of years ago, it is reasonable to assume that native microbial populations have undergone extensive and unique physiological and behavioral adaptations to adjust to the exceedingly high scCO2 content. Our study focuses on the microbial communities associated with the dolomite limestone McElmo Dome scCO2 Field in the Colorado Plateau region, approximately 1,000 m below the surface. Fluid samples were collected from 10 wells at an industrial CO2 production facility outside Cortez, CO. Subsamples preserved on site in 3.7% formaldehyde were treated in the lab with Syto 9 green-fluorescent nucleic acid stain, revealing 3.2E6 to 1.4E8 microbial cells per liter of produced fluid and 8.0E9 cells per liter of local pond water used in well drilling fluids. Extracted DNAs from sterivex 0.22 um filters containing 20 L of sample biomass were used as templates for PCR targeting the 16S rRNA gene. 16S rRNA amplicons from these samples were cloned, sequenced and subjected to microbial

  20. USING RECENT ADVANCES IN 2D SEISMIC TECHNOLOGY AND SURFACE GEOCHEMISTRY TO ECONOMICALLY REDEVELOP A SHALLOW SHELF CARBONATE RESERVOIR: VERNON FIELD, ISABELLA COUNTY, MI.

    SciTech Connect

    James R. Wood; T.J. Bornhorst; S.D. Chittick; William B. Harrison; W. Quinlan; E. Taylor

    2001-07-31

    A principal goal of the Budget Period I was to demonstrate that surface geochemistry could be used to locate bypassed hydrocarbons in old fields. This part of the program was successful. A surface geochemical survey, employing 5 different techniques, was carried out in the Spring and Summer of 2000 and a demonstration well, the State Vernon & Smock 13-23 HD1 (permit number: PN 53945) was drilled in Vernon Township, Isabella County, Michigan in the late fall of 2000. A demonstration well was selected and drilled based on geologic considerations and surface geochemistry. Over 460 soil samples were collected and analyzed over the drill site. A good anomaly was detected near the proposed well site and the demonstration well, the Smock 13-23, was drilled to a depth of 3157 feet by November 17, 2000. Two laterals were drilled, and hydrocarbons were located in a zone approximately 175 feet in length. However, it was determined that the pay zone was too small and difficult reservoir conditions (water production) prevented putting the well in production. The Smock 13-23 was shut in and abandoned January 15, 2001. A post-mortem determined that the main reason the well was not economic was because the zone was nearly completely flushed by earlier recovery operations. The post mortem also revealed the presence of an unmapped shale plug crossing the first lateral. It appears that this shale was detected by the geochemical survey, but its significance was not appreciated at the time. It is possible that sections of the well were faulty, ''porposing'' up and down so as to create water blockages. We are continuing to use the Vernon Field and the demonstration well to calibrate the geochemical data. Eventually, this study may provide a standard site that can be used to test and calibrate geochemical anomalies, something that does not presently exist. A postmortem report on the well, including the geology and geochemistry used to site the well, is presented in Appendix I. Five

  1. Channel characterization using multiple-point geostatistics, neural network, and modern analogy: A case study from a carbonate reservoir, southwest Iran

    NASA Astrophysics Data System (ADS)

    Hashemi, Seyyedhossein; Javaherian, Abdolrahim; Ataee-pour, Majid; Tahmasebi, Pejman; Khoshdel, Hossein

    2014-12-01

    In facies modeling, the ideal objective is to integrate different sources of data to generate a model that has the highest consistency to reality with respect to geological shapes and their facies architectures. Multiple-point (geo)statistics (MPS) is a tool that gives the opportunity of reaching this goal via defining a training image (TI). A facies modeling workflow was conducted on a carbonate reservoir located southwest Iran. Through a sequence stratigraphic correlation among the wells, it was revealed that the interval under a modeling process was deposited in a tidal flat environment. Bahamas tidal flat environment which is one of the most well studied modern carbonate tidal flats was considered to be the source of required information for modeling a TI. In parallel, a neural network probability cube was generated based on a set of attributes derived from 3D seismic cube to be applied into the MPS algorithm as a soft conditioning data. Moreover, extracted channel bodies and drilled well log facies came to the modeling as hard data. Combination of these constraints resulted to a facies model which was greatly consistent to the geological scenarios. This study showed how analogy of modern occurrences can be set as the foundation for generating a training image. Channel morphology and facies types currently being deposited, which are crucial for modeling a training image, was inferred from modern occurrences. However, there were some practical considerations concerning the MPS algorithm used for facies simulation. The main limitation was the huge amount of RAM and CPU-time needed to perform simulations.

