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Sample records for accurate reservoir description

  1. Coupling geostatistics to detailed reservoir description allows better visualization and more accurate characterization/simulation of turbidite reservoirs: Elk Hills oil field, California

    SciTech Connect

    Allan, M.E.; Wilson, M.L.; Wightman, J. )

    1996-01-01

    The Elk Hills giant oilfield, located in the southern San Joaquin Valley of California, has produced 1.1 billion barrels of oil from Miocene and shallow Pliocene reservoirs. 65% of the current 64,000 BOPD production is from the pressure-supported, deeper Miocene turbidite sands. In the turbidite sands of the 31 S structure, large porosity permeability variations in the Main Body B and Western 31 S sands cause problems with the efficiency of the waterflooding. These variations have now been quantified and visualized using geostatistics. The end result is a more detailed reservoir characterization for simulation. Traditional reservoir descriptions based on marker correlations, cross-sections and mapping do not provide enough detail to capture the short-scale stratigraphic heterogeneity needed for adequate reservoir simulation. These deterministic descriptions are inadequate to tie with production data as the thinly bedded sand/shale sequences blur into a falsely homogenous picture. By studying the variability of the geologic petrophysical data vertically within each wellbore and spatially from well to well, a geostatistical reservoir description has been developed. It captures the natural variability of the sands and shales that was lacking from earlier work. These geostatistical studies allow the geologic and petrophysical characteristics to be considered in a probabilistic model. The end-product is a reservoir description that captures the variability of the reservoir sequences and can be used as a more realistic starting point for history matching and reservoir simulation.

  2. Coupling geostatistics to detailed reservoir description allows better visualization and more accurate characterization/simulation of turbidite reservoirs: Elk Hills oil field, California

    SciTech Connect

    Allan, M.E.; Wilson, M.L.; Wightman, J.

    1996-12-31

    The Elk Hills giant oilfield, located in the southern San Joaquin Valley of California, has produced 1.1 billion barrels of oil from Miocene and shallow Pliocene reservoirs. 65% of the current 64,000 BOPD production is from the pressure-supported, deeper Miocene turbidite sands. In the turbidite sands of the 31 S structure, large porosity & permeability variations in the Main Body B and Western 31 S sands cause problems with the efficiency of the waterflooding. These variations have now been quantified and visualized using geostatistics. The end result is a more detailed reservoir characterization for simulation. Traditional reservoir descriptions based on marker correlations, cross-sections and mapping do not provide enough detail to capture the short-scale stratigraphic heterogeneity needed for adequate reservoir simulation. These deterministic descriptions are inadequate to tie with production data as the thinly bedded sand/shale sequences blur into a falsely homogenous picture. By studying the variability of the geologic & petrophysical data vertically within each wellbore and spatially from well to well, a geostatistical reservoir description has been developed. It captures the natural variability of the sands and shales that was lacking from earlier work. These geostatistical studies allow the geologic and petrophysical characteristics to be considered in a probabilistic model. The end-product is a reservoir description that captures the variability of the reservoir sequences and can be used as a more realistic starting point for history matching and reservoir simulation.

  3. Tracer testing for reservoir description

    SciTech Connect

    Brigham, W.E.; Abbaszadeh-Dehghani, M.

    1987-05-01

    When a reservoir is studied in detail for an EOR project, well-to-well tracers should be used as a tool to help understand the reservoir in a quantitative way. Tracers complement the more traditional reservoir evaluation tools. This paper discusses the concepts underlying tracer testing, the analysis methods used to produce quantitative results, and the meaning of these results in terms of conceptual picture of the reservoir. Some of the limitations of these analysis methods are discussed, along with ongoing research on tracer flow.

  4. The first accurate description of an aurora

    NASA Astrophysics Data System (ADS)

    Schröder, Wilfried

    2006-12-01

    As technology has advanced, the scientific study of auroral phenomena has increased by leaps and bounds. A look back at the earliest descriptions of aurorae offers an interesting look into how medieval scholars viewed the subjects that we study.Although there are earlier fragmentary references in the literature, the first accurate description of the aurora borealis appears to be that published by the German Catholic scholar Konrad von Megenberg (1309-1374) in his book Das Buch der Natur (The Book of Nature). The book was written between 1349 and 1350.

  5. 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.

  6. Accurate description of calcium solvation in concentrated aqueous solutions.

    PubMed

    Kohagen, Miriam; Mason, Philip E; Jungwirth, Pavel

    2014-07-17

    Calcium is one of the biologically most important ions; however, its accurate description by classical molecular dynamics simulations is complicated by strong electrostatic and polarization interactions with surroundings due to its divalent nature. Here, we explore the recently suggested approach for effectively accounting for polarization effects via ionic charge rescaling and develop a new and accurate parametrization of the calcium dication. Comparison to neutron scattering and viscosity measurements demonstrates that our model allows for an accurate description of concentrated aqueous calcium chloride solutions. The present model should find broad use in efficient and accurate modeling of calcium in aqueous environments, such as those encountered in biological and technological applications.

  7. Innovative techniques for the description of reservoir heterogeneity using tracers

    SciTech Connect

    Pope, G.; Sepehrnoori, K.

    1991-09-01

    The objective of this research is to develop an advanced, innovative technique for the description of reservoir heterogeneity. This proposed method consists of using tracers in single-well backflow tests. The general idea is to make use of fluid drift in the reservoir either due to naturally occurring pressure gradients in the reservoir, or by deliberately imposed pressure gradients using adjacent injection and production wells in the same reservoir. The analytical tool that will be used to design and interpret these tests is a compositional reservoir simulator with special features added and tested specifically for this purpose. 2 refs., 5 figs.

  8. Flow unit concept - integrated approach to reservoir description for engineering projects

    SciTech Connect

    Ebanks, W.J. Jr.

    1987-05-01

    The successful application of secondary and tertiary oil recovery technology requires an accurate understanding of the internal architecture of the reservoir. Engineers have difficulty incorporating geological heterogeneity in their numerical models for simulating reservoir behavior. The concept of flow units has been developed to integrate geological and engineering data into a system for reservoir description. A flow unit is a volume of the total reservoir rock within which geological and petrophysical properties that affect fluid flow are internally consistent and predictably different from properties of other rock volumes (i.e., flow units). Flow units are defined by geological properties, such as texture, mineralogy, sedimentary structures, bedding contacts, and the nature of permeability barriers, combined with quantitative petrophysical properties, such as porosity, permeability, capillarity, and fluid saturations. Studies in the subsurface and in surface outcrops have shown that flow units do not always coincide with geologic lithofacies. The flow unit approach provides a means of uniquely subdividing reservoirs into volumes that approximate the architecture of a reservoir at a scale consistent with reservoir simulations. Thus, reservoir engineers can incorporate critical geological information into a reservoir simulation without greatly increasing the complexity of their models. This approach has advantages over more traditional methods of reservoir zonation whereby model layers are determined on the basis of vertical distributions of permeability and porosity from core analyses and wireline logs.

  9. Evaluating oil, gas opportunities in western Siberia; Reservoir description

    SciTech Connect

    Connelly, W. ); Krug, J.A. )

    1992-12-07

    In this article, the authors discuss how to use the subsurface data to describe hydrocarbon reservoirs and estimate the original oil in place (OOIP) in western Siberia. The methodology for describing a reservoir and estimating the OOIP in western Siberia is similar to the approach for most reservoirs: Establish stratigraphic correlations across the field; Construct structure maps on key horizons; Construct porosity isopach maps for significant reservoirs; Construct net pay maps; Determine reservoir parameters; and Calculate pore-volume estimates of OOIP.

  10. Geophysics in the multidisciplinary reservoir description team: The RAZOR Project, Prudhoe Bay unit, Alaska

    SciTech Connect

    Gilbert, E.; Natenstedt, C.; Wiener, R.; Montague, S.; Clippard, M.; Gallagher, P.; Vralsted, D.; Romine, K.

    1994-12-31

    The RAZOR Project was a multi-disciplinary multi-company team formed to provide a detailed geologic description of the Lower Ivishak reservoir in support of comprehensive reservoir management efforts. Interpreting and mapping multiple stratigraphic horizons, interpreting and tying faults in three dimensions,and detailed integration with sequence stratigraphy resulted in an improved understanding of reservoir architecture. The overall impact has been to achieve a more proactive and effective integration of geoscience products into the reservoir management process.

  11. Advancing reservoir operation description in physically based hydrological models

    NASA Astrophysics Data System (ADS)

    Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir

  12. Reservoir description and future development plans for the Unam/Mfem Fields, OML 67, Nigeria

    SciTech Connect

    Kofron, B.M.; Jenkinson, J.T.; Maxwell, G.S.

    1995-08-01

    The Unam/Mfem fields, which are currently produced from three platforms, are, located 25 km offshore (southeastern Nigeria) in water depths of 60 feet to 100 feet. Over 100 MMBO have been produced to date from both unconformity bounded and fault trap reservoirs in the Upper and Middle Biafra Sands. These structural and stratigraphic geometries define at least eleven different reservoirs that are not interconnected. STOIIP for all eleven reservoirs is estimated to exceed 900 MMBO based on a recently completed reservoir characterization study. A two year reservoir description study followed the acquisition of a 1991 3-D seismic survey and resulted in the drilling of six successful wells and two sidetracks. A 3-D model of reservoir geometries and fluid flow properties was generated by integrating geologic, geophysical, and reservoir engineering data. These diverse data sets were interpreted using a combination of workstations, software packages, and displays that included Landmark, IREX, wireline log and seismic correlation charts. A detailed stratigraphic zonation scheme with 28 zones was defined and correlated field wide and subregionally to build the reservoir framework. Twenty seismic horizons were created. More than 300 critical compute, generated grids were then used to calculate STOIIP volumes. This study led to the identification of new pay zones along with a much better understanding of the spatial distribution of all pays within the fields. A revised exploitation strategy has subsequently been proposed which calls for 5 new platforms and the drilling of 21 additional wells over the next few years.

  13. Application of fractal theory in refined reservoir description for EOR pilot area

    SciTech Connect

    Yue Li; Yonggang Duan; Yun Li; Yuan Lu

    1997-08-01

    A reliable reservoir description is essential to investigate scenarios for successful EOR pilot test. Reservoir characterization includes formation composition, permeability, porosity, reservoir fluids and other petrophysical parameters. In this study, various new tools have been applied to characterize Kilamayi conglomerate formation. This paper examines the merits of various statistical methods for recognizing rock property correlation in vertical columns and gives out methods to determine fractal dimension including R/S analysis and power spectral analysis. The paper also demonstrates that there is obvious fractal characteristics in conglomerate reservoirs of Kilamayi oil fields. Well log data in EOR pilot area are used to get distribution profile of parameters including permeability, porosity, water saturation and shale content.

  14. Geomorphology: A key to filling gaps and increasing realism in reservoir descriptions

    SciTech Connect

    Tye, R.S.

    1996-12-31

    Combining core and wireline data with geomorphic analogs facilitates the quantification of geologic information for the numerical characterization of subsurface strata. Traditional three-dimensional geologic descriptions are limited by one- and two-dimensional data sources (outcrop or well data). Geomorphic analyses of fluvio-deltaic systems reveal log-normal distributions of discrete depositional environments. These provide statistical constraints for conditioning the area (X and Y dimensions), shape, placement, and preferred orientation(s) of geologic facies in three-dimensional models. Accurate stratigraphic and facies-association representations built from subsurface and analog data are integral parts of geologic modeling. Seismic, outcrop, and vertically oriented well data provide structural and chronostratigraphic information. Moreover, core and wireline-log data give lithofacies; type and thickness (Z dimension), in addition to petrophysical trends. The distribution of facies in the X and Y directions (between wells) is realistically accomplished by using geomorphic guidelines to distribute lithofacies or facies-associations as three-dimensional objects. Furthermore, geomorphic analogs aid the distribution of a lithofacies within a facies association. This is beneficial where individual beds contain permeability extreme. Given, a relationship between facies and permeability, a three-dimensional rendition of facies becomes a proxy for reservoir quality. Geomorphic data from appropriate modern fluvio-deltaic analogs are linked with core and wireline-log data to render conditioned, three-dimensional, geologic models. Model accuracy relies upon bed-thickness and chronostratigraphic constraints imposed by cores and stratigraphic correlations, as well as, the lateral extent of facies associations governed by geomorphology.

  15. Geomorphology: A key to filling gaps and increasing realism in reservoir descriptions

    SciTech Connect

    Tye, R.S. )

    1996-01-01

    Combining core and wireline data with geomorphic analogs facilitates the quantification of geologic information for the numerical characterization of subsurface strata. Traditional three-dimensional geologic descriptions are limited by one- and two-dimensional data sources (outcrop or well data). Geomorphic analyses of fluvio-deltaic systems reveal log-normal distributions of discrete depositional environments. These provide statistical constraints for conditioning the area (X and Y dimensions), shape, placement, and preferred orientation(s) of geologic facies in three-dimensional models. Accurate stratigraphic and facies-association representations built from subsurface and analog data are integral parts of geologic modeling. Seismic, outcrop, and vertically oriented well data provide structural and chronostratigraphic information. Moreover, core and wireline-log data give lithofacies; type and thickness (Z dimension), in addition to petrophysical trends. The distribution of facies in the X and Y directions (between wells) is realistically accomplished by using geomorphic guidelines to distribute lithofacies or facies-associations as three-dimensional objects. Furthermore, geomorphic analogs aid the distribution of a lithofacies within a facies association. This is beneficial where individual beds contain permeability extreme. Given, a relationship between facies and permeability, a three-dimensional rendition of facies becomes a proxy for reservoir quality. Geomorphic data from appropriate modern fluvio-deltaic analogs are linked with core and wireline-log data to render conditioned, three-dimensional, geologic models. Model accuracy relies upon bed-thickness and chronostratigraphic constraints imposed by cores and stratigraphic correlations, as well as, the lateral extent of facies associations governed by geomorphology.

  16. Accurate description of argon and water adsorption on surfaces of graphene-based carbon allotropes.

    PubMed

    Kysilka, Jiří; Rubeš, Miroslav; Grajciar, Lukáš; Nachtigall, Petr; Bludský, Ota

    2011-10-20

    Accurate interaction energies of nonpolar (argon) and polar (water) adsorbates with graphene-based carbon allotropes were calculated by means of a combined density functional theory (DFT)-ab initio computational scheme. The calculated interaction energy of argon with graphite (-9.7 kJ mol(-1)) is in excellent agreement with the available experimental data. The calculated interaction energy of water with graphene and graphite is -12.8 and -14.6 kJ mol(-1), respectively. The accuracy of combined DFT-ab initio methods is discussed in detail based on a comparison with the highly precise interaction energies of argon and water with coronene obtained at the coupled-cluster CCSD(T) level extrapolated to the complete basis set (CBS) limit. A new strategy for a reliable estimate of the CBS limit is proposed for systems where numerical instabilities occur owing to basis-set near-linear dependence. The most accurate estimate of the argon and water interaction with coronene (-8.1 and -14.0 kJ mol(-1), respectively) is compared with the results of other methods used for the accurate description of weak intermolecular interactions.

  17. Accurate electronic-structure description of Mn complexes: a GGA+U approach

    NASA Astrophysics Data System (ADS)

    Li, Elise Y.; Kulik, Heather; Marzari, Nicola

    2008-03-01

    Conventional density-functional approach often fail in offering an accurate description of the spin-resolved energetics in transition metals complexes. We will focus here on Mn complexes, where many aspects of the molecular structure and the reaction mechanisms are still unresolved - most notably in the oxygen-evolving complex (OEC) of photosystem II and the manganese catalase (MC). We apply a self-consistent GGA + U approach [1], originally designed within the DFT framework for the treatment of strongly correlated materials, to describe the geometry, the electronic and the magnetic properties of various manganese oxide complexes, finding very good agreement with higher-order ab-initio calculations. In particular, the different oxidation states of dinuclear systems containing the [Mn2O2]^n+ (n= 2, 3, 4) core are investigated, in order to mimic the basic face unit of the OEC complex. [1]. H. J. Kulik, M. Cococcioni, D. A. Scherlis, N. Marzari, Phys. Rev. Lett., 2006, 97, 103001

  18. Reservoir evaluation of thin-bedded turbidites and hydrocarbon pore thickness estimation for an accurate quantification of resource

    NASA Astrophysics Data System (ADS)

    Omoniyi, Bayonle; Stow, Dorrik

    2016-04-01

    One of the major challenges in the assessment of and production from turbidite reservoirs is to take full account of thin and medium-bedded turbidites (<10cm and <30cm respectively). Although such thinner, low-pay sands may comprise a significant proportion of the reservoir succession, they can go unnoticed by conventional analysis and so negatively impact on reserve estimation, particularly in fields producing from prolific thick-bedded turbidite reservoirs. Field development plans often take little note of such thin beds, which are therefore bypassed by mainstream production. In fact, the trapped and bypassed fluids can be vital where maximising field value and optimising production are key business drivers. We have studied in detail, a succession of thin-bedded turbidites associated with thicker-bedded reservoir facies in the North Brae Field, UKCS, using a combination of conventional logs and cores to assess the significance of thin-bedded turbidites in computing hydrocarbon pore thickness (HPT). This quantity, being an indirect measure of thickness, is critical for an accurate estimation of original-oil-in-place (OOIP). By using a combination of conventional and unconventional logging analysis techniques, we obtain three different results for the reservoir intervals studied. These results include estimated net sand thickness, average sand thickness, and their distribution trend within a 3D structural grid. The net sand thickness varies from 205 to 380 ft, and HPT ranges from 21.53 to 39.90 ft. We observe that an integrated approach (neutron-density cross plots conditioned to cores) to HPT quantification reduces the associated uncertainties significantly, resulting in estimation of 96% of actual HPT. Further work will focus on assessing the 3D dynamic connectivity of the low-pay sands with the surrounding thick-bedded turbidite facies.

  19. The application study on the multi-scales integrated prediction method to fractured reservoir description

    NASA Astrophysics Data System (ADS)

    Chen, Shuang-Quan; Zeng, Lian-Bo; Huang, Ping; Sun, Shao-Han; Zhang, Wan-Lu; Li, Xiang-Yang

    2016-03-01

    In this paper, we implement three scales of fracture integrated prediction study by classifying it to macro- (> 1/4 λ), meso- (> 1/100 λ and < 1/4 λ) and micro- (< 1/100 λ) scales. Based on the multi-scales rock physics modelling technique, the seismic azimuthal anisotropy characteristic is analyzed for distinguishing the fractures of meso-scale. Furthermore, by integrating geological core fracture description, image well-logging fracture interpretation, seismic attributes macro-scale fracture prediction and core slice micro-scale fracture characterization, an comprehensive multi-scale fracture prediction methodology and technique workflow are proposed by using geology, well-logging and seismic multi-attributes. Firstly, utilizing the geology core slice observation (Fractures description) and image well-logging data interpretation results, the main governing factors of fracture development are obtained, and then the control factors of the development of regional macro-scale fractures are carried out via modelling of the tectonic stress field. For the meso-scale fracture description, the poststack geometric attributes are used to describe the macro-scale fracture as well, the prestack attenuation seismic attribute is used to predict the meso-scale fracture. Finally, by combining lithological statistic inversion with superposed results of faults, the relationship of the meso-scale fractures, lithology and faults can be reasonably interpreted and the cause of meso-scale fractures can be verified. The micro-scale fracture description is mainly implemented by using the electron microscope scanning of cores. Therefore, the development of fractures in reservoirs is assessed by valuating three classes of fracture prediction results. An integrated fracture prediction application to a real field in Sichuan basin, where limestone reservoir fractures developed, is implemented. The application results in the study area indicates that the proposed multi-scales integrated

  20. The use of detailed reservoir description and simulation studies in investigating completion strategies, cormorant, UK North Sea

    SciTech Connect

    Stiles, J.H.; Valenti, N.P.

    1987-01-01

    A portion of the Cormorant field in the U.K. North Sea is being developed using a subsea production system. All layers in the stratified reservoir section are being waterflooded concurrently by perforating the entire interval in both producers and injectors. The permeability contrast among the layers is such that there is potential for severe imbalance in the movement of the waterflood fronts, resulting in large volumes of early water production from high permeability layers and incomplete displacement of oil from less permeable layers. With the high cost of expanding platform facilities or performing workovers on subsea wells to re-distribute production and/or injection, there is considerable incentive to optimise the completions in new wells. This paper describes studies undertaken by Esso Exploration and Production U.K. to evaluate various completion strategies for newe subsea wells. These studies were done to complement work done by the operator, Shell U.K. Explorations and Production. The studies included detailed reservoir description work to define the oil-in-pace and permeability distribution, followed by simulation of the waterflood for a representative reservoir cross-section. Wellbore, flowline and pipeline hydraulics for the complex productions and injection system were included to more accurately model well rates. The results provide general insight into the nature of the displacement when waterflooding a stratified section with a limited nuber of wells. They also provide specific guidance on: (1) dual vs. single completions, (2) perforating, testing and stimulation sequence and (3) the benefits of partially perforating high permeability sands.

  1. A Descriptive Decision Process Model for Hierarchical Management of Interconnected Reservoir Systems

    NASA Astrophysics Data System (ADS)

    Adigüzel, R. Ä.°Lker; CoşKunoǧLu, Osman

    1984-07-01

    A significant limitation of prescriptive optimization models is that their formulation is disassociated from the behavioral and organizational attributes of the problem addressed. In an attempt to alleviate this limitation a decision process model is formulated directly within a framework of decision agents involved in integrated long- and short-term planning and management of multipurpose and multireservoir system operations. The resulting model is ierarchical, multilevel, multilayer, and decentralized. As such it is descriptive of a reservoir system managed and operated by geographically separated multiple agents with different authorities and responsibilities. Robustness and performance of the model is investigated by using the Shasta-Trinity system of California as an example. Results are encouraging for the descriptive as well as prescriptive relevance of the model.

  2. Learning to write without writing: writing accurate descriptions of interactions after learning graph-printed description relations.

    PubMed

    Spear, Jack; Fields, Lanny

    2015-12-01

    Interpreting and describing complex information shown in graphs are essential skills to be mastered by students in many disciplines; both are skills that are difficult to learn. Thus, interventions that produce these outcomes are of great value. Previous research showed that conditional discrimination training that established stimulus control by some elements of graphs and their printed descriptions produced some improvement in the accuracy of students' written descriptions of graphs. In the present experiment, students wrote nearly perfect descriptions of the information conveyed in interaction-based graphs after the establishment of conditional relations between graphs and their printed descriptions. This outcome was achieved with the use of special conditional discrimination training procedures that required participants to attend to many of the key elements of the graphs and the phrases in the printed descriptions that corresponded to the elements in the graphs. Thus, students learned to write full descriptions of the information represented by complex graphs by an automated training procedure that did not involve the direct training of writing.

  3. The Description of Shale Reservoir Pore Structure Based on Method of Moments Estimation

    PubMed Central

    Li, Wenjie; Wang, Changcheng; Shi, Zejin; Wei, Yi; Zhou, Huailai; Deng, Kun

    2016-01-01

    Shale has been considered as good gas reservoir due to its abundant interior nanoscale pores. Thus, the study of the pore structure of shale is of great significance for the evaluation and development of shale oil and gas. To date, the most widely used approaches for studying the shale pore structure include image analysis, radiation and fluid invasion methods. The detailed pore structures can be studied intuitively by image analysis and radiation methods, but the results obtained are quite sensitive to sample preparation, equipment performance and experimental operation. In contrast, the fluid invasion method can be used to obtain information on pore size distribution and pore structure, but the relative simple parameters derived cannot be used to evaluate the pore structure of shale comprehensively and quantitatively. To characterize the nanoscale pore structure of shale reservoir more effectively and expand the current research techniques, we proposed a new method based on gas adsorption experimental data and the method of moments to describe the pore structure parameters of shale reservoir. Combined with the geological mixture empirical distribution and the method of moments estimation principle, the new method calculates the characteristic parameters of shale, including the mean pore size (x¯), standard deviation (σ), skewness (Sk) and variation coefficient (c). These values are found by reconstructing the grouping intervals of observation values and optimizing algorithms for eigenvalues. This approach assures a more effective description of the characteristics of nanoscale pore structures. Finally, the new method has been applied to analyze the Yanchang shale in the Ordos Basin (China) and Longmaxi shale from the Sichuan Basin (China). The results obtained well reveal the pore characteristics of shale, indicating the feasibility of this new method in the study of the pore structure of shale reservoir. PMID:26992168

  4. The Description of Shale Reservoir Pore Structure Based on Method of Moments Estimation.

    PubMed

    Li, Wenjie; Wang, Changcheng; Shi, Zejin; Wei, Yi; Zhou, Huailai; Deng, Kun

    2016-01-01

    Shale has been considered as good gas reservoir due to its abundant interior nanoscale pores. Thus, the study of the pore structure of shale is of great significance for the evaluation and development of shale oil and gas. To date, the most widely used approaches for studying the shale pore structure include image analysis, radiation and fluid invasion methods. The detailed pore structures can be studied intuitively by image analysis and radiation methods, but the results obtained are quite sensitive to sample preparation, equipment performance and experimental operation. In contrast, the fluid invasion method can be used to obtain information on pore size distribution and pore structure, but the relative simple parameters derived cannot be used to evaluate the pore structure of shale comprehensively and quantitatively. To characterize the nanoscale pore structure of shale reservoir more effectively and expand the current research techniques, we proposed a new method based on gas adsorption experimental data and the method of moments to describe the pore structure parameters of shale reservoir. Combined with the geological mixture empirical distribution and the method of moments estimation principle, the new method calculates the characteristic parameters of shale, including the mean pore size (mean), standard deviation (σ), skewness (Sk) and variation coefficient (c). These values are found by reconstructing the grouping intervals of observation values and optimizing algorithms for eigenvalues. This approach assures a more effective description of the characteristics of nanoscale pore structures. Finally, the new method has been applied to analyze the Yanchang shale in the Ordos Basin (China) and Longmaxi shale from the Sichuan Basin (China). The results obtained well reveal the pore characteristics of shale, indicating the feasibility of this new method in the study of the pore structure of shale reservoir.

  5. Reservoir sedimentology

    SciTech Connect

    Tillman, R.W.; Weber, K.J.

    1987-01-01

    Collection of papers focuses on sedimentology of siliclastic sandstone and carbonate reservoirs. Shows how detailed sedimentologic descriptions, when combined with engineering and other subsurface geologic techniques, yield reservoir models useful for reservoir management during field development and secondary and tertiary EOR. Sections cover marine sandstone and carbonate reservoirs; shoreline, deltaic, and fluvial reservoirs; and eolian reservoirs. References follow each paper.

  6. Can Raters with Reduced Job Descriptive Information Provide Accurate Position Analysis Questionnaire (PAQ) Ratings?

    ERIC Educational Resources Information Center

    Friedman, Lee; Harvey, Robert J.

    1986-01-01

    Job-naive raters provided with job descriptive information made Position Analysis Questionnaire (PAQ) ratings which were validated against ratings of job analysts who were also job content experts. None of the reduced job descriptive information conditions enabled job-naive raters to obtain either acceptable levels of convergent validity with…

  7. Geologic description of the San Andres reservoir facies in the Mabee field

    SciTech Connect

    Miller, K.D. )

    1992-04-01

    The Mabee field is located in Andrews and Martin counties, Texas, approximately 16 mi northwest of Midland in the Permian basin. Production is from the upper Permian San Andres dolomite at an average depth of 4700 ft. The San Andres/Grayburg formations are the most prolific oil-producing formations in the Permian basin, with total production over 10 billion bbl, and an estimated additional 3.8 billion bbl to be recovered by conventional secondary and tertiary methods. The Mabee field has produced over 90 MMBO by primary and secondary methods since its discovery in 1943. A tertiary CO{sub 2} flood will be implemented in 1992. An essential prerequisite to a successful CO{sub 2} project is a detailed reservoir description and facies analysis. Examination of over 5000 ft of core established six major facies in an overall shallowing-upward sequence. The cap rock consists of dense anhydritic dolomites of the supratidal and oncolite facies. Production primarily is from the underlying dolomitized subtidal and ooid facies. Sandstones interfinger with the ooid facies, but are tightly cemented and act as barriers to fluid migration. The lower-most open-marine facies is below the oil/water contact for the field. Reservoir characterization improves the planning and operation of an enhanced recovery project.

  8. Characterization of biocenoses in the storage reservoirs of liquid radioactive wastes of Mayak PA. Initial descriptive report.

    PubMed

    Pryakhin, E A; Mokrov, Yu G; Tryapitsina, G A; Ivanov, I A; Osipov, D I; Atamanyuk, N I; Deryabina, L V; Shaposhnikova, I A; Shishkina, E A; Obvintseva, N A; Egoreichenkov, E A; Styazhkina, E V; Osipova, O F; Mogilnikova, N I; Andreev, S S; Tarasov, O V; Geras'kin, S A; Trapeznikov, A V; Akleyev, A V

    2016-01-01

    As a result of operation of the Mayak Production Association (Mayak PA), Chelyabinsk Oblast, Russia, an enterprise for production and separation of weapon-grade plutonium in the Soviet Union, ecosystems of a number of water bodies have been radioactively contaminated. The article presents information about the current state of ecosystems of 6 special industrial storage reservoirs of liquid radioactive waste from Mayak PA: reservoirs R-3, R-4, R-9, R-10, R-11 and R-17. At present the excess of the radionuclide content in the water of the studied reservoirs and comparison reservoirs (Shershnyovskoye and Beloyarskoye reservoirs) is 9 orders of magnitude for (90)Sr and (137)Cs, and 6 orders of magnitude for alpha-emitting radionuclides. According to the level of radioactive contamination, the reservoirs of the Mayak PA could be arranged in the ascending order as follows: R-11, R-10, R-4, R-3, R-17 and R-9. In 2007-2012 research of the status of the biocenoses of these reservoirs in terms of phytoplankton, zooplankton, bacterioplankton, zoobenthos, aquatic plants, ichthyofauna, avifauna parameters was performed. The conducted studies revealed decrease in species diversity in reservoirs with the highest levels of radioactive and chemical contamination. This article is an initial descriptive report on the status of the biocenoses of radioactively contaminated reservoirs of the Mayak PA, and is the first article in a series of publications devoted to the studies of the reaction of biocenoses of the fresh-water reservoirs of the Mayak PA to a combination of natural and man-made factors, including chronic radiation exposure. PMID:26094572

  9. Characterization of biocenoses in the storage reservoirs of liquid radioactive wastes of Mayak PA. Initial descriptive report.

    PubMed

    Pryakhin, E A; Mokrov, Yu G; Tryapitsina, G A; Ivanov, I A; Osipov, D I; Atamanyuk, N I; Deryabina, L V; Shaposhnikova, I A; Shishkina, E A; Obvintseva, N A; Egoreichenkov, E A; Styazhkina, E V; Osipova, O F; Mogilnikova, N I; Andreev, S S; Tarasov, O V; Geras'kin, S A; Trapeznikov, A V; Akleyev, A V

    2016-01-01

    As a result of operation of the Mayak Production Association (Mayak PA), Chelyabinsk Oblast, Russia, an enterprise for production and separation of weapon-grade plutonium in the Soviet Union, ecosystems of a number of water bodies have been radioactively contaminated. The article presents information about the current state of ecosystems of 6 special industrial storage reservoirs of liquid radioactive waste from Mayak PA: reservoirs R-3, R-4, R-9, R-10, R-11 and R-17. At present the excess of the radionuclide content in the water of the studied reservoirs and comparison reservoirs (Shershnyovskoye and Beloyarskoye reservoirs) is 9 orders of magnitude for (90)Sr and (137)Cs, and 6 orders of magnitude for alpha-emitting radionuclides. According to the level of radioactive contamination, the reservoirs of the Mayak PA could be arranged in the ascending order as follows: R-11, R-10, R-4, R-3, R-17 and R-9. In 2007-2012 research of the status of the biocenoses of these reservoirs in terms of phytoplankton, zooplankton, bacterioplankton, zoobenthos, aquatic plants, ichthyofauna, avifauna parameters was performed. The conducted studies revealed decrease in species diversity in reservoirs with the highest levels of radioactive and chemical contamination. This article is an initial descriptive report on the status of the biocenoses of radioactively contaminated reservoirs of the Mayak PA, and is the first article in a series of publications devoted to the studies of the reaction of biocenoses of the fresh-water reservoirs of the Mayak PA to a combination of natural and man-made factors, including chronic radiation exposure.

  10. Doubly hybrid density functional for accurate descriptions of nonbond interactions, thermochemistry, and thermochemical kinetics

    PubMed Central

    Zhang, Ying; Xu, Xin; Goddard, William A.

    2009-01-01

    We develop and validate a density functional, XYG3, based on the adiabatic connection formalism and the Görling–Levy coupling-constant perturbation expansion to the second order (PT2). XYG3 is a doubly hybrid functional, containing 3 mixing parameters. It has a nonlocal orbital-dependent component in the exchange term (exact exchange) plus information about the unoccupied Kohn–Sham orbitals in the correlation part (PT2 double excitation). XYG3 is remarkably accurate for thermochemistry, reaction barrier heights, and nonbond interactions of main group molecules. In addition, the accuracy remains nearly constant with system size. PMID:19276116

  11. Accurate description of aqueous carbonate ions: an effective polarization model verified by neutron scattering.

    PubMed

    Mason, Philip E; Wernersson, Erik; Jungwirth, Pavel

    2012-07-19

    The carbonate ion plays a central role in the biochemical formation of the shells of aquatic life, which is an important path for carbon dioxide sequestration. Given the vital role of carbonate in this and other contexts, it is imperative to develop accurate models for such a high charge density ion. As a divalent ion, carbonate has a strong polarizing effect on surrounding water molecules. This raises the question whether it is possible to describe accurately such systems without including polarization. It has recently been suggested the lack of electronic polarization in nonpolarizable water models can be effectively compensated by introducing an electronic dielectric continuum, which is with respect to the forces between atoms equivalent to rescaling the ionic charges. Given how widely nonpolarizable models are used to model electrolyte solutions, establishing the experimental validity of this suggestion is imperative. Here, we examine a stringent test for such models: a comparison of the difference of the neutron scattering structure factors of K2CO3 vs KNO3 solutions and that predicted by molecular dynamics simulations for various models of the same systems. We compare standard nonpolarizable simulations in SPC/E water to analogous simulations with effective ion charges, as well as simulations in explicitly polarizable POL3 water (which, however, has only about half the experimental polarizability). It is found that the simulation with rescaled charges is in a very good agreement with the experimental data, which is significantly better than for the nonpolarizable simulation and even better than for the explicitly polarizable POL3 model.

  12. Accurate description of the optical response of a multilayered spherical system in the long wavelength approximation

    NASA Astrophysics Data System (ADS)

    Chung, H. Y.; Guo, G. Y.; Chiang, H.-P.; Tsai, D. P.; Leung, P. T.

    2010-10-01

    The optical response of a multilayered spherical system of unlimited number of layers (a “matryushka”) in the long wavelength limit can be accounted for from the knowledge of the static multipole polarizability of the system to first-order accuracy. However, for systems of ultrasmall dimensions or systems with sizes not-too-small compared to the wavelength, this ordinary quasistatic long wavelength approximation (LWA) becomes inaccurate. Here we introduce two significant modifications of the LWA for such a nanomatryushka in each of the two limits: the nonlocal optical response for ultrasmall systems (<10nm) , and the “finite-wavelength corrections” for systems ˜100nm . This is accomplished by employing the previous work for a single-layer shell, in combination with a certain effective-medium approach formulated recently in the literature. Numerical calculations for the extinction cross sections for such a system of different dimensions are provided as illustrations for these effects. This formulation thus provides significant improvements on the ordinary LWA, yielding enough accuracy for the description of the optical response of these nanoshell systems over an appreciable range of sizes, without resorting to more involved quantum mechanical or fully electrodynamic calculations.

  13. Electrostatics of proteins in dielectric solvent continua. I. An accurate and efficient reaction field description

    SciTech Connect

    Bauer, Sebastian; Mathias, Gerald; Tavan, Paul

    2014-03-14

    We present a reaction field (RF) method which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of an electrostatics calculation with polarizable molecular mechanics (MM) force fields. The method combines an approach originally suggested by Egwolf and Tavan [J. Chem. Phys. 118, 2039 (2003)] with concepts generalizing the Born solution [Z. Phys. 1, 45 (1920)] for a solvated ion. First, we derive an exact representation according to which the sources of the RF potential and energy are inducible atomic anti-polarization densities and atomic shielding charge distributions. Modeling these atomic densities by Gaussians leads to an approximate representation. Here, the strengths of the Gaussian shielding charge distributions are directly given in terms of the static partial charges as defined, e.g., by standard MM force fields for the various atom types, whereas the strengths of the Gaussian anti-polarization densities are calculated by a self-consistency iteration. The atomic volumes are also described by Gaussians. To account for covalently overlapping atoms, their effective volumes are calculated by another self-consistency procedure, which guarantees that the dielectric function ε(r) is close to one everywhere inside the protein. The Gaussian widths σ{sub i} of the atoms i are parameters of the RF approximation. The remarkable accuracy of the method is demonstrated by comparison with Kirkwood's analytical solution for a spherical protein [J. Chem. Phys. 2, 351 (1934)] and with computationally expensive grid-based numerical solutions for simple model systems in dielectric continua including a di-peptide (Ac-Ala-NHMe) as modeled by a standard MM force field. The latter example shows how weakly the RF conformational free energy landscape depends on the parameters σ{sub i}. A summarizing discussion highlights the achievements of the new theory and of its approximate solution

  14. Electrostatics of proteins in dielectric solvent continua. I. An accurate and efficient reaction field description.

    PubMed

    Bauer, Sebastian; Mathias, Gerald; Tavan, Paul

    2014-03-14

    We present a reaction field (RF) method which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of an electrostatics calculation with polarizable molecular mechanics (MM) force fields. The method combines an approach originally suggested by Egwolf and Tavan [J. Chem. Phys. 118, 2039 (2003)] with concepts generalizing the Born solution [Z. Phys. 1, 45 (1920)] for a solvated ion. First, we derive an exact representation according to which the sources of the RF potential and energy are inducible atomic anti-polarization densities and atomic shielding charge distributions. Modeling these atomic densities by Gaussians leads to an approximate representation. Here, the strengths of the Gaussian shielding charge distributions are directly given in terms of the static partial charges as defined, e.g., by standard MM force fields for the various atom types, whereas the strengths of the Gaussian anti-polarization densities are calculated by a self-consistency iteration. The atomic volumes are also described by Gaussians. To account for covalently overlapping atoms, their effective volumes are calculated by another self-consistency procedure, which guarantees that the dielectric function ε(r) is close to one everywhere inside the protein. The Gaussian widths σ(i) of the atoms i are parameters of the RF approximation. The remarkable accuracy of the method is demonstrated by comparison with Kirkwood's analytical solution for a spherical protein [J. Chem. Phys. 2, 351 (1934)] and with computationally expensive grid-based numerical solutions for simple model systems in dielectric continua including a di-peptide (Ac-Ala-NHMe) as modeled by a standard MM force field. The latter example shows how weakly the RF conformational free energy landscape depends on the parameters σ(i). A summarizing discussion highlights the achievements of the new theory and of its approximate solution particularly by

  15. Reducing the Need for Accurate Stream Flow Forecasting for Water Supply Planning by Augmenting Reservoir Operations with Seawater Desalination and Wastewater Recycling

    NASA Astrophysics Data System (ADS)

    Bhushan, R.; Ng, T. L.

    2014-12-01

    Accurate stream flow forecasts are critical for reservoir operations for water supply planning. As the world urban population increases, the demand for water in cities is also increasing, making accurate forecasts even more important. However, accurate forecasting of stream flows is difficult owing to short- and long-term weather variations. We propose to reduce this need for accurate stream flow forecasts by augmenting reservoir operations with seawater desalination and wastewater recycling. We develop a robust operating policy for the joint operation of the three sources. With the joint model, we tap into the unlimited reserve of seawater through desalination, and make use of local supplies of wastewater through recycling. However, both seawater desalination and recycling are energy intensive and relatively expensive. Reservoir water on the other hand, is generally cheaper but is limited and variable in its availability, increasing the risk of water shortage during extreme climate events. We operate the joint system by optimizing it using a genetic algorithm to maximize water supply reliability and resilience while minimizing vulnerability subject to a budget constraint and for a given stream flow forecast. To compute the total cost of the system, we take into account the pumping cost of transporting reservoir water to its final destination, and the capital and operating costs of desalinating seawater and recycling wastewater. We produce results for different hydro climatic regions based on artificial stream flows we generate using a simple hydrological model and an autoregressive time series model. The artificial flows are generated from precipitation and temperature data from the Canadian Regional Climate model for present and future scenarios. We observe that the joint operation is able to effectively minimize the negative effects of stream flow forecast uncertainty on system performance at an overall cost that is not significantly greater than the cost of a

  16. Accurate description of van der Waals complexes by density functional theory including empirical corrections.

    PubMed

    Grimme, Stefan

    2004-09-01

    An empirical method to account for van der Waals interactions in practical calculations with the density functional theory (termed DFT-D) is tested for a wide variety of molecular complexes. As in previous schemes, the dispersive energy is described by damped interatomic potentials of the form C6R(-6). The use of pure, gradient-corrected density functionals (BLYP and PBE), together with the resolution-of-the-identity (RI) approximation for the Coulomb operator, allows very efficient computations for large systems. Opposed to previous work, extended AO basis sets of polarized TZV or QZV quality are employed, which reduces the basis set superposition error to a negligible extend. By using a global scaling factor for the atomic C6 coefficients, the functional dependence of the results could be strongly reduced. The "double counting" of correlation effects for strongly bound complexes is found to be insignificant if steep damping functions are employed. The method is applied to a total of 29 complexes of atoms and small molecules (Ne, CH4, NH3, H2O, CH3F, N2, F2, formic acid, ethene, and ethine) with each other and with benzene, to benzene, naphthalene, pyrene, and coronene dimers, the naphthalene trimer, coronene. H2O and four H-bonded and stacked DNA base pairs (AT and GC). In almost all cases, very good agreement with reliable theoretical or experimental results for binding energies and intermolecular distances is obtained. For stacked aromatic systems and the important base pairs, the DFT-D-BLYP model seems to be even superior to standard MP2 treatments that systematically overbind. The good results obtained suggest the approach as a practical tool to describe the properties of many important van der Waals systems in chemistry. Furthermore, the DFT-D data may either be used to calibrate much simpler (e.g., force-field) potentials or the optimized structures can be used as input for more accurate ab initio calculations of the interaction energies.