  2. Polyurethane-derived N-doped porous carbon with interconnected sheet-like structure as polysulfide reservoir for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Xiao, Suo; Liu, Songhang; Zhang, Jianqiu; Wang, Yong

    2015-10-01

    Environmental pollution and energy deficiency are two key issues for the sustainable development of the modern society. Polyurethane foam is a typical commercial polymer with a large production quantity and its waste needs to be recycled. Lithium-sulfur battery is a promising energy-storage device with high energy density and low cost, but its demerits such as poor conductivity of the sulfur and severe capacity degradation due to the soluble lithium polysulfides are still a big challenge. This work reports a facile method to prepare nitrogen-doped porous carbon (NPC) from the polyurethane foam (PUF) waste and use it as a reservoir to impregnate sulfur for lithium-sulfur batteries. The obtained NPC has a unique interconnected sheet-like porous morphology with a large surface area of 1315 m2 g-1. The NPC-S composite delivers a large reversible capacity of 1118 mAh g-1 with good cycling performances and excellent high-rate capabilities. A large reversible capacity of 460 mAh g-1 can be retained at a large current of 5C (8.35 A g-1) after 100 cycles.

  3. Application of integrated reservoir management and reservoir characterization to optimize infill drilling. [Quarterly] report, March 13, 1995--June 12, 1995

    SciTech Connect

    Pande, P.K.

    1995-06-12

    The primary objective of this project is to conduct a cost-shared geologically targeted infill drilling filed demonstration that will enhance the domestic producibility of shallow shelf carbonate reservoirs by demonstration and technology transfer of the advanced recovery technologies employed, application of integrated reservoir management and reservoir characterization. Progress reports are presented for this past quarter for the following tasks: management and administration; reservoir characterization and analysis; integrated reservoir management; and technology transfer.

  4. Relationship between fracturing and porogenesis in a carbonate reservoir: Example from the Middle Turonian Bireno Member in Jebel M'rhila, Central Tunisia

    NASA Astrophysics Data System (ADS)

    Haj Ali, Hajer; Belghithi, Hanen; Ouali, Jamel Abdennaceur; Touir, Jamel

    2016-09-01

    The aim of the present work is to study the Middle Turonian carbonate Bireno Member in Jebel M'rhila area (Central Tunisia). This member mainly consists of dolostones. The sampling of the dolomitic rocks was carried out on both sides of the several fractures affecting the Bireno Member. We also measured the directions and dips of the fractures. The Studied dolomites basically consist of subhedral to euhedral dolospar. The porosity associated to the dolomites show a gradual variation both laterally and vertically. In fact, porosity increases respectively, laterally while going toward the fractures and vertically from the bottom to the top of the dolomitic member. The mineralogical and geochemical analyses of dolomite, carried out respectively by X-Ray Diffraction and Atomic Absorption, show that the studied dolomites broadly range from a sub-stoechiometric dolomite (48% CaCO3) far from the fractures to a dolomitic calcite (84% CaCO3) near the fractures. In the same way, the MgCO3 contents vary from 35% to 11%. Such high contents in Ca against low contents in Mg could probably related to the dilution of the dolomitizing marine waters by meteoric waters which would have been introduced within the platform during the Middle Turonian sea-level fall and the subsequent subaerial exposure of the Bireno platform. The Sr and Na contents (respectively, 4 ppm and 15 ppm in average) are rather low and they gradually decrease while approaching the fractures. Such a gradual decrease in Sr and Na concentrations may be the result of salinity lowering caused by the meteoric waters that would have circulated through the existing fractures networks. The previous analyses were supplemented by the SEM examination of the dolomite and the measurement of porosity and permeability. The SEM allowed us to identify the dolomite petrographic phases and the associated diagenetic products (solution, cementing, dedolomitization.), whereas the porosity and permeability evaluation highlights the

  5. Multiscale seismic signature of a small fault zone in a carbonate reservoir: Relationships between VP imaging, fault zone architecture and cohesion

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Guglielmi, Yves; Cappa, Frédéric

    2012-07-01

    The seismic (P-waves velocity, VP) signature of a small fault zone intersecting carbonate reservoir layers with contrasted properties of the southeastern French sedimentary basin was studied from the micro-scale to the fault zone pluri-meter scale architecture. VP measurements were done both at the meter scale, at 250-m depth in a gallery within the LSBB-URL, and at the centimeter scale (laboratory scale), on samples collected through boreholes. Results were compared to a VP tomography at the reservoir scale and to the fault rock mechanical properties. Our investigations indicated that P-wave velocity variations across the fault zone are strongly correlated to some key parameters, such as the uniaxial compressive strength (σc) of the fault core, the intact rock porosity (ϕ) and the fracturation intensity (RQD) of the damage zone. The seismic visibility of the fault zone depends on the contrasts between the porosity and the fracturation density of the sedimentary layers. In porous layers the fault induced deformations are mainly accommodated at the micro-scale (grain scale) with few macroscopic fractures, and the damage zone is thin leading to a high VP contrast with the fault core. In the low-porosity layers where deformations are mainly accommodated through brittle fractures, the seismic visibility of the fault is moderate, characterized by a decrease in the VP value which remains within the magnitude of the VP variations within the layers outside the fault zone. Interestingly, the fault seismic signature in the highly fractured layers appears clearly in the frequency domain at 3 dominant frequencies (2000, 9000 and 28,000 Hz), each of which exhibiting different spectral amplitudes for each components of the fault zone. Finally, the seismic signature of a relatively small fault zone included in a layered sedimentary series appears discontinuous, characterized by more or less thick high velocity patches more or less extended within the stratigraphic layers. We

  6. Different carbon reservoirs of auriferous fluids in African Archean and Proterozoic gold deposits? Constraints from stable carbon isotopic compositions of quartz-hosted CO2-rich fluid inclusions

    NASA Astrophysics Data System (ADS)

    Lüders, Volker; Klemd, Reiner; Oberthür, Thomas; Plessen, Birgit

    2015-04-01

    Stable carbon (and when present, nitrogen) isotope ratios of fluid inclusions in quartz from selected gold deposits in Ghana and Zimbabwe have been analyzed using a crushing device interfaced to an isotopic ratio mass spectrometer (IRMS) in order to constrain possible sources of the auriferous fluids. The study revealed a striking difference in stable carbon isotopic compositions of CO2 in quartz-hosted fluid inclusions from Archean and Paleoproterozoic orogenic gold deposits and points to diverse sources of CO2 in the studied deposits. Whether this finding can be generalized for other Archean and Proterozoic orogenic gold deposits worldwide remains open. However, a significant CO2 contribution by mantle degassing can be ruled out for every deposit studied. Devolatilization of greenstone belt rocks is the most likely source for CO2 in some Archean Au deposits in Zimbabwe, whereas CO2 in Proterozoic vein-type Au deposits in the West African Craton is most likely derived from Corg-bearing metasedimentary rocks. The δ13CCO2 values of high-density CO2-rich, water-poor inclusions hosted in quartz pebbles from the world-class Au-bearing conglomerate deposits at Tarkwa (Ghana) differ considerably from the δ13CCO2 values of similar high-density CO2-rich inclusions in vein quartz from the giant Ashanti deposit (Ghana) and disprove the idea of derivation of the Tarkwaian quartz (and gold?) from an older equivalent to the Ashanti vein-type gold deposit.