  17. Towards an accurate model of redshift-space distortions: a bivariate Gaussian description for the galaxy pairwise velocity distributions

    NASA Astrophysics Data System (ADS)

    Bianchi, Davide; Chiesa, Matteo; Guzzo, Luigi

    2016-10-01

    As a step towards a more accurate modelling of redshift-space distortions (RSD) in galaxy surveys, we develop a general description of the probability distribution function of galaxy pairwise velocities within the framework of the so-called streaming model. For a given galaxy separation , such function can be described as a superposition of virtually infinite local distributions. We characterize these in terms of their moments and then consider the specific case in which they are Gaussian functions, each with its own mean μ and variance σ2. Based on physical considerations, we make the further crucial assumption that these two parameters are in turn distributed according to a bivariate Gaussian, with its own mean and covariance matrix. Tests using numerical simulations explicitly show that with this compact description one can correctly model redshift-space distorsions on all scales, fully capturing the overall linear and nonlinear dynamics of the galaxy flow at different separations. In particular, we naturally obtain Gaussian/exponential, skewed/unskewed distribution functions, depending on separation as observed in simulations and data. Also, the recently proposed single-Gaussian description of redshift-space distortions is included in this model as a limiting case, when the bivariate Gaussian is collapsed to a two-dimensional Dirac delta function. More work is needed, but these results indicate a very promising path to make definitive progress in our program to improve RSD estimators.

  18. Towards a more accurate microscopic description of the moving contact line problem - incorporating nonlocal effects through a statistical mechanics framework

    NASA Astrophysics Data System (ADS)

    Nold, Andreas; Goddard, Ben; Sibley, David; Kalliadasis, Serafim

    2014-03-01

    Multiscale effects play a predominant role in wetting phenomena such as the moving contact line. An accurate description is of paramount interest for a wide range of industrial applications, yet it is a matter of ongoing research, due to the difficulty of incorporating different physical effects in one model. Important small-scale phenomena are corrections to the attractive fluid-fluid and wall-fluid forces in inhomogeneous density distributions, which often previously have been accounted for by the disjoining pressure in an ad-hoc manner. We systematically derive a novel model for the description of a single-component liquid-vapor multiphase system which inherently incorporates these nonlocal effects. This derivation, which is inspired by statistical mechanics in the framework of colloidal density functional theory, is critically discussed with respect to its assumptions and restrictions. The model is then employed numerically to study a moving contact line of a liquid fluid displacing its vapor phase. We show how nonlocal physical effects are inherently incorporated by the model and describe how classical macroscopic results for the contact line motion are retrieved. We acknowledge financial support from ERC Advanced Grant No. 247031 and Imperial College through a DTG International Studentship.

  19. A Preliminary Geochemical Description of the Geothermal Reservoir at Astor Pass, Northern Pyramid Lake, Nevada

    SciTech Connect

    Cooper, Clay A.; Thomas, James M.; Lyles, Brad F.; Reeves, Donald M.; Pohll, Greg M.; Parashar, Rishi

    2012-10-01

    Samples from a well drilled in the Astor Pass area six-km north of the Needle Rocks area of Pyramid Lake indicate that the reservoir fluid is dominantly sodium, chloride, and sulfate, with a pH between 8.6 and 8.9. The total dissolved solids in the reservoir is approximately 1600 mg/l, about half that of the TDS of the fluids in the Needle Rocks area. One sample of dissolved gas from fluids produced during a well test in the reservoir had 4He value of 2.32 x 1014 atoms 4He/g water, or approximately 100 times the value of atmospheric 4He. This measurement, in conjunction with a R/Ra measurement of 0.28, suggests that most of the reservoir helium is derived from the crust, with possibly a small value (~3.3 percent) derived from the mantle. Tritium concentration of the sample was 0.09 TU, indicating that the reservoir fluid was recharged more than 60 years ago; a simple model based upon carbon-14 suggests recharge has occurred within the past 1500 years.

  20. Innovative techniques for the description of reservoir heterogeneity using tracers. Second technical annual progress report, October 1991--September 1992

    SciTech Connect

    Pope, G.A.; Sepehrnoori, K.

    1992-12-31

    This second annual report on innovative uses of tracers for reservoir characterization contains four sections each describing a novel use of oilfield tracers. The first section describes and illustrates the use of a new single-well tracer test to estimate wettability. This test consists of the injection of brine containing tracers followed by oil containing tracers, a shut-in period to allow some of the tracers to react, and then production of the tracers. The inclusion of the oil injection slug with tracers is unique to this test, and this is what makes the test work. We adapted our chemical simulator, UTCHEM, to enable us to study this tracer method and made an extensive simulation study to evaluate the effects of wettability based upon characteristic curves for relative permeability and capillary pressure for differing wetting states typical of oil reservoirs. The second section of this report describes a new method for analyzing interwell tracer data based upon a type-curve approach. Theoretical frequency response functions were used to build type curves of ``transfer function`` and ``phase spectrum`` that have dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. We illustrate this method by analyzing field tracer data. The third section of this report describes a new theory for interpreting interwell tracer data in terms of channeling and dispersive behavior for reservoirs. Once again, a stochastic approach to reservoir description is taken. The fourth section of this report describes our simulation of perfluorocarbon gas tracers. This new tracer technology developed at Brookhaven National Laboratory is being tested at the Elk Hills Naval Petroleum Reserve No. 1 in California. We report preliminary simulations made of these tracers in one of the oil reservoirs under evaluation with these tracers in this field. Our compostional simulator (UTCOMP) was used for this simulation study.

  1. Geologic description of middle Devonian Chert Reservoir, Block 31 field, Crane County, Texas

    SciTech Connect

    Ebanks, W.J. Jr.

    1988-01-01

    Block 31 field is a large anticlinal structure that produces from six pay zones. The first miscible gas-injection enhanced oil recovery project has been operated by ARCO since 1952 in the middle Devonian reservoir, which is the main producing interval in the field. The middle Devonian unit was deposited as a siliceous, calcareous ooze in a basin-slope environment in the ancient Tobosa basin. Sedimentation buried earlier fault blocks, as the slope deposits aggraded and prograded mainly from the west and south. Subsequent diagenesis converted the ooze into calcareous chert. Reservoir quality of the chert depends on degree of compaction and quartz cementation. Gray, dense, glassy chert at the base of the sequence is nonporous except for small, incipient fractures in the brittle matrix. Creamy white, evenly laminated, microporous, calcareous chert, which alternates with and overlies the dense chert in the lower half of the middle Devonian interval, has porosity of 10-30% and permeability as great as 10 md. The upper half of the reservoir interval consists mainly of light-gray and white, partially porous, heterogeneous, calcareous chert. This rock type has porosity of 5-20%, but permeability is usually less than 3 md. Patchy silica cement, discontinuous low-permeability laminae, and thin beds of dense limestone reduce its effectiveness as a reservoir.

  2. Integrated reservoir description and analysis of the Lance formation at Jonah Field, Sublette County, Wyoming

    SciTech Connect

    Robinson, J.W.; Delozier, D.L.; Flinch, R.

    1996-06-01

    Log, core, and production data from the 16 wells in Jonah field have been used to characterize sandstone reservoirs in the Lance Formation (Cretaceous) in the northern Green River basin. The Lance Fm. is composed of 2500 feet of heterolithic fluvial strata that were deposited on a broad alluvial plain. Sandstones were deposited in east- flowing channels 10-20 feet deep and 150-4000 feet wide; some amalgamated sandstone intervals are >100 feet thick and over a mile wide. Fluvial architecture varies from isolated meandering river deposits to amalgamated braided river deposits. Sandstones are dominantly composed of detrital chert and quartz grains. The Lance Fm. has been divided into several informal pay intervals that have different reservoir character and performance. Wardell interval sandstones produce gas in eight wells and are poor reservoirs due to fine grain size, high clay and cement content, and greater depth. Yellow Point interval sandstones have shown average performance in five wells. The Jonah interval produces in 10 wells and is the most prolific pay zone with up to 150 net feet of sandstone having core porosity of 8-12% and permeability of .01-0.9 mD. Upper and middle Lance sandstones have better than average performance from five wells. All pay intervals require greater than 8% porosity and less than 35% water saturation. Pre-frac pressure build-up analysis indicates in situ permeabilities of 3-20 microdarcys and suggests that fractures are a significant contributor to deliverability. Estimated reserves of 0.4-4.0 BCFG/well are based on decline curve analysis. Liquid yields vary from 6-86 BO/MMCFG and increase with depth. Pressure gradients range from .55 to .59 psi/ft. Reservoir overpressure is a result of continuous migration of hydrocarbons into available pore space via microfracture seepage.

  3. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.

    1997-08-01

    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  4. 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.

  5. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    NASA Astrophysics Data System (ADS)

    Öz, E.; Batsch, F.; Muggli, P.

    2016-09-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE) (Assmann et al., 2014 [1]) project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook (Marlow, 1967 [2]) method and has been described in great detail in the work by Hill et al. (1986) [3]. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1% for the vapor density-length product. A single-mode, fiber-based, Mach-Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.

  6. Application of artifical intelligence to reservoir characterization: An interdisciplinary approach. Annual report, October 1993--October 1994

    SciTech Connect

    Kelkar, B.G.; Gamble, R.F.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1995-07-01

    This basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs.

  7. Electrical and electromagnetic methods for reservoir description and process monitoring. Annual report, October 1, 1992--September 30, 1993

    SciTech Connect

    Morrison, H.F.; Lee, K.H.; Becker, A.

    1995-07-01

    It is well known that electrical conductivity of rock is closely related to the porosity, hydrologic permeability, saturation, and the type of fluid in it. These rock parameters play important roles in the development and production of hydrocarbon (petroleum and natural gas) resources. For these reasons, resistivity well logs have long been used by geologists and reservoir engineers in petroleum industries to map variations in pore fluid, to distinguish between rock types, and to determine completion intervals in wells. Reservoir simulation and process monitoring rely heavily on the physical characteristics of the reservoir model. At the beginning of FY-91 a coordinated electrical and electromagnetic (EM) geophysical research program for petroleum reservoir characterization and process monitoring was initiated. Parties involved in this program include Lawrence Berkeley Laboratory (LBL), Lawrence Livermore Laboratory (LLNL), Sandia National Laboratory (SNL), and University of California at Berkeley (UCB). The overall objectives of the program were: to integrate research funded by DOE for hydrocarbon recovery into a focused effort to demonstrate the technology in the shortest time with the least cost; to assure industry acceptance of the technology developed by having industry involvement in the planning, implementation, and funding of the research; to focus the research on real world problems that have the potential for solution in the near term with significant energy payoff. Specific research activities conducted have been in the following areas: (1) EM modeling development; (2) data interpretation methods development; (3) hardware and instrumentation development; (4) EOR and reservoir characterization; (5) controlled field experiments. The primary focus of these activities was in the development of reliable inversion and imaging schemes that could yield conductivity distributions from measured electrical and EM field data.

  8. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    SciTech Connect

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  9. Quantum kinetic theory of localized system-reservoir interaction leading to a description of superfluid internal convection

    NASA Astrophysics Data System (ADS)

    Gilz, Lukas; Anglin, James R.

    2015-07-01

    Describing local system-reservoir interaction in a quantum kinetic approach allows a first-principles investigation of basic nonequilibirium effects in ultracold atomic vapors. We derive such a quantum kinetic theory and apply it to heat transport in a Bose-condensed gas coupled collisionally to two spatially separated reservoir gases at different temperatures. We show that in the collisionless regime, where a Bogoliubov expansion is applicable, heat is transported by counterpropagating steady currents of condensate and noncondensate fractions, with the condensate flowing towards the source of greater heat. This phenomenon has hitherto only be seen in more strongly interacting systems as superfluid helium and is known as superfluid internal convection. We derive explicit formulas for the steady-state energy current and differential particle currents (with zero net particle flux) in the collisionless regime. As a significant technical detail in this derivation, we show that a correct treatment of this nonequilibrium scenario requires the inclusion of post-Bogoliubov and nonresonant interaction effects.

  10. How Iron-Containing Proteins Control Dioxygen Chemistry: A Detailed Atomic Level Description Via Accurate Quantum Chemical and Mixed Quantum Mechanics/Molecular Mechanics Calculations.

    SciTech Connect

    Friesner, Richard A.; Baik, Mu-Hyun; Gherman, Benjamin F.; Guallar, Victor; Wirstam, Maria E.; Murphy, Robert B.; Lippard, Stephen J.

    2003-03-01

    Over the past several years, rapid advances in computational hardware, quantum chemical methods, and mixed quantum mechanics/molecular mechanics (QM/MM) techniques have made it possible to model accurately the interaction of ligands with metal-containing proteins at an atomic level of detail. In this paper, we describe the application of our computational methodology, based on density functional (DFT) quantum chemical methods, to two diiron-containing proteins that interact with dioxygen: methane monooxygenase (MMO) and hemerythrin (Hr). Although the active sites are structurally related, the biological function differs substantially. MMO is an enzyme found in methanotrophic bacteria and hydroxylates aliphatic C-H bonds, whereas Hr is a carrier protein for dioxygen used by a number of marine invertebrates. Quantitative descriptions of the structures and energetics of key intermediates and transition states involved in the reaction with dioxygen are provided, allowing their mechanisms to be compared and contrasted in detail. An in-depth understanding of how the chemical identity of the first ligand coordination shell, structural features, electrostatic and van der Waals interactions of more distant shells control ligand binding and reactive chemistry is provided, affording a systematic analysis of how iron-containing proteins process dioxygen. Extensive contact with experiment is made in both systems, and a remarkable degree of accuracy and robustness of the calculations is obtained from both a qualitative and quantitative perspective.

  11. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly report], April 1--June 30, 1995

    SciTech Connect

    Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1995-09-01

    Objective is to apply artificial intelligence and expert systems to capturing, integrating, and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. Goal is to develop a single expert system for use by small producers and independents to efficiently exploit reservoirs.

  12. 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.

  13. A mathematical recursive model for accurate description of the phase behavior in the near-critical region by Generalized van der Waals Equation

    NASA Astrophysics Data System (ADS)

    Kim, Jibeom; Jeon, Joonhyeon

    2015-01-01

    Recently, related studies on Equation Of State (EOS) have reported that generalized van der Waals (GvdW) shows poor representations in the near critical region for non-polar and non-sphere molecules. Hence, there are still remains a problem of GvdW parameters to minimize loss in describing saturated vapor densities and vice versa. This paper describes a recursive model GvdW (rGvdW) for an accurate representation of pure fluid materials in the near critical region. For the performance evaluation of rGvdW in the near critical region, other EOS models are also applied together with two pure molecule group: alkane and amine. The comparison results show rGvdW provides much more accurate and reliable predictions of pressure than the others. The calculating model of EOS through this approach gives an additional insight into the physical significance of accurate prediction of pressure in the nearcritical region.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. The water-quality monitoring program for the Baltimore reservoir system, 1981-2007—Description, review and evaluation, and framework integration for enhanced monitoring

    USGS Publications Warehouse

    Koterba, Michael T.; Waldron, Marcus C.; Kraus, Tamara E.C.

    2011-01-01

    The City of Baltimore, Maryland, and parts of five surrounding counties obtain their water from Loch Raven and Liberty Reservoirs. A third reservoir, Prettyboy, is used to resupply Loch Raven Reservoir. Management of the watershed conditions for each reservoir is a shared responsibility by agreement among City, County, and State jurisdictions. The most recent (2005) Baltimore Reservoir Watershed Management Agreement (RWMA) called for continued and improved water-quality monitoring in the reservoirs and selected watershed tributaries. The U.S. Geological Survey (USGS) conducted a retrospective review of the effectiveness of monitoring data obtained and analyzed by the RWMA jurisdictions from 1981 through 2007 to help identify possible improvements in the monitoring program to address RWMA water-quality concerns. Long-term water-quality concerns include eutrophication and sedimentation in the reservoirs, and elevated concentrations of (a) nutrients (nitrogen and phosphorus) being transported from the major tributaries to the reservoirs, (b) iron and manganese released from reservoir bed sediments during periods of deep-water anoxia, (c) mercury in higher trophic order game fish in the reservoirs, and (d) bacteria in selected reservoir watershed tributaries. Emerging concerns include elevated concentrations of sodium, chloride, and disinfection by-products (DBPs) in the drinking water from both supply reservoirs. Climate change and variability also could be emerging concerns, affecting seasonal patterns, annual trends, and drought occurrence, which historically have led to declines in reservoir water quality. Monitoring data increasingly have been used to support the development of water-quality models. The most recent (2006) modeling helped establish an annual sediment Total Maximum Daily Load to Loch Raven Reservoir, and instantaneous and 30-day moving average water-quality endpoints for chlorophyll-a (chl-a) and dissolved oxygen (DO) in Loch Raven and Prettyboy

  20. 3D reservoir visualization

    SciTech Connect

    Van, B.T.; Pajon, J.L.; Joseph, P. )

    1991-11-01

    This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

  1. Integration of advanced geoscience and engineering techniques to quantify interwell heterogeneity in reservoir models. First annual report, September 29, 1993--September 30, 1994

    SciTech Connect

    Martin, F.D.; Buckley, J.S.; Weiss, W.W.; Ouenes, A.

    1995-05-01

    The goal of this project is to provide a more quantitative definition of reservoir heterogeneity. This objective will be accomplished through the integration of geologic, geophysical, and engineering databases into a multidisciplinary understanding of reservoir architecture and associated fluid-rock and fluid-fluid interactions. The intent is to obtain a quantitative reservoir description incorporating outcrop, field, well-to-well, and laboratory core and fluid data of widely varying scales. This interdisciplinary effort will integrate geological and geophysical data with engineering and petrophysical results through reservoir simulation to quantify reservoir architecture and the dynamics of fluid-rock and fluid-fluid interactions. A more accurate reservoir description will allow greater accuracy and confidence during simulation and modeling as steps toward gaining greater recovery efficiency from existing reservoirs. A field laboratory, the Sulimar Queen Unit, is available for the field research activities that will be conducted.

  2. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly technical progress report], October 1--December 31, 1995

    SciTech Connect

    Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1995-12-31

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an AI-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an AI-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. The results of the integration are not merely limited to obtaining better characterizations of individual reservoirs. They have the potential to significantly impact and advance the discipline of reservoir characterization itself.

  3. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly progress report], January 1--March 31, 1994

    SciTech Connect

    Kelkar, B.G.; Gamble, R.F.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1994-06-01

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an Al-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an Al-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. With this plan, we have carefully allocated and sequenced the activities involved in each of the tasks to promote concurrent progress towards the research objectives. Moreover, the project duties are divided among the faculty member participants. Graduate students will work in teams with faculty members. The results of the integration are not merely limited to obtaining better characterizations of individual reservoirs. They have the potential to significantly impact and advance the discipline of reservoir characterization itself.

  4. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly report], January 1--March 31, 1995

    SciTech Connect

    Kelkar, B.G.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1995-07-01

    This basis search is to apply novel techniques from Artificial Intelligence (AI) and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The overall project plan to design the system to create integrated reservoir description begins by initially developing an AI-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an AI-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. With this plan, we have carefully allocated and sequenced the activities involved in each of the tasks to promote concurrent progress towards the research objectives. The results of the integration are not merely limited to obtaining better characterizations of individual reservoirs. They have the potential to significantly impact and advance the discipline of reservoir characterization itself.

  5. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly report], April 1--June 30, 1994

    SciTech Connect

    Kelkar, B.G.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1994-09-01

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an AI-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an AI-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. With this plan, we have carefully allocated and sequenced the activities involved in each of the tasks to promote concurrent progress towards the research objectives. Moreover, the project duties are divided among the faculty and graduate students. The results of the integration are not merely limited to obtaining better characterizations of individual reservoirs. They have the potential to significantly impact and advance the discipline of reservoir characterization itself.

  6. Petermann I and II spot size: Accurate semi analytical description involving Nelder-Mead method of nonlinear unconstrained optimization and three parameter fundamental modal field

    NASA Astrophysics Data System (ADS)

    Roy Choudhury, Raja; Roy Choudhury, Arundhati; Kanti Ghose, Mrinal

    2013-01-01

    A semi-analytical model with three optimizing parameters and a novel non-Gaussian function as the fundamental modal field solution has been proposed to arrive at an accurate solution to predict various propagation parameters of graded-index fibers with less computational burden than numerical methods. In our semi analytical formulation the optimization of core parameter U which is usually uncertain, noisy or even discontinuous, is being calculated by Nelder-Mead method of nonlinear unconstrained minimizations as it is an efficient and compact direct search method and does not need any derivative information. Three optimizing parameters are included in the formulation of fundamental modal field of an optical fiber to make it more flexible and accurate than other available approximations. Employing variational technique, Petermann I and II spot sizes have been evaluated for triangular and trapezoidal-index fibers with the proposed fundamental modal field. It has been demonstrated that, the results of the proposed solution identically match with the numerical results over a wide range of normalized frequencies. This approximation can also be used in the study of doped and nonlinear fiber amplifier.

  7. A name for the 'blueberry tetra', an aquarium trade popular species of Hyphessobrycon Durbin (Characiformes, Characidae), with comments on fish species descriptions lacking accurate type locality.

    PubMed

    Marinho, M M F; Dagosta, F C P; Camelier, P; Oyakawa, O T

    2016-07-01

    A new species of Hyphessobrycon is described from a tributary of the upper Rio Tapajós, Amazon basin, Mato Grosso, Brazil. Its exuberant colour in life, with blue to purple body and red fins, is appreciated in the aquarium trade. Characters to diagnose the new species from all congeners are the presence of a single humeral blotch, absence of a distinct caudal-peduncle blotch, absence of a well-defined dark mid-lateral stripe on body, the presence of 16-18 branched anal-fin rays, nine branched dorsal-fin rays and six branched pelvic-fin rays. A brief comment on fish species descriptions solely based on aquarium material and its consequence for conservation policies is provided.

  8. A name for the 'blueberry tetra', an aquarium trade popular species of Hyphessobrycon Durbin (Characiformes, Characidae), with comments on fish species descriptions lacking accurate type locality.

    PubMed

    Marinho, M M F; Dagosta, F C P; Camelier, P; Oyakawa, O T

    2016-07-01

    A new species of Hyphessobrycon is described from a tributary of the upper Rio Tapajós, Amazon basin, Mato Grosso, Brazil. Its exuberant colour in life, with blue to purple body and red fins, is appreciated in the aquarium trade. Characters to diagnose the new species from all congeners are the presence of a single humeral blotch, absence of a distinct caudal-peduncle blotch, absence of a well-defined dark mid-lateral stripe on body, the presence of 16-18 branched anal-fin rays, nine branched dorsal-fin rays and six branched pelvic-fin rays. A brief comment on fish species descriptions solely based on aquarium material and its consequence for conservation policies is provided. PMID:27245763

  9. Accurate Descriptions of Hot Flow Behaviors Across β Transus of Ti-6Al-4V Alloy by Intelligence Algorithm GA-SVR

    NASA Astrophysics Data System (ADS)

    Wang, Li-yong; Li, Le; Zhang, Zhi-hua

    2016-09-01

    Hot compression tests of Ti-6Al-4V alloy in a wide temperature range of 1023-1323 K and strain rate range of 0.01-10 s-1 were conducted by a servo-hydraulic and computer-controlled Gleeble-3500 machine. In order to accurately and effectively characterize the highly nonlinear flow behaviors, support vector regression (SVR) which is a machine learning method was combined with genetic algorithm (GA) for characterizing the flow behaviors, namely, the GA-SVR. The prominent character of GA-SVR is that it with identical training parameters will keep training accuracy and prediction accuracy at a stable level in different attempts for a certain dataset. The learning abilities, generalization abilities, and modeling efficiencies of the mathematical regression model, ANN, and GA-SVR for Ti-6Al-4V alloy were detailedly compared. Comparison results show that the learning ability of the GA-SVR is stronger than the mathematical regression model. The generalization abilities and modeling efficiencies of these models were shown as follows in ascending order: the mathematical regression model < ANN < GA-SVR. The stress-strain data outside experimental conditions were predicted by the well-trained GA-SVR, which improved simulation accuracy of the load-stroke curve and can further improve the related research fields where stress-strain data play important roles, such as speculating work hardening and dynamic recovery, characterizing dynamic recrystallization evolution, and improving processing maps.

  10. Accurate Descriptions of Hot Flow Behaviors Across β Transus of Ti-6Al-4V Alloy by Intelligence Algorithm GA-SVR

    NASA Astrophysics Data System (ADS)

    Wang, Li-yong; Li, Le; Zhang, Zhi-hua

    2016-07-01

    Hot compression tests of Ti-6Al-4V alloy in a wide temperature range of 1023-1323 K and strain rate range of 0.01-10 s-1 were conducted by a servo-hydraulic and computer-controlled Gleeble-3500 machine. In order to accurately and effectively characterize the highly nonlinear flow behaviors, support vector regression (SVR) which is a machine learning method was combined with genetic algorithm (GA) for characterizing the flow behaviors, namely, the GA-SVR. The prominent character of GA-SVR is that it with identical training parameters will keep training accuracy and prediction accuracy at a stable level in different attempts for a certain dataset. The learning abilities, generalization abilities, and modeling efficiencies of the mathematical regression model, ANN, and GA-SVR for Ti-6Al-4V alloy were detailedly compared. Comparison results show that the learning ability of the GA-SVR is stronger than the mathematical regression model. The generalization abilities and modeling efficiencies of these models were shown as follows in ascending order: the mathematical regression model < ANN < GA-SVR. The stress-strain data outside experimental conditions were predicted by the well-trained GA-SVR, which improved simulation accuracy of the load-stroke curve and can further improve the related research fields where stress-strain data play important roles, such as speculating work hardening and dynamic recovery, characterizing dynamic recrystallization evolution, and improving processing maps.

  11. Integrated computer aided reservoir management (CARM) using Landmark`s OpenWorks 3 database and Reservoir Management software

    SciTech Connect

    Ward, L.C.

    1995-08-01

    Multi-disciplinary asset teams in today`s oil industry are facing an information revolution. To assist them to more accurately define and develop known reservoirs, to visualise reservoirs in 3 dimensions, and to communicate more effectively, they require access to a single common dataset and a flexible, and comprehensive suite of reservoir description software, that allows delineation and refinement of quantitative 3D reservoir models. Landmark`s Computer Aided Reservoir Management (CARM) software provides the most complete integrated geo-information solution for data management, and a suite of integrated Reservoir Management software covering 3D & 2D seismic interpretation, 3D Geocellular modelling (Stratamodel), geological cross section building and deterministic and probabilistic petrophysical log analysis for 3D display. The OpenWorks 3 database provides a common framework not only for the integration of data between Landmark applications, but also with third party applications. Thus once the reservoir stratigraphic framework has been built in Stratamodel it can be used as direct input for stochastic modelling in Odin`s STORM, and also provide data direct to reservoir simulation applications. The key element to this integration is the OpenWorks 3 database which is a production oriented geo-science data model with over 500 tables and in excess of 2500 attributes. The OpenWorks 3 software permits seamless data transfer from one reservoir management application to another, and at every stage of reservoir management the latest updated interpretation is available to every team member. The goal of integrated reservoir management, to achieve effective exploitation of reserves, now utilises multi disciplinary analysis by cross functional teams, enabling the industry to maximise return on {open_quotes}knowledge assets{close_quotes} and physical reserves.

  12. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. Annual report, October 1994--October 1995

    SciTech Connect

    Kerr, D.; Thompson, L.; Shenoi, S.

    1996-01-01

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The main challenge of the proposed research is to automate the generation of detailed reservoir descriptions honoring all the available soft and hard data that ranges from qualitative and semi-quantitative geological interpretations to numeric data obtained from cores, well tests, well logs and production statistics. Additional challenges are the verification and validation of the expert system, since much of the interpretation of the experts is based on extended experience in reservoir characterization. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an AI-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an AI-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. With this plan, the authors have carefully allocated and sequenced the activities involved in each of the tasks to promote concurrent progress towards the research objectives. Moreover, the project duties are divided among the faculty member participants. Graduate students will work in terms with faculty members.

  13. Characterization of oil and gas reservoirs and recovery technology deployment on Texas State Lands

    SciTech Connect

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

    1997-08-01

    Texas State Lands oil and gas resources are estimated at 1.6 BSTB of remaining mobile oil, 2.1 BSTB, or residual oil, and nearly 10 Tcf of remaining gas. An integrated, detailed geologic and engineering characterization of Texas State Lands has created quantitative descriptions of the oil and gas reservoirs, resulting in delineation of untapped, bypassed compartments and zones of remaining oil and gas. On Texas State Lands, the knowledge gained from such interpretative, quantitative reservoir descriptions has been the basis for designing optimized recovery strategies, including well deepening, recompletions, workovers, targeted infill drilling, injection profile modification, and waterflood optimization. The State of Texas Advanced Resource Recovery program is currently evaluating oil and gas fields along the Gulf Coast (South Copano Bay and Umbrella Point fields) and in the Permian Basin (Keystone East, Ozona, Geraldine Ford and Ford West fields). The program is grounded in advanced reservoir characterization techniques that define the residence of unrecovered oil and gas remaining in select State Land reservoirs. Integral to the program is collaboration with operators in order to deploy advanced reservoir exploitation and management plans. These plans are made on the basis of a thorough understanding of internal reservoir architecture and its controls on remaining oil and gas distribution. Continued accurate, detailed Texas State Lands reservoir description and characterization will ensure deployment of the most current and economically viable recovery technologies and strategies available.

  14. Accurate reservoir evaluation from borehole imaging techniques and thin bed log analysis: Case studies in shaly sands and complex lithologies in Lower Eocene Sands, Block III, Lake Maracaibo, Venezuela

    SciTech Connect

    Coll, C.; Rondon, L.

    1996-08-01

    Computer-aided signal processing in combination with different types of quantitative log evaluation techniques is very useful for predicting reservoir quality in complex lithologies and will help to increase the confidence level to complete and produce a reservoir. The Lower Eocene Sands in Block III are one of the largest reservoirs in Block III and it has produced light oil since 1960. Analysis of Borehole Images shows the reservoir heterogeneity by the presence of massive sands with very few shale laminations and thinnly bedded sands with a lot of laminations. The effect of these shales is a low resistivity that has been interpreted in most of the cases as water bearing sands. A reduction of the porosity due to diagenetic processes has produced a high-resistivity behaviour. The presence of bed boundaries and shales is detected by the microconductivity curves of the Borehole Imaging Tools allowing the estimation of the percentage of shale on these sands. Interactive computer-aided analysis and various image processing techniques are used to aid in log interpretation for estimating formation properties. Integration between these results, core information and production data was used for evaluating producibility of the reservoirs and to predict reservoir quality. A new estimation of the net pay thickness using this new technique is presented with the consequent improvement on the expectation of additional recovery. This methodology was successfully applied in a case by case study showing consistency in the area.

  15. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. Quarterly report, October 1--December 31, 1994

    SciTech Connect

    1995-05-01

    This basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The main challenge of the proposed research is to automate the generation of detailed reservoir descriptions honoring all the available soft and hard data that ranges from qualitative and semi-quantitative geological interpretations to numeric data obtained from cores, well tests, well logs and production statistics. In this sense, the proposed research project is truly multi-disciplinary. Additional challenges are the verification and validation of the expert system, since much of the interpretation of the experts is based on extended experience in reservoir characterization. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an Al-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an Al-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be technology transfer. With this plan, the authors have carefully allocated and sequenced the activities involved in each of the tasks to promote concurrent progress towards the research objectives. The results of the integration are not merely limited to obtaining better characterizations of individual reservoirs. They have the potential to significantly impact and advance the discipline of reservoir characterization itself.

  16. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. Quarterly progress report, April 1 1996--June 30, 1996

    SciTech Connect

    Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1997-03-01

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The main challenge of the proposed research is to automate the generation of detailed reservoir descriptions honoring all the available {open_quotes}soft{close_quotes} and {open_quotes}hard{close_quotes} data that ranges from qualitative and semi-quantitative geological interpretations to numeric data obtained from cores, well tests, well logs and production statistics. It involves significant amount of information exchange between researchers in geology, geostatistics, and petroleum engineering. Computer science (and artificial intelligence) provides the means to effectively acquire, integrate and automate the key expertise in the various disciplines in a reservoir characterization expert system. Additional challenges are the verification and validation of the expert system, since much of the interpretation of the experts is based on extended experience in reservoir characterization. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an Al-based methodology for producing large-scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an Al-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data.

  17. Reservoir limnology

    SciTech Connect

    Thornton, K.W.; Kimmel, B.L.; Payne, F.E.

    1990-01-01

    This book addresses reservoirs as unique ecological systems and presents research indicating that reservoirs fall into two or three highly concatenated, interactive ecological systems ranging from riverine to lacustrine or hybrid systems. Includes some controversial concepts about the limnology of reservoirs.

  18. Eocene Upper-B reservoirs of the Bolivar Coastal Field, Venezuela - a classic stratigraphic trap with a strongly preferential reservoir orientation

    SciTech Connect

    Swanson, D.C. ); Salazar, J. )

    1993-02-01

    Eocene Upper-B reservoirs of Lake Maracaibo, Venezuela are textbook examples of truncated, overlapped, and sealed stratigraphic traps. They have produced an appreciable part of the more than 10 billion barrels of oil produced from the Lagunillas Area of the Bolivar Coastal Field. In these fields, correlation of Upper-B reservoirs has always been very difficult-so difficult that detailed geological description was very arduous. In 1981 it was found that the Upper-B Eocene section correlated perfectly in an east-west direction. This preferential correlation direction was evident in fine detail as well as in gross patterns. Correlation in any direction more than a few degrees different from east-west deteriorates rapidly. The excellent east-west correlation grain allowed a more accurate development of the stratigraphic, facies, and structural framework. The correlation phenomenon is a result of geological factors. Environmental facies of cores indicate the deposits are nearshore tidal deposits located in an overall prograding deltaic setting. Many of the reservoirs consist of parallel, narrow, and long east-west trending tidal bars, oriented due east-west. They are separated by inter-bar laminated claystone, silty claystone, siltstone, and thin sandstones. Discovery of the Upper B's preferential geologic and correlation direction was a breakthrough that allowed a more accurate geological description of the reservoirs. Routine testing for correlation grain or direction should be an early procedure in geological reservoir studies.

  19. Improved Detection System Description and New Method for Accurate Calibration of Micro-Channel Plate Based Instruments and Its Use in the Fast Plasma Investigation on NASA's Magnetospheric MultiScale Mission

    NASA Technical Reports Server (NTRS)

    Gliese, U.; Avanov, L. A.; Barrie, A. C.; Kujawski, J. T.; Mariano, A. J.; Tucker, C. J.; Chornay, D. J.; Cao, N. T.; Gershman, D. J.; Dorelli, J. C.; Zeuch, M. A.; Pollock, C. J.; Jacques, A. D.

    2015-01-01

    system calibration method that enables accurate and repeatable measurement and calibration of MCP gain, MCP efficiency, signal loss due to variation in gain and efficiency, crosstalk from effects both above and below the MCP, noise margin, and stability margin in one single measurement. More precise calibration is highly desirable as the instruments will produce higher quality raw data that will require less post-acquisition data correction using results from in-flight pitch angle distribution measurements and ground calibration measurements. The detection system description and the fundamental concepts of this new calibration method, named threshold scan, will be presented. It will be shown how to derive all the individual detection system parameters and how to choose the optimum detection system operating point. This new method has been successfully applied to achieve a highly accurate calibration of the DESs and DISs of the MMS mission. The practical application of the method will be presented together with the achieved calibration results and their significance. Finally, it will be shown that, with further detailed modeling, this method can be extended for use in flight to achieve and maintain a highly accurate detection system calibration across a large number of instruments during the mission.

  20. Method Description, Quality Assurance, Environmental Data, and other Information for Analysis of Pharmaceuticals in Wastewater-Treatment-Plant Effluents, Streamwater, and Reservoirs, 2004-2009

    USGS Publications Warehouse

    Phillips, Patrick J.; Smith, Steven G.; Kolpin, Dana W.; Zaugg, Steven D.; Buxton, Herbert T.; Furlong, Edward T.

    2010-01-01

    Abstract Wastewater-treatment-plant (WWTP) effluents are a demonstrated source of pharmaceuticals to the environment. During 2004-09, a study was conducted to identify pharmaceutical compounds in effluents from WWTPs (including two that receive substantial discharges from pharmaceutical formulation facilities), streamwater, and reservoirs. The methods used to determine and quantify concentrations of seven pharmaceuticals are described. In addition, the report includes information on pharmaceuticals formulated or potentially formulated at the two pharmaceutical formulation facilities that provide substantial discharge to two of the WWTPs, and potential limitations to these data are discussed. The analytical methods used to provide data on the seven pharmaceuticals (including opioids, muscle relaxants, and other pharmaceuticals) in filtered water samples also are described. Data are provided on method performance, including spike data, method detection limit results, and an estimation of precision. Quality-assurance data for sample collection and handling are included. Quantitative data are presented for the seven pharmaceuticals in water samples collected at WWTP discharge points, from streams, and at reservoirs. Occurrence data also are provided for 19 pharmaceuticals that were qualitatively identified. Flow data at selected WWTP and streams are presented. Between 2004-09, 35-38 effluent samples were collected from each of three WWTPs in New York and analyzed for seven pharmaceuticals. Two WWTPs (NY2 and NY3) receive substantial inflows (greater than 20 percent of plant flow) from pharmaceutical formulation facilities (PFF) and one (NY1) receives no PFF flow. Samples of effluents from 23 WWTPs across the United States were analyzed once for these pharmaceuticals as part of a national survey. Maximum pharmaceutical effluent concentrations for the national survey and NY1 effluent samples were generally less than 1 ug/L. Four pharmaceuticals (methadone, oxycodone

  1. 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.

  2. 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.

  3. Lakes and reservoirs

    SciTech Connect

    Taub, F.B.

    1984-01-01

    This volume in the Ecosystems of the World series studies lakes and reservoirs. The book opens with a discussion of the ecosystem processes that are common to all lakes and reservoirs and then proceeds to a description of mathematical models of these processes. The chapters concentrate on lakes and reservoirs in different parts of the world, ranging from polar to tropical lakes, and in many of the chapters the effects of human activities such as dam construction, increased nutrient inputs, toxic contaminants and fish introduction, are also considered. The book concludes with a summary of the efforts at lake restoration that are being undertaken in many communities in an attempt to undo the damage that has resulted from some of these activities.

  4. NNLOPS accurate associated HW production

    NASA Astrophysics Data System (ADS)

    Astill, William; Bizon, Wojciech; Re, Emanuele; Zanderighi, Giulia

    2016-06-01

    We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross section Working Group.

  5. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach, progress report, January 1, 1997--March 31, 1997

    SciTech Connect

    Kerr, D.R., Thompson, L.G., Shenoi, S.

    1993-10-01

    The basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The main challenge of the proposed research is to automate the generation of detailed reservoir descriptions honoring all the available `soft` and `hard` data that ranges from qualitative and semi-quantitative geological interpretations to numeric data obtained from cores, well tests, well logs and production statistics. In this sense, the proposed research project is multidisciplinary. It involves significant amounts of information exchange between researchers in geology, geostatistics, and petroleum engineering. Computer science (and artificial intelligence) provides the means to effectively acquire, integrate and automate the key expertise in the various disciplines in a reservoir characterization expert system. Additional challenges are the verification and validation of the expert system, since much of the interpretation of the experts is based on extended experience in reservoir characterization. The overall project plan to design the system to create integrated reservoir descriptions begins by initially developing an Al-based methodology for producing large- scale reservoir descriptions generated interactively from geology and well test data. Parallel to this task is a second task that develops an Al-based methodology that uses facies-biased information to generate small-scale descriptions of reservoir properties such as permeability and porosity. The third task involves consolidation and integration of the large-scale and small-scale methodologies to produce reservoir descriptions honoring all the available data. The final task will be

  6. 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.

  7. STORM: Integrated 3D stochastic reservoir modeling tool for geologists and reservoir engineers

    SciTech Connect

    Bratvold, R.B. [ODIN Reservoir Software and Services A Holden, L.; Svanes, T.; Tyler, K.

    1995-06-01

    The petroleum industry is focusing on improved reservoir characterization. Decision concerning development and depletion of hydrocarbon reservoirs must be made while giving consideration to the uncertainties of the formation involved. This requires combining geological and engineering data to develop a detailed reservoir model. Geostatistics and stochastic modeling techniques have emerged as promising approaches for integrating all relevant information and describing heterogeneous reservoirs. By use of stochastic techniques to generate a range of equiprobable reservoir descriptions, the uncertainty in the important reservoir parameters can be quantified. This quantification, together with the enhanced understanding of the reservoir characteristics given by stochastic reservoir modeling and visualization, provides an essential basis for making informed field-development decisions. This paper presents an integrated approach for stochastic reservoir evaluation. The presented approach has been implemented in the software system STORM.

  8. Sandstone reservoirs

    SciTech Connect

    Weimer, R.J.; Tillman, R.W.

    1982-01-01

    The Rocky Mountain province of the United States contains structural and stratigraphic traps from which petroleum is produced from all types of sandstone reservoirs ranging in age from Cambrian to the Eocene. Three large typical stratigraphic traps in this province, where reservoirs are of Cretaceous age, are described. The Cut Bank Field, Montana produces from aluvial point bar sandstones; Patrick Draw field, Wyoming produces from marine shoreline sandstones; and, Hartzog Draw field, Wyoming produces from marine shelf sandstone. 10 refs.

  9. Results from probability-based, simplified, off-shore Louisiana CSEM hydrocarbon reservoir modeling

    NASA Astrophysics Data System (ADS)

    Stalnaker, J. L.; Tinley, M.; Gueho, B.

    2009-12-01

    Perhaps the biggest impediment to the commercial application of controlled-source electromagnetic (CSEM) geophysics marine hydrocarbon exploration is the inefficiency of modeling and data inversion. If an understanding of the typical (in a statistical sense) geometrical and electrical nature of a reservoir can be attained, then it is possible to derive therefrom a simplified yet accurate model of the electromagnetic interactions that produce a measured marine CSEM signal, leading ultimately to efficient modeling and inversion. We have compiled geometric and resistivity measurements from roughly 100 known, producing off-shore Louisiana Gulf of Mexico reservoirs. Recognizing that most reservoirs could be recreated roughly from a sectioned hemi-ellipsoid, we devised a unified, compact reservoir geometry description. Each reservoir was initially fit to the ellipsoid by eye, though we plan in the future to perform a more rigorous least-squares fit. We created, using kernel density estimation, initial probabilistic descriptions of reservoir parameter distributions, with the understanding that additional information would not fundamentally alter our results, but rather increase accuracy. From the probabilistic description, we designed an approximate model consisting of orthogonally oriented current segments distributed across the ellipsoid--enough to define the shape, yet few enough to be resolved during inversion. The moment and length of the currents are mapped to geometry and resistivity of the ellipsoid. The probability density functions (pdfs) derived from reservoir statistics serve as a workbench. We first use the pdfs in a Monte Carlo simulation designed to assess the detectability off-shore Louisiana reservoirs using magnitude versus offset (MVO) anomalies. From the pdfs, many reservoir instances are generated (using rejection sampling) and each normalized MVO response is calculated. The response strength is summarized by numerically computing MVO power, and that

  10. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. January 1, 1996--March 31, 1996

    SciTech Connect

    Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1996-05-01

    The basis of this research is to apply novel techniques from artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The main challenge of the proposed research is to automate the generation of detailed reservoir descriptions honoring all the available ``software`` and ``hardware`` data that ranges from qualitative and semi-quantitative geological interpretations to numeric data obtained from cores, well tests, well logs and production statistics. In this sense, the proposed research project is truly multidisciplinary. It involves significant amount of information exchange between researchers in geology, geostatistics, and petroleum engineering. Computer science (and artificial intelligence) provides the means to effectively acquire, integrate and automate the key expertise in the various disciplines in a reservoir characterization expert system. Additional challenges are the verification and validation of the expert system, since much of the interpretation of the experts is based on extended experience in reservoir characterization. Accomplishments to date are discussed.