  7. Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality shallow shelf San Andres reservoir. Quarterly progress report, October 1--December 31, 1997

    SciTech Connect

    Taylor, A.R.; Hickman, T.S.; Justice, J.J.

    1998-01-31

    West Welch Unit is one of four large waterflood units in the Welch Field in the northwestern portion of Dawson County, Texas. The Welch Field produces oil under a solution gas drive mechanism from the San Andres formation at approximately 4,800 ft. The field has been under waterflood for 30 years and a significant portion has been infill-drilled on 20-ac density. A 1982--86 pilot CO{sub 2} injection project in the offsetting South Welch Unit yielded positive results. Recent installation of a CO{sub 2} pipeline near the field allowed the phased development of a miscible CO{sub 2} injection project at the South Welch Unit. The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: advanced petrophysics; three-dimensional seismic; cross-well bore tomography; advanced reservoir simulation; CO{sub 2} stimulation treatments; hydraulic fracturing design and monitoring; and mobility control agents. During the quarter, development of the project`s south expansion area was undertaken, work was continued on interpreting the crosswell seismic data and CO{sub 2} injection into 11 wells was initiated.

  8. Modeling the Injection of Carbon Dioxide and Nitrogen into a Methane Hydrate Reservoir and the Subsequent Production of Methane Gas on the North Slope of Alaska

    NASA Astrophysics Data System (ADS)

    Garapati, N.; McGuire, P. C.; Liu, Y.; Anderson, B. J.

    2012-12-01

    HydrateResSim (HRS) is an open-source finite-difference reservoir simulation code capable of simulating the behavior of gas hydrate in porous media. The original version of HRS was developed to simulate pure methane hydrates, and the relationship between equilibrium temperature and pressure is given by a simple, 1-D regression expression. In this work, we have modified HydrateResSim to allow for the formation and dissociation of gas hydrates made from gas mixtures. This modification allows one to model the ConocoPhillips Ignik Sikumi #1 field test performed in early 2012 on the Alaska North Slope. The Ignik Sikumi #1 test is the first field-based demonstration of gas production through the injection of a mixture of carbon dioxide and nitrogen gases into a methane hydrate reservoir and thereby sequestering the greenhouse gas CO2 into hydrate form. The primary change to the HRS software is the added capability of modeling a ternary mixture consisting of CH4 + CO2 + N2 instead of only one hydrate guest molecule (CH4), therefore the new software is called Mix3HydrateResSim. This Mix3HydrateResSim upgrade to the software was accomplished by adding primary variables (for the concentrations of CO2 and N2), governing equations (for the mass balances of CO2 and N2), and phase equilibrium data. The phase equilibrium data in Mix3HydrateResSim is given as an input table obtained using a statistical mechanical method developed in our research group called the cell potential method. An additional phase state describing a two-phase Gas-Hydrate (GsH) system was added to consider the possibility of converting all available free water to form hydrate with injected gas. Using Mix3HydrateResSim, a methane hydrate reservoir with coexisting pure-CH4-hydrate and aqueous phases at 7.0 MPa and 5.5°C was modeled after the conditions of the Ignik Sikumi #1 test: (i) 14-day injection of CO2 and N2 followed by (ii) 30-day production of CH4 (by depressurization of the well). During the

  9. Characterizing a Mississippian Carbonate Reservoir for CO2-EOR and Carbon Geosequestration: Applicability of Existing Rock Physics Models and Implications to Feasibility of a Time Lapse Monitoring Program in the Wellington Oil Field, Sumner County, Kansas.

    NASA Astrophysics Data System (ADS)

    Lueck, A. J.; Raef, A. E.