  11. Steamflood modeling and scale up in a hetrogeneous reservoir

    SciTech Connect

    Dehghani, K.; Basham, W.M.; Durlofsky, L.J.

    1996-12-31

    A study was undertaken to investigate the effects of different levels of reservoir description for modeling the steamflood process in Midway-Sunset 26C south. This reservoir is highly stratified and interbedded with fine scale heterogeneities. The study also included development of a methodology for coarsening very detailed geostatistically derived models so that the effects of fine scale heterogeneities on the steamflood performance prediction can be captured. porosity and permeability cubes with three different levels of detail in layering were generated geostatistically for a 30 acre area in the 26C south using data from 57 wells. Cross section models were extracted from these cubes in both dipping and non-dipping structures for steamflood simulations using field injection data and the results were compared.The most detailed models were coarsened by two methods. In the first method, the impermeable layers were retained and the permeable sands coarsened by averaging each 10 layers. In the second method the dominant flow paths in the cross section are identified and used to selectively scale up the reservoir properties, leaving detail in regions where required and coarsening in other regions. The results showed that the detailed geostatistical model gives a more accurate performance prediction than a coarse geostatistical model. The results also showed that the most accurate coarsened models were obtained by applying the general scale up technique.

  12. Steamflood modeling and scale up in a hetrogeneous reservoir

    SciTech Connect

    Dehghani, K.; Basham, W.M.; Durlofsky, L.J. )

    1996-01-01

    A study was undertaken to investigate the effects of different levels of reservoir description for modeling the steamflood process in Midway-Sunset 26C south. This reservoir is highly stratified and interbedded with fine scale heterogeneities. The study also included development of a methodology for coarsening very detailed geostatistically derived models so that the effects of fine scale heterogeneities on the steamflood performance prediction can be captured. porosity and permeability cubes with three different levels of detail in layering were generated geostatistically for a 30 acre area in the 26C south using data from 57 wells. Cross section models were extracted from these cubes in both dipping and non-dipping structures for steamflood simulations using field injection data and the results were compared.The most detailed models were coarsened by two methods. In the first method, the impermeable layers were retained and the permeable sands coarsened by averaging each 10 layers. In the second method the dominant flow paths in the cross section are identified and used to selectively scale up the reservoir properties, leaving detail in regions where required and coarsening in other regions. The results showed that the detailed geostatistical model gives a more accurate performance prediction than a coarse geostatistical model. The results also showed that the most accurate coarsened models were obtained by applying the general scale up technique.

  13. Reservoir characterization of Pennsylvanian Sandstone Reservoirs. Annual report

    SciTech Connect

    Kelkar, M.

    1992-09-01

    This annual report describes the progress during the second year of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description and scale-up procedures; (ii) outcrop investigation; (iii) in-fill drilling potential. The first section describes the methods by which a reservoir can be characterized, can be described in three dimensions, and can be scaled up with respect to its properties, appropriate for simulation purposes. The second section describes the progress on investigation of an outcrop. The outcrop is an analog of Bartlesville Sandstone. We have drilled ten wells behind the outcrop and collected extensive log and core data. The cores have been slabbed, photographed and the several plugs have been taken. In addition, minipermeameter is used to measure permeabilities on the core surface at six inch intervals. The plugs have been analyzed for the permeability and porosity values. The variations in property values will be tied to the geological descriptions as well as the subsurface data collected from the Glen Pool field. The third section discusses the application of geostatistical techniques to infer in-fill well locations. The geostatistical technique used is the simulated annealing technique because of its flexibility. One of the important reservoir data is the production data. Use of production data will allow us to define the reservoir continuities, which may in turn, determine the in-fill well locations. The proposed technique allows us to incorporate some of the production data as constraints in the reservoir descriptions. The technique has been validated by comparing the results with numerical simulations.

  14. Trends in reservoir simulation

    SciTech Connect

    Nolen, J.S.

    1995-06-01

    The future of reservoir simulation is driven by two different and, on the surface, paradoxical trends. On the one hand, the user base is on average becoming less experienced, and on the other, increasingly complex models are being built to honor the advances in reservoir-description technology. The job of the software development community is to create software that satisfies both the ease-of-use needs of the novice and the accuracy needs of the integrated geoscience team. One of the near-term effects of these demands will be to improve the capabilities and quality of the fully integrated geoscience work-station. This will include the need for implementation of industry-wide data standards. Reservoir simulators will need to incorporate increasing amounts of interactivity and built-in expertise. Accuracy of results will be improved by increased use of unstructured grids, including automatic gridding software with dynamic capabilities. Additional research will focus on complex wells, including both in-flow performance and wellbore hydraulics. Finally, grid size will continue to escalate in step with advances in hardware and software. The growth of grid size will be mitigated by substantial efforts in upscaling, but ultimately parallel computing must provide the mechanism for continued growth.

  15. Surrogate Reservoir Model

    NASA Astrophysics Data System (ADS)

    Mohaghegh, Shahab

    2010-05-01

    Surrogate Reservoir Model (SRM) is new solution for fast track, comprehensive reservoir analysis (solving both direct and inverse problems) using existing reservoir simulation models. SRM is defined as a replica of the full field reservoir simulation model that runs and provides accurate results in real-time (one simulation run takes only a fraction of a second). SRM mimics the capabilities of a full field model with high accuracy. Reservoir simulation is the industry standard for reservoir management. It is used in all phases of field development in the oil and gas industry. The routine of simulation studies calls for integration of static and dynamic measurements into the reservoir model. Full field reservoir simulation models have become the major source of information for analysis, prediction and decision making. Large prolific fields usually go through several versions (updates) of their model. Each new version usually is a major improvement over the previous version. The updated model includes the latest available information incorporated along with adjustments that usually are the result of single-well or multi-well history matching. As the number of reservoir layers (thickness of the formations) increases, the number of cells representing the model approaches several millions. As the reservoir models grow in size, so does the time that is required for each run. Schemes such as grid computing and parallel processing helps to a certain degree but do not provide the required speed for tasks such as: field development strategies using comprehensive reservoir analysis, solving the inverse problem for injection/production optimization, quantifying uncertainties associated with the geological model and real-time optimization and decision making. These types of analyses require hundreds or thousands of runs. Furthermore, with the new push for smart fields in the oil/gas industry that is a natural growth of smart completion and smart wells, the need for real time

  16. Computed microtomography of reservoir core samples

    SciTech Connect

    Coles, M.E.; Muegge, E.L.; Spanne, P.; Jones, K.W.

    1995-03-01

    X-ray computed tomography (CT) is often utilized to evaluate and characterize structural characteristics within reservoir core material systems. Generally, medical CT scanners have been employed because of their availability and ease of use. Of interest lately has been the acquisition of three-dimensional, high resolution descriptions of rock and pore structures for characterization of the porous media and for modeling of single and multiphase transport processes. The spatial resolution of current medical CT scanners is too coarse for pore level imaging of most core samples. Recently developed high resolution computed microtomography (CMT) using synchrotron X-ray sources is analogous to conventional medical CT scanning and provides the ability to obtain three-dimensional images of specimens with a spatial resolution on the order of micrometers. Application of this technique to the study of core samples provides two- and three-dimensional high resolution description of pore structure and mineral distributions. Pore space and interconnectivity is accurately characterized and visualized. Computed microtomography data can serve as input into pore-level simulation techniques. A generalized explanation of the technique is provided, with comparison to conventional CT scanning techniques and results. Computed microtomographic results of several sandstone samples are presented and discussed. Bulk porosity values and mineralogical identification were obtained from the microtomograms and compared with gas porosity and scanning electron microscope results on tandem samples.

  17. Modern Reservoir Sedimentation Management Techniques with Examples

    NASA Astrophysics Data System (ADS)

    Annandale, G. W.

    2014-12-01

    Implementation of reservoir sedimentation management approaches results in a win-win scenario, it assists in enhancing the environment by preserving river function downstream of dams while concurrently providing opportunities to sustainably manage water resource infrastructure. This paper summarizes the most often used reservoir sedimentation management techniques with examples of where they have been implemented. Three categories can be used to classify these technologies, i.e. catchment management, sediment routing and sediment removal. The objective of catchment management techniques is to minimize the amount of sediment that may discharge into a reservoir, thereby reducing the loss of storage space due to sedimentation. Reservoir routing is a set of techniques that aim at minimizing the amount of sediment that may deposit in a reservoir, thereby maximizing the amount of sediment that may be passed downstream. The third group consists of techniques that may be used to remove previously deposited sediment from reservoirs. The selection of reservoir sedimentation management approaches is site specific and depends on various factors, including dam height, reservoir volume, reservoir length, valley shape, valley slope, sediment type and hydrology. Description of the different reservoir sedimentation management techniques that are used in practice will be accompanied by case studies, including video, illustrating criteria that may be used to determine the potential success of implementing the techniques.

  18. Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel.

    PubMed

    Fernández-Colino, A; Bermudez, J M; Arias, F J; Quinteros, D; Gonzo, E

    2016-04-01

    Transversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate “lumped” kinetics model to correctly fit the experimentally observed drug-release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices.

  19. Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel.

    PubMed

    Fernández-Colino, A; Bermudez, J M; Arias, F J; Quinteros, D; Gonzo, E

    2016-04-01

    Transversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate “lumped” kinetics model to correctly fit the experimentally observed drug-release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices. PMID:26838852

  20. 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.

  1. Application of artificial intelligence to reservoir characterization: An interdisciplinary approach. [Quarterly progress report], October 1--December 30, 1993

    SciTech Connect

    Gamble, R.F.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    1993-12-31

    This basis of this research is to apply novel techniques from Artificial Intelligence and Expert Systems in capturing, integrating and articulating key knowledge from geology, geostatistics, and petroleum engineering to develop accurate descriptions of petroleum reservoirs. The ultimate goal is to design and implement a single powerful expert system for use by small producers and independents to efficiently exploit reservoirs. The first task under each of the concurrent phases of developing large-scale and small-scale reservoir descriptions is to identify the main knowledge sources. This task involves the identification of the critical variables that have an impact on large-scale heterogeneities. Because of the interdisciplinary nature of the project, we have had to develop a common vocabulary among the researchers to accomplish this identification task of Phases I and II. It was necessary for the computer science faculty and students to familiarize themselves with the information processed in geology geostatistics, and petroleum engineering. In addition, the geology and petroleum engineering researchers required instruction in the process of building expert systems. As part of the simulation task of Phase I and II, we have decomposed the design of the expert system into smaller component parts to get a clearer picture of what expert knowledge is needed. This decomposition will facilities that validation and verification of a complex expert system. We will develop concurrently three small prototype systems that will interface with a central repository of reservoir descriptions. The three component systems will be representative of how each of the experts in geology, geostatistics, and engineering characterizes the reservoir. The repository will hold all descriptions that are consistent with the currently known information.

  2. Oil Reservoir Properties Estimation Using Neutal Networks

    NASA Technical Reports Server (NTRS)

    Toomarian, N. B.; Barhen, J.; Glover, C. W.; Aminzadeh, F.

    1997-01-01

    This paper investigates the applicability as well as the accuracy of artificial neural networks for estimating specific parameters that describe reservoir properties based on seismic data. Our approach relies on JPL's adjoint operators general purpose neural network code to determine the best suited architecture. We believe that results presented in this work demonstrate that artificial neural networks produce surprisingly accurate estimates of the reservoir parameters.

  3. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Not Available

    1991-01-01

    The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

  4. AUTOMATED TECHNIQUE FOR FLOW MEASUREMENTS FROM MARIOTTE RESERVOIRS.

    USGS Publications Warehouse

    Constantz, Jim; Murphy, Fred

    1987-01-01

    The mariotte reservoir supplies water at a constant hydraulic pressure by self-regulation of its internal gas pressure. Automated outflow measurements from mariotte reservoirs are generally difficult because of the reservoir's self-regulation mechanism. This paper describes an automated flow meter specifically designed for use with mariotte reservoirs. The flow meter monitors changes in the mariotte reservoir's gas pressure during outflow to determine changes in the reservoir's water level. The flow measurement is performed by attaching a pressure transducer to the top of a mariotte reservoir and monitoring gas pressure changes during outflow with a programmable data logger. The advantages of the new automated flow measurement techniques include: (i) the ability to rapidly record a large range of fluxes without restricting outflow, and (ii) the ability to accurately average the pulsing flow, which commonly occurs during outflow from the mariotte reservoir.

  5. Drought description

    USGS Publications Warehouse

    Matalas, N.C.

    1991-01-01

    What constitutes a comprehensive description of drought, a description forming a basis for answering why a drought occurred is outlined. The description entails two aspects that are "naturally" coupled, named physical and economic, and treats the set of hydrologic measures of droughts in terms of their multivariate distribution, rather than in terms of a collection of the marginal distributions. ?? 1991 Springer-Verlag.

  6. An index of reservoir habitat impairment

    USGS Publications Warehouse

    Miranda, L.E.; Hunt, K.M.

    2011-01-01

    Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

  7. Integrated reservoir characterization of a complex carbonate field

    SciTech Connect

    Bard, K.C.; Arestad, J.F.; Al-Bastaki, A.

    1995-12-31

    Multidisciplinary teams of geologists, geophysicists, and petroleum engineers create unique working environments as each member brings his own different perspective to the team. These different viewpoints make integrated teams effective in solving reservoir management problems. A full understanding of the spatial distribution and interdependency of reservoir properties such as porosity, water saturation, permeability, formation volume factors, and rock properties is essential for reservoir management plans to be effective. The integrated team working on Joffre field, Alberta has successfully brought together the available data from the three disciplines to form a comprehensive understanding of the reservoir. The Reservoir Characterization Project (RCP) at the Colorado School of Mines conducts research into the application of 3-D, 3-C (multicomponent) reflection seismology for improved reservoir description and exploitation. The current research is oriented towards using shear waves to characterize reservoirs where compressional seismic data have not been effective. In the Joffre field the compressional seismic data has been ineffective in discerning porous and non-porous reservoir development. A 3-D multicomponent (3-D, 3-C) seismic survey was collected over the northeastern limit of Joffre field, Alberta by RCP. Application of this new technology towards reservoir description is a key element of this multidisciplinary study. The focus of this research and survey is lithology and porosity discrimination within the upper Devonian, Nisku dolomite reservoir. Detailed geologic studies of cores from this reservoir revealed depositional and diagenetic heterogeneities, which influence production.

  8. Application of a delumping procedure to compositional reservoir simulations

    SciTech Connect

    Stenby, E.H.; Christensen, J.R.; Knudsen, K.; Leibovici, C.

    1996-12-31

    Characterization and lumping are always performed when dealing with reservoir fluids. The number of pseudocomponents in a compositional reservoir simulation is normally between three and eight. In order to optimize the reservoir performance, it is necessary to know a detailed composition of the product stream from the reservoir. This paper deals with the problems of how to come from the lumped system (for which the reservoir simulation was performed) to a description of the full system (which is important in order to optimize the down-stream facilities). The equations of the delumping procedure are shown and the application of the method is illustrated through examples, including a constant volume depletion experiment and the fifth SPE Comparative example with a fluid description from a North Sea reservoir (with the calculated composition after a lumping, an experiment and a delumping).

  9. Models in biology: 'accurate descriptions of our pathetic thinking'.

    PubMed

    Gunawardena, Jeremy

    2014-01-01

    In this essay I will sketch some ideas for how to think about models in biology. I will begin by trying to dispel the myth that quantitative modeling is somehow foreign to biology. I will then point out the distinction between forward and reverse modeling and focus thereafter on the former. Instead of going into mathematical technicalities about different varieties of models, I will focus on their logical structure, in terms of assumptions and conclusions. A model is a logical machine for deducing the latter from the former. If the model is correct, then, if you believe its assumptions, you must, as a matter of logic, also believe its conclusions. This leads to consideration of the assumptions underlying models. If these are based on fundamental physical laws, then it may be reasonable to treat the model as 'predictive', in the sense that it is not subject to falsification and we can rely on its conclusions. However, at the molecular level, models are more often derived from phenomenology and guesswork. In this case, the model is a test of its assumptions and must be falsifiable. I will discuss three models from this perspective, each of which yields biological insights, and this will lead to some guidelines for prospective model builders. PMID:24886484

  10. Study on detailed geological modelling for fluvial sandstone reservoir in Daqing oil field

    SciTech Connect

    Zhao Hanqing; Fu Zhiguo; Lu Xiaoguang

    1997-08-01

    Guided by the sedimentation theory and knowledge of modern and ancient fluvial deposition and utilizing the abundant information of sedimentary series, microfacies type and petrophysical parameters from well logging curves of close spaced thousands of wells located in a large area. A new method for establishing detailed sedimentation and permeability distribution models for fluvial reservoirs have been developed successfully. This study aimed at the geometry and internal architecture of sandbodies, in accordance to their hierarchical levels of heterogeneity and building up sedimentation and permeability distribution models of fluvial reservoirs, describing the reservoir heterogeneity on the light of the river sedimentary rules. The results and methods obtained in outcrop and modem sedimentation studies have successfully supported the study. Taking advantage of this method, the major producing layers (PI{sub 1-2}), which have been considered as heterogeneous and thick fluvial reservoirs extending widely in lateral are researched in detail. These layers are subdivided into single sedimentary units vertically and the microfacies are identified horizontally. Furthermore, a complex system is recognized according to their hierarchical levels from large to small, meander belt, single channel sandbody, meander scroll, point bar, and lateral accretion bodies of point bar. The achieved results improved the description of areal distribution of point bar sandbodies, provide an accurate and detailed framework model for establishing high resolution predicting model. By using geostatistic technique, it also plays an important role in searching for enriched zone of residual oil distribution.

  11. Improved characterization of reservoir behavior by integration of reservoir performances data and rock type distributions

    SciTech Connect

    Davies, D.K.; Vessell, R.K.; Doublet, L.E.

    1997-08-01

    An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.

  12. Status of Norris Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Norris Reservoir summarizes reservoir and watershed characteristics, reservoir uses, conditions that impair reservoir uses, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most up-to-date publications and data available, and from interviews with water resource professionals in various federal, state, and local agencies, and in public and private water supply and wastewater treatment facilities. 14 refs., 3 figs.

  13. An experimental unification of reservoir computing methods.

    PubMed

    Verstraeten, D; Schrauwen, B; D'Haene, M; Stroobandt, D

    2007-04-01

    Three different uses of a recurrent neural network (RNN) as a reservoir that is not trained but instead read out by a simple external classification layer have been described in the literature: Liquid State Machines (LSMs), Echo State Networks (ESNs) and the Backpropagation Decorrelation (BPDC) learning rule. Individual descriptions of these techniques exist, but a overview is still lacking. Here, we present a series of experimental results that compares all three implementations, and draw conclusions about the relation between a broad range of reservoir parameters and network dynamics, memory, node complexity and performance on a variety of benchmark tests with different characteristics. Next, we introduce a new measure for the reservoir dynamics based on Lyapunov exponents. Unlike previous measures in the literature, this measure is dependent on the dynamics of the reservoir in response to the inputs, and in the cases we tried, it indicates an optimal value for the global scaling of the weight matrix, irrespective of the standard measures. We also describe the Reservoir Computing Toolbox that was used for these experiments, which implements all the types of Reservoir Computing and allows the easy simulation of a wide range of reservoir topologies for a number of benchmarks.

  14. Predicting deep reservoir quality, offshore Norway

    SciTech Connect

    Welton, J.E. )

    1996-01-01

    Reducing risk by predicting deep reservoir potential has long been the goal of the explorationist. To successfully evaluate deep reservoir potential requires the integration of information on depositional setting, mineralogy, texture (i.e. grain size and sorting), burial history, temperature, porosity, and permeability. In 1991, prior to the 14th Round, exploration potential on the Halten Terrace (Offshore Norway) was limited by reservoir predictions (based on generalized mineralogy trends) which suggested economic basement was 4000m. However, an integrated reservoir study conducted between 1991-1993 concluded that in certain Jurassic facies, significant deep reservoir potential existed. The study predicted that coarser-grained, quartz-rich braided stream, delta front, and offshore shelf sandbodies would have good porosity and permeability below 4000m, particularly there early chlorite grain coatings were present to inhibit silica cement. In the spring of 1995, the discovery of significant hydrocarbon reserves below 4000m on Block 6406/2 confirmed these predictions and proved that integrated reservoir characterization can lead to accurate deep reservoir quality predictions. The integrated methodology used will be discussed.

  15. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  16. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  17. Status of Cherokee Reservoir

    SciTech Connect

    Not Available

    1990-08-01

    This is the first in a series of reports prepared by Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overviews of Cherokee Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports, publications, and data available, and interviews with water resource professionals in various Federal, state, and local agencies and in public and private water supply and wastewater treatment facilities. 11 refs., 4 figs., 1 tab.

  18. Status of Wheeler Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  19. SEISMIC EVALUATION OF HYDROCARBON SATURATION IN DEEP-WATER RESERVOIRS

    SciTech Connect

    Michael Batzle; D-h Han; R. Gibson; Huw James

    2005-01-22

    During this last quarter of the ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' project (Grant/Cooperative Agreement DE-FC26-02NT15342), we have moved forward on several fronts, including data acquisition as well as analysis and application. During this quarter we have: (1) Completed our site selection (finally); (2) Measured fluid effects in Troika deep water sand sample; (3) Applied the result to Ursa ''fizz gas'' zone; (4) Compared thin layer property averaging on AVO response; (5) Developed target oriented NMO stretch correction; (6) Examined thin bed effects on A-B crossplots; and (7) Begun incorporating outcrop descriptive models in seismic forward models. Several factors can contribute to limit our ability to extract accurate hydrocarbon saturations in deep water environments. Rock and fluid properties are one factor, since, for example, hydrocarbon properties will be considerably different with great depths (high pressure) when compared to shallow properties. Significant over pressure, on the other hand will make the rocks behave as if they were shallower. In addition to the physical properties, the scale and tuning will alter our hydrocarbon indicators. Reservoirs composed of thin bed effects will broaden the reflection amplitude distribution with incident angle. Normal move out (NMO) stretch corrections based on frequency shifts can be applied to offset this effect. Tuning will also disturb the location of extracted amplitudes on AVO intercept and gradient (A-B) plots. Many deep water reservoirs fall this tuning thickness range. Our goal for the remaining project period is to systematically combine and document these various effects for use in deep water exploration.

  20. Seismic Evaluation of Hydorcarbon Saturation in Deep-Water Reservoirs

    SciTech Connect

    Michael Batzle; D-h Han; R. Gibson; Huw James

    2005-10-31

    During this last quarter of the ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' project (Grant/Cooperative Agreement DE-FC26-02NT15342), we have moved forward on several fronts, including data acquisition as well as analysis and application. During this quarter we have: (1) Completed our site selection (finally); (2) Measured fluid effects in Troika deep water sand sample; (3) Applied the result to Ursa ''fizz gas'' zone; (4) Compared thin layer property averaging on AVO response; (5) Developed target oriented NMO stretch correction; (6) Examined thin bed effects on A-B crossplots; and (7) Begun incorporating outcrop descriptive models in seismic forward models. Several factors can contribute to limit our ability to extract accurate hydrocarbon saturations in deep water environments. Rock and fluid properties are one factor, since, for example, hydrocarbon properties will be considerably different with great depths (high pressure) when compared to shallow properties. Significant over pressure, on the other hand will make the rocks behave as if they were shallower. In addition to the physical properties, the scale and tuning will alter our hydrocarbon indicators. Reservoirs composed of thin bed effects will broaden the reflection amplitude distribution with incident angle. Normal move out (NMO) stretch corrections based on frequency shifts can be applied to offset this effect. Tuning will also disturb the location of extracted amplitudes on AVO intercept and gradient (A-B) plots. Many deep water reservoirs fall this tuning thickness range. Our goal for the remaining project period is to systematically combine and document these various effects for use in deep water exploration.

  1. Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs

    SciTech Connect

    Michael Batzle

    2006-04-30

    During this last period of the ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' project (Grant/Cooperative Agreement DE-FC26-02NT15342), we finalized integration of rock physics, well log analysis, seismic processing, and forward modeling techniques. Most of the last quarter was spent combining the results from the principal investigators and come to some final conclusions about the project. Also much of the effort was directed towards technology transfer through the Direct Hydrocarbon Indicators mini-symposium at UH and through publications. As a result we have: (1) Tested a new method to directly invert reservoir properties, water saturation, Sw, and porosity from seismic AVO attributes; (2) Constrained the seismic response based on fluid and rock property correlations; (3) Reprocessed seismic data from Ursa field; (4) Compared thin layer property distributions and averaging on AVO response; (5) Related pressures and sorting effects on porosity and their influence on DHI's; (6) Examined and compared gas saturation effects for deep and shallow reservoirs; (7) Performed forward modeling using geobodies from deepwater outcrops; (8) Documented velocities for deepwater sediments; (9) Continued incorporating outcrop descriptive models in seismic forward models; (10) Held an open DHI symposium to present the final results of the project; (11) Relations between Sw, porosity, and AVO attributes; (12) Models of Complex, Layered Reservoirs; and (14) Technology transfer Several factors can contribute to limit our ability to extract accurate hydrocarbon saturations in deep water environments. Rock and fluid properties are one factor, since, for example, hydrocarbon properties will be considerably different with great depths (high pressure) when compared to shallow properties. Significant over pressure, on the other hand will make the rocks behave as if they were shallower. In addition to the physical properties, the scale and tuning will alter our

  2. 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.

  3. Towards an HIV-1 cure: measuring the latent reservoir

    PubMed Central

    Bruner, Katherine M.; Hosmane, Nina N.; Siliciano, Robert F.

    2015-01-01

    The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the latent reservoir, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measure the latent reservoir. PMID:25747663

  4. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  5. A two-stage method of quantitative flood risk analysis for reservoir real-time operation using ensemble-based hydrologic forecasts

    NASA Astrophysics Data System (ADS)

    Liu, P.

    2013-12-01

    Quantitative analysis of the risk for reservoir real-time operation is a hard task owing to the difficulty of accurate description of inflow uncertainties. The ensemble-based hydrologic forecasts directly depict the inflows not only the marginal distributions but also their persistence via scenarios. This motivates us to analyze the reservoir real-time operating risk with ensemble-based hydrologic forecasts as inputs. A method is developed by using the forecast horizon point to divide the future time into two stages, the forecast lead-time and the unpredicted time. The risk within the forecast lead-time is computed based on counting the failure number of forecast scenarios, and the risk in the unpredicted time is estimated using reservoir routing with the design floods and the reservoir water levels of forecast horizon point. As a result, a two-stage risk analysis method is set up to quantify the entire flood risks by defining the ratio of the number of scenarios that excessive the critical value to the total number of scenarios. The China's Three Gorges Reservoir (TGR) is selected as a case study, where the parameter and precipitation uncertainties are implemented to produce ensemble-based hydrologic forecasts. The Bayesian inference, Markov Chain Monte Carlo, is used to account for the parameter uncertainty. Two reservoir operation schemes, the real operated and scenario optimization, are evaluated for the flood risks and hydropower profits analysis. With the 2010 flood, it is found that the improvement of the hydrologic forecast accuracy is unnecessary to decrease the reservoir real-time operation risk, and most risks are from the forecast lead-time. It is therefore valuable to decrease the avarice of ensemble-based hydrologic forecasts with less bias for a reservoir operational purpose.

  6. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  7. An integrated approach to reservoir engineering at Pleasant Bayou Geopressured-Geothermal reservoir

    SciTech Connect

    Shook, G.M.

    1992-12-01

    A numerical model has been developed for the Pleasant Bayou Geothermal-Geopressured reservoir. This reservoir description is the result of integration of a variety of data, including geological and geophysical interpretations, pressure transient test analyses, and well operations. Transient test analyses suggested several enhancements to the geologic description provided by University of Texas Bureau of Economic Geology (BEG), including the presence of an internal fault not previously identified. The transient tests also suggested water influx from an adjacent aquifer during the long-term testing of Pleasant Bayou; comparisons between transient test analyses and the reservoir description from BEG suggests that this fault exhibits pressure-dependent behavior. Below some pressure difference across the fault, it remains a no-flow barrier; above this threshold pressure drop the barrier fails, and fluid moves across the fault. A history match exercise is presented, using the hypothesized {open_quotes}leaky fault.{close_quotes} Successful match of 4 years of production rates and estimates of average reservoir pressure supports the reservoir description developed herein. Sensitivity studies indicate that the degree of communication between the perforated interval and the upper and lower sands in the reservoir (termed {open_quotes}distal volume{close_quotes} by BEG) impact simulation results very little, whereas results are quite sensitive to storage and transport properties of this distal volume. The prediction phase of the study indicates that Pleasant Bayou is capable of producing 20,000 STB/d through 1997, with the final bottomhole pressure approximately 1600 psi above abandonment pressure.

  8. Functional age as an indicator of reservoir senescence

    USGS Publications Warehouse

    Miranda, Leandro E.; Krogman, R. M.

    2015-01-01

    It has been conjectured that reservoirs differ in the rate at which they manifest senescence, but no attempt has been made to find an indicator of senescence that performs better than chronological age. We assembled an indicator of functional age by creating a multimetric scale consisting of 10 metrics descriptive of reservoir environments that were expected to change directionally with reservoir senescence. In a sample of 1,022 U.S. reservoirs, chronological age was not correlated with functional age. Functional age was directly related to percentage of cultivated land in the catchment and inversely related to reservoir depth. Moreover, aspects of reservoir fishing quality and fish population characteristics were related to functional age. A multimetric scale to indicate reservoir functional age presents the possibility for management intervention from multiple angles. If a reservoir is functionally aging at an accelerated rate, action may be taken to remedy the conditions contributing most to functional age. Intervention to reduce scores of selected metrics in the scale can potentially reduce the rate of senescence and increase the life expectancy of the reservoir. This leads to the intriguing implication that steps can be taken to reduce functional age and actually make the reservoir grow younger.

  9. Seismic modeling of complex stratified reservoirs

    NASA Astrophysics Data System (ADS)

    Lai, Hung-Liang

    Turbidite reservoirs in deep-water depositional systems, such as the oil fields in the offshore Gulf of Mexico and North Sea, are becoming an important exploration target in the petroleum industry. Accurate seismic reservoir characterization, however, is complicated by the heterogeneous of the sand and shale distribution and also by the lack of resolution when imaging thin channel deposits. Amplitude variation with offset (AVO) is a very important technique that is widely applied to locate hydrocarbons. Inaccurate estimates of seismic reflection amplitudes may result in misleading interpretations because of these problems in application to turbidite reservoirs. Therefore, an efficient, accurate, and robust method of modeling seismic responses for such complex reservoirs is crucial and necessary to reduce exploration risk. A fast and accurate approach generating synthetic seismograms for such reservoir models combines wavefront construction ray tracing with composite reflection coefficients in a hybrid modeling algorithm. The wavefront construction approach is a modern, fast implementation of ray tracing that I have extended to model quasi-shear wave propagation in anisotropic media. Composite reflection coefficients, which are computed using propagator matrix methods, provide the exact seismic reflection amplitude for a stratified reservoir model. This is a distinct improvement over conventional AVO analysis based on a model with only two homogeneous half spaces. I combine the two methods to compute synthetic seismograms for test models of turbidite reservoirs in the Ursa field, Gulf of Mexico, validating the new results against exact calculations using the discrete wavenumber method. The new method, however, can also be used to generate synthetic seismograms for the laterally heterogeneous, complex stratified reservoir models. The results show important frequency dependence that may be useful for exploration. Because turbidite channel systems often display complex

  10. Geothermal reservoir technology

    SciTech Connect

    Lippmann, M.J.

    1985-09-01

    A status report on Lawrence Berkeley Laboratory's Reservoir Technology projects under DOE's Hydrothermal Research Subprogram is presented. During FY 1985 significant accomplishments were made in developing and evaluating methods for (1) describing geothermal systems and processes; (2) predicting reservoir changes; (3) mapping faults and fractures; and (4) field data analysis. In addition, LBL assisted DOE in establishing the research needs of the geothermal industry in the area of Reservoir Technology. 15 refs., 5 figs.

  11. 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.

  12. Anaphoric Descriptions

    ERIC Educational Resources Information Center

    Beller, Charley

    2013-01-01

    The study of definite descriptions has been a central part of research in linguistics and philosophy of language since Russell's seminal work "On Denoting" (Russell 1905). In that work Russell quickly dispatches analyses of denoting expressions with forms like "no man," "some man," "a man," and "every…

  13. 95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  14. Accurate Optical Reference Catalogs

    NASA Astrophysics Data System (ADS)

    Zacharias, N.

    2006-08-01

    Current and near future all-sky astrometric catalogs on the ICRF are reviewed with the emphasis on reference star data at optical wavelengths for user applications. The standard error of a Hipparcos Catalogue star position is now about 15 mas per coordinate. For the Tycho-2 data it is typically 20 to 100 mas, depending on magnitude. The USNO CCD Astrograph Catalog (UCAC) observing program was completed in 2004 and reductions toward the final UCAC3 release are in progress. This all-sky reference catalogue will have positional errors of 15 to 70 mas for stars in the 10 to 16 mag range, with a high degree of completeness. Proper motions for the about 60 million UCAC stars will be derived by combining UCAC astrometry with available early epoch data, including yet unpublished scans of the complete set of AGK2, Hamburg Zone astrograph and USNO Black Birch programs. Accurate positional and proper motion data are combined in the Naval Observatory Merged Astrometric Dataset (NOMAD) which includes Hipparcos, Tycho-2, UCAC2, USNO-B1, NPM+SPM plate scan data for astrometry, and is supplemented by multi-band optical photometry as well as 2MASS near infrared photometry. The Milli-Arcsecond Pathfinder Survey (MAPS) mission is currently being planned at USNO. This is a micro-satellite to obtain 1 mas positions, parallaxes, and 1 mas/yr proper motions for all bright stars down to about 15th magnitude. This program will be supplemented by a ground-based program to reach 18th magnitude on the 5 mas level.

  15. Reservoir characterization and enhanced oil recovery research

    SciTech Connect

    Lake, L.W.; Pope, G.A.; Schechter, R.S.

    1992-03-01

    The research in this annual report falls into three tasks each dealing with a different aspect of enhanced oil recovery. The first task strives to develop procedures for accurately modeling reservoirs for use as input to numerical simulation flow models. This action describes how we have used a detail characterization of an outcrop to provide insights into what features are important to fluid flow modeling. The second task deals with scaling-up and modeling chemical and solvent EOR processes. In a sense this task is the natural extension of task 1 and, in fact, one of the subtasks uses many of the same statistical procedures for insight into the effects of viscous fingering and heterogeneity. The final task involves surfactants and their interactions with carbon dioxide and reservoir minerals. This research deals primarily with phenomena observed when aqueous surfactant solutions are injected into oil reservoirs.

  16. Accurate phase-shift velocimetry in rock.

    PubMed

    Shukla, Matsyendra Nath; Vallatos, Antoine; Phoenix, Vernon R; Holmes, William M

    2016-06-01

    Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models. PMID:27111139

  17. Accurate phase-shift velocimetry in rock

    NASA Astrophysics Data System (ADS)

    Shukla, Matsyendra Nath; Vallatos, Antoine; Phoenix, Vernon R.; Holmes, William M.

    2016-06-01

    Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models.

  18. Accurate phase-shift velocimetry in rock.

    PubMed

    Shukla, Matsyendra Nath; Vallatos, Antoine; Phoenix, Vernon R; Holmes, William M

    2016-06-01

    Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models.

  19. Geothermal reservoir engineering research

    NASA Technical Reports Server (NTRS)

    Ramey, H. J., Jr.; Kruger, P.; Brigham, W. E.; London, A. L.

    1974-01-01

    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs.

  20. Integrated reservoir management doubles Nigerian field reserves

    SciTech Connect

    Akinlawon, Y.; Nwosu, T.; Satter, A.; Jespersen, R.

    1996-10-01

    An integrated alliance across disciplines, companies and countries enabled Texaco to conduct a comprehensive reservoir analysis of the North Apoi/Funiwa field in Nigeria. Recommendations implemented in 3 months doubled the book reserves of this mature field. The paper discusses the objectives, the integration of organizations, reservoir analysis, and conclusions. The conclusions made from the integrated study are: (1) 3-D seismic data dramatically improved reservoir description. (2) OOIP is considerably more than the booked values and reserves additions are substantial. (3) Significant value has been added to TOPCON`s assets as a result of teamwork and a multidisciplinary approach to evaluating the reservoirs and optimizing the scenarios for reservoir management. (4) Teamwork and integration of professionals, data, technology and tools was critical to the projects success. (5) The study set an example for effective and expeditious technology transfer and applications. (6) Partnering of TOPCON, DPR, NAPIMS, EPTD and SSI resulted in a quick cycle time and set an excellent example of integration and alliance.

  1. Optoelectronic reservoir computing.

    PubMed

    Paquot, Y; Duport, F; Smerieri, A; Dambre, J; Schrauwen, B; Haelterman, M; Massar, S

    2012-01-01

    Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an optoelectronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations.

  2. Reservoir Temperature Estimator

    SciTech Connect

    Palmer, Carl D.

    2014-12-08

    The Reservoir Temperature Estimator (RTEst) is a program that can be used to estimate deep geothermal reservoir temperature and chemical parameters such as CO2 fugacity based on the water chemistry of shallower, cooler reservoir fluids. This code uses the plugin features provided in The Geochemist’s Workbench (Bethke and Yeakel, 2011) and interfaces with the model-independent parameter estimation code Pest (Doherty, 2005) to provide for optimization of the estimated parameters based on the minimization of the weighted sum of squares of a set of saturation indexes from a user-provided mineral assemblage.

  3. Optoelectronic Reservoir Computing

    NASA Astrophysics Data System (ADS)

    Paquot, Y.; Duport, F.; Smerieri, A.; Dambre, J.; Schrauwen, B.; Haelterman, M.; Massar, S.

    2012-02-01

    Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an optoelectronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations.

  4. Reservoir Temperature Estimator

    2014-12-08

    The Reservoir Temperature Estimator (RTEst) is a program that can be used to estimate deep geothermal reservoir temperature and chemical parameters such as CO2 fugacity based on the water chemistry of shallower, cooler reservoir fluids. This code uses the plugin features provided in The Geochemist’s Workbench (Bethke and Yeakel, 2011) and interfaces with the model-independent parameter estimation code Pest (Doherty, 2005) to provide for optimization of the estimated parameters based on the minimization of themore » weighted sum of squares of a set of saturation indexes from a user-provided mineral assemblage.« less

  5. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    SciTech Connect

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for

  6. Accurate modeling of parallel scientific computations

    NASA Technical Reports Server (NTRS)

    Nicol, David M.; Townsend, James C.

    1988-01-01

    Scientific codes are usually parallelized by partitioning a grid among processors. To achieve top performance it is necessary to partition the grid so as to balance workload and minimize communication/synchronization costs. This problem is particularly acute when the grid is irregular, changes over the course of the computation, and is not known until load time. Critical mapping and remapping decisions rest on the ability to accurately predict performance, given a description of a grid and its partition. This paper discusses one approach to this problem, and illustrates its use on a one-dimensional fluids code. The models constructed are shown to be accurate, and are used to find optimal remapping schedules.

  7. [Greenhouse gas emission from reservoir and its influence factors].

    PubMed

    Zhao, Xiao-jie; Zhao, Tong-qian; Zheng, Hua; Duan, Xiao-nan; Chen, Fa-lin; Ouyang, Zhi-yun; Wang, Xiao-ke

    2008-08-01

    Reservoirs are significant sources of emissions of the greenhouse gases. Discussing greenhouse gas emission from the reservoirs and its influence factors are propitious to evaluate emission of the greenhouse gas accurately, reduce gas emission under hydraulic engineering and hydropower development. This paper expatiates the mechanism of the greenhouse gas production, sums three approaches of the greenhouse gas emission, which are emissions from nature emission of the reservoirs, turbines and spillways and downstream of the dam, respectively. Effects of greenhouse gas emission were discussed from character of the reservoirs, climate, pH of the water, vegetation growing in the reservoirs and so on. Finally, it has analyzed the heterogeneity of the greenhouse gas emission as well as the root of the uncertainty and carried on the forecast with emphasis to the next research.

  8. Potential Mammalian Filovirus Reservoirs

    PubMed Central

    Carroll, Darin S.; Mills, James N.; Johnson, Karl M.

    2004-01-01

    Ebola and Marburg viruses are maintained in unknown reservoir species; spillover into human populations results in occasional human cases or epidemics. We attempted to narrow the list of possibilities regarding the identity of those reservoir species. We made a series of explicit assumptions about the reservoir: it is a mammal; it supports persistent, largely asymptomatic filovirus infections; its range subsumes that of its associated filovirus; it has coevolved with the virus; it is of small body size; and it is not a species that is commensal with humans. Under these assumptions, we developed priority lists of mammal clades that coincide distributionally with filovirus outbreak distributions and compared these lists with those mammal taxa that have been tested for filovirus infection in previous epidemiologic studies. Studying the remainder of these taxa may be a fruitful avenue for pursuing the identity of natural reservoirs of filoviruses. PMID:15663841

  9. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  10. Session: Reservoir Technology

    SciTech Connect

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  11. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.

    1992-10-01

    Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a heterogeneity matrix'' based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.

  12. Paonia Reservoir Sediment Management

    NASA Astrophysics Data System (ADS)

    Kimbrel, S.; Collins, K.; Williams, C.

    2014-12-01

    Paonia Dam and Reservoir are located on Muddy Creek, a tributary of the North Fork Gunnison River in western Colorado. Since dam closure in 1962, the 2002 survey estimates an annual sedimentation rate of 153,000 m3/y, resulting in a 25% loss of total reservoir capacity. Long before sediment levels completely fill the reservoir, the outlet works have recently plugged with sediment and debris, adversely impacting operations, and emphasizing the urgency of formulating an effective sediment management plan. Starting in 2010-2011, operations were changed to lower the reservoir and flush sediment through the outlet works in early spring before filling the pool for irrigation. Even though the flushing strategy through the long, narrow reservoir (~5 km long and 0.3 km wide) has prevented outlet works plugging, a long term plan is needed to manage inflowing and deposited sediment more efficiently. Reclamation's Sedimentation and River Hydraulics Group is leading an effort to study the past and current sediment issues at Paonia Dam and Reservoir, evaluate feasible sediment management alternatives, and formulate a plan for future operations and monitoring. The study is building on previously collected data and the existing knowledge base to develop a comprehensive, sustainable sediment management plan. The study is being executed in three phases: Phase 1 consisted of an initial site visit to map and sample existing reservoir bottom sediments, a preliminary site evaluation upstream and downstream of the dam, and establishment of time-lapse photo sites and taking initial ground-based photos. Phase 2 includes a bathymetric survey of entire reservoir and 11 km of the river downstream of the dam, continuous suspended sediment monitoring upstream and downstream of the reservoir, and collection of additional core samples of reservoir bottom sediments. Phase 3 involves the evaluation of current and past operations and sediment management practices, evaluate feasible sediment

  13. Characterization of Reservoir Heterogeneity from Surface Deformation

    NASA Astrophysics Data System (ADS)

    Maharramov, M.; Zoback, M. D.

    2015-12-01

    In our earlier work we resolved complex evolution of pressure fronts in a heavyoil reservoir undergoing cyclic steam stimulation. Our method was based onsolving a regularized inverse problem for inverting the pore pressure changefrom surface displacements. In this work we extend our method to recoversharp contrasts in induced reservoir pressure that may be due to permeabilitybarriers or hydraulically conductive faults. We demonstrate our method byinverting the pressure change from uplift observations for a synthetic modelof a heterogeneous reservoir undergoing fluid injection. Using the theory ofconstrained optimization, we invert values and locations of sharp pressurecontrasts from noisy measurements of surface deformation, and estimate thelocation of an impermeable boundary between reservoir compartments. In our synthetic model, two highly permeable reservoir compartmentsseparated by a nearly impermeable barrier (first panel) undergo fluid injec-tion. We simulate pressure evolution within the reservoir (second panel) andmodel surface deformation induced by the subsurface pressure change (thirdpanel), adding measurement noise to the result. We invert the noisy sur-face uplift measurements by solving a constrained optimization problem withTikhonov regularization (fourth panel). The result achieves a good inversionquality in areas of finite pressure change but provides only a rough estimatefor the barrier location. However, applying our new inversion technique with atotal-variation regularization that favors sharp model contrasts while penalizingoscillations, we achieve a more accurate approximation of the permeabilitybarrier as a level set of the inverted pressure field (fifth panel). Our new method provides a potentially useful tool for locating sharpsubsurface pressure contrasts from surface uplift observations. The methodcan be used in a variety of applications for identifying subsurface permeabil-ity heterogeneities (such as seals and hydraulically conductive

  14. An Intelligent Systems Approach to Reservoir Characterization

    SciTech Connect

    Shahab D. Mohaghegh; Jaime Toro; Thomas H. Wilson; Emre Artun; Alejandro Sanchez; Sandeep Pyakurel

    2005-08-01

    Today, the major challenge in reservoir characterization is integrating data coming from different sources in varying scales, in order to obtain an accurate and high-resolution reservoir model. The role of seismic data in this integration is often limited to providing a structural model for the reservoir. Its relatively low resolution usually limits its further use. However, its areal coverage and availability suggest that it has the potential of providing valuable data for more detailed reservoir characterization studies through the process of seismic inversion. In this paper, a novel intelligent seismic inversion methodology is presented to achieve a desirable correlation between relatively low-frequency seismic signals, and the much higher frequency wireline-log data. Vertical seismic profile (VSP) is used as an intermediate step between the well logs and the surface seismic. A synthetic seismic model is developed by using real data and seismic interpretation. In the example presented here, the model represents the Atoka and Morrow formations, and the overlying Pennsylvanian sequence of the Buffalo Valley Field in New Mexico. Generalized regression neural network (GRNN) is used to build two independent correlation models between; (1) Surface seismic and VSP, (2) VSP and well logs. After generating virtual VSP's from the surface seismic, well logs are predicted by using the correlation between VSP and well logs. The values of the density log, which is a surrogate for reservoir porosity, are predicted for each seismic trace through the seismic line with a classification approach having a correlation coefficient of 0.81. The same methodology is then applied to real data taken from the Buffalo Valley Field, to predict inter-well gamma ray and neutron porosity logs through the seismic line of interest. The same procedure can be applied to a complete 3D seismic block to obtain 3D distributions of reservoir properties with less uncertainty than the geostatistical

  15. Engineering studies of g-1, g-2, and g-3 reservoirs, Meren field, Nigeria

    SciTech Connect

    Thakur, G.C.; Haulenbeek, R.B.; Jain, A.; Koza, W.P.; Kurak, S.D.; Poston, S.W.

    1982-04-01

    A description is given of an engineering study of two large reservoirs in the G sands of Meren field, offshore Nigeria. The purpose of this study was to investigate various operating schemes for optimizing oil recovery from each of these gravity-segragated reservoirs. Geologic evaluation, material-balance calculations, and three-phase, two-dimensional (2D) (areal and cross-sectional) reservoir simulation models were used. 7 refs.

  16. Transit losses and traveltimes of reservoir releases along the Arkansas River from Pueblo Reservoir to John Martin Reservoir, southeastern Colorado

    USGS Publications Warehouse

    Livingston, Russell K.

    1978-01-01

    The volumes of reservoir releases are decreased or delayed during transit by bank storage, channel storage, and evaporation. Results from a computer model, calibrated by a controlled test release from Pueblo Reservoir, Colo., indicate that transit losses are greatest for small releases of a short duration when made during periods of low Antecedent streamflow. For equivalent releases, transit losses during the winter are about 7 percent less than losses during the summer. Based on available streamflow records, the velocity of reservoir releases ranges from about 0.6 miles per hour at the downstream end of the study reach, when antecedent streamflow is 10 cubic feet per second, to about 6.8 miles per hour at the upstream end of the study reach, when antecedent streamflow is 3,000 cubic feet per second. Consequently, the traveltime of a release increases as antecedent streamflow diminishes. Management practices that may be used to benefit water users in the study area include selection of the optimum time, rate, and duration of a reservoir release to minimize the transit losses, determination of an accurate traveltime, and diversion at several incremental rates. (Woodard-USGS)

  17. Descriptive thermodynamics

    NASA Astrophysics Data System (ADS)

    Ford, David; Huntsman, Steven

    2006-06-01

    Thermodynamics (in concert with its sister discipline, statistical physics) can be regarded as a data reduction scheme based on partitioning a total system into a subsystem and a bath that weakly interact with each other. Whereas conventionally, the systems investigated require this form of data reduction in order to facilitate prediction, a different problem also occurs, in the context of communication networks, markets, etc. Such “empirically accessible” systems typically overwhelm observers with the sort of information that in the case of (say) a gas is effectively unobtainable. What is required for such complex interacting systems is not prediction (this may be impossible when humans besides the observer are responsible for the interactions) but rather, description as a route to understanding. Still, the need for a thermodynamical data reduction scheme remains. In this paper, we show how an empirical temperature can be computed for finite, empirically accessible systems, and further outline how this construction allows the age-old science of thermodynamics to be fruitfully applied to them.

  18. Sustainable reservoir operation

    SciTech Connect

    Smith, Brennan T; Jager, Yetta; March, Patrick

    2007-07-01

    Reservoir releases are typically operated to maximize the efficiency of hydropower production and the value of hydropower produced. In practice, ecological considerations are limited to those required by law. We first describe reservoir optimization methods that include mandated constraints on environmental and other water uses. Next, we describe research to formulate and solve reservoir optimization problems involving both energy and environmental water needs as objectives. Evaluating ecological objectives is a challenge in these problems for several reasons. First, it is difficult to predict how biological populations will respond to flow release patterns. This problem can be circumvented by using ecological models. Second, most optimization methods require complex ecological responses to flow to be quantified by a single metric, preferably a currency that can also represent hydropower benefits. Ecological valuation of instream flows can make optimization methods that require a single currency for the effects of flow on energy and river ecology possible. Third, holistic reservoir optimization problems are unlikely to be structured such that simple solution methods can be used, necessitating the use of flexible numerical methods. One strong advantage of optimal control is the ability to plan for the effects of climate change. We present ideas for developing holistic methods to the point where they can be used for real-time operation of reservoirs. We suggest that developing ecologically sound optimization tools should be a priority for hydropower in light of the increasing value placed on sustaining both the ecological and energy benefits of riverine ecosystems long into the future.

  19. G-2 and G-3 reservoirs, Delta South field, Nigeria - 2. Simulation of water injection

    SciTech Connect

    Thakur, G.C.; Stanat, P.L.; Aruna, M.; Ajayi, S.A.; Poston, S.

    1982-01-01

    A description is given of a two-dimensional, three-phase, black-oil simulation of the G-2 and G-3 reservoirs in the Delta South field offshore Nigeria. The purpose of these studies was to investigate, from an engineering standpoint, various operating schemes for optimizing the oil recovery from each of these highly gravity-segregated reservoirs. 4 refs.

  20. Optoelectronic Reservoir Computing

    PubMed Central

    Paquot, Y.; Duport, F.; Smerieri, A.; Dambre, J.; Schrauwen, B.; Haelterman, M.; Massar, S.

    2012-01-01

    Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an optoelectronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations. PMID:22371825

  1. Atlas of Northern Gulf of Mexico Gas and Oil Reservoirs: Procedures and examples of resource distribution

    SciTech Connect

    Seni, S.J.; Finley, R.J.

    1995-06-01

    The objective of the program is to produce a reservoir atlas series of the Gulf of Mexico that (1) classifies and groups offshore oil and gas reservoirs into a series of geologically defined reservoir plays, (2) compiles comprehensive reservoir play information that includes descriptive and quantitative summaries of play characteristics, cumulative production, reserves, original oil and gas in place, and various other engineering and geologic data, (3) provides detailed summaries of representative type reservoirs for each play, and (4) organizes computerized tables of reservoir engineering data into a geographic information system (GIS). The primary product of the program will be an oil and gas atlas series of the offshore Northern Gulf of Mexico and a computerized geographical information system of geologic and engineering data linked to reservoir location.

  2. Manicouagin Reservoir of Canada

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Recorded by the Space Shuttle Atlantis STS-110 mission, this is a photograph of the ice- covered Manicouagin Reservoir located in the Canadian Shield of Quebec Province in Eastern Canada, partially obscured by low clouds. This reservoir marks the site of an impact crater, 60 miles (100 kilometers) wide, which according to geologists was formed 212 million years ago when a meteorite crashed into this area. Over millions of years, the crater has been worn down by glaciers and other erosional processes. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

  3. Reservoir High's TE Site Wins Web Site of the Month

    ERIC Educational Resources Information Center

    Tech Directions, 2008

    2008-01-01

    This article features "Mr. Rhine's Technology Education Web Site," a winner of the Web Site of the Month. This Web site was designed by Luke Rhine, a teacher at the Reservoir High School in Fulton, Maryland. Rhine's Web site offers course descriptions and syllabuses, class calendars, lectures and presentations, design briefs and other course…

  4. LBL/Industry fractured reservoir performance definition project

    SciTech Connect

    Benson, S.M.

    1995-04-01

    One of the problems facing the petroleum industry is the recovery of oil from heterogeneous, fractured reservoirs and from reservoirs that have been partially depleted. In response to this need, several companies, notably British Petroleum USA, (BP) and Continental Oil Company (CONOCO), have established integrated reservoir description programs. Concurrently, LBL is actively involved in developing characterization technology for heterogeneous, fractured rock, mainly for DOE`s Civilian Nuclear Waste Program as well as Geothermal Energy programs. The technology developed for these programs was noticed by the petroleum industry and resulted in cooperative research centered on the petroleum companies test facilities. The emphasis of this work is a tightly integrated interdisciplinary approach to the problem of characterizing complex, heterogeneous earth materials. In this approach we explicitly combine the geologic, geomechanical, geophysical and hydrologic information in a unified model for predicting fluid flow. The overall objective is to derive improved integrated approaches to characterizing naturally fractured gas reservoirs.

  5. Putting integrated reservoir characterization into practice - in house training

    SciTech Connect

    Wright, F.M. Jr.; Best, D.A.; Clarke, R.T.

    1997-08-01

    The need for even more efficient reservoir characterization and management has forced a change in the way Mobil Oil provides technical support to its production operations. We`ve learned that to be successful, a good understanding of the reservoir is essential. This includes an understanding of the technical and business significance of reservoir heterogeneities at different stages of field development. A multi-disciplinary understanding of the business of integrated reservoir characterization is essential and to facilitate this understanding, Mobil has developed a highly successful {open_quotes}Reservoir Characterization Field Seminar{close_quotes}. Through specific team based case studies that incorporate outcrop examples and data the program provides participants the opportunity to explore historic and alternative approaches to reservoir description, characterization and management. We explore appropriate levels and timing of data gathering, technology applications, risk assessment and management practices at different stages of field development. The case studies presented throughout the course are a unique element of the program which combine real life and hypothetical problem sets that explore how different technical disciplines interact, the approaches to a problem solving they use, the assumptions and uncertainties contained in their contributions and the impact those conclusions may have on other disciplines involved in the overall reservoir management process. The team building aspect of the course was an added bonus.

  6. Reinjection into geothermal reservoirs

    SciTech Connect

    Bodvarsson, G.S.; Stefansson, V.

    1987-08-01

    Reinjection of geothermal wastewater is practiced as a means of disposal and for reservoir pressure support. Various aspects of reinjection are discussed, both in terms of theoretical studies as well as specific field examples. The discussion focuses on the major effects of reinjection, including pressure maintenance and chemical and thermal effects. (ACR)

  7. Interactive reservoir simulation

    SciTech Connect

    McVay, D.A.; Bastian, P.A. ); Epperson, B.D. )

    1991-11-01

    This paper describes a system that allows engineers to monitor and control a reservoir simulation run during its execution. The system consists of a 3D, three-phase black-oil reservoir simulator running simultaneously with an interactive graphics pre- and postprocessor. Previous authors have described systems that allow monitoring of job execution with simultaneous graphics displays; the system described here is unique in that the engineer can modify simulator and well-control parameters during the execution. While the system will be helpful in detection and correction of time-dependent data problems, it will be very useful in optimizing reservoir management decisions in future performance projections. The system is implemented on an IBM-compatible 486 microcomputer with commercially available multitasking software, although it can be implemented easily on any microcomputer or workstation capable of multitasking. The authors show that implementation of the system required only a moderate amount of modification of the pre- and postprocessor and even less modification of the reservoir simulator.

  8. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    SciTech Connect

    Durlofsky, Louis J.

    2000-08-28

    This project targets the development of (1) advanced reservoir simulation techniques for modeling non-conventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and well index (for use in simulation models), including the effects of wellbore flow; and (3) accurate approaches to account for heterogeneity in the near-well region.

  9. Development of luminescent bacteria as tracers for geological reservoir characterization

    SciTech Connect

    King, J.W.

    1990-09-01

    This research project resulted from recognizing the problem of being unable to accurately distinguish communication between wells in producing oil zones which may or may not be continuous. Bioluminescent bacteria are being developed for use as tracers in reservoir characterization. A pure culture of Photobacterium phosphoreum is being studied in the laboratory for accurate monitoring schemes. A search of the literature and communications with marine microbiologists indicate that bioluminescent bacteria can be easily studied in vitro.

  10. Stream, Lake, and Reservoir Management.

    PubMed

    Mei, Ying; Chang, Chein-Chi; Dong, Zhanfeng; Wei, Li

    2016-10-01

    This review on stream, lake, and reservoir management covers selected 2015 publications on the focus of the following sections: • Biota • Climate effect • Models • Remediation and restoration • Reservoir operations • Stream, Lake, and Reservoir Management • Water quality.

  11. Stream, Lake, and Reservoir Management.

    PubMed

    Mei, Ying; Chang, Chein-Chi; Dong, Zhanfeng; Wei, Li

    2016-10-01

    This review on stream, lake, and reservoir management covers selected 2015 publications on the focus of the following sections: • Biota • Climate effect • Models • Remediation and restoration • Reservoir operations • Stream, Lake, and Reservoir Management • Water quality. PMID:27620102

  12. Hydraulic Fracture Stimulation and Acid Treatment of Well Baca 20; Geothermal Reservoir Well Stimulation Program

    SciTech Connect

    1983-07-01

    The U.S. Department of Energy-sponsored Geothermal Reservoir Well Stimulation Program was initiated in February 1979 to pursue industry interest in geothermal well stimulation work and to develop technical expertise in areas directly related to geothermal well stimulation activities. This report provides an overview of the two experiments conducted in the high-temperature reservoir in Baca, New Mexico. The report discusses resource and reservoir properties, and provides a description of the stimulation experiment, a description of the treatment evaluation, and a summary of the experiment costs. (DJE-2005)

  13. Prediction of fracture-cavity system in carbonate reservoir: A case study in the Tahe oilfield

    NASA Astrophysics Data System (ADS)

    Wang, Shixing; Guan, Luping; Zhu, Hailong

    2004-07-01

    The carbonate rocks in Tahe oilfield, which suffered from multi-period polycycle karstification and structure deformation, are heterogeneous reservoirs that are rich in pores, cavities, and fractures. The reservoirs are diversified in scale, space configuration, and complex in filling. For this kind of reservoir, a suite of seismic prestack or poststack prediction techniques has been developed based on the separation of seismic wavefields. Through cross-verification of the estimated results, a detailed description of palaeogeomorphology and structural features such as pores, cavities, and fractures in unaka has been achieved, the understanding of the spatial distribution of reservoir improved.

  14. Accurate basis set truncation for wavefunction embedding

    NASA Astrophysics Data System (ADS)

    Barnes, Taylor A.; Goodpaster, Jason D.; Manby, Frederick R.; Miller, Thomas F.

    2013-07-01

    Density functional theory (DFT) provides a formally exact framework for performing embedded subsystem electronic structure calculations, including DFT-in-DFT and wavefunction theory-in-DFT descriptions. In the interest of efficiency, it is desirable to truncate the atomic orbital basis set in which the subsystem calculation is performed, thus avoiding high-order scaling with respect to the size of the MO virtual space. In this study, we extend a recently introduced projection-based embedding method [F. R. Manby, M. Stella, J. D. Goodpaster, and T. F. Miller III, J. Chem. Theory Comput. 8, 2564 (2012)], 10.1021/ct300544e to allow for the systematic and accurate truncation of the embedded subsystem basis set. The approach is applied to both covalently and non-covalently bound test cases, including water clusters and polypeptide chains, and it is demonstrated that errors associated with basis set truncation are controllable to well within chemical accuracy. Furthermore, we show that this approach allows for switching between accurate projection-based embedding and DFT embedding with approximate kinetic energy (KE) functionals; in this sense, the approach provides a means of systematically improving upon the use of approximate KE functionals in DFT embedding.

  15. Status of Blue Ridge Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  16. Rock-fabric/petrophysical classification of carbonate pore space for reservoir characterization

    SciTech Connect

    Lucia, F.J.

    1995-09-01

    This paper defines the important geologic parameters that can be described and mapped to allow accurate petrophysical quantification of carbonate geologic models. All pore space is divided into interparticle (intergrain and intercrystal) and vuggy pores. In nonvuggy carbonate rocks, permeability and capillary properties can be described in terms of particle size, sorting, and interparticle porosity (total porosity minus vuggy porosity). Particle size and sorting in limestones can be described using a modified Dunham approach, classifying packstone as grain dominated or mud dominated, depending on the presence or absence of intergrain pore space. To describe particle size and sorting in dolostones, dolomite crystal size must be added to the modified Dunham terminology. Larger dolomite crystal size improves petrophysical properties in mud-dominated fabrics, wheras variations in dolomite crystal size have little effect on the petrophysical properties of grain-dominated fabrics. A description of vuggy pore space that relates to petrophysical properties must be added to the description of interparticle pore space to complete the petrophysical characterization. Vuggy pore space is divided into separate vugs and touching vugs on the basis of vug interconnection. Separate vugs are fabric selective and are connected only through the interparticle pore network. Separate vug porosity contributes little to permeability and should be subtracted from total porosity to obtain interparticle porosity for permeability estimation. Separate-vug pore space is generally considered to by hydrocarbon filled in reservoirs; however, intragranular microporosity is composed of small pore sizes and may contain capillary-held connate water within the reservoir. Touching vugs are nonfabric selective and form an interconnected pore system independent of the interparticle system.

  17. Hydrodynamic modeling of petroleum reservoirs using simulator MUFITS

    NASA Astrophysics Data System (ADS)

    Afanasyev, Andrey

    2015-04-01

    MUFITS is new noncommercial software for numerical modeling of subsurface processes in various applications (www.mufits.imec.msu.ru). To this point, the simulator was used for modeling nonisothermal flows in geothermal reservoirs and for modeling underground carbon dioxide storage. In this work, we present recent extension of the code to petroleum reservoirs. The simulator can be applied in conventional black oil modeling, but it also utilizes a more complicated models for volatile oil and gas condensate reservoirs as well as for oil rim fields. We give a brief overview of the code by providing the description of internal representation of reservoir models, which are constructed of grid blocks, interfaces, stock tanks as well as of pipe segments and pipe junctions for modeling wells and surface networks. For conventional black oil approach, we present the simulation results for SPE comparative tests. We propose an accelerated compositional modeling method for sub- and supercritical flows subjected to various phase equilibria, particularly to three-phase equilibria of vapour-liquid-liquid type. The method is based on the calculation of the thermodynamic potential of reservoir fluid as a function of pressure, total enthalpy and total composition and storing its values as a spline table, which is used in hydrodynamic simulation for accelerated PVT properties prediction. We provide the description of both the spline calculation procedure and the flashing algorithm. We evaluate the thermodynamic potential for a mixture of two pseudo-components modeling the heavy and light hydrocarbon fractions. We develop a technique for converting black oil PVT tables to the potential, which can be used for in-situ hydrocarbons multiphase equilibria prediction under sub- and supercritical conditions, particularly, in gas condensate and volatile oil reservoirs. We simulate recovery from a reservoir subject to near-critical initial conditions for hydrocarbon mixture. We acknowledge

  18. Computation of dimensional changes in isotropic cesium-graphite reservoirs

    NASA Astrophysics Data System (ADS)

    Smith, Joe N.; Heffernan, Timothy

    1992-01-01

    Cs-graphite reservoirs have been utilized in many operating thermionic converters and TFEs, in both in-core and out-of-core tests. The vapor pressure of cesium over Cs-intercalated graphite is well documented for unirradiated reservoirs. The vapor pressure after irradiation is the subject of on-going study. Dimensional changes due to both intercalation and to neutron irradiation have been quantified only for highly oriented graphite. This paper describes extrapolation of the data for intercalated oriented graphite, to provide a qualitative description of the response of isotropic graphite to exposure to both cesium and neutrons.

  19. Geological Factors Influencing Reservoir Performance of the Hartzog Draw Field, Wyoming

    SciTech Connect

    Hearn, C.L.; Ebanks, W.J.; Ranganathan, V.; Tye, R.S.

    1984-05-01

    The Hartzog Draw field, a major sandstone oil reservoir in the Powder River basin of Wyoming, was discovered in 1975 and unitized in 1980. The field is under waterflood and is being considered for carbon dioxide miscible flooding. To aid in evaluating enhanced recovery, the working interest owners approved a comprehensive geological-engineering study using data from existing wells and new infill wells. Geologic facies identified in the study provided the stratigraphic basis for mapping reservoir flow-units. These flow-units more precisely describe variations in rock properties that control fluid flow. Within the flow-units, bedding characteristics of the reservoir sandstones cause permeability anisotropy. Mineralogy and diagenesis affect permeability, porosity, water saturation, and sensitivity to injection fluids. The reservoir description resulting from this study provides insight into reservoir performance and forms the framework for reservoir engineering studies to predict waterflood and carbon dioxide flood recovery.

  20. Geological factors influencing reservoir performance of the Hartzog Draw field, Wyoming

    SciTech Connect

    Hearn, C.L.; Ebanks, W.J.; Ranganathan, V.; Tye, R.S.

    1983-10-01

    The Hartzog Draw field, a major sandstone oil reservoir in the Powder River basin of Wyoming, was discovered in 1975 and unitized in 1980. The field is under waterflood and is being considered for carbon dioxide miscible flooding. To aid in evaluating enhanced recovery, the working interest owners approved a comprehensive geological-engineering study using data from existing wells and new infill wells. Geologic facies identified in the study provided the stratigraphic basis for mapping reservoir flow-units. These flow-units more precisely describe variations in rock properties that control fluid flow. Within the flow-units, bedding characteristics of the reservoir sandstones cause permeability anisotropy. Mineralogy and diagenesis affect permeability, porosity, water saturation, and sensitivity to injection fluids. The reservoir description resulting from this study provides insight into reservoir performance and forms the framework for reservoir engineering studies to predict waterflood and carbon dioxide flood recovery.

  1. Geological factors influencing reservoir performance of the Hartzog Draw Field, Wyoming

    SciTech Connect

    Hearn, C.L.; Ebanks, W.J.; Ranganathan, V.; Tye, R.S.

    1984-08-01

    The Hartzog Draw field, a major sandstone oil reservoir in the Powder River basin of Wyoming, was discovered in 1975 and unitized in 1980. The field is under waterflood and is being considered for CO/sub 2/ miscible flooding. To aid in evaluating enhanced recovery, the working interest owners approved a comprehensive geological-engineering study using data from existing wells and new infill wells. Geologic facies identified in the study provided the stratigraphic basis for mapping reservoir flow units. These flow units more precisely describe variations in rock properties that control fluid flow. Within the flow units, bedding characteristics of the reservoir sandstones cause permeability anisotropy. Mineralogy and diagenesis affect permeability, porosity, water saturation, and sensitivity to injection fluids. The reservoir description resulting from this study provides insight into reservoir performance and forms the framework for reservoir engineering studies to predict waterflood and CO/sub 2/-flood recovery.

  2. Reservoir characterization of the Lower B sands VLC 100/949 Reservoirs, Block III, Lake Maracaibo

    SciTech Connect

    Gonzalez, G.; Coll, C.; Mora, J.L.; Meza, E.

    1996-08-01

    The Lower B Misoa Formation of Middle Eocene age is characterized by massive sand bodies. These sands were successfully tested in the northern part of Block III in Lake Maracaibo in 1956. Subsequent drilling during the next 27 years has failed to locate any productive pay zones. Only during the past 8 years, new seismic and well data have delineated a number of minor oil reservoirs resulting in extensive production from Misoa Lower B sands. The oil production came primarily from small structural traps located on the hanging walls of normal listric faults. Fault diagnosis and locations were more accurately mapped with the availability of 3-D seismic data. Consequently VLC-100 and VLC-949 reservoirs are now considered to be part of the same trap instead of being separated. A careful review of the fluid distribution and material balance calculations has confirmed that the wells from these reservoirs have, in fact, been producing from the same accumulation thereby validating the new geological model. The new model has defined new opportunities of oil exploitation. Firstly, it has led to the drilling of 4 new wells and increased production by 4500 STB/D. Secondly, it has indicated additional recovery opportunities in the form of drilling horizontal wells in the updip area. Finally, the new model indicates the existence of an aquifer of much lower strength than was previously thought. This has caused a revision in our reservoir management strategy, and we now recommend water injection to supplement the aquifer support and enhance oil recovery.

  3. Reservoir modeling and simulation of a middle eastern carbonate reservoir

    SciTech Connect

    Sibley, M.J.; Bent, J.V.; Davis, D.W.

    1996-12-31

    A giant Middle Eastern reservoir was modeled and history matched during reservoir simulation. The model was used to help predict reservoir performance under various scenarios and to evaluate the impact on production rates, ultimate recovery and economics. Implementation of an infill, extension, and pressure maintenance plan is in progress. This model overcame shortcomings of previous models of this reservoir through detailed integration of geologic, geophysical, and engineering data. Among the data incorporated were slabbed core, thin sections, core analyses, seismic, isotope, open-hole logs, TDTs, RFTs, field pressure surveys, oil and water production data, and production tests. Significant modifications were made to internal and external reservoir architecture, and a diagenetic barrier was discovered that is the primary barrier to aquifer support. Results of the study include increased booked reserves and production rates, additional infill wells, two reservoir extension area discoveries, and the design and implementation of a pressure maintenance program.

  4. Determining the 3-D fracture structure in the Geysers geothermal reservoir

    SciTech Connect

    Sammis, Charles G.; Linji An; Iraj Ershaghi

    1992-01-01

    The bulk of the steam at the Geysers geothermal field is produced from fractures in a relatively impermeable graywacke massif which has been heated by an underlying felsite intrusion. The largest of these fractures are steeply dipping right lateral strike-slip faults which are subparallel to the NW striking Collayomi and Mercuryville faults which form the NE and SW boundaries of the known reservoir. Where the graywacke source rock outcrops at the surface it is highly sheared and fractured over a wide range of scale lengths. Boreholes drilled into the reservoir rock encounter distinct ''steam entries'' at which the well head pressure jumps from a few to more than one hundred psi. This observation that steam is produced from a relatively small number of major fractures has persuaded some analysts to use the Warren and Root (1963) dual porosity model for reservoir simulation purposes. The largest fractures in this model are arranged in a regular 3-D array which partitions the reservoir into cubic ''matrix'' blocks. The net storage and transport contribution of all the smaller fractures in the reservoir are lumped into average values for the porosity and permeability of these matrix blocks which then feed the large fractures. Recent improvements of this model largely focus on a more accurate representation of the transport from matrix to fractures (e.g. Pruess et al., 1983; Ziminerman et al., 1992), but the basic geometry is rarely questioned. However, it has long been recognized that steam entries often occur in clusters separated by large intervals of unproductive rock (Thomas et al., 1981). Such clustering of fixtures at all scale lengths is one characteristic of self-similar distributions in which the fracture distribution is scale-independent. Recent studies of the geometry of fracture networks both in the laboratory and in the field are finding that such patterns are self-similar and can be best described using fractal geometry. Theoretical simulations of

  5. Profitable capitation requires accurate costing.

    PubMed

    West, D A; Hicks, L L; Balas, E A; West, T D

    1996-01-01

    In the name of costing accuracy, nurses are asked to track inventory use on per treatment basis when more significant costs, such as general overhead and nursing salaries, are usually allocated to patients or treatments on an average cost basis. Accurate treatment costing and financial viability require analysis of all resources actually consumed in treatment delivery, including nursing services and inventory. More precise costing information enables more profitable decisions as is demonstrated by comparing the ratio-of-cost-to-treatment method (aggregate costing) with alternative activity-based costing methods (ABC). Nurses must participate in this costing process to assure that capitation bids are based upon accurate costs rather than simple averages. PMID:8788799

  6. Coupled Planetary Reservoirs

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.

    2008-12-01

    We can look beyond the Earth, to Venus and Mars, to find opportunities to understand interactions among crust, mantle, hydrosphere, and atmosphere reservoirs. There has obviously been coupling among some of these reservoirs on other worlds, and in some cases feedback may have been in play but that is more difficult to demonstrate. The massive CO2 atmosphere of Venus has likely fluctuated significantly over its history due to exchange with other reservoirs, with attendant greenhouse effects strongly modulating surface temperature. Additionally, release of H2O and SO2 from large-scale magmatic events may have led to significant surface temperature increases, ΔT0, and the details depend on the competition between IR radiation warming and planetary albedo increase due to cloud formation. Diffusion of Δ T0 into the shallow crust may be responsible for the rapid global formation of compressional wrinkle ridges following widespread volcanic resurfacing [Solomon et al., 1999]. Diffusion of ΔT0 into the venusian upper mantle could have increased the rate of partial melting. The accompanying increase in volatile release to the atmosphere could set up a positive feedback because of increased greenhouse warming diffusing into the planet's interior [Phillips et al., 2001, Venus]. Another outcome of deep penetration of a greenhouse-induced positive ΔT0 is the lowering of mantle viscosity and an accompanying decrease in convective stress, which could shut down an exisiting lithospheric recycling regime [Lenardic et al., 2008]. Mars offers a rich set of possibilities for coupling between reservoirs [Jakosky and Phillips, 2001]. Magmatism at the massive Tharsis volcanic complex possibly induced episodic climate changes in the latter part of the Noachian era (~3.6-4.2 Ga). This could have led to clement conditions, forming valley networks that follow a regional slope caused partly by the mass load of Tharsis itself [Phillips et al., 2001, Mars]. Earlier in the Noachian

  7. Evaporation from seven reservoirs in the Denver water-supply system, central Colorado

    USGS Publications Warehouse

    Ficke, John F.; Adams, D. Briane; Danielson, T.W.

    1977-01-01

    Seven reservoirs in central Colorado, operated by the Denver Board of Water Commissioners, were studied during 1967-73 to determine evaporation losses. These reservoirs, Elevenmile Canyon, Dillon, Gross, Antero, Cheesman, Williams Fork, and Ralston, are located on both sides of the Continental Divide. Methods for computing evaporation include energy-budget, mass-transfer, and pan relationships. Three reservoirs, Elevenmile Canyon, Dillon, and Gross, had mass-transfer coefficients calibrated by energy-budget studies. At the remaining reservoirs, an empirical technique was used to estimate the mass-transfer coefficient. The enery-budget-calibrated methods give the most accurate evaporation values; the empirical coefficients give only a best estimate of evaporation. All reservoirs should be calibrated by energy-budget studies. The pan method of computing evaporation is the least reliable method because of problems of advected energy through the sides of the pan, representative pan exposure , and the irregularity of ratios of reservoir to pan evaporation. (Woodard-USGS)

  8. A classification system for large reservoirs of the contiguous United States.

    PubMed

    Krogman, Rebecca M; Miranda, L E

    2015-04-01

    Degradation of reservoir fish habitat has become a serious concern. Habitat issues-such as sedimentation, excessive nutrient loadings, and lack of submerged structure-may emerge and worsen over time and are accompanied by undesirable shifts in the fish community and fisheries. To prioritize habitat rehabilitation efforts in reservoirs, we developed a classification system for large reservoirs in the contiguous U.S. We used a four-step classification approach based on over 50 variables descriptive of habitat impairment in a sample of almost 1300 reservoirs. To account for the broad geographic heterogeneity in climate and landscape, reservoirs were assigned to a spatial framework relevant to aquatic resources, selected based on how well it recognized regional differences in fish habitat. To account for differences among reservoirs within geographical regions, we used cluster analysis to identify classes of reservoirs with similar characteristics. Classes were compared regarding habitat impairment, the fish community, the recreational fishery, and other variables from an external dataset to seek support for the classification system. A method for classifying new reservoirs not included in the original sample was also developed. The resulting classification system identified nine geographical regions distributed throughout the contiguous U.S. and 24 reservoir classes within the nine regions. The system can serve as the framework for a reservoir assessment mechanism. Our approach may be applicable elsewhere a broad-scale dataset is not available and needs to be obtained quickly and inexpensively, whether in regards to fish habitat or other environmental information needs.

  9. An assessment of reservoir storage change accuracy from SWOT

    NASA Astrophysics Data System (ADS)

    Clark, Elizabeth; Moller, Delwyn; Lettenmaier, Dennis

    2013-04-01

    , which we then compared to observed total storage. Two reservoir forms emerge: 1) reservoirs with conical-type volumes, for which a linear fit is appropriate, and 2) reservoirs with horn-shaped volumes, which require a nonlinear fit. The ability to distinguish between these forms depends on the variability of both elevation and area during SWOT's lifetime. The synthetic SWOT-based estimates of storage change, which will arguably provide a reasonable estimate of variability in active storage, are highly accurate for both of these forms.

  10. Reservoir management cost-cutting

    SciTech Connect

    Gulati, M.S.

    1996-12-31

    This article by Mohinder S. Gulati, Chief Engineer, Unocal Geothermal Operations, discusses cost cutting in geothermal reservoir management. The reservoir engineer or geoscientist can make a big difference in the economical outcome of a project by improving well performance and thus making geothermal energy more competitive in the energy marketplace. Bringing plants online in less time and proving resources to reduce the cycle time are some of the ways to reduce reservoir management costs discussed in this article.

  11. Encapsulated microsensors for reservoir interrogation

    DOEpatents

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  12. All-optical reservoir computing.

    PubMed

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-24

    Reservoir Computing is a novel computing paradigm that uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  13. All-optical reservoir computing

    NASA Astrophysics Data System (ADS)

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-01

    Reservoir Computing is a novel computing paradigm which uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  14. Calderas and magma reservoirs

    NASA Astrophysics Data System (ADS)

    Cashman, Katharine; Giordano, Guido

    2015-04-01

    Large caldera-forming eruptions have long been a focus of both petrological and volcanological studies; traditionally, both have assumed that eruptible magma is stored within a single long-lived melt body. Over the past decade, however, advances in analytical techniques have provided new views of magma storage regions, many of which provide evidence of multiple melt lenses feeding a single eruption, and/or rapid pre-eruptive assembly of large volumes of melt. These new petrological views of magmatic systems have not yet been fully integrated into volcanological perspectives of caldera-forming eruptions. We discuss the implications of syn-eruptive melt extraction from complex, rather than simple, reservoirs and its potential control over eruption size and style, and caldera collapse timing and style. Implications extend to monitoring of volcanic unrest and eruption progress under conditions where successive melt lenses may be tapped. We conclude that emerging views of complex magma reservoir configurations provide exciting opportunities for re-examining volcanological concepts of caldera-forming systems

  15. Stochastic control of reservoir systems using indicator functions: New enhancements

    NASA Astrophysics Data System (ADS)

    Fletcher, S. G.; Ponnambalam, K.

    2008-12-01

    In our previous works, deterministic release policies were considered for the development of approximations of the two lower moments of the storage volume defined by the dynamic equation of the reservoir in discrete time but in continuous state space. Important innovation in that work was the incorporation of the lower and upper bounds of reservoir systems into the dynamic equation for the storage volume using indicator functions. The current work, which also does not use discretization, looks at an extension of previous developments that incorporates standard operating policies, and also a new randomized release policy, both of which make the moments calculations exact under the assumptions that (1) the sum of current random inflow and the previous storage volume can be described by just the two lower moments and (2) only the means and variances of the inflows are known. First- and second-moment expressions are derived for the stochastic storage state variable and include terms for the failure probabilities (probabilities of spills or deficits). Expected values of the storage state, variances of storage, release policies, and failure probabilities are obtained by solving the optimal reservoir operations problem using nonlinear programming. The various statistics thus obtained from this optimization compare extremely well with those obtained from simulation for the single-reservoir monthly operations problem studied. The exact characterization of the mean and variance of the storage state variable is derived, which is a difficulty in existing formulations based on linear quadratic Gaussian methods. For example, the latter methods have been unable to estimate these moments reasonably accurately, especially for long-term operations, whereas the traditional storage theory based on discretization brings on the "curse of dimensionality." The presentation herein is directed to both traditional reservoir storage theorists who are interested in the design of a reservoir

  16. Accurate documentation and wound measurement.

    PubMed

    Hampton, Sylvie

    This article, part 4 in a series on wound management, addresses the sometimes routine yet crucial task of documentation. Clear and accurate records of a wound enable its progress to be determined so the appropriate treatment can be applied. Thorough records mean any practitioner picking up a patient's notes will know when the wound was last checked, how it looked and what dressing and/or treatment was applied, ensuring continuity of care. Documenting every assessment also has legal implications, demonstrating due consideration and care of the patient and the rationale for any treatment carried out. Part 5 in the series discusses wound dressing characteristics and selection.

  17. Soft Biometrics; Human Identification Using Comparative Descriptions.

    PubMed

    Reid, Daniel A; Nixon, Mark S; Stevenage, Sarah V

    2014-06-01

    Soft biometrics are a new form of biometric identification which use physical or behavioral traits that can be naturally described by humans. Unlike other biometric approaches, this allows identification based solely on verbal descriptions, bridging the semantic gap between biometrics and human description. To permit soft biometric identification the description must be accurate, yet conventional human descriptions comprising of absolute labels and estimations are often unreliable. A novel method of obtaining human descriptions will be introduced which utilizes comparative categorical labels to describe differences between subjects. This innovative approach has been shown to address many problems associated with absolute categorical labels-most critically, the descriptions contain more objective information and have increased discriminatory capabilities. Relative measurements of the subjects' traits can be inferred from comparative human descriptions using the Elo rating system. The resulting soft biometric signatures have been demonstrated to be robust and allow accurate recognition of subjects. Relative measurements can also be obtained from other forms of human representation. This is demonstrated using a support vector machine to determine relative measurements from gait biometric signatures-allowing retrieval of subjects from video footage by using human comparisons, bridging the semantic gap.

  18. Soft Biometrics; Human Identification Using Comparative Descriptions.

    PubMed

    Reid, Daniel A; Nixon, Mark S; Stevenage, Sarah V

    2014-06-01

    Soft biometrics are a new form of biometric identification which use physical or behavioral traits that can be naturally described by humans. Unlike other biometric approaches, this allows identification based solely on verbal descriptions, bridging the semantic gap between biometrics and human description. To permit soft biometric identification the description must be accurate, yet conventional human descriptions comprising of absolute labels and estimations are often unreliable. A novel method of obtaining human descriptions will be introduced which utilizes comparative categorical labels to describe differences between subjects. This innovative approach has been shown to address many problems associated with absolute categorical labels-most critically, the descriptions contain more objective information and have increased discriminatory capabilities. Relative measurements of the subjects' traits can be inferred from comparative human descriptions using the Elo rating system. The resulting soft biometric signatures have been demonstrated to be robust and allow accurate recognition of subjects. Relative measurements can also be obtained from other forms of human representation. This is demonstrated using a support vector machine to determine relative measurements from gait biometric signatures-allowing retrieval of subjects from video footage by using human comparisons, bridging the semantic gap. PMID:26353282

  19. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset field, San Joaquin basin, California. Quarterly report, January 1--March 31, 1996

    SciTech Connect

    Schamel, S.

    1996-06-28

    This project will reactivate ARCO`s idle Pru Fee lease in the Midway-Sunset field, California and conduct a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. The objectives of the project are: (1) to return the shut-in portion of the reservoir to commercial production; (2) to accurately describe the reservoir and recovery process; and (3) convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program. The producibility problems initially thought to be responsible for the low recovery in the Pru Fee property are: (a) the shallow dip of the bedding; (b) complex reservoir structure, (c) thinning pay zone; and (d) the presence of bottom water. The project is using tight integration of reservoir characterization and simulation modeling to evaluate the magnitude of and alternative solutions to these problems. Two main activities were brought to completion during the first quarter of 1996: (1) lithologic and petrophysical description of the core taken form the new well Pru 101 near the center of the demonstration site and (2) development of a stratigraphic model for the Pru Fee project area. In addition, the first phase of baseline cyclic steaming of the Pru Fee demonstration site was continued with production tests and formation temperature monitoring.