    2015-12-01

    This study will focus on characterizing subsurface rock formations of the Wellington Field, in Sumner County, Kansas, for both geosequestration of carbon dioxide (CO2) in the saline Arbuckle formation and enhanced oil recovery of a depleting Mississippian oil reservoir. Multi-scale data including lithofacies core samples, X-ray diffraction, digital rock physics scans, scanning electron microscope (SEM) imaging, well log data including sonic and dipole sonic, and surface 3D seismic reflection data will be integrated to establish and/or validate a new or existing rock physics model that best represents our reservoir rock types and characteristics. We will acquire compressional wave velocity and shear wave velocity data from Mississippian and Arbuckle cores by running ultrasonic tests using an Ult 100 Ultrasonic System and a 12 ton hydraulic jack located in the geophysics lab in Thompson Hall at Kansas State University. The elastic constants Young's Modulus, Bulk Modulus, Shear (Rigidity) Modulus and Poisson's Ratio will be extracted from these velocity data. Ultrasonic velocities will also be compared to sonic and dipole sonic log data from the Wellington 1-32 well. These data will be integrated to validate a lithofacies classification statistical model, which will be and partially has been applied to the largely unknown saline Arbuckle formation, with hopes for a connection, perhaps via Poisson's ratio, allowing a time-lapse seismic feasibility assessment and potentially developing a transformation of compressional wave sonic velocities to shear wave sonic for all wells, where compressional wave sonic is available. We will also be testing our rock physics model by predicting effects of changing effective (brine + CO2 +hydrocarbon) fluid composition on seismic properties and the implications on feasibility of seismic monitoring. Lessons learned from characterizing the Mississippian are essential to understanding the potential of utilizing similar workflows for the

  10. Reservoir Technology

    SciTech Connect

    Renner, J.L.

    1992-03-24

    The reservoir technology program supports the utilization of geothermal resources through development and verification of new earth science technologies for: exploration, fluid production and injection; and prediction of reservoir lifetimes. A two-fold strategy of conducting DOE-sponsored research to meet higher-risk, longer-term needs and cost-shared research with industry in areas of greatest current need is utilized to maximize the benefit of the program to the geothermal industry. The program uses a coordinated, multi-disciplinary approach to investigating and solving reservoir problems facing the industry. Research at The Geysers geothermal field has received major emphasis in the past three years. Recent progress in that work will be reviewed in detail by The Geysers operators, federal, state and local regulators and other interested parties during a meeting in Santa Rosa on May 5 and 6, 1992. Hence the papers by Lipman, Bodvarsson et al., Wannamaker, et al., Horne, and Shook in this proceedings volume emphasize non-Geysers research in the program.

  11. Infanticide and illegal infant abandonment in Malaysia.

    PubMed

    Razali, Salmi; Kirkman, Maggie; Ahmad, S Hassan; Fisher, Jane

    2014-10-01

    Infant abandonment and infanticide are poorly understood in Malaysia. The information available in the public arena comes predominantly from anecdotal sources. The aim of this study was to describe the prevalence and characteristics of infanticide and illegal infant abandonment in Malaysia and to estimate annual rates for the most recent decade. Summaries of data about infanticide and illegal infant abandonment were gathered from police records; the annual number of live births was ascertained from the national registry. The estimated inferred infanticide rates for Malaysia were compared with the infanticide rates among countries of very high, high, medium, and low rankings on the Human Development, Gender Inequality, and Gini indices. From 1999 to 2011, 1,069 cases of illegal infant abandonment were recorded and 1,147 people were arrested as suspected perpetrators. The estimated inferred infanticide rate fluctuated between 4.82 and 9.11 per 100,000 live births, a moderate rate relative to the infanticide rates of other countries. There are substantial missing data, with details undocumented for about 78-87% of cases and suspected perpetrators. Of the documented cases, it appeared that more boys than girls were victims and that suspected perpetrators were predominantly Malays who were women, usually mothers of the victim; the possibility of arrest bias must be acknowledged. Economic and social inequality, particularly gender inequality, might contribute to the phenomena of infanticide and abandonment. Strategies to reduce rates of infanticide and illegal infant abandonment in Malaysia will require strengthening of the surveillance system and attention to the gender-based inequalities that underpin human development. PMID:25048164

  12. Impact of CO2 leakage from sub-seabed carbon dioxide capture and storage (CCS) reservoirs on benthic virus-prokaryote interactions and functions.