  20. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf San Andres Reservoir.

    SciTech Connect

    Taylor, A.R.; Hickman, T.S.; Justice, J.J.

    1997-07-30

    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 lower quality shallow shelf carbonate reservoirs. The research and development phase (Budget Period 1) primarily involved advance and reservoir characterization. The current demonstration phase (Budget Period 2) will implement the reservoir management plan for an optimum miscible CO{sub 2} flood design based on the reservoir characterization. Although Budget Period I officially ended 12/31/96, reservoir characterization and optimum flood design has continued into the first part of Budget Period 2. Specifically, the geologic model was enhanced by integration of the 3-D seismic interpretations. This resulted in improved history match by the simulator and more accurate predictions of flood performance on which to base the project design. The majority of the project design work has been completed, material specifications provided and bids solicited. Preparation of the demonstration area is well underway.

  1. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  2. Volume 3: Characterization of representative reservoirs -- South Marsh Island 73, B35K and B65G Reservoirs

    SciTech Connect

    Young, M.A.; Salamy, S.P.; Reeves, T.K.; Kimbrell, W.C.; Sawyer, W.K.

    1998-07-01

    This report documents the results of a detailed study of two Gulf of Mexico salt dome related reservoirs and the application of a publicly available PC-based black oil simulator to model the performances of gas injection processes to recover attic oil. The overall objective of the research project is to assess the oil reserve potential that could result from the application of proven technologies to recover bypassed oil from reservoirs surrounding piercement salt domes in the Gulf of Mexico. The specific study objective was to simulate the primary recovery and attic gas injection performance of the two subject reservoirs to: (1) validate the BOAST model; (2) quantify the attic volume; and (3) predict the attic oil recovery potential that could result from additional updip gas injection. The simulation studies were performed on the B-35K Reservoir and the B-65G Reservoir in the South Marsh Island Block 73 Field using data provided by one of the field operators. A modified PC-version of the BOAST II model was used to match the production and injection performances of these reservoirs in which numerous gas injection cycles had been conducted to recover attic oil. The historical performances of the gas injection cycles performed on both the B-35K Reservoir and B-65G Reservoir were accurately matched, and numerous predictive runs were made to define additional potential for attic oil recovery using gas injection. Predictive sensitivities were conducted to examine the impact of gas injection rate, injection volume, post-injection shut-in time, and the staging of gas injection cycles on oil recovery.

  3. The Simulation of Inflow Discharge and Suspended Sediment Transport Rate for a Reservoir

    NASA Astrophysics Data System (ADS)

    Wu, Ching-Hsien; Chen, Ching-Nuo; Tsai, Chih-Heng; Tsai, Chang-Tai

    2010-05-01

    The major functions of a reservoir include flood-protection, public water-supply, irrigation, hydropower and tourism. Consequently, these functions can provide great contributions for economic development. Therefore, important issues associated with reservoir watersheds such as soil erosion and deposition must be carefully studied in order to enhance watershed management. Accurate and timely estimation of peak flow discharges into a reservoir is very crucial for flood protection strategies and the general safety of the reservoir. In this study, GIS is applied to a physiographical soil erosion-deposition model, using rainfall data as the primary input, to simulate both stream flow hydrographs and sediment transport into a reservoir. In this study, the Shihmen Reservoir watershed is used as an illustrative example. The Shihmen Reservoir, a multiple-purpose reservoir for irrigation, hydropower, public water-supply, flood-protection, and tourism, is located on the mid-stream reach of the Tahan River. High-concentration sediment-containing flood flow events during storm periods are primarily responsible for the turbidity and sedimentation in the Shihmen Reservoir. Therefore, if incoming stream flow and sediment concentration hydrographs can be determined promptly during storm periods, high-concentration turbid water can be diverted from the reservoir and low-concentration water, during the recession, can be stored. Consequently, the deposition of the reservoir can be reduced extending the life of the reservoir. Therefore, the purpose of this project is to establish a physiographic soil erosion-deposition model for the Shihmen Reservoir watershed. Using rainfall data as input, we can simulate the hydrographs of both stream flow and sediment concentration entering the reservoir. The results obtained from our model can be used as a reference to aid in the operation of the Shihmen Reservoir concerning deposition prevention. The numerical studies show that the peak flow and

  4. TVA sediment-disturbing activities within the Watts Bar Reservoir and Melton Hill Reservoir areas of the Clinch River

    SciTech Connect

    1993-12-31

    The objectives of Task 5 were to review: (1) the extent of dredging, construction, and other sediment-disturbing activities conducted by the Tennessee Valley Authority (TVA) in potentially contaminated areas of Watts Bar Reservoir; and (2) the disposition of the materials from these activities. This memorandum is the final report for Task 5. This memorandum describes major activities in the Watts Bar Reservoir and Melton Hill Reservoir areas of the Clinch River that possibly resulted in significant disturbance of potentially contaminated sediments. TVA records from the construction of Watts Bar Dam, Kingston Fossil Plant, and Melton Hill Dam were reviewed to facilitate qualitative description of the effect of these activities in disturbing potentially contaminated sediments. The critical period for these activities in disturbing contaminated sediments was during or after 1956 when the peak releases of radioactive contaminants occurred from the Oak Ridge Reservation.

  5. Analysis of fracture patterns and local stress field variations in fractured reservoirs

    NASA Astrophysics Data System (ADS)

    Deckert, Hagen; Drews, Michael; Fremgen, Dominik; Wellmann, J. Florian

    2010-05-01

    A meaningful qualitative evaluation of permeabilities in fractured reservoirs in geothermal or hydrocarbon industry requires the spatial description of the existing discontinuity pattern within the area of interest and an analysis how these fractures might behave under given stress fields. This combined information can then be used for better estimating preferred fluid pathway directions within the reservoir, which is of particular interest for defining potential drilling sites. A description of the spatial fracture pattern mainly includes the orientation of rock discontinuities, spacing relationships between single fractures and their lateral extent. We have examined and quantified fracture patterns in several outcrops of granite at the Costa Brava, Spain, and in the Black Forest, Germany, for describing reservoir characteristics. For our analysis of fracture patterns we have used photogrammetric methods to create high-resolution georeferenced digital 3D images of outcrop walls. The advantage of this approach, compared to conventional methods for fracture analysis, is that it provides a better 3D description of the fracture geometry as the entity of position, extent and orientation of single fractures with respect to their surrounding neighbors is conserved. Hence for instance, the method allows generating fracture density maps, which can be used for a better description of the spatial distribution of discontinuities in a given outcrop. Using photogrammetric techniques also has the advantage to acquire very large data sets providing statistically sound results. To assess whether the recorded discontinuities might act as fluid pathways information on the stress field is needed. A 3D model of the regional tectonic structure was created and the geometry of the faults was put into a mechanical 3D Boundary Element (BE) Model. The model takes into account the elastic material properties of the geological units and the orientation of single fault segments. The

  6. 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

  7. Reservoir Modeling for Production Management

    SciTech Connect

    Brown, Donald W.

    1989-03-21

    For both petroleum and geothermal resources, many of the reservoirs are fracture dominated--rather than matrix-permeability controlled. For such reservoirs, a knowledge of the pressure-dependent permeability of the interconnected system of natural joints (i.e., pre-existing fractures) is critical to the efficient exploitation of the resource through proper pressure management. Our experience and that reported by others indicates that a reduction in the reservoir pressure sometimes leads to an overall reduction in production rate due to the ''pinching off'' of the joint network, rather than the anticipated increase in production rate. This effect occurs not just in the vicinity of the wellbore, where proppants are sometimes employed, but throughout much of the reservoir region. This follows from the fact that under certain circumstances, the decline in fracture permeability (or conductivity) with decreasing reservoir pressure exceeds the far-field reservoir ''drainage'' flow rate increase due to the increased pressure gradient. Further, a knowledge of the pressure-dependent joint permeability could aid in designing more appropriate secondary recovery strategies in petroleum reservoirs or reinjection procedures for geothermal reservoirs.

  8. Reservoir shore development in long range terrestrial laser scanning monitoring.

    NASA Astrophysics Data System (ADS)

    Kaczmarek, Halina

    2016-04-01

    Shore zones of reservoirs are in most cases very active, getting transformed as a result of coastal processes and mass movements initiated on the slopes surrounding the reservoir. From the point of view of the users of water reservoirs shore recession strongly undesirable as it causes destruction to infrastructure and buildings located in the immediate vicinity of the reservoir. For this reason, reservoir shores require continuous geodetic monitoring. Fast and accurate geodetic measurements covering shore sections several kilometers long, often in poorly accessible areas, are available using long range terrestrial laser scanning (TLS). The possibilities of using long range terrestrial laser scanning are shown on the example of the reservoir Jeziorsko on the Warta River (Central Poland). This reservoir, created in the years 1986-1992, is a typical retention reservoir, the annual fluctuations of which reach 5 m. Depending on the water level its surface area ranges from 42.3 to 19.6 km2. The width of the reservoir is 2.5 km. The total shore length of the reservoir, developed in Quaternary till and sand-till sediments, is 44.3 km, including 30.1 km of the unreinforced shore. Out of the unreinforced shore 27% is subject to coastal erosion. The cliff heights vary from a few cm to 12.5 meters, and the current rate of the cliff recession ranges from 0 to 1.12 m/y. The study used a terrestrial long range laser scanner Riegl VZ-4000 of a range of up to 4000 m. It enabled conducting the measurements of the cliff recession from the opposite shore of the reservoir, with an angular resolution of 0.002°, which gives about 50 measurement points per 1 m2. The measurements were carried out in the years 2014-2015, twice a year, in early spring before high water level, and in late autumn at a dropping water level. This allowed the separation of the impact of coastal processes and frost weathering on the cliff recession and their quantitative determination. The size and nature of

  9. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    SciTech Connect

    Franklin M. Orr, Jr; Martin J. Blunt

    1998-03-31

    This project performs research in four main areas: laboratory experiments to measure three-phase relative permeability; network modeling to predict three-phase relative perme- ability; benchmark simulations of gas injection and waterfl ooding at the field scale; and the development of fast streamline techniques to study field-scale oil. The aim of the work is to achieve a comprehensive description of gas injection processes from the pore to the core to the reservoir scale. In this report we provide a detailed description of our measurements of three-phase relative permeability.

  10. Meandering stream reservoirs

    SciTech Connect

    Richardson, J.G.; Sangree, J.B.; Sneider, R.M.

    1987-12-01

    Braided stream deposits, described in a previous article in this series, and meandering stream deposits commonly are excellent reservoirs. Meandering high-sinuousity channels are found on flat alluvial plains with slopes less than 1 1/2/sup 0/ (0.026 rad). These rivers have wide ranges of discharges from low-water flow to flood stage. Two main processes are responsible for development of sand bodies. These are point-bar deposits left by channel migration, and oxbow-lake deposits left in loops of the river course abandoned when the stream cuts a new course during flooding. Extremely high floods spill over the banks and deposit sheets of very fine sand, silt, and clay onto the flood plain.

  11. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  12. SPLASH: Accurate OH maser positions

    NASA Astrophysics Data System (ADS)

    Walsh, Andrew; Gomez, Jose F.; Jones, Paul; Cunningham, Maria; Green, James; Dawson, Joanne; Ellingsen, Simon; Breen, Shari; Imai, Hiroshi; Lowe, Vicki; Jones, Courtney

    2013-10-01

    The hydroxyl (OH) 18 cm lines are powerful and versatile probes of diffuse molecular gas, that may trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. In this proposal, we request ATCA time to follow up OH maser candidates. This will give us accurate (~10") positions of the masers, which can be compared to other maser positions from HOPS, MMB and MALT-45 and will provide full polarisation measurements towards a sample of OH masers that have not been observed in MAGMO.

  13. Accurate thickness measurement of graphene

    NASA Astrophysics Data System (ADS)

    Shearer, Cameron J.; Slattery, Ashley D.; Stapleton, Andrew J.; Shapter, Joseph G.; Gibson, Christopher T.

    2016-03-01

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.

  14. Accurate thickness measurement of graphene.

    PubMed

    Shearer, Cameron J; Slattery, Ashley D; Stapleton, Andrew J; Shapter, Joseph G; Gibson, Christopher T

    2016-03-29

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.

  15. DEVELOPMENT OF AN ADVANCED APPROACH FOR NEXT-GENERATION INTEGRATED RESERVOIR CHARACTERIZATION

    SciTech Connect

    Scott R. Reeves

    2005-04-01

    Accurate, high-resolution, three-dimensional (3D) reservoir characterization can provide substantial benefits for effective oilfield management. By doing so, the predictive reliability of reservoir flow models, which are routinely used as the basis for investment decisions involving hundreds of millions of dollars and designed to recover millions of barrels of oil, can be significantly improved. Even a small improvement in incremental recovery for high-value assets can result in important contributions to bottom-line profitability. Today's standard practice for developing a 3D reservoir description is to use seismic inversion techniques. These techniques make use of geostatistics and other stochastic methods to solve the inverse problem, i.e., to iteratively construct a likely geologic model and then upscale and compare its acoustic response to that actually observed in the field. This method has several inherent flaws, such as: (1) The resulting models are highly non-unique; multiple equiprobable realizations are produced, meaning (2) The results define a distribution of possible outcomes; the best they can do is quantify the uncertainty inherent in the modeling process, and (3) Each realization must be run through a flow simulator and history matched to assess it's appropriateness, and therefore (4) The method is labor intensive and requires significant time to complete a field study; thus it is applied to only a small percentage of oil and gas producing assets. A new approach to achieve this objective was first examined in a Department of Energy (DOE) study performed by Advanced Resources International (ARI) in 2000/2001. The goal of that study was to evaluate whether robust relationships between data at vastly different scales of measurement could be established using virtual intelligence (VI) methods. The proposed workflow required that three specific relationships be established through use of artificial neural networks (ANN's): core-to-log, log

  16. Spatially pooled depth-dependent reservoir storage, elevation, and water-quality data for selected reservoirs in Texas, January 1965-January 2010

    USGS Publications Warehouse

    Burley, Thomas E.; Asquith, William H.; Brooks, Donald L.

    2011-01-01

    temperature, reservoir storage, reservoir elevation, specific conductance, dissolved oxygen, pH, unfiltered salinity, unfiltered total nitrogen, filtered total nitrogen, unfiltered nitrate plus nitrite, unfiltered phosphorus, filtered phosphorus, unfiltered carbon, carbon in suspended sediment, total hardness, unfiltered noncarbonate hardness, filtered noncarbonate hardness, unfiltered calcium, filtered calcium, unfiltered magnesium, filtered magnesium, unfiltered sodium, filtered sodium, unfiltered potassium, filtered potassium, filtered chloride, filtered sulfate, unfiltered fluoride, and filtered fluoride. When possible, USGS and Texas Commission on Environmental Quality water-quality properties and constituents were matched using the database parameter codes for individual physical properties and constituents, descriptions of each physical property or constituent, and their reporting units. This report presents a collection of delimited text files of source-aggregated, spatially pooled, depth-dependent, instantaneous water-quality data as well as instantaneous, daily, and monthly storage and elevation reservoir data.

  17. Collapsible sheath fluid reservoirs for flow cytometers

    DOEpatents

    Mark, Graham A.

    2000-01-01

    The present invention is a container in the form of a single housing for holding fluid, including a first collapsible reservoir having a first valve. The first reservoir initially contains a volume of fluid. The container also includes a second reservoir, initially empty (or substantially empty), expandable to a second volume. The second reservoir has a second valve. As the volume of said first reservoir decreases, the volume of the second reservoir proportionally increases.

  18. Water resources review: Ocoee reservoirs, 1990

    SciTech Connect

    Cox, J.P.

    1990-08-01

    Tennessee Valley Authority (TVA) is preparing a series of reports to make technical information on individual TVA reservoirs readily accessible. These reports provide a summary of reservoir purpose and operation; physical characteristics of the reservoir and watershed; water quality conditions; aquatic biological conditions; and designated, actual and potential uses of the reservoir and impairments of those use. This reservoir status report addressed the three Ocoee Reservoirs in Polk County, Tennessee.

  19. Data Integration for the Generation of High Resolution Reservoir Models

    SciTech Connect

    Albert Reynolds; Dean Oliver; Gaoming Li; Yong Zhao; Chaohui Che; Kai Zhang; Yannong Dong; Chinedu Abgalaka; Mei Han

    2009-01-07

    The goal of this three-year project was to develop a theoretical basis and practical technology for the integration of geologic, production and time-lapse seismic data in a way that makes best use of the information for reservoir description and reservoir performance predictions. The methodology and practical tools for data integration that were developed in this research project have been incorporated into computational algorithms that are feasible for large scale reservoir simulation models. As the integration of production and seismic data require calibrating geological/geostatistical models to these data sets, the main computational tool is an automatic history matching algorithm. The following specific goals were accomplished during this research. (1) We developed algorithms for calibrating the location of the boundaries of geologic facies and the distribution of rock properties so that production and time-lapse seismic data are honored. (2) We developed and implemented specific procedures for conditioning reservoir models to time-lapse seismic data. (3) We developed and implemented algorithms for the characterization of measurement errors which are needed to determine the relative weights of data when conditioning reservoir models to production and time-lapse seismic data by automatic history matching. (4) We developed and implemented algorithms for the adjustment of relative permeability curves during the history matching process. (5) We developed algorithms for production optimization which accounts for geological uncertainty within the context of closed-loop reservoir management. (6) To ensure the research results will lead to practical public tools for independent oil companies, as part of the project we built a graphical user interface for the reservoir simulator and history matching software using Visual Basic.

  20. Improved recovery from Gulf of Mexico reservoirs. Quarterly status report, January 1--March 31, 1996

    SciTech Connect

    Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

    1996-04-30

    On February 18, 1992, Louisiana State University with two technical subcontractors, BDM, Inc. and ICF, Inc., began a research program to estimate the potential oil and gas reserve additions that could result from the application of advanced secondary and enhanced oil recovery technologies and the exploitation of undeveloped and attic oil zones in the Gulf of Mexico oil fields that are related to piercement salt domes. This project is a one year continuation of this research and will continue work in reservoir description, extraction processes, and technology transfer. Detailed data will be collected for two previously studies reservoirs: a South Marsh Island reservoir operated by Taylor Energy and one additional Gulf of Mexico reservoir operated by Mobil. Additional reservoirs identified during the project will also be studied if possible. Data collected will include reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. The new data will be used to refine reservoir and geologic characterization of these reservoirs. Further laboratory investigation will provide additional simulation input data in the form of PVT properties, relative permeabilities, capillary pressure, and water compatibility. Geological investigations will be conducted to refine the models of mud-rich submarine fan architectures used by seismic analysts and reservoir engineers. Research on advanced reservoir simulation will also be conducted. This report describes a review of fine-grained submarine fans and turbidite systems.

  1. Reservoir characterization of lacustrine sediments from the Late Triassic, Beryl Field, UK North Sea

    SciTech Connect

    Bond, J.; Welton, J.E.

    1996-12-31

    Located on the western flank of the Viking Graben, the Beryl Field has been producing from the Late Triassic Lewis reservoir since first oil in 1976. The Beryl A Triassic contains an estimated STOIIP of 256 mmstb, with a cumulative production of 31 mmstb (8/95) (12% recovery). Low recovery to date, coupled with high remaining reserves potential, necessitated a new simulation model and optimized development program for the Lewis reservoir. This paper summarizes the revised reservoir description of the Beryl A Triassic, a complex lacustrine and fluvial system, and its integration with the reservoir simulation. The Triassic reservoir is subdivided into four zones: Lewis Units I, II, III and IV. Six lithofacies associations are identified in core: offshore lacustrine, lacustrine sandflat, marginal lacustrine, floodplain, sheetflood/overbank, and fluvial. Detailed petrological studies were conducted which confirmed that both depositional and diagenetic processes influenced reservoir properties and quality. Optimal reservoir quality is preserved in fluvial and lacustrine sandflat deposits. Argillaceous floodplain and lacustrine facies are non-reservoir and form barriers to vertical fluid migration. Calcrete lags (concentrated at the base of fluvial channels) and carbonate paleosols form baffles to flow. Fieldwide correlation of core and log facies resulted in the identification of 27 genetic flow-units. This geologically-based layering scheme was integrated with production data to generate the framework for vertical zonation for the new reservoir simulation. The simulation studies produced as accelerated development program for the Beryl A Triassic. Reserves have increased as result of optimizing secondary recovery.

  2. Reservoir characterization of lacustrine sediments from the Late Triassic, Beryl Field, UK North Sea

    SciTech Connect

    Bond, J. ); Welton, J.E. )

    1996-01-01

    Located on the western flank of the Viking Graben, the Beryl Field has been producing from the Late Triassic Lewis reservoir since first oil in 1976. The Beryl A Triassic contains an estimated STOIIP of 256 mmstb, with a cumulative production of 31 mmstb (8/95) (12% recovery). Low recovery to date, coupled with high remaining reserves potential, necessitated a new simulation model and optimized development program for the Lewis reservoir. This paper summarizes the revised reservoir description of the Beryl A Triassic, a complex lacustrine and fluvial system, and its integration with the reservoir simulation. The Triassic reservoir is subdivided into four zones: Lewis Units I, II, III and IV. Six lithofacies associations are identified in core: offshore lacustrine, lacustrine sandflat, marginal lacustrine, floodplain, sheetflood/overbank, and fluvial. Detailed petrological studies were conducted which confirmed that both depositional and diagenetic processes influenced reservoir properties and quality. Optimal reservoir quality is preserved in fluvial and lacustrine sandflat deposits. Argillaceous floodplain and lacustrine facies are non-reservoir and form barriers to vertical fluid migration. Calcrete lags (concentrated at the base of fluvial channels) and carbonate paleosols form baffles to flow. Fieldwide correlation of core and log facies resulted in the identification of 27 genetic flow-units. This geologically-based layering scheme was integrated with production data to generate the framework for vertical zonation for the new reservoir simulation. The simulation studies produced as accelerated development program for the Beryl A Triassic. Reserves have increased as result of optimizing secondary recovery.

  3. OPTIMIZATION OF INFILL DRILLING IN NATURALLY-FRACTURED TIGHT-GAS RESERVOIRS

    SciTech Connect

    Lawrence W. Teufel; Her-Yuan Chen; Thomas W. Engler; Bruce Hart

    2004-05-01

    A major goal of industry and the U.S. Department of Energy (DOE) fossil energy program is to increase gas reserves in tight-gas reservoirs. Infill drilling and hydraulic fracture stimulation in these reservoirs are important reservoir management strategies to increase production and reserves. Phase II of this DOE/cooperative industry project focused on optimization of infill drilling and evaluation of hydraulic fracturing in naturally-fractured tight-gas reservoirs. The cooperative project involved multidisciplinary reservoir characterization and simulation studies to determine infill well potential in the Mesaverde and Dakota sandstone formations at selected areas in the San Juan Basin of northwestern New Mexico. This work used the methodology and approach developed in Phase I. Integrated reservoir description and hydraulic fracture treatment analyses were also conducted in the Pecos Slope Abo tight-gas reservoir in southeastern New Mexico and the Lewis Shale in the San Juan Basin. This study has demonstrated a methodology to (1) describe reservoir heterogeneities and natural fracture systems, (2) determine reservoir permeability and permeability anisotropy, (3) define the elliptical drainage area and recoverable gas for existing wells, (4) determine the optimal location and number of new in-fill wells to maximize economic recovery, (5) forecast the increase in total cumulative gas production from infill drilling, and (6) evaluate hydraulic fracture simulation treatments and their impact on well drainage area and infill well potential. Industry partners during the course of this five-year project included BP, Burlington Resources, ConocoPhillips, and Williams.

  4. 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

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  5. Acquisition of teleological descriptions

    NASA Astrophysics Data System (ADS)

    Franke, David W.

    1992-03-01

    Teleology descriptions capture the purpose of an entity, mechanism, or activity with which they are associated. These descriptions can be used in explanation, diagnosis, and design reuse. We describe a technique for acquiring teleological descriptions expressed in the teleology language TeD. Acquisition occurs during design by observing design modifications and design verification. We demonstrate the acquisition technique in an electronic circuit design.

  6. Writing job descriptions.

    PubMed

    Schaffner, M

    1990-01-01

    The skill of writing job descriptions begins with an understanding of the advantages, as well as the basic elements, of a well written description. The end result should be approved and updated as needed. Having a better understanding of this process makes writing the job description a challenge rather than a chore.

  7. Data requirements and acquisition for reservoir characterization

    SciTech Connect

    Jackson, S.; Chang, Ming Ming; Tham, Min.

    1993-03-01

    This report outlines the types of data, data sources and measurement tools required for effective reservoir characterization, the data required for specific enhanced oil recovery (EOR) processes, and a discussion on the determination of the optimum data density for reservoir characterization and reservoir modeling. The two basic sources of data for reservoir characterization are data from the specific reservoir and data from analog reservoirs, outcrops, and modern environments. Reservoir data can be divided into three broad categories: (1) rock properties (the container) and (2) fluid properties (the contents) and (3)interaction between reservoir rock and fluid. Both static and dynamic measurements are required.

  8. Growth of the deposit wedge in the mountain reservoir

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Song, G.

    2011-12-01

    The sedimentary problem of mountain reservoirs in Taiwan is getting serious year by year.Due to eroded sediments enter downstream reservoirs,the loss of sediment transport capacity may cause deposition of sediment in reservoirs.This phenomenon make problems to small mountain reservoirs.To realize the interaction between deposit wedges and mountain reservoirs,we selected Wushe reservoir which is situated in central Taiwan for a case study. Wushe reservoir is long and narrow.In recent years,most sediment is introduced during rain events that now accompany climate change are very important in sediment supply.In this thesis,we collected data of underwater landform and sub-bottom bedding information by using high resolution Multibeam Survey System(MBS) and seismic-reflection system.Up to now,we already had the bathymetric data for more than ten years,moreover,in 2010,we used 3.5kHz sub-bottom seismic profiler to analysis the sedimentary bedding situation in this area.These methods provide us accurate reservoir topography,sediment accumulation and the major ways of sediment transportation.The study purposes are as follows: First,according to the available underwater data for last ten years,we recognize the geomorphological characters of sedimentation as well as complete the mappings.Comparing to bathymetric images each year,we evaluate the carried ways of sediment.The flow water which enters this area transports along the thalweg,which in eastern reservoir.The range of water level variation cause alteration of sedimentary morphology,it also affects the scope of alluvial fan.The alluvial fan is located in the middle of the reservoir,the edge of it had moved forward 500 meters for last ten years.The annual mean of forward velocity was 50 meters,the elevation of fan edge also accelerated 10 meters per year.In a word,the large volume of the sedimentary delta is in Wushe reservoir now. Second,trying to clarify the composition of sedimentation and explain the sub

  9. Geomechanically Coupled Simulation of Flow in Fractured Reservoirs

    NASA Astrophysics Data System (ADS)

    Barton, C.; Moos, D.; Hartley, L.; Baxter, S.; Foulquier, L.; Holl, H.; Hogarth, R.

    2012-12-01

    Capturing the necessary and sufficient detail of reservoir hydraulics to accurately evaluate reservoir behavior remains a significant challenge to the exploitation and management of fracture-dominated geothermal reservoirs. In these low matrix permeability reservoirs, stimulation response is controlled largely by the properties of natural and induced fracture networks, which are in turn controlled by the in situ stresses, the fracture distribution and connectivity and the hydraulic behavior of the fractures. This complex interaction of fracture flow systems with the present-day stress field compounds the problem of developing an effective and efficient simulation to characterize, model and predict fractured reservoir performance. We discuss here a case study of the integration of geological, geophysical, geomechanical, and reservoir engineering data to characterize the in situ stresses, the natural fracture network and the controls on fracture permeability in geothermal reservoirs. A 3D geomechanical reservoir model includes constraints on stress magnitudes and orientations, and constraints on mechanical rock properties and the fractures themselves. Such a model is essential to understanding reservoir response to stimulation and production in low matrix permeability, fracture-dominated reservoirs. The geomechanical model for this study was developed using petrophysical, drilling, and wellbore image data along with direct well test measurements and was mapped to a 3D structural grid to facilitate coupled simulation of the fractured reservoir. Wellbore image and stimulation test data were used along with microseismic data acquired during the test to determine the reservoir fracture architecture and to provide control points for a realistic inter-connected discrete fracture network. As most fractures are stress-sensitive, their hydraulic conductivities will change with changes in bottomhole flowing and reservoir pressures, causing variations in production profiles

  10. Monitoring compaction and compressibility changes in offshore chalk reservoirs

    SciTech Connect

    Dean, G.; Hardy, R. ); Eltvik, P. )

    1994-03-01

    Some of the North Sea's largest and most important oil fields are in chalk reservoirs. In these fields, it is important to measure reservoir compaction and compressibility because compaction can result in platform subsidence. Also, compaction drive is a main drive mechanism in these fields, so an accurate reserves estimate cannot be made without first measuring compressibility. Estimating compaction and reserves is difficult because compressibility changes throughout field life. Installing of accurate, permanent downhole pressure gauges on offshore chalk fields makes it possible to use a new method to monitor compressibility -- measurement of reservoir pressure changes caused by the tide. This tidal-monitoring technique is an in-situ method that can greatly increase compressibility information. It can be used to estimate compressibility and to measure compressibility variation over time. This paper concentrates on application of the tidal-monitoring technique to North Sea chalk reservoirs. However, the method is applicable for any tidal offshore area and can be applied whenever necessary to monitor in-situ rock compressibility. One such application would be if platform subsidence was expected.

  11. Supersonic beams at high particle densities: model description beyond the ideal gas approximation.

    PubMed

    Christen, Wolfgang; Rademann, Klaus; Even, Uzi

    2010-10-28

    Supersonic molecular beams constitute a very powerful technique in modern chemical physics. They offer several unique features such as a directed, collision-free flow of particles, very high luminosity, and an unsurpassed strong adiabatic cooling during the jet expansion. While it is generally recognized that their maximum flow velocity depends on the molecular weight and the temperature of the working fluid in the stagnation reservoir, not a lot is known on the effects of elevated particle densities. Frequently, the characteristics of supersonic beams are treated in diverse approximations of an ideal gas expansion. In these simplified model descriptions, the real gas character of fluid systems is ignored, although particle associations are responsible for fundamental processes such as the formation of clusters, both in the reservoir at increased densities and during the jet expansion. In this contribution, the various assumptions of ideal gas treatments of supersonic beams and their shortcomings are reviewed. It is shown in detail that a straightforward thermodynamic approach considering the initial and final enthalpy is capable of characterizing the terminal mean beam velocity, even at the liquid-vapor phase boundary and the critical point. Fluid properties are obtained using the most accurate equations of state available at present. This procedure provides the opportunity to naturally include the dramatic effects of nonideal gas behavior for a large variety of fluid systems. Besides the prediction of the terminal flow velocity, thermodynamic models of isentropic jet expansions permit an estimate of the upper limit of the beam temperature and the amount of condensation in the beam. These descriptions can even be extended to include spinodal decomposition processes, thus providing a generally applicable tool for investigating the two-phase region of high supersaturations not easily accessible otherwise.

  12. Interdisciplinary study of reservoir compartments. [Quarterly report, April 1, 1994--June 30, 1994

    SciTech Connect

    Van Kirk, C.W.; Thompson, R.S.

    1994-07-26

    This DOE research project was established to document the integrated team approach for solving reservoir engineering problems. A field study integrating the disciplines of geology, geophysics, and petroleum engineering will be the mechanism for documenting the integrated approach. This is an area of keen interest to the oil and gas industry. The goal will be to provide tools and approaches that can be used to detect reservoir compartments, reach a better reserve estimate, and improve profits early in the life of a field. Progress reports are presented for the following tasks: reservoir selection and data gathering; outcrop/core/log analysis/ and correlations, internal architecture description; seismic analysis; and permeability experimental work.

  13. A Parallel Stochastic Framework for Reservoir Characterization and History Matching

    DOE PAGES

    Thomas, Sunil G.; Klie, Hector M.; Rodriguez, Adolfo A.; Wheeler, Mary F.

    2011-01-01

    The spatial distribution of parameters that characterize the subsurface is never known to any reasonable level of accuracy required to solve the governing PDEs of multiphase flow or species transport through porous media. This paper presents a numerically cheap, yet efficient, accurate and parallel framework to estimate reservoir parameters, for example, medium permeability, using sensor information from measurements of the solution variables such as phase pressures, phase concentrations, fluxes, and seismic and well log data. Numerical results are presented to demonstrate the method.

  14. Improved technique for stochastic interpolation of reservoir properties

    SciTech Connect

    Painter, S.; Paterson, L.

    1995-12-31

    Stochastic interpolation methods for generating input for reservoir simulations require accurate models for spatial variability. New models based on fractional Levy motion, a generalization of fractional Brownian motion, have strong empirical support. Stochastic interpolations based on the Levy model have a higher degree of spatial variability compared to Gaussian fractals. In two-dimensional waterflood simulations, the breakthrough curves for the Levy interpolation method are better clustered around predicted production behavior based directly on outcrop data.

  15. Modeling and scaleup of steamflood in a heterogeneous reservoir

    SciTech Connect

    Dehghani, K.; Basham, W.M.; Durlofsky, L.J.; Tucker, K.E.

    1995-11-01

    A series of simulation runs was conducted for different geostatistically derived cross-sectional models to study the degree of heterogeneity required for proper modeling of steamfloods in a thick, heavy-oil reservoir with thin diatomite barriers Different methods for coarsening the most detailed models were applied, and performance predictions for the coarsened and detailed models compared. Use of a general scaleup method provided the most accurate coarse grid models.

  16. Integrated hydraulic flow units analysis for carbonate and clastic conventional and unconventional petroleum reservoirs

    NASA Astrophysics Data System (ADS)

    Ivakhnenko, Aleksandr; Abirov, Rustem; Gulnur, Asan; Shopenova, Aigerim; Makarova, Maria; Telman, Meruert

    2014-05-01

    Thorough understanding of the phenomena in variation of pore properties and permeability in lithofacies of conventional carbonate and clastic petroleum reservoirs together with unconventional reservoirs before and after their hydraulic fracturing is the main concept in reservoir description. It is known that new reservoir description techniques will cut off the amount of unexplored hydrocarbon reserves. Discrepancies in pore geometry are the evidence of that there exist hydraulic flow units with similar or different characteristics. So the rock type determination processes cannot be accomplished only by one way. There is demand for several techniques in order to make away with different uncertainties by proper correlation and analysing the results. Classic determination of rock types is realized by geological observations and by the porosity versus permeability log. In this paper, the new methodology is proposed for determination of flow zones. The methodology is based on the Kozeny-Carmen equation where we can get the reservoir quality index which indicates the porosity versus permeability data. The specialty of this new technique is that it takes into account the influence of depositional and diagenetic units controlling the fluid flow besides the reservoir quality index. The proposed technique has been successfully tested in reservoirs. The paper describes the hydraulic flow units and presents graphs demonstrating the utility of this method.

  17. Operation of TVA reservoirs. Annual report, 1981

    SciTech Connect

    Not Available

    1984-09-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1981. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1981. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storages and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plotting of midnight reservoir elevations during calendar year 1981 are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  18. Operation of TVA reservoirs: annual 1980

    SciTech Connect

    Not Available

    1983-10-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1980. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1980. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storage and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plottings of midnight reservoir elevations are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  19. Joint Control and the Selection of Stimuli from Their Description

    ERIC Educational Resources Information Center

    Lowenkron, Barry

    2006-01-01

    This research examined the role the two constituents of joint control, the tact and the echoic, play in producing accurate selections of novel stimuli in response to their spoken descriptions. Experiment 1 examined the role of tacts. In response to unfamiliar spoken descriptions, children learned to select from among six successively presented…

  20. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM

    SciTech Connect

    Murphy, Mark B.

    1999-02-24

    The Nash Draw Brushy Canyon Pool in Eddy County New Mexico is a cost-shared field demonstration project in the US Department of Energy Class II Program. A major goal of the Class III Program is to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques are being used at the Nash Draw project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. Analysis, interpretation, and integration of recently acquired geologic, geophysical, and engineering data revealed that the initial reservoir characterization was too simplistic to capture the critical features of this complex formation. Contrary to the initial characterization, a new reservoir description evolved that provided sufficient detail regarding the complexity of the Brushy Canyon interval at Nash Draw. This new reservoir description is being used as a risk reduction tool to identify ''sweet spots'' for a development drilling program as well as to evaluate pressure maintenance strategies. The reservoir characterization, geological modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well simulation, and well spacing to improve recovery from this reservoir.

  1. How well will the Surface Water and Ocean Topography (SWOT) mission observe global reservoirs?

    NASA Astrophysics Data System (ADS)

    Solander, Kurt C.; Reager, John T.; Famiglietti, James S.

    2016-03-01

    Accurate observations of global reservoir storage are critical to understand the availability of managed water resources. By enabling estimates of surface water area and height for reservoir sizes exceeding 250 m2 at a maximum repeat orbit of up to 21 days, the NASA Surface Water and Ocean Topography (SWOT) satellite mission (anticipated launch date 2020) is expected to greatly improve upon existing reservoir monitoring capabilities. It is thus essential that spatial and temporal measurement uncertainty for water bodies is known a priori to maximize the utility of SWOT observations as the data are acquired. In this study, we evaluate SWOT reservoir observations using a three-pronged approach that assesses temporal aliasing, errors due to specific reservoir spatial properties, and SWOT performance over actual reservoirs using a combination of in situ and simulated reservoir observations from the SWOTsim instrument simulator. Results indicate temporal errors to be less than 5% for the smallest reservoir sizes (< 10 km2) with errors less than 0.1% for larger sizes (>100 km2). Surface area and height errors were found to be minimal (area <5%, height <15 cm) above 1 km2 unless the reservoir exhibited a strong elliptical shape with high aspect ratio oriented parallel to orbit, was set in mountainous terrain, or swath coverage fell below 30%. Experiments from six real reservoir test cases generally support these results. By providing a comprehensive blueprint on the observability of reservoirs from SWOT, this study will be have important implications for future applications of SWOT reservoir measurements in global monitoring systems and models.

  2. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    SciTech Connect

    Mohan Kelkar

    2004-10-01

    West Carney field--one of the newest fields discovered in Oklahoma--exhibits many unique production characteristics. These characteristics include: (1) decreasing water-oil ratio; (2) decreasing gas-oil ratio followed by an increase; (3) poor prediction capability of the reserves based on the log data; and (4) low geological connectivity but high hydrodynamic connectivity. The purpose of this investigation is to understand the principal mechanisms affecting the production, and propose methods by which we can extend the phenomenon to other fields with similar characteristics. In our experimental investigation section, we present the data on surfactant injection in near well bore region. We demonstrate that by injecting the surfactant, the relative permeability of water could be decreased, and that of gas could be increased. This should result in improved gas recovery from the reservoir. Our geological analysis of the reservoir develops the detailed stratigraphic description of the reservoir. Two new stratigraphic units, previously unrecognized, are identified. Additional lithofacies are recognized in new core descriptions. Our engineering analysis has determined that well density is an important parameter in optimally producing Hunton reservoirs. It appears that 160 acre is an optimal spacing. The reservoir pressure appears to decline over time; however, recovery per well is only weakly influenced by the pressure. This indicates that additional opportunity to drill wells exists in relatively depleted fields. A simple material balance technique is developed to validate the recovery of gas, oil and water. This technique can be used to further extrapolate recoveries from other fields with similar field characteristics.

  3. Reducing uncertainty in geostatistical description with well testing pressure data

    SciTech Connect

    Reynolds, A.C.; He, Nanqun; Oliver, D.S.

    1997-08-01

    Geostatistics has proven to be an effective tool for generating realizations of reservoir properties conditioned to static data, e.g., core and log data and geologic knowledge. Due to the lack of closely spaced data in the lateral directions, there will be significant variability in reservoir descriptions generated by geostatistical simulation, i.e., significant uncertainty in the reservoir descriptions. In past work, we have presented procedures based on inverse problem theory for generating reservoir descriptions (rock property fields) conditioned to pressure data and geostatistical information represented as prior means for log-permeability and porosity and variograms. Although we have shown that the incorporation of pressure data reduces the uncertainty below the level contained in the geostatistical model based only on static information (the prior model), our previous results assumed did not explicitly account for uncertainties in the prior means and the parameters defining the variogram model. In this work, we investigate how pressure data can help detect errors in the prior means. If errors in the prior means are large and are not taken into account, realizations conditioned to pressure data represent incorrect samples of the a posteriori probability density function for the rock property fields, whereas, if the uncertainty in the prior mean is incorporated properly into the model, one obtains realistic realizations of the rock property fields.

  4. Modelling sub-daily evaporation from a small reservoir.

    NASA Astrophysics Data System (ADS)

    McGloin, Ryan; McGowan, Hamish; McJannet, David; Burn, Stewart

    2013-04-01

    Accurate quantification of evaporation from small water storages is essential for water management and is also required as input in some regional hydrological and meteorological models. Global estimates of the number of small storages or lakes (< 0.1 kilometers) are estimated to be in the order of 300 million (Downing et al., 2006). However, direct evaporation measurements at small reservoirs using the eddy covariance or scintillometry techniques have been limited due to their expensive and complex nature. To correctly represent the effect that small water bodies have on the regional hydrometeorology, reliable estimates of sub-daily evaporation are necessary. However, evaporation modelling studies at small reservoirs have so far been limited to quantifying daily estimates. In order to ascertain suitable methods for accurately modelling hourly evaporation from a small reservoir, this study compares evaporation results measured by the eddy covariance method at a small reservoir in southeast Queensland, Australia, to results from several modelling approaches using both over-water and land-based meteorological measurements. Accurate predictions of hourly evaporation were obtained by a simple theoretical mass transfer model requiring only over-water measurements of wind speed, humidity and water surface temperature. An evaporation model that was recently developed for use in small reservoir environments by Granger and Hedstrom (2011), appeared to overestimate the impact stability had on evaporation. While evaporation predictions made by the 1-dimensional hydrodynamics model, DYRESM (Dynamic Reservoir Simulation Model) (Imberger and Patterson, 1981), showed reasonable agreement with measured values. DYRESM did not show any substantial improvement in evaporation prediction when inflows and out flows were included and only a slighter better correlation was shown when over-water meteorological measurements were used in place of land-based measurements. Downing, J. A., Y. T

  5. Characterization of oil and gas reservoir heterogeneity. Annual report, November 1, 1990--October 31, 1991

    SciTech Connect

    Not Available

    1991-12-31

    The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

  6. Fully analogue photonic reservoir computer.

    PubMed

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-03-03

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers.

  7. Trends in reservoir performance prediction

    SciTech Connect

    Mackenzie, A.S.

    1994-12-31

    Stronger links between geoscience and petroleum engineering are being fostered by new tools and organizations. These linkages are improving the effectiveness of business decisions concerning reservoir performance, and are generating new challenges for the next generation of tools.

  8. Cascade Reservoirs Floodwater Resources Utilization

    NASA Astrophysics Data System (ADS)

    Wang, Y.

    2015-12-01

    A reasonable floodwater resources utilization method is put forward by dynamic controlling of cascade reservoirs flood control limited level in this paper. According to the probability distribution of the beginning time of the first flood and the ending time of the final flood from July to September, the Fuzzy Statistic Analysis was used to divide the main flood season. By fitting the flood season membership functions of each period, the cascade reservoirs flood control limited water level for each period were computed according to the characteristic data of reservoirs. In terms of the benefit maximization and risk minimum principle, the reasonable combination of flood control limited water level of cascade reservoirs was put forward.

  9. Fully analogue photonic reservoir computer

    PubMed Central

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-01-01

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers. PMID:26935166

  10. Towards Accurate Application Characterization for Exascale (APEX)

    SciTech Connect

    Hammond, Simon David

    2015-09-01

    Sandia National Laboratories has been engaged in hardware and software codesign activities for a number of years, indeed, it might be argued that prototyping of clusters as far back as the CPLANT machines and many large capability resources including ASCI Red and RedStorm were examples of codesigned solutions. As the research supporting our codesign activities has moved closer to investigating on-node runtime behavior a nature hunger has grown for detailed analysis of both hardware and algorithm performance from the perspective of low-level operations. The Application Characterization for Exascale (APEX) LDRD was a project concieved of addressing some of these concerns. Primarily the research was to intended to focus on generating accurate and reproducible low-level performance metrics using tools that could scale to production-class code bases. Along side this research was an advocacy and analysis role associated with evaluating tools for production use, working with leading industry vendors to develop and refine solutions required by our code teams and to directly engage with production code developers to form a context for the application analysis and a bridge to the research community within Sandia. On each of these accounts significant progress has been made, particularly, as this report will cover, in the low-level analysis of operations for important classes of algorithms. This report summarizes the development of a collection of tools under the APEX research program and leaves to other SAND and L2 milestone reports the description of codesign progress with Sandia’s production users/developers.

  11. Understanding satellite-based monthly-to-seasonal reservoir outflow estimation as a function of hydrologic controls

    NASA Astrophysics Data System (ADS)

    Bonnema, Matthew; Sikder, Safat; Miao, Yabin; Chen, Xiaodong; Hossain, Faisal; Ara Pervin, Ismat; Mahbubur Rahman, S. M.; Lee, Hyongki

    2016-05-01

    Growing population and increased demand for water is causing an increase in dam and reservoir construction in developing nations. When rivers cross international boundaries, the downstream stakeholders often have little knowledge of upstream reservoir operation practices. Satellite remote sensing in the form of radar altimetry and multisensor precipitation products can be used as a practical way to provide downstream stakeholders with the fundamentally elusive upstream information on reservoir outflow needed to make important and proactive water management decisions. This study uses a mass balance approach of three hydrologic controls to estimate reservoir outflow from satellite data at monthly and annual time scales: precipitation-induced inflow, evaporation, and reservoir storage change. Furthermore, this study explores the importance of each of these hydrologic controls to the accuracy of outflow estimation. The hydrologic controls found to be unimportant could potentially be neglected from similar future studies. Two reservoirs were examined in contrasting regions of the world, the Hungry Horse Reservoir in a mountainous region in northwest U.S. and the Kaptai Reservoir in a low-lying, forested region of Bangladesh. It was found that this mass balance method estimated the annual outflow of both reservoirs with reasonable skill. The estimation of monthly outflow from both reservoirs was however less accurate. The Kaptai basin exhibited a shift in basin behavior resulting in variable accuracy across the 9 year study period. Monthly outflow estimation from Hungry Horse Reservoir was compounded by snow accumulation and melt processes, reflected by relatively low accuracy in summer and fall, when snow processes control runoff. Furthermore, it was found that the important hydrologic controls for reservoir outflow estimation at the monthly time scale differs between the two reservoirs, with precipitation-induced inflow being the most important control for the Kaptai

  12. Capacity sharing of water reservoirs

    NASA Astrophysics Data System (ADS)

    Dudley, Norman J.; Musgrave, Warren F.

    1988-05-01

    The concept of a water use property right is developed which does not apply to water volumes as such but to a share of the capacity (not contents) of river storage reservoirs and their inflows. The shareholders can withdraw water from their share over time in accordance with their preferences for stability of water deliveries. The reservoir authority does not manage reservoir releases but keeps record of individual shareholder's withdrawals and net inflows to monitor the quantity of water in each shareholder's capacity share. A surplus of total reservoir contents over the sum of the contents of the individual shareholder's capacity shares will accrue over time. Two different criteria for its periodic distribution among shareholders are compared. A previous paper Dudley (this issue(b)) noted a loss of short-run economic efficiency as reservoir and farm management decision making become separated. This is largely overcome by capacity sharing which allows each user to integrate the management of their portion of the reservoir and their farming operations. The nonattenuated nature of the capacity sharing water rights also promotes long-run economic efficiency.

  13. Chickamauga reservoir embayment study - 1990

    SciTech Connect

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  14. Bathymetric maps and water-quality profiles of Table Rock and North Saluda Reservoirs, Greenville County, South Carolina

    USGS Publications Warehouse

    Clark, Jimmy M.; Journey, Celeste A.; Nagle, Doug D.; Lanier, Timothy H.

    2014-01-01

    Lakes and reservoirs are the water-supply source for many communities. As such, water-resource managers that oversee these water supplies require monitoring of the quantity and quality of the resource. Monitoring information can be used to assess the basic conditions within the reservoir and to establish a reliable estimate of storage capacity. In April and May 2013, a global navigation satellite system receiver and fathometer were used to collect bathymetric data, and an autonomous underwater vehicle was used to collect water-quality and bathymetric data at Table Rock Reservoir and North Saluda Reservoir in Greenville County, South Carolina. These bathymetric data were used to create a bathymetric contour map and stage-area and stage-volume relation tables for each reservoir. Additionally, statistical summaries of the water-quality data were used to provide a general description of water-quality conditions in the reservoirs.

  15. Operation of TVA reservoirs. Annual 1979

    SciTech Connect

    Not Available

    1982-04-01

    Data for 1979 on the operation of TVA reservoirs for flood control, power generation and navigational purposes are reported. The operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1979 is described. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Any reference in this report to all reservoirs in the Tennessee or Cumberland River Basins refer to these specific reservoirs. Tabulated data are included on: reservation elevation and storage volume; turbine and gate discharges; and head water elevation. (LCL)

  16. Characterization of oil and gas reservoir heterogeneity. Final report

    SciTech Connect

    Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.

    1992-10-01

    Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a ``heterogeneity matrix`` based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.

  17. 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.

  18. Multimedia content description framework

    NASA Technical Reports Server (NTRS)

    Bergman, Lawrence David (Inventor); Kim, Michelle Yoonk Yung (Inventor); Li, Chung-Sheng (Inventor); Mohan, Rakesh (Inventor); Smith, John Richard (Inventor)

    2003-01-01

    A framework is provided for describing multimedia content and a system in which a plurality of multimedia storage devices employing the content description methods of the present invention can interoperate. In accordance with one form of the present invention, the content description framework is a description scheme (DS) for describing streams or aggregations of multimedia objects, which may comprise audio, images, video, text, time series, and various other modalities. This description scheme can accommodate an essentially limitless number of descriptors in terms of features, semantics or metadata, and facilitate content-based search, index, and retrieval, among other capabilities, for both streamed or aggregated multimedia objects.

  19. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  20. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  1. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  2. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  3. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  4. Reservoir characterization and geostatistical modeling of an eolian reservoir for simulation, East Painter reservoir field, Wyoming

    SciTech Connect

    Singdahlsen, D.S. )

    1991-06-01

    The East Painter structure is a doubly plunging, asymmetric anticline formed on the hanging wall of a back-thrust imbricate near the leading edge of the Absaroka Thrust. The Jurassic Nugget Sandstone is the productive horizon in the East Painter structure. The approximately 900-ft-thick Nugget is a stratigraphically complex and heterogeneous unit deposited by eolian processes in a complex erg setting. The high degree of heterogeneity iwthin the Nugget results from variations in grain size, sorting, mineralogy, and degree and distribution of lamination. The Nugget is comprised of dune, transitional toeset, and interdune facies, each exhibiting different porosity and permeability distributions. Gacies architecture results in both vertical and horizontal stratification of the reservoir. Adequate representation of reservoir heterogeneity is the key to successful modeling of past and future production performance. In addition, a detailed geologic model, based on depositional environment, must be integrated into the simulation to ensure realistic results. Geostatistics provide a method for modeling the spatial reservoir property distirbution while honoring all data values at their sample location. Conditional simulation is a geostatistical technique that generates several equally probably realizations that observe the data and spatial constraints imposed upon them while including fractal variability. Flow simulations of multiple reservoir realizations can provide a probability distribution of reservoir performance that can be used to evaluate risk associated with a project caused by the imcomplete sampling of the reservoir property distribution.

  5. Two pre-Willan descriptions of psoriasis.

    PubMed

    De Bersaques, Jean

    2012-01-01

    Accurate descriptions of skin lesions, and in particular of those of what we now call osiriasis vulgaris, are rare before the book of Willan's On Cutaneous Diseases at the very beginning of the 19th century. Here we present two instances in which such clinical descriptions are given. Benjamin Franklin wrote about his own skin lesions and their evolution. Dr. Willam Falconer, physician in Bath, England, presents the clinical symptoms and his results with 83 patients with 'lepra graecorum' (the name used at that time) treated between 1772 and 1775. One can wonder why such a now frequent, obvious and distinctive disease had not attracted more attention. PMID:22902228

  6. The FLUKA Code: An Accurate Simulation Tool for Particle Therapy

    PubMed Central

    Battistoni, Giuseppe; Bauer, Julia; Boehlen, Till T.; Cerutti, Francesco; Chin, Mary P. W.; Dos Santos Augusto, Ricardo; Ferrari, Alfredo; Ortega, Pablo G.; Kozłowska, Wioletta; Magro, Giuseppe; Mairani, Andrea; Parodi, Katia; Sala, Paola R.; Schoofs, Philippe; Tessonnier, Thomas; Vlachoudis, Vasilis

    2016-01-01

    Monte Carlo (MC) codes are increasingly spreading in the hadrontherapy community due to their detailed description of radiation transport and interaction with matter. The suitability of a MC code for application to hadrontherapy demands accurate and reliable physical models capable of handling all components of the expected radiation field. This becomes extremely important for correctly performing not only physical but also biologically based dose calculations, especially in cases where ions heavier than protons are involved. In addition, accurate prediction of emerging secondary radiation is of utmost importance in innovative areas of research aiming at in vivo treatment verification. This contribution will address the recent developments of the FLUKA MC code and its practical applications in this field. Refinements of the FLUKA nuclear models in the therapeutic energy interval lead to an improved description of the mixed radiation field as shown in the presented benchmarks against experimental data with both 4He and 12C ion beams. Accurate description of ionization energy losses and of particle scattering and interactions lead to the excellent agreement of calculated depth–dose profiles with those measured at leading European hadron therapy centers, both with proton and ion beams. In order to support the application of FLUKA in hospital-based environments, Flair, the FLUKA graphical interface, has been enhanced with the capability of translating CT DICOM images into voxel-based computational phantoms in a fast and well-structured way. The interface is capable of importing also radiotherapy treatment data described in DICOM RT standard. In addition, the interface is equipped with an intuitive PET scanner geometry generator and automatic recording of coincidence events. Clinically, similar cases will be presented both in terms of absorbed dose and biological dose calculations describing the various available features. PMID:27242956

  7. The FLUKA Code: An Accurate Simulation Tool for Particle Therapy.

    PubMed

    Battistoni, Giuseppe; Bauer, Julia; Boehlen, Till T; Cerutti, Francesco; Chin, Mary P W; Dos Santos Augusto, Ricardo; Ferrari, Alfredo; Ortega, Pablo G; Kozłowska, Wioletta; Magro, Giuseppe; Mairani, Andrea; Parodi, Katia; Sala, Paola R; Schoofs, Philippe; Tessonnier, Thomas; Vlachoudis, Vasilis

    2016-01-01

    Monte Carlo (MC) codes are increasingly spreading in the hadrontherapy community due to their detailed description of radiation transport and interaction with matter. The suitability of a MC code for application to hadrontherapy demands accurate and reliable physical models capable of handling all components of the expected radiation field. This becomes extremely important for correctly performing not only physical but also biologically based dose calculations, especially in cases where ions heavier than protons are involved. In addition, accurate prediction of emerging secondary radiation is of utmost importance in innovative areas of research aiming at in vivo treatment verification. This contribution will address the recent developments of the FLUKA MC code and its practical applications in this field. Refinements of the FLUKA nuclear models in the therapeutic energy interval lead to an improved description of the mixed radiation field as shown in the presented benchmarks against experimental data with both (4)He and (12)C ion beams. Accurate description of ionization energy losses and of particle scattering and interactions lead to the excellent agreement of calculated depth-dose profiles with those measured at leading European hadron therapy centers, both with proton and ion beams. In order to support the application of FLUKA in hospital-based environments, Flair, the FLUKA graphical interface, has been enhanced with the capability of translating CT DICOM images into voxel-based computational phantoms in a fast and well-structured way. The interface is capable of importing also radiotherapy treatment data described in DICOM RT standard. In addition, the interface is equipped with an intuitive PET scanner geometry generator and automatic recording of coincidence events. Clinically, similar cases will be presented both in terms of absorbed dose and biological dose calculations describing the various available features. PMID:27242956

  8. Gypsy Field Project in Reservoir Characterization

    SciTech Connect

    John P. Castagna; William J. Lamb; Carlos Moreno; Roger Young; Lynn Soreghan

    2000-09-19

    The objective of the Gypsy Project was to properly calculate seismic attributes and integrate these into a reservoir characterization project. Significant progress was made on the project in four areas. (1) Attenuation: In order for seismic inversion for rock properties or calculation of seismic attributes used to estimate rock properties to be performed validly, it is necessary to deal with seismic data that has had true amplitude and frequency content restored to account for earth filtering effects that are generally not included in seismic reservoir characterization methodologies. This requires the accurate measurement of seismic attenuation, something that is rarely achieved in practice. It is hoped that such measurements may also provide additional independent seismic attributes for use in reservoir characterization studies. In 2000, we were concerned with the ground truthing of attenuation measurements in the vicinity of wells. Our approach to the problem is one of extracting as time varying wavelet and relating temporal variations in the wavelet to an attenuation model of the earth. This method has the advantage of correcting for temporal variations in the reflectivity spectrum of the earth which confound the spectral ratio methodology which is the most commonly applied means of measuring attenuation from surface seismic data. Part I of the report describes our efforts in seismic attenuation as applied to the Gypsy data. (2) Optimal Attributes: A bewildering array of seismic attributes is available to the reservoir geoscientist to try to establish correlations to rock properties. Ultimately, the use of such a large number of degrees of freedom in the search for correlations with limited well control leads to common misapplication of statistically insignificant results which yields invalid predictions. Cross-validation against unused wells can be used to recognize such problems, but does not offer a solution to the question of which attributes should be used

  9. Water injection into vapor- and liquid-dominated reservoirs: Modeling of heat transfer and mass transport

    SciTech Connect

    Pruess, K.; Oldenburg, C.; Moridis, G.; Finsterle, S.

    1997-12-31

    This paper summarizes recent advances in methods for simulating water and tracer injection, and presents illustrative applications to liquid- and vapor-dominated geothermal reservoirs. High-resolution simulations of water injection into heterogeneous, vertical fractures in superheated vapor zones were performed. Injected water was found to move in dendritic patterns, and to experience stronger lateral flow effects than predicted from homogeneous medium models. Higher-order differencing methods were applied to modeling water and tracer injection into liquid-dominated systems. Conventional upstream weighting techniques were shown to be adequate for predicting the migration of thermal fronts, while higher-order methods give far better accuracy for tracer transport. A new fluid property module for the TOUGH2 simulator is described which allows a more accurate description of geofluids, and includes mineral dissolution and precipitation effects with associated porosity and permeability change. Comparisons between numerical simulation predictions and data for laboratory and field injection experiments are summarized. Enhanced simulation capabilities include a new linear solver package for TOUGH2, and inverse modeling techniques for automatic history matching and optimization.

  10. Modeling Shear-Enhanced Permeability as the Mechanism for Fluid Flow in Fractured Reservoirs - A Promising Improvement to Predicting Reservoir Production

    NASA Astrophysics Data System (ADS)

    Barton, C.; Moos, D.

    2011-12-01

    An accurate geomechanical reservoir model including constraints on stress magnitudes and orientations, mechanical rock properties, and the orientations and characteristics of natural fractures is essential to understanding reservoir response to stimulation and production in low permeability reservoirs such as crystalline basement geothermal or oil and gas reservoirs. In these low permeability reservoirs, stimulation response is controlled largely by the properties of natural and induced fracture networks which are in turn controlled by the in situ stresses, the fracture distribution and the hydraulic behavior of the fractures. These hydraulic properties of the fractures, their width, stiffness and strength are often difficult to quantify, leading to large uncertainties in predicted response to stimulation of fractured reservoirs. A well-constrained and calibrated fracture model makes it possible not only to predict reservoir response to stimulation, including the shape and orientation of the stimulated region, but also to predict the required stimulation pressure. Such a model also makes it possible to predict the change in flow properties during production due to depletion, resulting in better predictions of production rate and ultimate recovery. As part of the evaluation process of a compartmentalized fractured basement reservoir, wellbore image and other data were used to develop a 3D geomechanical model of stress and natural fractures through the reservoir volume. Although the results clearly defined the optimal directions in which to drill wells to exploit pre-existing natural fractures, large uncertainties in the models resulted in significant uncertainties in predictions of stimulation response. Because the pre-existing natural fractures were insufficiently permeable and operational constraints precluded the use of hydraulic fracturing to stimulate the reservoir, an innovative approach was taken to determine the extent to which injection at pressures below

  11. Evaluation of field development plans using 3-D reservoir modelling

    SciTech Connect

    Seifert, D.; Lewis, J.J.M.; Newbery, J.D.H.

    1997-08-01

    Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.

  12. Log-Derived evaluation of shaly sandstone reservoirs

    SciTech Connect

    Fertl, W.H.

    1984-04-01

    Significant natural gas resources are known to exist in the United States in tight, low-permeability sandstones that cover a prospective area of 1,000,000 mi/sup 2/ (2,590,000 km/sup 2/). Characterization and reliable estimation of their production potential based on well logs are important although difficult task. Proper evaluation of low permeability sands based on conventional log-interpretation techniques is frequently inadequate. Furthermore, while empirical rules of thumb assist in the evaluation of localized conditions, they only provide guidelines. Recent developments in quantitative log-analysis techniques incorporate natural-gamma-ray spectral data and application of the Waxman-Smits model for detailed reservoir description. Quantitative correlations of cation exchange capacity (CEC), water salinity, porosity, and conductivity of water- and hydrocarbon-bearing shaly sand reservoirs are based on resistivity, density, neutron and natural-gamma-ray spectral data. These correlations provide important information about clay volume, reservoir porosities (total, effective) and fluid-saturation distribution (total, effective), type of clay minerals (smectite, illite, chlorite/kaolinite), their distribution in the reservoir (dispersed, laminated, structural), and log-derived indicators of potential formation damage. Field experiences are reviewed for logging and evaluating tight formations in south Texas; the Jurassic Cotton Valley trend in east Texas, Louisiana, and Arkansas; and the Tertiary Fort Union and Cretaceous Mesaverde Formations of the Piceance basin in Colorado.

  13. Long-term Reservoir Routing Simulations Using Data-Driven Approaches

    NASA Astrophysics Data System (ADS)

    Ashouri, H.; Chowdhary, H.; Chinnayakanahalli, K.; Dodov, B.

    2015-12-01

    Flood is a highly complex natural hazard that accounts for major losses to human societies worldwide. Dams built with the aim of mitigating the flood risk significantly modify river flow regimes but unavailability and/or inaccessibility of proper information about reservoir operational rules impose a big hurdle to global flood modeling. This is specifically critical for flood-prone regions where lack of proper representation of reservoir operation can lead to significant under- or overestimation of the flood magnitude, risk, and losses. With the availability of longer in-situ observational data records, as well as advancements in satellite altimetry techniques for measuring reservoir levels, operational rules can be indirectly deduced. In this study, the observed reservoir levels as well as the historical and forecast time series of inflows are incorporated into a stochastic autoregressive moving average statistical modeling scheme to simulate the releases from the dam at each time step. The resulting operational rule curve is used in a reservoir simulation model to simulate the outflows from the reservoirs. The efficiency of the model is examined for three case studies in the United States, including John Martin Reservoir (CO), Coralville Lake (IA, and specifically for the devastating 2008 flood in the state), and Boca Reservoir (CA). Statistical measures are derived and tested to evaluate the accuracy of the simulated hydrographs against USGS streamflow gauge observations. The results prove the capability of the developed model in simulating reasonably accurate outflows from dams and will be presented at the meeting.

  14. Using microstructure observations to quantify fracture properties and improve reservoir simulations. Final report, September 1998

    SciTech Connect

    Laubach, S.E.; Marrett, R.; Rossen, W.; Olson, J.; Lake, L.; Ortega, O.; Gu, Y.; Reed, R.

    1999-01-01

    The research for this project provides new technology to understand and successfully characterize, predict, and simulate reservoir-scale fractures. Such fractures have worldwide importance because of their influence on successful extraction of resources. The scope of this project includes creation and testing of new methods to measure, interpret, and simulate reservoir fractures that overcome the challenge of inadequate sampling. The key to these methods is the use of microstructures as guides to the attributes of the large fractures that control reservoir behavior. One accomplishment of the project research is a demonstration that these microstructures can be reliably and inexpensively sampled. Specific goals of this project were to: create and test new methods of measuring attributes of reservoir-scale fractures, particularly as fluid conduits, and test the methods on samples from reservoirs; extrapolate structural attributes to the reservoir scale through rigorous mathematical techniques and help build accurate and useful 3-D models of the interwell region; and design new ways to incorporate geological and geophysical information into reservoir simulation and verify the accuracy by comparison with production data. New analytical methods developed in the project are leading to a more realistic characterization of fractured reservoir rocks. Testing diagnostic and predictive approaches was an integral part of the research, and several tests were successfully completed.

  15. 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.

  16. Provocative Opinion: Descriptive Chemistry.

    ERIC Educational Resources Information Center

    Bent, Henry A.; Bent, Brian E.

    1987-01-01

    Discusses many of the distinctions that chemists draw between theoretical chemistry and descriptive chemistry, along with the tendency for chemical educators to adopt the type of chemistry they feel is most important to teach. Uses examples to argue that theoretical chemistry and descriptive chemistry are, at the bottom line, the same. (TW)

  17. A Descriptive Experiment.

    ERIC Educational Resources Information Center

    Brand, Josef

    1979-01-01

    In this experiment in description, students in a high school honors English class were asked to select a surrealistic painting and capture it in writing. Their compositions were given to art students who tried to reproduce the paintings from the written descriptions. (SJL)

  18. Physics 3204. Course Description.

    ERIC Educational Resources Information Center

    Newfoundland and Labrador Dept. of Education.

    A description of the physics 3204 course in Newfoundland and Labrador is provided. The description includes: (1) statement of purpose, including general objectives of science education; (2) a list of six course objectives; (3) course content for units on sound, light, optical instruments, electrostatics, current electricity, Michael Faraday and…

  19. Job descriptions made easy.

    PubMed

    Miller, Larry

    2014-01-01

    The act of writing a job description can be a daunting and difficult task for many managers. This article focuses on the key concepts of What, How, and Measureable Results as they relate to an employee's job duties. When the answers to these three elements are articulated, they define the core responsibilities of any job that form the basis for an effective job description.

  20. Prediction of the Fate and Transport Processes of Atrazine in a Reservoir

    NASA Astrophysics Data System (ADS)

    Chung, Se-Woong; Gu, Roy R.

    2009-07-01

    The fate and transport processes of a toxic chemical such as atrazine, an herbicide, in a reservoir are significantly influenced by hydrodynamic regimes of the reservoir. The two-dimensional (2D) laterally-integrated hydrodynamics and mass transport model, CE-QUAL-W2, was enhanced by incorporating a submodel for toxic contaminants and applied to Saylorville Reservoir, Iowa. The submodel describes the physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. The simulation results from the enhanced 2D reservoir model were validated by measured temperatures and atrazine concentrations in the reservoir. Although a strong thermal stratification was not identified from both observed and predicted water temperatures, the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the results showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A good agreement between predicted and observed times and magnitudes of peak concentrations was obtained. The use of time-variable decay rates of atrazine led to more accurate prediction of atrazine concentrations, while the use of a constant half-life (60 days) over the entire period resulted in a 40% overestimation of peak concentrations. The results provide a better understanding of the fate and transport of atrazine in the reservoir and information useful in the development of reservoir operation strategies with respect to timing, amount, and depth of withdrawal.

  1. 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.

  2. 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.

  3. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    1998-01-01

    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.

  4. Miniature Reservoir Cathode: An Update

    NASA Technical Reports Server (NTRS)

    Vancil, Bernard K.; Wintucky, Edwin G.

    2002-01-01

    We report on recent work to produce a small low power, low cost reservoir cathode capable of long life (more than 100,000 hours) at high loading (> 5 A/sq cm). Our objective is a highly manufacturable, commercial device costing less than $30. Small highly loaded cathodes are needed, especially for millimeter wave tubes, where focusing becomes difficult when area convergence ratios are too high. We currently have 3 models ranging from .060-inch diameter to. 125-inch diameter. Reservoir type barium dispenser cathodes have a demonstrated capability for simultaneous high emission density and long life. Seven reservoir cathodes continue to operate on the cathode life test facility at NSWC, Crane, Indiana at 2 and 4 amps/sq cm. They have accumulated nearly 100,000 hours with practically no change in emission levels or knee temperature.

  5. 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

  6. Calculation of petrophysical properties for Mishrif carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Kadhim, Fadhil Sarhan; Samsuri, Ariffin; Idris, Ahmad Kamal

    2014-10-01

    The accurate calculations of petrophysical properties in carbonate reservoirs are the most challenging aspects of well log analysis. Many equations have been developed over the years based on known physical principles or on empirically derived relationships, which are used to calculate carbonate rock petrophysical properties. Carbonate reservoirs in the Middle East are very heterogeneous in terms of rock types. Therefore the reservoir should be split into layers on the basis of the dominant rock type in order to define average values and trends of petrophysical parameters in the reservoir rock. The saturation exponent (n) and cementation exponent (m) are calculated from well log data using Pickett method. The study made across the Mishrif carbonate formation, which is the shallowest formation of the hydrocarbon bearing zone in the NS oil field in the Middle East. Results show that the average formation water resistivity (Rw= 0.0243), average mud filtrate resistivity (Rmf= 0.199), Irreducible Water Saturation (Swi=0. 18), and Archie's parameters (m=1. 78, n= 2, and a=1). While porosity, true resistivity, and water saturation values with depth of formation were calculated by using Interactive Petrophysics software (IP V3.5, 2008). The computer process interpretation (CPI) illustrates that the shale member splits the Mishrif formation into two parts; Upper and Lower Mishrif. This study is a step to investigate petrophysical properties, which used to calculate water saturation that should use to estimate original oil in place and detected the perforation zones.

  7. Reservoir technology research at Lawrence Berkeley Laboratory

    SciTech Connect

    Lippmann, M.J.

    1987-04-01

    The research being carried out at LBL as part of DOE/GTD's Reservoir Technology Program includes field, theoretical and modeling activities. The purpose is to develop, improve and validate methods and instrumentation to: (1) determine geothermal reservoir parameters, (2) detect and characterize reservoir fractures and boundaries, and (3) identify and evaluate the importance of reservoir processes. The ultimate objective of this work is to advance the state-of-the-art for characterizing geothermal reservoirs and evaluating their productive capacity and longevity under commercial exploitation. LBL's FY1986 accomplishments, FY1987 progress to date, and possible future activities under DOE's Reservoir Technology Program are discussed.

  8. Lumbar reservoir for intrathecal chemotherapy.

    PubMed

    Dyck, P

    1985-06-15

    The Ommaya ventricular reservoir has been the standby of intrathecal chemotherapy for more than a decade, in spite of some specific drawbacks. A general anaesthetic is often required. The scalp must be shaven. Ventricular puncture may not always be easy and keeping the ventricular catheter patent is sometimes difficult. Hence the author has adapted a commercially available lumbar peritoneal shunt system to function as a lumbar intrathecal reservoir. The procedure is simple and can be performed expeditiously under local anaesthesia. To date, eight cases have received intrathecal chemotherapy by this means. PMID:3838918

  9. How good do seasonal streamflow forecasts need to be to improve reservoir operation?

    NASA Astrophysics Data System (ADS)

    Anghileri, D.; Voisin, N.; Pianosi, F.; Castelletti, A.; Nijssen, B.; Lettenmaier, D. P.

    2013-12-01

    Reservoir operating rules inform release decisions based on competing demands, priorities, available storage, and reservoir characteristics. Reservoir inflow forecasts over a range of forecast lead times (from days or less to seasons or longer) can improve release decisions and lead to more efficient use of reservoir storage. However, the utility or value of inflow forecasts is directly related to forecast quality. Through a case study of the Oroville-Thermalito reservoir complex in the Feather River Basin, California, we explore the effect of forecast quality on optimal release strategies. Streamflow in the Upper Feather Basin is strongly seasonal signal, with most of the flow occurring during the winter (mostly from rainfall at lower elevations) and spring (from melt of the previous winter's snow accumulation). Accurate prediction of the volume and timing of snowmelt (which is possible via various means, including monitoring of accumulated winter precipitation, and measurements of high elevation snowpack) has the potential to improve reservoir operation. In this study, we use Deterministic Dynamic Programming to optimize medium-range and seasonal reservoir operation based on different forecasts of reservoir inflows. We determine maximum reservoir performance by forcing the optimization with observed inflows, which is equivalent to a perfect forecast. The forecast quality is then progressively degraded to allow forecast skill to be related to changes in release decisions and to determine the minimum forecast skill that is required to affect decision-making. We generate forecasted inflow sequences using the Variable Infiltration Capacity (VIC) hydrology model. Forecast initial conditions are created using observed meteorology, including streamflow and snow data assimilation, while inflow forecasts are based on seasonal climate forecasts. Although the specific forecast skill level is specific to the Feather River basin, the methodology should be transferable to

  10. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dams. (2) During the season of navigation on the upper Mississippi River, the volume of water... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs...

  11. Reservoir transport and poroelastic properties from oscillating pore pressure experiments

    NASA Astrophysics Data System (ADS)

    Hasanov, Azar K.

    Hydraulic transport properties of reservoir rocks, permeability and storage capacity are traditionally defined as rock properties, responsible for the passage of fluids through the porous rock sample, as well as their storage. The evaluation of both is an important part of any reservoir characterization workflow. Moreover, permeability and storage capacity are main inputs into any reservoir simulation study, routinely performed by reservoir engineers on almost any major oil and gas field in the world. An accurate reservoir simulation is essential for production forecast and economic analysis, hence the transport properties directly control the profitability of the petroleum reservoir and their estimation is vital for oil and gas industry. This thesis is devoted to an integrated study of reservoir rocks' hydraulic, streaming potential and poroelastic properties as measured with the oscillating pore pressure experiment. The oscillating pore pressure method is traditionally used to measure hydraulic transport properties. We modified the method and built an experimental setup, capable of measuring all aforementioned rock properties simultaneously. The measurements were carried out for four conventional reservoir-rock quality samples at a range of oscillation frequencies and effective stresses. An apparent frequency dependence of permeability and streaming potential coupling coefficient was observed. Measured frequency dispersion of drained poroelastic properties indicates an intrinsically inelastic nature of the porous mineral rock frame. Standard Linear Model demonstrated the best fit to the experimental dispersion data. Pore collapse and grain crushing effects took place during hydrostatic loading of the dolomitic sample and were observed in permeability, coupling coefficient and poroelastic measurements simultaneously. I established that hydraulically-measured storage capacities are overestimated by almost one order of magnitude when compared to elastically

  12. Models in biology: ‘accurate descriptions of our pathetic thinking’

    PubMed Central

    2014-01-01

    In this essay I will sketch some ideas for how to think about models in biology. I will begin by trying to dispel the myth that quantitative modeling is somehow foreign to biology. I will then point out the distinction between forward and reverse modeling and focus thereafter on the former. Instead of going into mathematical technicalities about different varieties of models, I will focus on their logical structure, in terms of assumptions and conclusions. A model is a logical machine for deducing the latter from the former. If the model is correct, then, if you believe its assumptions, you must, as a matter of logic, also believe its conclusions. This leads to consideration of the assumptions underlying models. If these are based on fundamental physical laws, then it may be reasonable to treat the model as ‘predictive’, in the sense that it is not subject to falsification and we can rely on its conclusions. However, at the molecular level, models are more often derived from phenomenology and guesswork. In this case, the model is a test of its assumptions and must be falsifiable. I will discuss three models from this perspective, each of which yields biological insights, and this will lead to some guidelines for prospective model builders. PMID:24886484

  13. The use of experimental bending tests to more accurate numerical description of TBC damage process

    NASA Astrophysics Data System (ADS)

    Sadowski, T.; Golewski, P.

    2016-04-01

    Thermal barrier coatings (TBCs) have been extensively used in aircraft engines to protect critical engine parts such as blades and combustion chambers, which are exposed to high temperatures and corrosive environment. The blades of turbine engines are additionally exposed to high mechanical loads. These loads are created by the high rotational speed of the rotor (30 000 rot/min), causing the tensile and bending stresses. Therefore, experimental testing of coated samples is necessary in order to determine strength properties of TBCs. Beam samples with dimensions 50×10×2 mm were used in those studies. The TBC system consisted of 150 μm thick bond coat (NiCoCrAlY) and 300 μm thick top coat (YSZ) made by APS (air plasma spray) process. Samples were tested by three-point bending test with various loads. After bending tests, the samples were subjected to microscopic observation to determine the quantity of cracks and their depth. The above mentioned results were used to build numerical model and calibrate material data in Abaqus program. Brittle cracking damage model was applied for the TBC layer, which allows to remove elements after reaching criterion. Surface based cohesive behavior was used to model the delamination which may occur at the boundary between bond coat and top coat.

  14. Toward an Accurate Density-Functional Tight-Binding Description of Zinc-Containing Compounds.

    PubMed

    Moreira, Ney H; Dolgonos, Grygoriy; Aradi, Bálint; da Rosa, Andreia L; Frauenheim, Thomas

    2009-03-10

    An extended self-consistent charge density-functional tight-binding (SCC-DFTB) parametrization for Zn-X (X = H, C, N, O, S, and Zn) interactions has been derived. The performance of this new parametrization has been validated by calculating the structural and energetic properties of zinc solid phases such as bulk Zn, ZnO, and ZnS; ZnO surfaces and nanostructures; adsorption of small species (H, CO2, and NH3) on ZnO surfaces; and zinc-containing complexes mimicking the biological environment. Our results show that the derived parameters are universal and fully transferable, describing all the above-mentioned systems with accuracies comparable to those of first-principles DFT results. PMID:26610226

  15. Interdisciplinary study of reservoir compartments. Quarterly technical progress report, October 1, 1994--December 31, 1994

    SciTech Connect

    Van Kirk, C.W.

    1995-01-27

    This DOE research project was established to document the integrated team approach for solving reservoir engineering problems. A field study integrating the disciplines of geology, geophysics, and petroleum engineering will be the mechanism for documenting the integrated approach. This is an area of keen interest to the oil and gas industry. The goal will be to provide tools and approaches that can be used to detect reservoir compartments, reach a better reserve estimate, and improve profits early in the life of a field. Brief summaries are provided for the following six tasks: reservoir selection and data gathering; outcrop/core/log analysis/and correlations; internal architecture description; seismic analysis; detailed reservoir engineering evaluation; and permeability experimental work. Where appropriate reports by the research professors and the research assistants are included in the appendix.

  16. Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs (Annex 1)

    SciTech Connect

    Watney, W.L.

    1992-01-01

    Interdisciplinary studies of the Upper Pennsylvanian Lansing and Kansas City groups have been undertaken in order to improve the geologic characterization of petroleum reservoirs and to develop a quantitative understanding of the processes responsible for formation of associated depositional sequences. To this end, concepts and methods of sequence stratigraphy are being used to define and interpret the three-dimensional depositional framework of the Kansas City Group. The investigation includes characterization of reservoir rocks in oil fields in western Kansas, description of analog equivalents in near-surface and surface sites in southeastern Kansas, and construction of regional structural and stratigraphic framework to link the site specific studies. Geologic inverse and simulation models are being developed to integrate quantitative estimates of controls on sedimentation to produce reconstructions of reservoir-bearing strata in an attempt to enhance our ability to predict reservoir characteristics.

  17. Hardware description languages

    NASA Technical Reports Server (NTRS)

    Tucker, Jerry H.

    1994-01-01

    Hardware description languages are special purpose programming languages. They are primarily used to specify the behavior of digital systems and are rapidly replacing traditional digital system design techniques. This is because they allow the designer to concentrate on how the system should operate rather than on implementation details. Hardware description languages allow a digital system to be described with a wide range of abstraction, and they support top down design techniques. A key feature of any hardware description language environment is its ability to simulate the modeled system. The two most important hardware description languages are Verilog and VHDL. Verilog has been the dominant language for the design of application specific integrated circuits (ASIC's). However, VHDL is rapidly gaining in popularity.

  18. Description scheme for video editing work

    NASA Astrophysics Data System (ADS)

    Ruiloba, Rosa I.; Joly, Philippe

    2001-03-01

    This article presents a Description Scheme (DS) to describe the audio-visual documents from the video editing work point of view. This DS is based on edition techniques used in the video edition domain. The main objective of this DS is to provide a complete, modular and extensible description of the structure of the video documents based on editing process. This VideoEditing DS is generic in the sense that it may be used in a large number of applications such as video document indexing and analysis, description of Edit Decision List and elaboration of editing patterns. It is based on accurate and complete definitions of shots and transition effects required for video document analysis applications. The VideoEditing DS allows three levels of description : analytic, synthetic and semantic. In the DS, the higher (resp. the lower) is the element of description, the more analytic (resp. synthetic) is the information. %Phil This DS allows describing the editing work made by editing boards, using more detailed descriptors of Shots and Transition DSs. These elements are provided to define editing patterns that allow several possible reconstructions of movies depending on, for example, the target audience. A part of the video description made with this DS may be automatically produced by the video to shots segmentation algorithms (analytic DSs ) or by editing software, at the same time the edition work is made. This DS gives an answer to the needs related to the exchange of editing work descriptions between editing softwares. At the same time, the same DS provide an analytic description of editing work which is complementary to existing standards for Edit Decision Lists like SMPTE or AAF.

  19. 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.

  20. 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.

  1. Characterization of a Delaware slope basin reservoir for optimal development

    SciTech Connect

    Weiss, W.W.; Ouenes, A.; Sultan, A.J.

    1995-12-31

    A reliable reservoir description is essential to various scenarios for successful field development. In this study, various new tools have been applied to fully characterize the East Livingston Ridge Delaware reservoir. The Delaware formations in their slope/basin environment are difficult to characterize due to the channels in the submarine fans. Using well logs, a complex 3-D reservoir model composed of a channel through the bottom three layers of a seven layer model with one non-oil bearing zone was constructed to represent this complex depositional setting. Drastic changes in layer lithologies resulting in multiple oil/water contacts and varying water saturations required detailed log interpretation. The porosity logs were tuned with available sidewall core information. Log porosity was determined for each layer at each well and kriging was used to estimate the areal distribution of the porosity. Porosity-permeability correlations for each layer were developed from sidewall core data. The correlations were used to make an initial estimate of the interwell permeabilities. A production history match was not possible with the initial characterization of the reservoir. The production rates of the oil, gas, and water phases of each of the twenty-three wells in the East Livingston Ridge field and the pressure data were automatically history matched using a recently developed simulated annealing technique. The absolute and relative permeabilities of the layers were varied automatically during the history matching phase of the reservoir study. The larger scale properties resulting from the calibrated model were used to forecast the results of continued primary, infill drilling and/or waterflooding.

  2. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    SciTech Connect

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore

  3. High performance computing for domestic petroleum reservoir simulation

    SciTech Connect

    Zyvoloski, G.; Auer, L.; Dendy, J.

    1996-06-01

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory. High-performance computing offers the prospect of greatly increasing the resolution at which petroleum reservoirs can be represented in simulation models. The increases in resolution can be achieved through large increases in computational speed and memory, if machine architecture and numerical methods for solution of the multiphase flow equations can be used to advantage. Perhaps more importantly, the increased speed and size of today`s computers make it possible to add physical processes to simulation codes that heretofore were too expensive in terms of computer time and memory to be practical. These factors combine to allow the development of new, more accurate methods for optimizing petroleum reservoir production.

  4. Population dynamics of aquatic snails in Pampulha reservoir.

    PubMed

    Freitas, J R; Bedê, L C; De Marco Júnior, P; Rocha, L A; Santos, M B

    1987-01-01

    An attempt was made to determine more accurately the density of molluskan populations in the Pampulha reservoir, using the quadrate method, intending to detect the fluctuation of the populations density, the habitat conditions and the possible competitive interactions among Biomphalaria tenagophila, Melanoides tuberculata, Pomacea haustrum and Biomphalaria glabrata, through the analysis of populational parameters. Among the most significative facts observed in the reservoir it has to be mentioned: the almost disappearance of B. glabrata; the invasion, colonization, fixation and fast growing of M. tuberculata population until reaching about 11,000 individuals/m2; the density fluctuations of B. tenagophila, P. haustrum and M. tuberculata alives and deads; differences on the habitat preference of these three molluskan species at the edge (at the limit earth-water, at 0.70m and 1.40m from the shore line); monthly mortality rates and reproduction seasons of the species. PMID:3509186

  5. Population dynamics of aquatic snails in Pampulha reservoir.

    PubMed

    Freitas, J R; Bedê, L C; De Marco Júnior, P; Rocha, L A; Santos, M B

    1987-01-01

    An attempt was made to determine more accurately the density of molluskan populations in the Pampulha reservoir, using the quadrate method, intending to detect the fluctuation of the populations density, the habitat conditions and the possible competitive interactions among Biomphalaria tenagophila, Melanoides tuberculata, Pomacea haustrum and Biomphalaria glabrata, through the analysis of populational parameters. Among the most significative facts observed in the reservoir it has to be mentioned: the almost disappearance of B. glabrata; the invasion, colonization, fixation and fast growing of M. tuberculata population until reaching about 11,000 individuals/m2; the density fluctuations of B. tenagophila, P. haustrum and M. tuberculata alives and deads; differences on the habitat preference of these three molluskan species at the edge (at the limit earth-water, at 0.70m and 1.40m from the shore line); monthly mortality rates and reproduction seasons of the species.