    PubMed

    Rastelli, Eugenio; Corinaldesi, Cinzia; Dell'Anno, Antonio; Amaro, Teresa; Queirós, Ana M; Widdicombe, Stephen; Danovaro, Roberto

    2015-01-01

    Atmospheric CO2 emissions are a global concern due to their predicted impact on biodiversity, ecosystems functioning, and human life. Among the proposed mitigation strategies, CO2 capture and storage, primarily the injection of CO2 into marine deep geological formations has been suggested as a technically practical option for reducing emissions. However, concerns have been raised that possible leakage from such storage sites, and the associated elevated levels of pCO2 could locally impact the biodiversity and biogeochemical processes in the sediments above these reservoirs. Whilst a number of impact assessment studies have been conducted, no information is available on the specific responses of viruses and virus-host interactions. In the present study, we tested the impact of a simulated CO2 leakage on the benthic microbial assemblages, with specific focus on microbial activity and virus-induced prokaryotic mortality (VIPM). We found that exposure to levels of CO2 in the overlying seawater from 1,000 to 20,000 ppm for a period up to 140 days, resulted in a marked decrease in heterotrophic carbon production and organic matter degradation rates in the sediments, associated with lower rates of VIPM, and a progressive accumulation of sedimentary organic matter with increasing CO2 concentrations. These results suggest that the increase in seawater pCO2 levels that may result from CO2 leakage, can severely reduce the rates of microbial-mediated recycling of the sedimentary organic matter and viral infections, with major consequences on C cycling and nutrient regeneration, and hence on the functioning of benthic ecosystems. PMID:26441872

  13. Development and application of a new biotechnology of the molasses in-situ method; detailed evaluation for selected wells in the Romashkino carbonate reservoir

    SciTech Connect

    Wagner, M.; Lungerhausen, D.; Murtada, H.; Rosenthal, G.

    1995-12-31

    On the basis of different laboratory studies, by which special strains of the type Clostridium tyrobutyricum were found, the application of molasses in-situ method for the enhanced recovery of oil in Romashkino oil field was executed. In an anaerobic, 6%-molasses medium the strains produce about 11,400 mg/l of organic acids (especially butyric acid), 3,200 mg/l ethanol, butanol, etc., and more than 350 ml/g of molasses biogas with a content of 80% C0{sub 2} and 20% H{sub 2}. The metabolics of Clostridium tyrobutyricum depress the growth of SRB, whereas methanogenic bacteria grow in an undiluted fermented molasses medium very well. In this way the dominant final fermentation process is methanogenesis. By laboratory studies with original cores under the conditions of the carbonate reservoir in Bashkir, the recovery of oil increased from 15% after waterflooding to 29% OOIP during the treatment with molasses and bacteria. We developed a new biotechnological method for a self-regulated, automatic continuous culture and constructed a special pilot plant with a high technical standard. The plant produced during the pilot on Romashkino field (September 1992 to August 1994) about 1,000 m{sup 3} of clean inoculum with a content of 3-4 billion cells per ml. This inoculum was injected in slugs together with 15,000 m{sup 3} of molasses medium, first in one, later in five wells. We will demonstrate for two example wells the complex microbiological and chemical changes in the oil, gas, and water phases, and their influences on the recover of oil.

  14. The influence of reservoirs, climate, land use and hydrologic conditions on loads and chemical quality of dissolved organic carbon in the Colorado River

    NASA Astrophysics Data System (ADS)

    Miller, Matthew P.

    2012-09-01

    Longitudinal patterns in dissolved organic carbon (DOC) loads and chemical quality were identified in the Colorado River from the headwaters in the Rocky Mountains to the United States-Mexico border from 1994 to 2011. Watershed- and reach-scale climate, land use, river discharge and hydrologic modification conditions that contribute to patterns in DOC were also identified. Principal components analysis (PCA) identified site-specific precipitation and reach-scale discharge as being correlated with sites in the upper basin, where there were increases in DOC load from the upstream to downstream direction. In the lower basin, where DOC load decreased from upstream to downstream, sites were correlated with site-specific temperature and reach-scale population, urban land use and hydrologic modification. In the reaches containing Lakes Powell and Mead, the two largest reservoirs in the United States, DOC quantity decreased, terrestrially derived aromatic DOC was degraded and/or autochthonous less aromatic DOC was produced. Taken together, these results suggest that longitudinal patterns in the relatively unregulated upper basin are influenced by watershed inputs of water and DOC, whereas DOC patterns in the lower basin are reflective of a balance between watershed contribution of water and DOC to the river and loss of water and DOC due to hydrologic modification and/or biogeochemical processes. These findings suggest that alteration of constituent fluxes in rivers that are highly regulated may overshadow watershed processes that would control fluxes in comparable unregulated rivers. Further, these results provide a foundation for detailed assessments of factors controlling the transport and chemical quality of DOC in the Colorado River.

  15. Impact of CO2 leakage from sub-seabed carbon dioxide capture and storage (CCS) reservoirs on benthic virus–prokaryote interactions and functions

    PubMed Central

    Rastelli, Eugenio; Corinaldesi, Cinzia; Dell’Anno, Antonio; Amaro, Teresa; Queirós, Ana M.; Widdicombe, Stephen; Danovaro, Roberto

    2015-01-01

    Atmospheric CO2 emissions are a global concern due to their predicted impact on biodiversity, ecosystems functioning, and human life. Among the proposed mitigation strategies, CO2 capture and storage, primarily the injection of CO2 into marine deep geological formations has been suggested as a technically practical option for reducing emissions. However, concerns have been raised that possible leakage from such storage sites, and the associated elevated levels of pCO2 could locally impact the biodiversity and biogeochemical processes in the sediments above these reservoirs. Whilst a number of impact assessment studies have been conducted, no information is available on the specific responses of viruses and virus–host interactions. In the present study, we tested the impact of a simulated CO2 leakage on the benthic microbial assemblages, with specific focus on microbial activity and virus-induced prokaryotic mortality (VIPM). We found that exposure to levels of CO2 in the overlying seawater from 1,000 to 20,000 ppm for a period up to 140 days, resulted in a marked decrease in heterotrophic carbon production and organic matter degradation rates in the sediments, associated with lower rates of VIPM, and a progressive accumulation of sedimentary organic matter with increasing CO2 concentrations. These results suggest that the increase in seawater pCO2 levels that may result from CO2 leakage, can severely reduce the rates of microbial-mediated recycling of the sedimentary organic matter and viral infections, with major consequences on C cycling and nutrient regeneration, and hence on the functioning of benthic ecosystems. PMID:26441872

  16. Multiphase Flow and Cavern Abandonment in Salt

    SciTech Connect

    Ehgartner, Brian; Tidwell, Vince

    2001-02-13

    This report will explore the hypothesis that an underground cavity in gassy salt will eventually be gas filled as is observed on a small scale in some naturally occurring salt inclusions. First, a summary is presented on what is known about gas occurrences, flow mechanisms, and cavern behavior after abandonment. Then, background information is synthesized into theory on how gas can fill a cavern and simultaneously displace cavern fluids into the surrounding salt. Lastly, two-phase (gas and brine) flow visualization experiments are presented that demonstrate some of the associated flow mechanisms and support the theory and hypothesis that a cavity in salt can become gas filled after plugging and abandonment

  17. Opportunities to improve oil productivity in unstructured deltaic reservoirs

    SciTech Connect

    Not Available

    1991-01-01

    This report contains presentations presented at a technical symposium on oil production. Chapter 1 contains summaries of the presentations given at the Department of Energy (DOE)-sponsored symposium and key points of the discussions that followed. Chapter 2 characterizes the light oil resource from fluvial-dominated deltaic reservoirs in the Tertiary Oil Recovery Information System (TORIS). An analysis of enhanced oil recovery (EOR) and advanced secondary recovery (ASR) pot