  6. Prevention of Reservoir Interior Discoloration

    SciTech Connect

    Arnold, K.F.

    2001-04-03

    Contamination is anathema in reservoir production. Some of the contamination is a result of welding and some appears after welding but existed before. Oxygen was documented to be a major contributor to discoloration in welding. This study demonstrates that it can be controlled and that some of the informal cleaning processes contribute to contamination.

  7. Unconventional Reservoirs: Ideas to Commercialization

    NASA Astrophysics Data System (ADS)

    Tinker, S. W.

    2015-12-01

    There is no shortage of coal, oil, and natural gas in the world. What are sometimes in short supply are fresh ideas. Scientific innovation combined with continued advances in drilling and completion technology revitalized the natural gas industry in North America by making production from shale economic. Similar advances are now happening in shale oil. The convergence of ideas and technology has created a commercial environment in which unconventional reservoirs could supply natural gas to the North American consumer for 50 years or more. And, although not as far along in terms of resource development, oil from the Eagle Ford and Bakken Shales and the oil sands in Alberta could have a similar impact. Without advanced horizontal drilling, geosteering, staged hydraulic-fracture stimulation, synthetic and natural proppants, evolution of hydraulic fluid chemistry, and high-end monitoring and simulation, many of these plays would not exist. Yet drilling and completion technology cannot stand alone. Also required for success are creative thinking, favorable economics, and a tolerance for risk by operators. Current understanding and completion practices will leave upwards of 80% of oil and natural gas in the shale reservoirs. The opportunity to enhance recovery through advanced reservoir understanding and imaging, as well as through recompletions and infill drilling, is considerable. The path from ideas to commercialization will continue to provide economic results in unconventional reservoirs.

  8. SNC Meteorites and Martian Reservoirs

    NASA Technical Reports Server (NTRS)

    Jones, J. H.

    2002-01-01

    Jones first suggested that the inverse covariation of initial epsilon (Nd-143) and Sr-87/Sr-86 of the shergottites could be explained by interaction between mantle-derived magmas with another isotopic reservoir(s) (i.e., assimilation or contamination). In that model, magmas were generated in a source region that was isotopically similar to the Nakhla source and the second reservoir(s) was presumed to be crust. The text also permitted the second reservoir to be another type of mantle, but I can confirm that a second mantle reservoir was never seriously considered by that author. Other features of this model were that (i) it occurred at a particular time, 180 m.y. ago, and (ii) the interacting reservoirs had been separated at approximately 4.5 b.y. In a later paper Jones explored this mixing model more quantitatively and concluded that magmas from a Nakhla-like source region at 180 m.y. would fall on or near an isotopic Nd-Sr-Pb hyperplane defined by the shergottites. This criterion was a necessary prerequisite for the parent magma(s) of the shergottites to have initially been Nakhla-like isotopically. At this juncture, it is perhaps worthwhile to note that this mixing model was not presented to explain geochemical variations but as a justification for a 180 m.y. crystallization age for the shergottites and a 1.3 b.y. crystallization age for the nakhlites. In the mid-1980's crystallization ages estimated for Nakhla ranged from approximately 1.3 b.y to 4.5 b.y. Similarly, preferred crystallization ages for the shergottites ranged from 360 m.y., to 1.3 b.y., to 4.5 b.y. In all these models, the 180 m.y. event seen in the shergottites was deemed to be metamorphic. The fit between the Nakhla-like source region and the shergottite hyperplane was a validation both of the 1.3 b.y. igneous age of Nakhla and the 180 m.y. igneous age of the shergottites.

  9. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM

    SciTech Connect

    Mark B. Murphy

    2005-09-30

    The Nash Draw Brushy Canyon Pool in Eddy County New Mexico was a cost-shared field demonstration project in the U.S. Department of Energy Class III Program. A major goal of the Class III Program was to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques were used at the Nash Draw Pool (NDP) project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. The objective of the project was to demonstrate that a development program, which was based on advanced reservoir management methods, could significantly improve oil recovery at the NDP. Initial goals were (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to other oil and gas producers. Analysis, interpretation, and integration of recently acquired geological, geophysical, and engineering data revealed that the initial reservoir characterization was too simplistic to capture the critical features of this complex formation. Contrary to the initial characterization, a new reservoir description evolved that provided sufficient detail regarding the complexity of the Brushy Canyon interval at Nash Draw. This new reservoir description was used as a risk reduction tool to identify 'sweet spots' for a development drilling program as well as to evaluate pressure maintenance strategies. The reservoir characterization, geological modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well stimulation, and well spacing to improve recovery from this reservoir. An Advanced

  10. Integration of advanced geoscience and engineering techniques to quantify interwell heterogeneity in reservoir models. Final report, September 29, 1993--September 30, 1996

    SciTech Connect

    Weiss, W.W.; Buckley, J.S.; Ouenes, A.

    1997-05-01

    The goal of this three-year project was to provide a quantitative definition of reservoir heterogeneity. This objective was accomplished through the integration of geologic, geophysical, and engineering databases into a multi-disciplinary understanding of reservoir architecture and associated fluid-rock and fluid-fluid interactions. This interdisciplinary effort integrated geological and geophysical data with engineering and petrophysical results through reservoir simulation to quantify reservoir architecture and the dynamics of fluid-rock and fluid-fluid interactions. An improved reservoir description allows greater accuracy and confidence during simulation and modeling as steps toward gaining greater recovery efficiency from existing reservoirs. A field laboratory, the Sulimar Queen Unit, was available for the field research. Several members of the PRRC staff participated in the development of improved reservoir description by integration of the field and laboratory data as well as in the development of quantitative reservoir models to aid performance predictions. Subcontractors from Stanford University and the University of Texas at Austin (UT) collaborated in the research and participated in the design and interpretation of field tests. The three-year project was initiated in September 1993 and led to the development and application of various reservoir description methodologies. A new approach for visualizing production data graphically was developed and implemented on the Internet. Using production data and old gamma rays logs, a black oil reservoir model that honors both primary and secondary performance was developed. The old gamma ray logs were used after applying a resealing technique, which was crucial for the success of the project. In addition to the gamma ray logs, the development of the reservoir model benefitted from an inverse Drill Stem Test (DST) technique which provided initial estimates of the reservoir permeability at different wells.

  11. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    SciTech Connect

    Nurhandoko, Bagus Endar B. E-mail: bagusnur@rock-fluid.com; Susilowati E-mail: bagusnur@rock-fluid.com

    2015-04-16

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  12. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  13. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  14. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  15. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  16. Ekofisk reservoir voidage and seabed subsidence

    SciTech Connect

    Mes, M.J. )

    1990-11-01

    Field data describing the time lag between Ekofisk subsidence and reservoir voidage are given. A method to discriminate between real subsidence variations and random-data errors and a procedure to derive a contemporary relationship between reservoir voidage and seabed subsidence are presented. At Ekofisk, most subsidence lags reservoir voidage by 2 to 3 months.

  17. Operation of TVA reservoirs. Annual 1982

    SciTech Connect

    Not Available

    1985-09-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1982. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir and Woods Reservoir. Data for the Cumberland Basin projects of the US Army Corps of Engineers have been included beginning with the 1954 report. Plates are included tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1982. Additional plates show the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storages and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of reservoir operations. Tables of monthly and annual storages and flows (in inches) for the principal Tennessee River Basin tributary projects are included. Individual plottings of midnight reservoir elevations during calendar year 1982 are included for all principal reservoirs.

  18. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  19. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  20. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  1. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  2. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  3. Tenth workshop on geothermal reservoir engineering: proceedings

    SciTech Connect

    Not Available

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  4. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  5. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  6. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  7. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  8. Hydrographic surveying of reservoirs using differential GPS navigation and GIS data analysis

    SciTech Connect

    White, C.O.

    1995-12-31

    In 1993 and 1994, the Pacific Gas and Electric Company (PG&E) conducted hydrographic surveys on their Rock Creek and Cresta reservoirs. PG&E`s Rock Creek and Cresta reservoirs are located on the North Fork of the Feather River in northern California. Hydrographic surveys were conducted to determine sedimentation levels in the two reservoirs. This paper outlines PG&E`s efforts to monitor sedimentation levels from year-to-year. A survey-grade recording fathometer was used to record the reservoir depths. Survey vessel location was monitored using a Global Positioning System (GPS). Bathymetric contours and reservoir volumes were calculated using a Geographic Information System (GIS). This paper presents the methodology, results, and limitations of this technique for conducting hydrographic surveys. The results of the 1993 and 1994 hydrographic surveys and comparisons to a 1986 photogrammetric survey when the reservoirs were completely drawn down are presented. It is concluded that the GPS hydrographic survey methodology is an accurate and cost effective technique to monitor and address the long-term sediment balance in the reservoirs.

  9. Overcoming data scarcity: Seasonal forecasting of reservoir inflows using public domain resources in Central Asia

    NASA Astrophysics Data System (ADS)

    Dixon, Samuel G.; Wilby, Robert L.

    2016-04-01

    Management of large hydropower reservoirs can be politically and strategically problematic. Traditional flow forecasting techniques rely on accurate ground based observations, a requirement not met in many areas of the globe (Artan et al., 2007). In particular, access to real-time observational data in transnational river basins is often not possible. In these regions, novel techniques are required to combat the challenges of flow forecasting for efficient reservoir management. Near real time remotely sensed information regarding flow predictors (e.g. satellite precipitation estimates) could combat data availability issues, improving the utility of seasonal reservoir inflow forecasts. This study investigates the potential for river flow forecasting using public domain resources, including satellite and re-analysis precipitation as well as climate indices for several strategically important reservoirs throughout Central Asia (including Toktogul, Andijan, Kayrakkum and Nurek). Using reservoir inflows from 2001-2010, parsimonious numerical models were created for each study site using selected significant predictors for lead times of 1-3 months as well half year averages. Preliminary investigation has shown that parsimonious statistical models can explain over 80% of the variance in monthly inflows with three month lead to the Toktogul reservoir, Kyrgyzstan (Dixon and Wilby, 2015). Such findings show promise for improving the safety and efficiency of reservoir operations as well as reducing risks emerging from climate change.

  10. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management, Class III

    SciTech Connect

    Koerner, Roy; Clarke, Don; Walker, Scott; Phillips, Chris; Nguyen, John; Moos, Dan; Tagbor, Kwasi

    2001-08-07

    This project was intended to increase recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs, transferring technology so that it can be applied in other sections of the Wilmington field and by operators in other slope and basin reservoirs is a primary component of the project.

  11. Accurate thermoelastic tensor and acoustic velocities of NaCl

    NASA Astrophysics Data System (ADS)

    Marcondes, Michel L.; Shukla, Gaurav; da Silveira, Pedro; Wentzcovitch, Renata M.

    2015-12-01

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  12. Accurate thermoelastic tensor and acoustic velocities of NaCl

    SciTech Connect

    Marcondes, Michel L.; Shukla, Gaurav; Silveira, Pedro da; Wentzcovitch, Renata M.

    2015-12-15

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  13. 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.

  14. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, M.L.; Evans, R.D.; Brown, R.L.; Gupta, A.

    2001-03-28

    This report focuses on integrating geoscience and engineering data to develop a consistent characterization of the naturally fractured reservoirs. During this reporting period, effort was focused on relating seismic data to reservoir properties of naturally fractured reservoirs, scaling well log data to generate interwell descriptors of these reservoirs, enhancing and debugging a naturally fractured reservoir simulator, and developing a horizontal wellbore model for use in the simulator.

  15. New Heat Flow Models in Fractured Geothermal Reservoirs - Final Report

    SciTech Connect

    Reis, John

    2001-03-31

    . Although they are not as accurate as numerical simulators, they are simple, easy and inexpensive to use. These new models can be used to get general information about reservoir behavior before committing to the considerable greater expense of numerical simulation.

  16. 4. International reservoir characterization technical conference

    SciTech Connect

    1997-04-01

    This volume contains the Proceedings of the Fourth International Reservoir Characterization Technical Conference held March 2-4, 1997 in Houston, Texas. The theme for the conference was Advances in Reservoir Characterization for Effective Reservoir Management. On March 2, 1997, the DOE Class Workshop kicked off with tutorials by Dr. Steve Begg (BP Exploration) and Dr. Ganesh Thakur (Chevron). Tutorial presentations are not included in these Proceedings but may be available from the authors. The conference consisted of the following topics: data acquisition; reservoir modeling; scaling reservoir properties; and managing uncertainty. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.

  17. 49 CFR 229.31 - Main reservoir tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Main reservoir tests. 229.31 Section 229.31... reservoir tests. (a) Before it is placed in service, each main reservoir other than an aluminum reservoir... intervals that do not exceed 736 calendar days, each main reservoir other than an aluminum reservoir...

  18. 49 CFR 229.31 - Main reservoir tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Main reservoir tests. 229.31 Section 229.31... reservoir tests. (a) Before it is placed in service, each main reservoir other than an aluminum reservoir... intervals that do not exceed 736 calendar days, each main reservoir other than an aluminum reservoir...

  19. 49 CFR 229.31 - Main reservoir tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Main reservoir tests. 229.31 Section 229.31... reservoir tests. (a) Before it is placed in service, each main reservoir other than an aluminum reservoir... intervals that do not exceed 736 calendar days, each main reservoir other than an aluminum reservoir...

  20. 49 CFR 229.31 - Main reservoir tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Main reservoir tests. 229.31 Section 229.31... reservoir tests. (a) Before it is placed in service, each main reservoir other than an aluminum reservoir... intervals that do not exceed 736 calendar days, each main reservoir other than an aluminum reservoir...

  1. 49 CFR 229.31 - Main reservoir tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Main reservoir tests. 229.31 Section 229.31... reservoir tests. (a) Before it is placed in service, each main reservoir other than an aluminum reservoir... intervals that do not exceed 736 calendar days, each main reservoir other than an aluminum reservoir...

  2. Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality shallow shelf San Andres Reservoir. Annual report, August 4, 1996--August 3, 1997

    SciTech Connect

    Taylor, A.R.; Hickman, T.S.; Justice, J.J.

    1997-07-30

    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 lower quality shallow shelf carbonate reservoirs. The research and development phase (Budget Period 1) primarily involved advanced reservoir characterization. The current demonstration phase (Budget Period 2) will implement the reservoir management plan for an optimum miscible CO{sub 2} flood design based on the reservoir characterization. Although Budget Period 1 officially ended 12/31/96, reservoir characterization and optimum flood design has continued into the first part of Budget Period 2. Specifically, the geologic model was enhanced by integration of the 3-D seismic interpretations. This resulted in improved history match by the simulator and more accurate predictions of flood performance on which to base the project design. The majority of the project design work has been completed, material specifications provided and bids solicited. Preparation of the demonstration area is well underway.

  3. Correlations between watershed and reservoir characteristics, and algal blooms in subtropical reservoirs.

    PubMed

    Burford, Michele A; Johnson, Suzanne A; Cook, Andrew J; Packer, Timothy V; Taylor, Bradley M; Townsley, E Robert

    2007-10-01

    This study examined the correlations between watershed and reservoir characteristics, and water quality parameters related to algal blooms in seven subtropical reservoirs. Analysis of the dissimilarity of physico-chemical parameters resulted in separation of the reservoirs into three main groups: four reservoirs with the highest proportion of agriculture and/or urban land use in their watersheds; two reservoirs with a high proportion of forest cover; and one small reservoir with a relatively pristine watershed intermediate between the other two groups. All reservoirs were dominated by cyanobacteria, and at times, had species capable of producing toxins. However, the three reservoirs with the lowest percentage forest cover ( approximately 50%) had the highest frequency and magnitude of toxic species, principally Cylindrospermopsis raciborskii. Analysis of dissimilarity of algal species composition resulted in three reservoir groups similar to that for the physico-chemical parameters, with the exception of the reservoir with the highest percentage urban land use being an outlier. Across all reservoirs, percentage forest cover in the watershed, watershed area and reservoir volume were all significantly correlated with algal cell concentrations and total nitrogen (TN), but not with chlorophyll a concentrations. Total phosphorus (TP) was only correlated with the proportion forest cover in the watershed, suggesting that reservoir volume and depth were of less importance for TP than for algal cell concentrations or TN. These results suggest that watershed pattern and reservoir characteristics, such as water volume and depth, have a measurable effect on the type of algal blooms in reservoirs. PMID:17632205

  4. Development of luminescent bacteria as tracers for geological reservoir characterization

    SciTech Connect

    King, J.W.

    1991-01-01

    This research project resulted from recognizing the problem of being unable to accurately distinguish communication between wells in producing oil zones which may or may not be continuous. Such a determination is necessary when considering Enhanced Oil Recovery (EOR) whether it is water flooding, carbon dioxide, or other methods which increase the sweep efficiency. Various kinds of chemical tracers are available, but they are expensive and many might be considered hazardous for underground aquifers. Other biological tracers are available, but have never been developed for oil reservoir conditions. Bioluminescent bacteria seemed an obvious candidate because they thrive in saline waters (usually 3% salt) which have been contaminated by oil spills.

  5. Galerkin finite-element simulation of a geothermal reservoir

    USGS Publications Warehouse

    Mercer, J.W.; Pinder, G.F.

    1973-01-01

    The equations describing fluid flow and energy transport in a porous medium can be used to formulate a mathematical model capable of simulating the transient response of a hot-water geothermal reservoir. The resulting equations can be solved accurately and efficiently using a numerical scheme which combines the finite element approach with the Galerkin method of approximation. Application of this numerical model to the Wairakei geothermal field demonstrates that hot-water geothermal fields can be simulated using numerical techniques currently available and under development. ?? 1973.

  6. The role of reservoir characterization in the reservoir management process (as reflected in the Department of Energy`s reservoir management demonstration program)

    SciTech Connect

    Fowler, M.L.; Young, M.A.; Madden, M.P.

    1997-08-01

    Optimum reservoir recovery and profitability result from guidance of reservoir practices provided by an effective reservoir management plan. Success in developing the best, most appropriate reservoir management plan requires knowledge and consideration of (1) the reservoir system including rocks, and rock-fluid interactions (i.e., a characterization of the reservoir) as well as wellbores and associated equipment and surface facilities; (2) the technologies available to describe, analyze, and exploit the reservoir; and (3) the business environment under which the plan will be developed and implemented. Reservoir characterization is the essential to gain needed knowledge of the reservoir for reservoir management plan building. Reservoir characterization efforts can be appropriately scaled by considering the reservoir management context under which the plan is being built. Reservoir management plans de-optimize with time as technology and the business environment change or as new reservoir information indicates the reservoir characterization models on which the current plan is based are inadequate. BDM-Oklahoma and the Department of Energy have implemented a program of reservoir management demonstrations to encourage operators with limited resources and experience to learn, implement, and disperse sound reservoir management techniques through cooperative research and development projects whose objectives are to develop reservoir management plans. In each of the three projects currently underway, careful attention to reservoir management context assures a reservoir characterization approach that is sufficient, but not in excess of what is necessary, to devise and implement an effective reservoir management plan.

  7. CRAC2 model description

    SciTech Connect

    Ritchie, L.T.; Alpert, D.J.; Burke, R.P.; Johnson, J.D.; Ostmeyer, R.M.; Aldrich, D.C.; Blond, R.M.

    1984-03-01

    The CRAC2 computer code is a revised version of CRAC (Calculation of Reactor Accident Consequences) which was developed for the Reactor Safety Study. This document provides an overview of the CRAC2 code and a description of each of the models used. Significant improvements incorporated into CRAC2 include an improved weather sequence sampling technique, a new evacuation model, and new output capabilities. In addition, refinements have been made to the atmospheric transport and deposition model. Details of the modeling differences between CRAC2 and CRAC are emphasized in the model descriptions.

  8. Task 5: TVA sediment-disturbing activities within the Watts Bar Reservoir and Melton Hill Reservoir areas of the Clinch River

    SciTech Connect

    1997-06-01

    The objectives of Task 5 of the Interagency Agreement No. DE-AI05-91OR22007 were to review: (1) the extent of dredging, construction, and other sediment-disturbing activities conducted by the Tennessee Valley Authority (TVA) in potentially contaminated areas of Watts Bar Reservoir, and (2) the disposition of the materials from these activities. This memorandum is the final report for Task 5. This memorandum describes major activities in the Watts Bar Reservoir and Melton Hill Reservoir areas of the Clinch River that possibly resulted in significant disturbance of potentially contaminated sediments. TVA records from the construction of Watts Bar Dam, Kingston Fossil Plant, and Melton Hill Dam were reviewed to facilitate qualitative description of the effect of these activities in disturbing potentially contaminated sediments. The critical period for these activities in disturbing contaminated sediments was during or after 1956 when the peak releases of radioactive contaminants occurred from the Oak Ridge Reservation.

  9. Reservoir floodplains support distinct fish assemblages

    USGS Publications Warehouse

    Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D.

    2014-01-01

    Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  10. Factors affecting water quality in Cherokee Reservoir

    SciTech Connect

    Iwanski, M.L.; Higgins, J.M.; Kim, B.R.; Young, R.C.

    1980-07-01

    The purpose was to: (1) define reservoir problems related to water quality conditions; (2) identify the probable causes of these problems; and (3) recommend procedures for achieving needed reservoir water quality improvements. This report presents the project findings to date and suggests steps for upgrading the quality of Cherokee Reservoir. Section II presents background information on the characteristics of the basin, the reservoir, and the beneficial uses of the reservoir. Section III identifies the impacts of existing reservoir water quality on uses of the reservoir for water supply, fishery resources, recreation, and waste assimilation. Section IV presents an assessment of cause-effect relationships. The factors affecting water quality addressed in Section IV are: (1) reservoir thermal stratification and hydrodynamics; (2) dissolved oxygen depletion; (3) eutrophication; (4) toxic substances; and (5) reservoir fisheries. Section V presents a preliminary evaluation of alternatives for improving the quality of Cherokee Reservoir. Section VI presents preliminary conclusions and recommendations for developing and implementing a reservoir water quality management plan. 7 references, 22 figures, 21 tables.

  11. Trophic status evaluation of TVA reservoirs

    SciTech Connect

    Placke, J.F.

    1983-10-01

    TVA tributary and mainstem reservoirs show generalized differences in morphometry, hydraulics, nutrient loads, and response to nutrient concentrations. Neither type of reservoir is strictly comparable to the natural lakes on which classical eutrophication studies have been based. The majority of published trophic state indices and standards (e.g., hypolimnetic dissolved oxygen depletion, Secchi depth, areas nutrient loading rates, in-reservoir phosphorus concentrations) are inappropriate for evaluation of some or all TVA reservoirs. No single trophic potential or trophic response variable summarizes the mechanisms and manifestations of eutrophication sufficiently to be used as a sole criterion for judging or regulating TVA reservoir water quality. Relative multivariate trophic state indices were developed for mainstem and tributary reservoirs. Ranking of the mainstem reservoirs is based on chlorophyll, macrophyte coverage, hydraulic retention time, reservoir area less than five feet deep, annual pool elevation drawdown, and Secchi depth. Based on available data, the rank from least eutrophic to most eutrophic is: Pickwick, Kentucky, Chickamauga, Nickajack, Wilson, Fort Loudoun, Watts Bar, Wheeler, and Guntersville Reservoirs. Ranking of the tributary reservoirs is based on chlorophyll, total phosphorus and total nitrogen weighted by the N:P ratio, and bio-available inorganic carbon levels. The rank from least eutrophic to most eutrophic is: Hiwassee, Blue Ridge, Chatuge, Norris and Fontana, Watauga, South Holston, Tims Ford, Cherokee, Douglas, and Boone Reservoirs. 130 references, 18 figures, 30 tables.

  12. An overview of advanced cesium reservoir technology

    SciTech Connect

    Lamp, T.R. )

    1993-01-20

    The cesium reservoir is a critical component pacing development of a long life thermionic power system. A variety of cesium reservoirs have been researched during the existence of thermionics technology. Cesium is the ionization medium of choice and reservoir research is directed at containing and controlling this material. Historically, reservoirs of interest have included porous tungsten, highly oriented pyrolytic graphite (HOPG), charcoal, POCO graphite, binary compounds, and gas buffered reservoirs. Russian researchers are also working on a variety of reservoirs and cesiation techniques which are generically referred to as interelectrode medium maintenance systems. Russian work follows the general thrust of US work (heat pipe based concepts, graphite reservoir concepts, and chemical compounds of cesium.) This paper discusses the merits of several of these cesiation techniques which are in various stages of development in the United States. Russian work will be addressed only as a matter of historical record.

  13. An overview of advanced cesium reservoir technology

    NASA Astrophysics Data System (ADS)

    Lamp, Thomas R.

    1993-01-01

    The cesium reservoir is a critical component pacing development of a long life thermionic power system. A variety of cesium reservoirs have been researched during the existence of thermionics technology. Cesium is the ionization medium of choice and reservoir research is directed at containing and controlling this material. Historically, reservoirs of interest have included porous tungsten, highly oriented pyrolytic graphite (HOPG), charcoal, POCO graphite, binary compounds, and gas buffered reservoirs. Russian researchers are also working on a variety of reservoirs and cesiation techniques which are generically referred to as interelectrode medium maintenance systems. Russian work follows the general thrust of US work (heat pipe based concepts, graphite reservoir concepts, and chemical compounds of cesium.) This paper discusses the merits of several of these cesiation techniques which are in various stages of development in the United States. Russian work will be addressed only as a matter of historical record.

  14. Mill profiler machines soft materials accurately

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1966-01-01

    Mill profiler machines bevels, slots, and grooves in soft materials, such as styrofoam phenolic-filled cores, to any desired thickness. A single operator can accurately control cutting depths in contour or straight line work.

  15. Gypsy Field project in reservoir characterization. Final report

    SciTech Connect

    O`Meara, Jr., D. J.

    1997-05-01

    The overall objective of this project is to use the extensive Gypsy Field laboratory and data set as a focus for developing and testing reservoir characterization methods that are targeted at improved recovery of conventional oil. The Gypsy Field laboratory consists of coupled outcrop and subsurface sites which have been characterized to a degree of detail not possible in a production operation. Data from these sites entail geological descriptions, core measurements, well logs, vertical seismic surveys, a 3D seismic survey, crosswell seismic surveys, and pressure transient well tests. The overall project consists of four interdisciplinary sub-projects which are closely interlinked: modeling depositional environments; sweep efficiency; tracer testing; and integrated 3D seismic interpretation. The first of these aims at improving the ability to model complex depositional environments which trap movable oil. The second is a development geophysics project which proposes to improve the quality of reservoir geological models through better use of 3D seismic data. The third investigates the usefulness of a new numerical technique for identifying unswept oil through rapid calculation of sweep efficiency in large reservoir models. The fourth explores what can be learned from tracer tests in complex depositional environments, particularly those which are fluvial dominated.

  16. Application of a new scale up methodology to the simulation of displacement processes in heterogeneous reservoirs

    SciTech Connect

    Durlofsky, L.J.; Milliken, W.J.; Dehghani, K.; Jones, R.C.

    1994-12-31

    A general method for the scale up of highly detailed, heterogeneous reservoir cross sections is presented and applied to the simulation of several recovery processes in a variety of geologic settings. The scale up technique proceeds by first identifying portions of the fine scale reservoir description which could potentially lead to high fluid velocities, typically regions of connected, high permeability. These regions are then modeled in detail while the remainder of the domain is coarsened using a general numerical technique for the calculation of effective permeability. The overall scale up method is applied to the cross sectional simulation of three actual fields. Waterflood, steamflood and miscible flood recovery processes are considered. In all these cases, the scale up technique is shown to give coarsened reservoir descriptions which provide simulation results in very good agreement with those of the detailed reservoir descriptions. For these simulations, speedups in computation times, for the coarsened models relative to their fine grid counterparts, range from a factor of 10 to a factor of 200.

  17. Teaching Descriptive Style.

    ERIC Educational Resources Information Center

    Brashers, H. C.

    1968-01-01

    As the inexperienced writer becomes aware of the issues involved in the composition of effective descriptive prose, he also develops a consistent control over his materials. The persona he chooses, if coherently thought out, can function as an index of many choices, helping him to manipulate the tone, intent, and mood of this style; to regulate…

  18. 3D modelling and characterization of delta reservoir in SE-Hungary

    SciTech Connect

    Geiger, J.; Komlosi, J.

    1995-08-01

    The Algyo field is the largest field of Hungary consisting of more than 40 oil and gas bearing layers. The upper part of this field developed in delta slope and delta plain units of a progradational delta system, the lower members are turbidity rock bodies of prodelta and deep basin fans. As a type analogy ofthe reservoirs developed in Miocene-Pliocene progradational delta systems, the reservoir {open_quotes}Szeged-1{close_quotes} of the Algyo field has been chosen. It has been penetrated by 912 wells over an area of about 60 square km. This reservoir is interpreted as an alternation of distributary channels and inter-distributary swamp areas. About 40 cores with 100% core recovery was taken. The reservoir has been on stream since the late 60`-s, the geological model can be controlled by the data of the reservoir engineering. An integrated 3-D reservoir description based on a grid-oriented 3-D geostatistical visualisation of the internal lithological and petrophysical heterogeneity has been developed, This system integrates data of core descriptions, standard and special core analyses, and petrophysical well-log interpretations. The reservoir geometry and lithological heterogenity have been characterized by two models: Markov-model for the lithological transitions, and the 3D-grid-based geostatistical model for the visualisation. The 3-D visualization of the petrophysical data expresses the dependence of recovery mechanism, and injection schemes on the real internal heterogeneity. These images may be generalized and used as conditional constraints for the simulation of internal heterogeneity of other Pannonian fields developed only by few wells.

  19. Study on fine geological modelling of the fluvial sandstone reservoir in Daqing oilfield

    SciTech Connect

    Zhoa Han-Qing

    1997-08-01

    These paper aims at developing a method for fine reservoir description in maturing oilfields by using close spaced well logging data. The main productive reservoirs in Daqing oilfield is a set of large fluvial-deltaic deposits in the Songliao Lake Basin, characterized by multi-layers and serious heterogeneities. Various fluvial channel sandstone reservoirs cover a fairly important proportion of reserves. After a long period of water flooding, most of them have turned into high water cut layers, but there are considerable residual reserves within them, which are difficult to find and tap. Making fine reservoir description and developing sound a geological model is essential for tapping residual oil and enhancing oil recovery. The principal reason for relative lower precision of predicting model developed by using geostatistics is incomplete recognition of complex distribution of fluvial reservoirs and their internal architecture`s. Tasking advantage of limited outcrop data from other regions (suppose no outcrop data available in oilfield) can only provide the knowledge of subtle changing of reservoir parameters and internal architecture. For the specific geometry distribution and internal architecture of subsurface reservoirs (such as in produced regions) can be gained only from continuous infilling logging well data available from studied areas. For developing a geological model, we think the first important thing is to characterize sandbodies geometries and their general architecture`s, which are the framework of models, and then the slight changing of interwell parameters and internal architecture`s, which are the contents and cells of the model. An excellent model should possess both of them, but the geometry is the key to model, because it controls the contents and cells distribution within a model.

  20. Foam flooding reservoir simulation algorithm improvement and application

    NASA Astrophysics Data System (ADS)

    Wang, Yining; Wu, Xiaodong; Wang, Ruihe; Lai, Fengpeng; Zhang, Hanhan

    2014-05-01

    As one of the important enhanced oil recovery (EOR) technologies, Foam flooding is being used more and more widely in the oil field development. In order to describe and predict foam flooding, experts at domestic and abroad have established a number of mathematical models of foam flooding (mechanism, empirical and semi-empirical models). Empirical models require less data and apply conveniently, but the accuracy is not enough. The aggregate equilibrium model can describe foam generation, burst and coalescence by mechanism studying, but it is very difficult to accurately describe. The research considers the effects of critical water saturation, critical concentration of foaming agent and critical oil saturation on the sealing ability of foam and considers the effect of oil saturation on the resistance factor for obtaining the gas phase relative permeability and the results were amended by laboratory test, so the accuracy rate is higher. Through the reservoir development concepts simulation and field practical application, the calculation is more accurate and higher.

  1. Modeling taste and odor phytoplankton in Normandy Reservoir

    SciTech Connect

    Beard, L.M.; Brown, R.T.

    1984-03-01

    The feasibility of modeling particular algae associated with taste and odors was investigated as part of an effort to develop a two-dimensional water quality model applicable to Normandy and Columbia Reservoirs (Duck River, Tennessee). There does not appear to be any dominant factor controlling the occurrence and abundance of taste and odor causing algae. A summary of dominant algal patterns observed in Normandy Reservoir is provided. A simplified algal model using a fully mixed surface volume (bag) was developed to explore the possibility of modeling several algae types simultaneously. The results of a field algal assay involving nutrient additions to bags of indigenous algae suspended in the Duck River at Columbia, Tennessee, were summarized and simulated using the algae model. Some of the observed algal responses were reproduced with the model, while others remain unexplained. The specification of growth characteristics for individual algal types is the limiting factor in this approach because these have not been well documented. Growth characteristics for dominant algal species must be determined for more accurate modeling of taste and odor potential in Normandy and Columbia Reservoirs. 21 references, 25 figures, 1 table.

  2. Influence of lithofacies and diagensis on Norwegian North Sea chalk reservoirs

    SciTech Connect

    Brasher, J.E.; Vagle, K.R.

    1996-05-01

    The depositional mechanism of chalk is a key influence in the chalk`s ultimate reservoir quality. Classically, the depositional mechanism is interpreted from core descriptions. Where core data are lacking, dipmeter and borehole imagery logs have proven useful in making lithofacies assessments. Criteria for recognition of three chalk categories are established. Category III chalks correspond to those chalks that have been deposited by gravity flows or slumping and tend to have the best reservoir parameters. Category I chalks are most often affiliated with pelagic deposition and tend to have the poorest reservoir parameters. Category II chalks are intermediate between I and III. Anomalously high primary porosities have been maintained in Norwegian North Sea chalks where the effects of mechanical and chemical compaction have been limited. The diagenetic pathway of a chalk reflects changes brought about by mechanical and chemical compaction. Five factors most heavily influence the diagenetic pathway: (1) burial depth, (2) chalk type, (3) overpressuring, (4) presence of hydrocarbons, and (5) original grain size. Assessments of the sedimentological model, diagenetic pathway, and resultant reservoir quality are provided in case studies of Edda, Tor, and Eldfisk fields. Because the distribution of chalk is largely independent of existing structures, most fields have a component of stratigraphic/diagenetic trapping. Each case study shows unique examples of how petrophysical and reservoir engineering data can be incorporated in assessments of chalk type and the diagenetic pathway and how they may affect reservoir parameters and productivity.

  3. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, D.W.

    1997-11-11

    A method is described for extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid inventory of the reservoir. 4 figs.

  4. Sedimentation and sustainability of western American reservoirs

    NASA Astrophysics Data System (ADS)

    Graf, William L.; Wohl, Ellen; Sinha, Tushar; Sabo, John L.

    2010-12-01

    Reservoirs are sustainable only as long as they offer sufficient water storage space to achieve their design objectives. Life expectancy related to sedimentation is a measure of reservoir sustainability. We used data from the Army Corps of Engineers, U.S. Bureau of Reclamation, and U.S. Geological Survey (Reservoir Sedimentation Survey Information System II (RESIS II)) to explore the sustainability of American reservoirs. Sustainability varied by region, with the longest life expectancies in New England and the Tennessee Valley and the shortest in the interior west. In the Missouri and Colorado River basins, sedimentation and rates of loss of reservoir storage capacity were highly variable in time and space. In the Missouri River Basin, the larger reservoirs had the longest life expectancies, with some exceeding 1000 years, while smaller reservoirs in the basin had the shortest life expectancies. In the Colorado River Basin at the site of Glen Canyon Dam, sediment inflow varied with time, declining by half beginning in 1942 because of hydroclimate and upstream geomorphic changes. Because of these changes, the estimated life expectancy of Lake Powell increased from 300 to 700 years. Future surprise changes in sedimentation delivery and reservoir filling area are expected. Even though large western reservoirs were built within a limited period, their demise will not be synchronous because of varying sedimentation rates. Popular literature has incorrectly emphasized the possibility of rapid, synchronous loss of reservoir storage capacity and underestimated the sustainability of the water control infrastructure.

  5. Longitudinal gradients along a reservoir cascade

    USGS Publications Warehouse

    Miranda, L.E.; Habrat, M.D.; Miyazono, S.

    2008-01-01

    Reservoirs have traditionally been regarded as spatially independent entities rather than as longitudinal segments of a river system that are connected upstream and downstream to the river and other reservoirs. This view has frustrated advancement in reservoir science by impeding adequate organization of available information and by hindering interchanges with allied disciplines that often consider impounded rivers at the basin scale. We analyzed reservoir morphology, water quality, and fish assemblage data collected in 24 reservoirs of the Tennessee River; we wanted to describe longitudinal changes occurring at the scale of the entire reservoir series (i.e., cascade) and to test the hypothesis that fish communities and environmental factors display predictable gradients like those recognized for unimpounded rivers. We used a data set collected over a 7-year period; over 3 million fish representing 94 species were included in the data set. Characteristics such as reservoir mean depth, relative size of the limnetic zone, water retention time, oxygen stratification, thermal stratification, substrate size, and water level fluctuations increased in upstream reservoirs. Conversely, reservoir area, extent of riverine and littoral zones, access to floodplains and associated wetlands, habitat diversity, and nutrient and sediment inputs increased in downstream reservoirs. Upstream reservoirs included few, largely lacustrine, ubiquitous fish taxa that were characteristic of the lentic upper reaches of the basin. Fish species richness increased in a downstream direction from 12 to 67 species/ reservoir as riverine species became more common. Considering impoundments at a basin scale by viewing them as sections in a river or links in a chain may generate insight that is not always available when the impoundments are viewed as isolated entities. Basin-scale variables are rarely controllable but constrain the expression of processes at smaller scales and can facilitate the

  6. Naturally fractured tight gas reservoir detection optimization. Final report

    SciTech Connect

    1997-11-19

    This DOE-funded research into seismic detection of natural fractures is one of six projects within the DOE`s Detection and Analysis of Naturally Fractured Gas Reservoirs Program, a multidisciplinary research initiative to develop technology for prediction, detection, and mapping of naturally fractured gas reservoirs. The demonstration of successful seismic techniques to locate subsurface zones of high fracture density and to guide drilling orientation for enhanced fracture permeability will enable better returns on investments in the development of the vast gas reserves held in tight formations beneath the Rocky Mountains. The seismic techniques used in this project were designed to capture the azimuthal anisotropy within the seismic response. This seismic anisotropy is the result of the symmetry in the rock fabric created by aligned fractures and/or unequal horizontal stresses. These results may be compared and related to other lines of evidence to provide cross-validation. The authors undertook investigations along the following lines: Characterization of the seismic anisotropy in three-dimensional, P-wave seismic data; Characterization of the seismic anisotropy in a nine-component (P- and S-sources, three-component receivers) vertical seismic profile; Characterization of the seismic anisotropy in three-dimensional, P-to-S converted wave seismic data (P-wave source, three-component receivers); and Description of geological and reservoir-engineering data that corroborate the anisotropy: natural fractures observed at the target level and at the surface, estimation of the maximum horizontal stress in situ, and examination of the flow characteristics of the reservoir.

  7. A Method to Recover Useful Geothermal-Reservoir Parameters from Production Characteristic Curves (2) Hot Water Reservoirs

    SciTech Connect

    Iglesias, E.; Arellano, V.; Molinar, R.

    1983-12-15

    In this paper we develop and demonstrate a method to estimate the reservoir pressure, a mass productivity index, and a thermal power productivity index for vertical water-fed geothermal wells, from its production characteristic (also called output) curves. In addition, the method allows to estimate the radius of influence of the well, provided that a value of the reservoir transmisivity is available. The basic structure of the present method is: first, the measured wellhead mass flowrate; and pressures are transformed to downhole conditions by means of a numerical simulator; then, the computed downhole variables are fitted to a simple radial model that predicts the sandface flowrate in terms of the flowing pressure. For demonstration, the method was applied to several wells from the Cerro Prieto geothermal field. We found very good agreement of the model with this ample set of field data. The main advantages of our method are that it provides a way to retrieve important reservoir information from usually available production characteristic curves, that it works from easily and accurately taken wellhead measurements, and that its results address the two main aspects of geothermal resource utilization, namely, mass and heat production.

  8. Status of the Ocoee Reservoirs: An overview of reservoir conditions and uses

    SciTech Connect

    Not Available

    1991-04-01

    The Ocoee projects are three hydroelectric facilities in Polk County, Tennessee. TVA purchased Ocoee Reservoirs Nos. 1 an 2 in 1939 and impounded Ocoee No. 3 Reservoir in 1942 for the sole purpose of hydropower generation. Although their sole purpose is power generation, the Ocoee Reservoirs provide numerous opportunities for recreation. The Ocoee Reservoirs have been seriously impacted by erosion and siltation as a result of mining and mineral processing in the Copper Basin. Cooperative efforts to revegetate the Copper Basin are expected to improve the water quality and aquatic ecology of the Ocoee Reservoirs. The Ocoee reservoirs are among the smallest in the TVA system. Sediments from erosion in the Copper Basin have filled about 80 percent of the original volume of Ocoee No. 3 Reservoir and about 24 percent of the original volume of Ocoee No. 1 Reservoir. The water quality of the Ocoee Reservoirs is dominated by the effects of erosion and industrial discharges in the Copper Basin. The aquatic ecology of the Ocoee Reservoirs is also dominated by the effects of the Copper Basin. High concentrations of suspended sediments and metals severely limit the development of the food web in the reservoirs. Ocoee Nos. 2 and 3 Reservoirs have been called biological deserts.'' The fishery in Ocoee No. 1 Reservoir, which as historically been extremely limited, is showing some signs of improvement. 3 figs., 2 tabs.

  9. Reservoir monitoring: 1990 summary of vital signs and use impairment monitoring on Tennessee Valley Reservoirs

    SciTech Connect

    Dycus, D.L.; Meinert, D.L.

    1991-08-01

    The Tennessee Valley Authority (TVA) initiated a Reservoir Monitoring Program on 12 TVA reservoirs (the nine main stream Tennessee river reservoirs -- Kentucky through Fort Loudoun and three major tributary storage reservoirs -- Cherokee, Douglas, and Norris) in autumn 1989. The objective of the Reservoir Monitoring Program is to provide basic information on the health'' or integrity of the aquatic ecosystem in each TVA reservoir ( Vital Signs'') and to provide screening level information for describing how well each reservoir meets the swimmable and fishable goals of the Clean Water Act (Use Impairments). This is the first time in the history of the agency that a commitment to a long-term, systematic sampling of major TVA reservoirs has been made. The basis of the Vital Signs Monitoring is examination of appropriate physical, chemical, and biological indicators in three areas of each reservoir. These three areas are the forebay immediately upstream of the dam; the transition zone (the mid-reservoir region where the water changes from free flowing to more quiescent, impounded water); and the inflow or headwater region of the reservoir. The Use Impairments monitoring provides screening level information on the suitability of selected areas within TVA reservoirs for water contact activities (swimmable) and suitability of fish from TVA reservoirs for human consumption (fishable).

  10. Spacelab J experiment descriptions

    SciTech Connect

    Miller, T.Y.

    1993-08-01

    Brief descriptions of the experiment investigations for the Spacelab J Mission which was launched from the Kennedy Space Center aboard the Endeavour in Sept. 1992 are presented. Experiments cover the following: semiconductor crystals; single crystals; superconducting composite materials; crystal growth; bubble behavior in weightlessness; microgravity environment; health monitoring of Payload Specialists; cultured plant cells; effect of low gravity on calcium metabolism and bone formation; and circadian rhythm. Separate abstracts have been prepared for articles from this report.

  11. Spacelab J experiment descriptions

    NASA Technical Reports Server (NTRS)

    Miller, Teresa Y. (Editor)

    1993-01-01

    Brief descriptions of the experiment investigations for the Spacelab J Mission which was launched from the Kennedy Space Center aboard the Endeavour in Sept. 1992 are presented. Experiments cover the following: semiconductor crystals; single crystals; superconducting composite materials; crystal growth; bubble behavior in weightlessness; microgravity environment; health monitoring of Payload Specialists; cultured plant cells; effect of low gravity on calcium metabolism and bone formation; and circadian rhythm.

  12. Zooplankton Distribution in Tropical Reservoirs, South China

    NASA Astrophysics Data System (ADS)

    Lin, Qiu-Qi; Duan, Shun-Shan; Hu, Ren; Han, Bo-Ping

    2003-11-01

    The zooplankton of 18 reservoirs of South China was investigated in 2000. 61 Rotifera species, 23 Cladoceras and 14 Copepodas were identified. The most frequent Rotifera genera were Keratella, Brachionus, Trichocerca, Diurella, Ascomorpha, Polyarthra, Ploesoma, Asplanchna, Pompholyx and Conochilus. Bosmina longirostris, Bosminopsis deitersi, Diaphanosoma birgei, D. brachyurum and Moina micrura were typical of Cladocera in the reservoirs. Phyllodiaptomus tunguidus, Neodiaptomus schmackeri and Mesocyclops leuckarti were the most frequent Copepoda and M. leuckarti dominated Copepoda in most reservoirs. High zooplankton species richness with low abundance was characteristic of the throughflowing reservoir, whereas low species richness with low abundance was found in the reservoir with the longest retention time. Relative high abundance and medium species diversity were the distinction of intermediate retention time reservoirs.

  13. Management control system description

    SciTech Connect

    Bence, P. J.

    1990-10-01

    This Management Control System (MCS) description describes the processes used to manage the cost and schedule of work performed by Westinghouse Hanford Company (Westinghouse Hanford) for the US Department of Energy, Richland Operations Office (DOE-RL), Richland, Washington. Westinghouse Hanford will maintain and use formal cost and schedule management control systems, as presented in this document, in performing work for the DOE-RL. This MCS description is a controlled document and will be modified or updated as required. This document must be approved by the DOE-RL; thereafter, any significant change will require DOE-RL concurrence. Westinghouse Hanford is the DOE-RL operations and engineering contractor at the Hanford Site. Activities associated with this contract (DE-AC06-87RL10930) include operating existing plant facilities, managing defined projects and programs, and planning future enhancements. This document is designed to comply with Section I-13 of the contract by providing a description of Westinghouse Hanford's cost and schedule control systems used in managing the above activities. 5 refs., 22 figs., 1 tab.

  14. Modified chemiluminescent NO analyzer accurately measures NOX

    NASA Technical Reports Server (NTRS)

    Summers, R. L.

    1978-01-01

    Installation of molybdenum nitric oxide (NO)-to-higher oxides of nitrogen (NOx) converter in chemiluminescent gas analyzer and use of air purge allow accurate measurements of NOx in exhaust gases containing as much as thirty percent carbon monoxide (CO). Measurements using conventional analyzer are highly inaccurate for NOx if as little as five percent CO is present. In modified analyzer, molybdenum has high tolerance to CO, and air purge substantially quenches NOx destruction. In test, modified chemiluminescent analyzer accurately measured NO and NOx concentrations for over 4 months with no denegration in performance.

  15. Estimation of cyanobacteria biovolume in water reservoirs by MERIS sensor.

    PubMed

    Medina-Cobo, M; Domínguez, J A; Quesada, A; de Hoyos, C

    2014-10-15

    Planktonic cyanobacteria primarily develop in lentic water bodies, such as lakes and water reservoirs. In certain instances, toxin-producing cyanobacterial populations might dominate the phytoplankton community. Satellite remote sensing is a useful tool for large spatial scale monitoring of cyanobacteria, and the MERIS sensor from the Envisat satellite has taken worldwide images at a high frequency for over 10 years. This short time lapse image collection has provided an extensive record of images for the analysis of variation in the cyanobacterial communities in water reservoirs for management and scientific purposes. The objective of this work is to determine the relationship between measured cyanobacterial biomass as biovolume and the estimations derived from MERIS imagery. This study encompasses two independent studies relying on data from 23 water reservoirs. First, a long-term global limnological research study was conducted that provided a field data collection that included cyanobacterial biovolume, among other variables. Second, a survey was conducted that applied the processed images derived from the Envisat MERIS sensor. The chlorophyll-a (Chl a) content and phycocyanin concentration (PC) were estimated from the MERIS images. The PC estimated by remote sensing and total cyanobacterial biovolume measured from the field samples were found to be significantly correlated (R(2) = 0.6219; p < 0.001). No relevant differences were found among the taxonomical groups, which indicated that this tool provides accurate estimations irrespective of the cyanobacterial group. For validation, the algorithm derived from the entire dataset was applied to the MERIS image dataset of the Rosarito reservoir. An estimated cyanobacterial biovolume time series was performed and compared to the biovolume data collected in an extensive sampling schedule spanning 4 years. The results indicated a strong correlation (R(2) = 0.72; p < 0.001) between the measured and estimated

  16. Integrated stochastic modeling and reservoir technique for project evaluation and risk assessment

    SciTech Connect

    Tyler, K.J.; Sandsdalen, C; M`Land, L.; Aasen, J.O.; Siring, E.; Barbieri, M.

    1996-08-01

    Uncertainties in geosciences are often down-played or neglected at the early stages of field development. In traditional reservoir studies a single reservoir description and set of dynamic reservoir properties are used for reservoir simulation. However, in the offshore field presented, large distances between exploration wells and the poor quality of seismic data resulted in little data for field appraisal and field development planning. Creative techniques for integrating the available data for better understanding of the dynamic behavior of the reservoir and quantification of uncertainty have been applied. A multidisciplinary modeling approach has been used to achieve a consistent assessment of the reservoir uncertainties for a field in project evaluation. The uncertainty in-place hydrocarbon pore volumes, including uncertainties in petro- physical properties, contact depths, segmentation, and depth conversion were included in this uncertainty. Stochastic modeling for representation of the uncertainty in sedimentology, petrology, petrophysics and geology for this tidal dominated estuarine environment. These uncertainties have been quantified in 99 realizations where ranking has been used to establish P10, P50 and P90 cases for further integration into dynamic simulation and Monte Carlo simulation. P10, P50 and P90 scenarios of heterogeneities, hydrocarbon pore volumes, and other reservoir technical parameters (i.e., skin, relative permeability and fluid properties) have been combined in dynamic reservoir simulations. Regression analysis of these simulations allowed for assessment of the uncertainties for plateau length and recoverable reserves. Monte Carlo simulation incorporating uncertainty distribution functions of the uncertain parameters was then used to obtain P10, P50 and P90 production profiles used for economical project assessment and project planning.

  17. Reservoirs of antibiotic resistance genes.

    PubMed

    Salyers, Abigail; Shoemaker, Nadja B

    2006-01-01

    A potential concern about the use of antibiotics in animal husbundary is that, as antibiotic resistant bacteria move from the farm into the human diet, they may pass antibiotic resistance genes to bacteria that normally reside in a the human intestinal tract and from there to bacteria that cause human disease (reservoir hypothesis). In this article various approaches to evaluating the risk of agricultural use of antibiotics are assessed critically. In addition, the potential benefits of applying new technology and using new insights from the field of microbial ecology are explained.

  18. Skimming' a reservoir for trash

    SciTech Connect

    Shenman, L.E. )

    1993-02-01

    Several hydropower facilities are using a new technology for removing floating trash in reservoirs. Representatives from the facilities say the boat, called a trashskimmer, is efficient, easy to maneuver, and transportable. Designed by United Marine International, Inc., the pontoon boat features an operators cab that straddles an open hull between the skis of the pontoon, and uses dual propellers to maneuver through the water. The Marineskimmer allows the operator to approach the trash from the water side upstream of the plant. The Tennessee Valley Authority has used the boat since 1990.

  19. a Review of Hydropower Reservoir and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Rosa, L. P.; Dos Santos, M. A.

    2013-05-01

    Like most manmade projects, hydropower dams have multiple effects on the environment that have been studied in some depth over the past two decades. Among their most important effects are potential changes in water movement, flowing much slower than in the original river. This favors the appearance of phytoplankton as nutrients increase, with methanogenesis replacing oxidative water and generating anaerobic conditions. Although research during the late 1990s highlighted the problems caused by hydropower dams emitting greenhouse gases, crucial aspects of this issue still remain unresolved. Similar to natural water bodies, hydropower reservoirs have ample biota ranging from microorganisms to aquatic vertebrates. Microorganisms (bacteria) decompose organic matter producing biogenic gases under water. Some of these biogenic gases cause global warming, including methane, carbon dioxide and nitrous oxide. The levels of GHG emissions from hydropower dams are a strategic matter of the utmost importance, and comparisons with other power generation options such as thermo-power are required. In order to draw up an accurate assessment of the net emissions caused by hydropower dams, significant improvements are needed in carbon budgets and studies of representative hydropower dams. To determine accurately the net emissions caused by hydro reservoir formation is required significant improvement of carbon budgets studies on different representatives' hydro reservoirs at tropical, boreal, arid, semi arid and temperate climate. Comparisons must be drawn with emissions by equivalent thermo power plants, calculated and characterized as generating the same amount of energy each year as the hydropower dams, burning different fuels and with varying technology efficiency levels for steam turbines as well as coal, fuel oil and natural gas turbines and combined cycle plants. This paper brings to the scientific community important aspects of the development of methods and techniques applied

  20. A virtual company concept for reservoir management

    SciTech Connect

    Martin, F.D.; Kendall, R.P.; Whitney, E.M.

    1998-12-31

    This paper describes how reservoir management problems were pursued with a virtual company concept via the Internet and World Wide Web. The focus of the paper is on the implementation of virtual asset management teams that were assembled with small independent oil companies. The paper highlights the mechanics of how the virtual team transferred data and interpretations, evaluated geological models of complex reservoirs, and used results of simulation studies to analyze various reservoir management strategies.

  1. Reservoir characterization by crosshole seismic imaging

    SciTech Connect

    Turpening, R.

    1992-06-10

    This report covers the investigation on the field use of crosshole measurements in reservoir characterization. This investigation was planned for a four year effort. (Year 1) Preparation. (Year 2) Use of vertically polarized shear waves. (Year 3) Addition of horizontally polarized shear waves. (Year 4) Present static image of reservoir properties and observe the time varying phenomena in reservoir by reshooting high frequency compressional (P) survey. This report covers the first six months of the third year.

  2. Mercury and methylmercury in reservoirs in Indiana

    USGS Publications Warehouse

    Risch, Martin R.; Fredericksen, Amanda L.

    2015-01-01

    Mercury and MeHg concentrations and the concentration ratios of MeHg to Hg in water varied among the six reservoirs in Indiana, and the differences were related to a combination of factors that could apply to other reservoirs. In areas with moderate to high rates of atmospheric Hg wet and dry deposition, Hg runoff and transport to streams and reservoirs was pot

  3. Improved energy recovery from geothermal reservoirs

    SciTech Connect

    Bodvarsson, G.S.; Pruess, K.; Lippmann, M.J.

    1981-01-01

    The behavior of a liquid-dominated geothermal reservoir in response to production from different horizons is studied using numerical simulation methods. The Olkaria geothermal field in Kenya is used as an example where a two-phase vapor-dominated zone overlies the main liquid-dominated reservoir. The possibility of improving energy recovery from vapor-dominated reservoirs by tapping deeper horizons is considered.

  4. Stretch due to Penile Prosthesis Reservoir Migration

    PubMed Central

    Baten, E.; Vandewalle, T.; van Renterghem, K.

    2016-01-01

    A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely rare but can cause several complications, such as stretch. PMID:26793592

  5. Reservoir management of the Hartzog Draw field

    SciTech Connect

    Hunt, R.D.; Hearn, C.L.

    1982-07-01

    The Hartzog Draw field is a recently discovered major oil reservoir in northwestern Wyoming. Initial reservoir performance indicated that the field soon would be depleted below the bubble-point pressure. To evaluate secondary recovery possibiliites, the working interest owners cooperated in an extensive reservoir study. Although there were some unique problems, both in evaluating reservoir data and in obtaining a unitization agreement, this effort led to the formation of the Hartzog Draw Unit within 5 years of field discovery. Secondary recovery by waterflooding has begun, and enhanced recovery possibilities are being evaluated.

  6. Reservoir management of the Hartzog draw field

    SciTech Connect

    Hunt, R.D.; Hearn, C.H.

    1982-07-01

    The Hartzog draw field is a recently discovered major oil reservoir in northeastern Wyoming. Initial reservoir performance indicated that the field soon would be depleted below the bubble-point pressure. To evaluate secondary recovery possibilities, the working interest owners cooperated in an extensive reservoir study. Although there were some unique problems, both in evaluating reservoir data and in obtaining a unitization agreement, this effort led to the formation of the Hartzog Draw Unit within 5 years of field discovery. Secondary recovery by waterflooding has begun, and enhanced recovery possibilities are being evaluated.

  7. Slimholes for geothermal reservoir evaluation - An overview

    SciTech Connect

    Hickox, C.E.

    1996-08-01

    The topics covered in this session include: slimhole testing and data acquisition, theoretical and numerical models for slimholes, and an overview of the analysis of slimhole data acquired by the Japanese. The fundamental issues discussed are concerned with assessing the efficacy of slimhole testing for the evaluation of geothermal reservoirs. the term reservoir evaluation is here taken to mean the assessment of the potential of the geothermal reservoir for the profitable production of electrical power. As an introduction to the subsequent presentations and discussions, a brief summary of the more important aspects of the use of slimholes in reservoir evaluation is given.

  8. Geothermal reservoirs in hydrothermal convection systems

    SciTech Connect

    Sorey, M.L.

    1982-01-01

    Geothermal reservoirs commonly exist in hydrothermal convection systems involving fluid circulation downward in areas of recharge and upwards in areas of discharge. Because such reservoirs are not isolated from their surroundings, the nature of thermal and hydrologic connections with the rest of the system may have significant effects on the natural state of the reservoir and on its response to development. Conditions observed at numerous developed and undeveloped geothermal fields are discussed with respect to a basic model of the discharge portion of an active hydrothermal convection system. Effects of reservoir development on surficial discharge of thermal fluid are also delineated.

  9. Stretch due to Penile Prosthesis Reservoir Migration.

    PubMed

    Baten, E; Vandewalle, T; van Renterghem, K

    2016-03-01

    A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely rare but can cause several complications, such as stretch.

  10. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, Donald W.

    1997-01-01

    A method of extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid

  11. Can Appraisers Rate Work Performance Accurately?

    ERIC Educational Resources Information Center

    Hedge, Jerry W.; Laue, Frances J.

    The ability of individuals to make accurate judgments about others is examined and literature on this subject is reviewed. A wide variety of situational factors affects the appraisal of performance. It is generally accepted that the purpose of the appraisal influences the accuracy of the appraiser. The instrumentation, or tools, available to the…

  12. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  13. Measuring Joint Stimulus Control by Complex Graph/Description Correspondences

    ERIC Educational Resources Information Center

    Fields, Lanny; Spear, Jack

    2012-01-01

    Joint stimulus control occurs when responding is determined by the correspondence of elements of a complex sample and a complex comparison stimulus. In academic settings, joint stimulus control of behavior would be evidenced by the selection of an accurate description of a complex graph in which each element of a graph corresponded to particular…

  14. Interdisciplinary study of reservoir compartments. Quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Van Kirk, C.W.; Thompson, R.S.

    1994-04-27

    This DOE research project was established to document the integrated team approach for solving reservoir engineering problems. A field study integrating the disciplines of geology, geophysics, and petroleum engineering will be the mechanism for documenting the integrated approach. This is an area of keen interest to the oil and gas industry The goal will be to provide tools and approaches that can be used to detect reservoir compartments, reach a better reserve estimate, and improve profits early in the life of a field. Brief summaries of the project status are presented for: reservoir selection and data gathering; outcrop/corel log analysis/and correlations; internal architecture description; seismic analysis; and permeability experimental work.

  15. Geomechanical Analysis with Rigorous Error Estimates for a Double-Porosity Reservoir Model

    SciTech Connect

    Berryman, J G

    2005-04-11

    A model of random polycrystals of porous laminates is introduced to provide a means for studying geomechanical properties of double-porosity reservoirs. Calculations on the resulting earth reservoir model can proceed semi-analytically for studies of either the poroelastic or transport coefficients. Rigorous bounds of the Hashin-Shtrikman type provide estimates of overall bulk and shear moduli, and thereby also provide rigorous error estimates for geomechanical constants obtained from up-scaling based on a self-consistent effective medium method. The influence of hidden (or presumed unknown) microstructure on the final results can then be evaluated quantitatively. Detailed descriptions of the use of the model and some numerical examples showing typical results for the double-porosity poroelastic coefficients of a heterogeneous reservoir are presented.

  16. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

    SciTech Connect

    Koerner, Roy; Clarke, Don; Walker, Scott

    1999-11-09

    The objectives of this quarterly report was to summarize the work conducted under each task during the reporting period April - June 1998 and to report all technical data and findings as specified in the ''Federal Assistance Reporting Checklist''. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology.

  17. Evaluation on an original resistivity inversion method of water flooding a conglomerate reservoir based on petrophysical analysis

    NASA Astrophysics Data System (ADS)

    Liu, Renqiang; Duan, Yonggang; Tan, Fengqi; Wang, Guochang; Qin, Jianhua; Neupane, Bhupati

    2015-10-01

    An accurate inversion of original reservoir resistivity is an important problem for waterflood development in oilfields in the middle-late development period. This paper describes the theoretical model of original resistivity recovery for a conglomerate reservoir established by petrophysical models, based on the stratigraphic model of reservoir vertical invasion of the conglomerate reservoir of an oilfield. Likewise two influencing factors of the resistivity change with a water-flooded reservoir were analyzed. The first one is the clay volume decrease due to an injected water wash argillaceous particle and the reservoir resistivity changes are influenced by it, and the other is to inject water to displace crude oil in the pore space leading to the increase of the water-bearing volume. Moreover the conductive ions of the injected water and the original formation water exchange and balance because of their salinity difference, and the reservoir resistivity changes are also influenced by them. Through the analysis of the above influential factors based on the fine identification of conglomerate lithologies the inversion models of three variables, including changes in the amount of clay, the resistivity of the irreducible water and the increase of the water bearing volume, were established by core analysis data, production performance and well logging curves information, and accurately recovered the original reservoir resistivity of the conglomerate. The original oil saturation of the reservoir was calculated according to multiple linear regression models. Finally, the produced index is defined as the difference of the original oil saturation and current oil saturation to the original oil saturation ratio, and it eliminates the effects of conglomerate lithologies and heterogeneity for the quantitative evaluation of flooded layers by the use of the principle of relative value. Compared with traditional flooding sensitive parameters which are oil saturation and water

  18. Reservoir Engineering for Unconventional Gas Reservoirs: What Do We Have to Consider?

    SciTech Connect

    Clarkson, Christopher R

    2011-01-01

    The reservoir engineer involved in the development of unconventional gas reservoirs (UGRs) is required to integrate a vast amount of data from disparate sources, and to be familiar with the data collection and assessment. There has been a rapid evolution of technology used to characterize UGR reservoir and hydraulic fracture properties, and there currently are few standardized procedures to be used as guidance. Therefore, more than ever, the reservoir engineer is required to question data sources and have an intimate knowledge of evaluation procedures. We propose a workflow for the optimization of UGR field development to guide discussion of the reservoir engineer's role in the process. Critical issues related to reservoir sample and log analysis, rate-transient and production data analysis, hydraulic and reservoir modeling and economic analysis are raised. Further, we have provided illustrations of each step of the workflow using tight gas examples. Our intent is to provide some guidance for best practices. In addition to reviewing existing methods for reservoir characterization, we introduce new methods for measuring pore size distribution (small-angle neutron scattering), evaluating core-scale heterogeneity, log-core calibration, evaluating core/log data trends to assist with scale-up of core data, and modeling flow-back of reservoir fluids immediately after well stimulation. Our focus in this manuscript is on tight and shale gas reservoirs; reservoir characterization methods for coalbed methane reservoirs have recently been discussed.

  19. Accurate Drawbead Modeling in Stamping Simulations

    NASA Astrophysics Data System (ADS)

    Sester, M.; Burchitz, I.; Saenz de Argandona, E.; Estalayo, F.; Carleer, B.

    2016-08-01

    An adaptive line bead model that continually updates according to the changing conditions during the forming process has been developed. In these calculations, the adaptive line bead's geometry is treated as a 3D object where relevant phenomena like hardening curve, yield surface, through thickness stress effects and contact description are incorporated. The effectiveness of the adaptive drawbead model will be illustrated by an industrial example.

  20. Feedback about More Accurate versus Less Accurate Trials: Differential Effects on Self-Confidence and Activation

    ERIC Educational Resources Information Center

    Badami, Rokhsareh; VaezMousavi, Mohammad; Wulf, Gabriele; Namazizadeh, Mahdi

    2012-01-01

    One purpose of the present study was to examine whether self-confidence or anxiety would be differentially affected by feedback from more accurate rather than less accurate trials. The second purpose was to determine whether arousal variations (activation) would predict performance. On Day 1, participants performed a golf putting task under one of…

  1. The Case for Descriptive Writing.

    ERIC Educational Resources Information Center

    Hauck, Marian K.

    An approach to teaching descriptive writing and its values are discussed. Benefits derived from a descriptive writing unit are said to be the following: (1) Descriptive writing is fun; (2) It enables the instructor to demonstrate that the first word that pops into the writer's mind is often not the best one; (3) There is no easier way in which to…

  2. Three Approaches to Descriptive Research.

    ERIC Educational Resources Information Center

    Svensson, Lennart

    This report compares three approaches to descriptive research, focusing on the kinds of descriptions developed and on the methods used to develop the descriptions. The main emphasis in all three approaches is on verbal data. In these approaches the importance of interpretation and its intuitive nature are emphasized. The three approaches, however,…

  3. Feedback about more accurate versus less accurate trials: differential effects on self-confidence and activation.

    PubMed

    Badami, Rokhsareh; VaezMousavi, Mohammad; Wulf, Gabriele; Namazizadeh, Mahdi

    2012-06-01

    One purpose of the present study was to examine whether self-confidence or anxiety would be differentially affected byfeedback from more accurate rather than less accurate trials. The second purpose was to determine whether arousal variations (activation) would predict performance. On day 1, participants performed a golf putting task under one of two conditions: one group received feedback on the most accurate trials, whereas another group received feedback on the least accurate trials. On day 2, participants completed an anxiety questionnaire and performed a retention test. Shin conductance level, as a measure of arousal, was determined. The results indicated that feedback about more accurate trials resulted in more effective learning as well as increased self-confidence. Also, activation was a predictor of performance. PMID:22808705

  4. Small reservoirs in the West African savanna: Usage, monitoring and impact (Invited)

    NASA Astrophysics Data System (ADS)

    Van De Giesen, N.; Liebe, J. R.; Annor, F.; Andreini, M.

    2013-12-01

    The West African savanna is dotted with thousands of small reservoirs. These reservoirs were primarily built for irrigation purposes, supplying supplementary irrigation in the rainy season and full irrigation in the dry season. Some reservoirs were specifically constructed for watering cattle. Most reservoirs, however, now fulfill a multitude of functions in addition to irrigation and cattle watering, such as fishing, bathing, household water, supply of construction materials, and recreation. In the framework of the Small Reservoirs Project (www.smallreservoirs.org), extensive research has been undertaken over the past ten years that addresses the functioning of these reservoirs and the development of new monitoring methods. This presentation will give a general overview of our findings with respect to history, usage, and hydrological impact of small reservoirs in West Africa. In general, no comprehensive databases are available to local and national governments that contain all reservoirs and their attributes. Remote sensing, therefore, offers an interesting alternative to produce inventories of small reservoirs in a cost effective way. The most straightforward application is the mapping of small reservoirs with the aid of optical satellite images. Open water tends to stand out clearly from its surroundings in such images, allowing for relatively accurate determination of the location and surface area of the reservoirs. An important early discovery was that within a given geomorphological region, there is a very good correlation between surface area and storage volume. Once this correlation is established through a small sub-sample of the reservoirs, all volumes can be calculated on the basis of surfaces as determined through remote sensing. In turn, this opens up the opportunity to monitor water storage over the year by means of satellite images. Optical images are usually not available during large parts of the year due to cloud cover. This holds especially true

  5. 3D characterization of the fracture network in a deformed chalk reservoir analogue: The Lagerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1994-12-31

    Quantitative descriptions of the 3D fracture networks in terms of connectivity, fracture types, fracture surface roughness and flow characteristics are necessary for reservoir evaluation, management, and enhanced oil recovery programs of fractured reservoirs. For a period of 2 years, a research project focused on an analogue to fractured chalk reservoirs excellently exposed near Laegerdorf, NW Germany. Upper Cretaceous chalk has been uplifted and deformed by an underlying salt diapir, and is now exploited for the cement industry. In the production wall of a quarry, the fracture network of the deformed chalk was characterized and mapped at different scales. The wall was scraped off as chalk exploitation proceeded, continuously revealing new sections through the faulted and fractured chalk body. A 230 m long part of the 35m high production wall was investigated during its recess of 25m. The large amount of fracture data were analyzed with respect to parameters such as fracture density distribution, orientation- and length distribution, and in terms of the representativity of data sets collected from restricted rock volumes. This 3D description and analysis of a fracture network revealed quantitative generic parameters of importance for modeling chalk reservoirs with less data and lower data quality.

  6. Characterization of oil and gas reservoir heterogeneity; Final report, November 1, 1989--June 30, 1993

    SciTech Connect

    Sharma, G.D.

    1993-09-01

    The Alaskan North Slope comprises one of the Nation`s and the world`s most prolific oil province. Original oil in place (OOIP) is estimated at nearly 70 BBL (Kamath and Sharma, 1986). Generalized reservoir descriptions have been completed by the University of Alaska`s Petroleum Development Laboratory over North Slope`s major fields. These fields include West Sak (20 BBL OOIP), Ugnu (15 BBL OOIP), Prudhoe Bay (23 BBL OOIP), Kuparuk (5.5 BBL OOIP), Milne Point (3 BBL OOIP), and Endicott (1 BBL OOIP). Reservoir description has included the acquisition of open hole log data from the Alaska Oil and Gas Conservation Commission (AOGCC), computerized well log analysis using state-of-the-art computers, and integration of geologic and logging data. The studies pertaining to fluid characterization described in this report include: experimental study of asphaltene precipitation for enriched gases, CO{sup 2} and West Sak crude system, modeling of asphaltene equilibria including homogeneous as well as polydispersed thermodynamic models, effect of asphaltene deposition on rock-fluid properties, fluid properties of some Alaskan north slope reservoirs. Finally, the last chapter summarizes the reservoir heterogeneity classification system for TORIS and TORIS database.

  7. Two highly accurate methods for pitch calibration

    NASA Astrophysics Data System (ADS)

    Kniel, K.; Härtig, F.; Osawa, S.; Sato, O.

    2009-11-01

    Among profiles, helix and tooth thickness pitch is one of the most important parameters of an involute gear measurement evaluation. In principle, coordinate measuring machines (CMM) and CNC-controlled gear measuring machines as a variant of a CMM are suited for these kinds of gear measurements. Now the Japan National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) and the German national metrology institute the Physikalisch-Technische Bundesanstalt (PTB) have each developed independently highly accurate pitch calibration methods applicable to CMM or gear measuring machines. Both calibration methods are based on the so-called closure technique which allows the separation of the systematic errors of the measurement device and the errors of the gear. For the verification of both calibration methods, NMIJ/AIST and PTB performed measurements on a specially designed pitch artifact. The comparison of the results shows that both methods can be used for highly accurate calibrations of pitch standards.

  8. Accurate guitar tuning by cochlear implant musicians.

    PubMed

    Lu, Thomas; Huang, Juan; Zeng, Fan-Gang

    2014-01-01

    Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼ 30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task. PMID:24651081

  9. Accurate Guitar Tuning by Cochlear Implant Musicians

    PubMed Central

    Lu, Thomas; Huang, Juan; Zeng, Fan-Gang

    2014-01-01

    Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task. PMID:24651081

  10. Preparation and accurate measurement of pure ozone.

    PubMed

    Janssen, Christof; Simone, Daniela; Guinet, Mickaël

    2011-03-01

    Preparation of high purity ozone as well as precise and accurate measurement of its pressure are metrological requirements that are difficult to meet due to ozone decomposition occurring in pressure sensors. The most stable and precise transducer heads are heated and, therefore, prone to accelerated ozone decomposition, limiting measurement accuracy and compromising purity. Here, we describe a vacuum system and a method for ozone production, suitable to accurately determine the pressure of pure ozone by avoiding the problem of decomposition. We use an inert gas in a particularly designed buffer volume and can thus achieve high measurement accuracy and negligible degradation of ozone with purities of 99.8% or better. The high degree of purity is ensured by comprehensive compositional analyses of ozone samples. The method may also be applied to other reactive gases. PMID:21456766

  11. Accurate guitar tuning by cochlear implant musicians.

    PubMed

    Lu, Thomas; Huang, Juan; Zeng, Fan-Gang

    2014-01-01

    Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼ 30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.

  12. Line gas sampling system ensures accurate analysis

    SciTech Connect

    Not Available

    1992-06-01

    Tremendous changes in the natural gas business have resulted in new approaches to the way natural gas is measured. Electronic flow measurement has altered the business forever, with developments in instrumentation and a new sensitivity to the importance of proper natural gas sampling techniques. This paper reports that YZ Industries Inc., Snyder, Texas, combined its 40 years of sampling experience with the latest in microprocessor-based technology to develop the KynaPak 2000 series, the first on-line natural gas sampling system that is both compact and extremely accurate. This means the composition of the sampled gas must be representative of the whole and related to flow. If so, relative measurement and sampling techniques are married, gas volumes are accurately accounted for and adjustments to composition can be made.

  13. Accurate mask model for advanced nodes

    NASA Astrophysics Data System (ADS)

    Zine El Abidine, Nacer; Sundermann, Frank; Yesilada, Emek; Ndiaye, El Hadji Omar; Mishra, Kushlendra; Paninjath, Sankaranarayanan; Bork, Ingo; Buck, Peter; Toublan, Olivier; Schanen, Isabelle

    2014-07-01

    Standard OPC models consist of a physical optical model and an empirical resist model. The resist model compensates the optical model imprecision on top of modeling resist development. The optical model imprecision may result from mask topography effects and real mask information including mask ebeam writing and mask process contributions. For advanced technology nodes, significant progress has been made to model mask topography to improve optical model accuracy. However, mask information is difficult to decorrelate from standard OPC model. Our goal is to establish an accurate mask model through a dedicated calibration exercise. In this paper, we present a flow to calibrate an accurate mask enabling its implementation. The study covers the different effects that should be embedded in the mask model as well as the experiment required to model them.

  14. Economics of Developing Hot Stratigraphic Reservoirs

    SciTech Connect

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  15. Electromagnetic Heating Methods for Heavy Oil Reservoirs

    SciTech Connect

    Sahni, A.; Kumar, M.; Knapp, R.B.

    2000-05-01

    The most widely used method of thermal oil recovery is by injecting steam into the reservoir. A well-designed steam injection project is very efficient in recovering oil, however its applicability is limited in many situations. Simulation studies and field experience has shown that for low injectivity reservoirs, small thickness of the oil-bearing zone, and reservoir heterogeneity limits the performance of steam injection. This paper discusses alternative methods of transferring heat to heavy oil reservoirs, based on electromagnetic energy. They present a detailed analysis of low frequency electric resistive (ohmic) heating and higher frequency electromagnetic heating (radio and microwave frequency). They show the applicability of electromagnetic heating in two example reservoirs. The first reservoir model has thin sand zones separated by impermeable shale layers, and very viscous oil. They model preheating the reservoir with low frequency current using two horizontal electrodes, before injecting steam. The second reservoir model has very low permeability and moderately viscous oil. In this case they use a high frequency microwave antenna located near the producing well as the heat source. Simulation results presented in this paper show that in some cases, electromagnetic heating may be a good alternative to steam injection or maybe used in combination with steam to improve heavy oil production. They identify the parameters which are critical in electromagnetic heating. They also discuss past field applications of electromagnetic heating including technical challenges and limitations.

  16. European Rabbits as Reservoir for Coxiella burnetii.

    PubMed

    González-Barrio, David; Maio, Elisa; Vieira-Pinto, Madalena; Ruiz-Fons, Francisco

    2015-06-01

    We studied the role of European rabbits (Oryctolagus cuniculus) as a reservoir for Coxiella burnetii in the Iberian region. High individual and population seroprevalences observed in wild and farmed rabbits, evidence of systemic infections, and vaginal shedding support the reservoir role of the European rabbit for C. burnetii.

  17. European Rabbits as Reservoir for Coxiella burnetii.

    PubMed

    González-Barrio, David; Maio, Elisa; Vieira-Pinto, Madalena; Ruiz-Fons, Francisco

    2015-06-01

    We studied the role of European rabbits (Oryctolagus cuniculus) as a reservoir for Coxiella burnetii in the Iberian region. High individual and population seroprevalences observed in wild and farmed rabbits, evidence of systemic infections, and vaginal shedding support the reservoir role of the European rabbit for C. burnetii. PMID:25988670

  18. Temperature and oxygen in Missouri reservoirs

    USGS Publications Warehouse

    Jones, John R.; Knowlton, Matthew F.; Obrecht, Daniel V.; Graham, Jennifer L.

    2011-01-01

    Vertical profiles of water temperature (n = 7193) and dissolved oxygen (n = 6516) were collected from 235 Missouri reservoirs during 1989–2007; most data were collected during May–August and provide a regional summary of summer conditions. Collectively, surface water temperature ranged from a mean of ~22 C in May to 28 C in July, and individual summer maxima typically were 28–32 C. Most (~95%) reservoirs stably stratify by mid-May, but few are deep enough to have hypolimnia with near-uniform temperatures. Among stratified reservoirs, maximum effective length and maximum depth accounted for 75% of the variation in mixed depth and thermocline depth. Ephemeral, near-surface thermoclines occurred in 39% of summer profiles and were most frequent in small, turbid reservoirs. Isotherms below the mixed layer deepen during stratification, and the water column is >20 C by August in all but the deepest reservoirs. Most reservoirs showed incipient dissolved oxygen (DO) depletion by mid-May, and by August, 80% of profiles had DO minima of 50% of variation in DO below the mixed layer during summer. Warm summer temperatures and widespread low DO often limit available fish habitat in Missouri reservoirs and compress warm-water fish communities into subsurface layers that exceed their thermal preferences. This study provides a regional baseline of reservoir temperature and oxygen conditions useful for future evaluations of eutrophication and the effects of a warming climate.

  19. Reservoir management of Valhall Field, Norway

    SciTech Connect

    York, S.D.; Peng, C.P. )

    1992-08-01

    This paper presents the historical development and the evolution of reservoir simulation models for the Valhall field. Reservoir simulators were used as management tools to determine possible effects of high rock compressibility, fracturing, and fracture permeability decline on primary recovery. These evaluations identified additional development opportunities, resulting in higher ultimate recoveries.

  20. 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.

  1. 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

  2. Mycobacterium bovis: characteristics of wildlife reservoir hosts.

    PubMed

    Palmer, M V

    2013-11-01

    Mycobacterium bovis is the cause of tuberculosis in animals and sometimes humans. Many developed nations have long-standing programmes to eradicate tuberculosis in livestock, principally cattle. As disease prevalence in cattle decreases these efforts are sometimes impeded by passage of M. bovis from wildlife to cattle. In epidemiological terms, disease can persist in some wildlife species, creating disease reservoirs, if the basic reproduction rate (R0) and critical community size (CCS) thresholds are achieved. Recognized wildlife reservoir hosts of M. bovis include the brushtail possum (Trichosurus vulpecula) in New Zealand, European badger (Meles meles) in Great Britain and Ireland, African buffalo (Syncerus caffer) in South Africa, wild boar (Sus scrofa) in the Iberian Peninsula and white-tailed deer (Odocoileus virginianus) in Michigan, USA. The epidemiological concepts of R0 and CCS are related to more tangible disease/pathogen characteristics such as prevalence, pathogen-induced pathology, host behaviour and ecology. An understanding of both epidemiological and disease/pathogen characteristics is necessary to identify wildlife reservoirs of M. bovis. In some cases, there is a single wildlife reservoir host involved in transmission of M. bovis to cattle. Complexity increases, however, in multihost systems where multiple potential reservoir hosts exist. Bovine tuberculosis eradication efforts require elimination of M. bovis transmission between wildlife reservoirs and cattle. For successful eradication identification of true wildlife reservoirs is critical, as disease control efforts are most effective when directed towards true reservoirs.

  3. Mycobacterium bovis: characteristics of wildlife reservoir hosts.

    PubMed

    Palmer, M V

    2013-11-01

    Mycobacterium bovis is the cause of tuberculosis in animals and sometimes humans. Many developed nations have long-standing programmes to eradicate tuberculosis in livestock, principally cattle. As disease prevalence in cattle decreases these efforts are sometimes impeded by passage of M. bovis from wildlife to cattle. In epidemiological terms, disease can persist in some wildlife species, creating disease reservoirs, if the basic reproduction rate (R0) and critical community size (CCS) thresholds are achieved. Recognized wildlife reservoir hosts of M. bovis include the brushtail possum (Trichosurus vulpecula) in New Zealand, European badger (Meles meles) in Great Britain and Ireland, African buffalo (Syncerus caffer) in South Africa, wild boar (Sus scrofa) in the Iberian Peninsula and white-tailed deer (Odocoileus virginianus) in Michigan, USA. The epidemiological concepts of R0 and CCS are related to more tangible disease/pathogen characteristics such as prevalence, pathogen-induced pathology, host behaviour and ecology. An understanding of both epidemiological and disease/pathogen characteristics is necessary to identify wildlife reservoirs of M. bovis. In some cases, there is a single wildlife reservoir host involved in transmission of M. bovis to cattle. Complexity increases, however, in multihost systems where multiple potential reservoir hosts exist. Bovine tuberculosis eradication efforts require elimination of M. bovis transmission between wildlife reservoirs and cattle. For successful eradication identification of true wildlife reservoirs is critical, as disease control efforts are most effective when directed towards true reservoirs. PMID:24171844

  4. Heat Exchanger With Reservoir And Controls

    NASA Technical Reports Server (NTRS)

    Brown, Richard F.; Edelstein, Fred

    1989-01-01

    Heat-pipe assembly operates as evaporator or as condenser. New heat exchanger incorporates important improvements over previous designs. By adding reservoir to primary loop, locating ultrasonic liquid-level sensors on reservoir rather than directly on one of heat pipes, and revising control logic, uneven distribution of flow among heat pipes and erroneous behavior of valves eliminated.

  5. Water resources review: Wheeler Reservoir, 1990

    SciTech Connect

    Wallus, R.; Cox, J.P.

    1990-09-01

    Protection and enhancement of water quality is essential for attaining the full complement of beneficial uses of TVA reservoirs. The responsibility for improving and protecting TVA reservoir water quality is shared by various federal, state, and local agencies, as well as the thousands of corporations and property owners whose individual decisions affect water quality. TVA's role in this shared responsibility includes collecting and evaluating water resources data, disseminating water resources information, and acting as a catalyst to bring together agencies and individuals that have a responsibility or vested interest in correcting problems that have been identified. This report is one in a series of status reports that will be prepared for each of TVA's reservoirs. The purpose of this status report is to provide an up-to-date overview of the characteristics and conditions of Wheeler Reservoir, including: reservoir purposes and operation; physical characteristics of the reservoir and the watershed; water quality conditions: aquatic biological conditions: designated, actual, and potential uses of the reservoir and impairments of those uses; ongoing or planned reservoir management activities. Information and data presented here are form the most recent reports, publications, and original data available. 21 refs., 8 figs., 29 tabs.

  6. Seismic determination of saturation in fractured reservoirs

    USGS Publications Warehouse

    Brown, R.L.; Wiggins, M.L.; Gupta, A.

    2002-01-01

    Detecting the saturation of a fractured reservoir using shear waves is possible when the fractures have a geometry that induces a component of movement perpendicular to the fractures. When such geometry is present, vertically traveling shear waves can be used to examine the saturation of the fractured reservoir. Tilted, corrugated, and saw-tooth fracture models are potential examples.

  7. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2003-02-11

    This research was directed toward developing a systematic reservoir characterization methodology which can be used by the petroleum industry to implement infill drilling programs and/or enhanced oil recovery projects in naturally fractured reservoir systems in an environmentally safe and cost effective manner. It was anticipated that the results of this research program will provide geoscientists and engineers with a systematic procedure for properly characterizing a fractured reservoir system and a reservoir/horizontal wellbore simulator model which can be used to select well locations and an effective EOR process to optimize the recovery of the oil and gas reserves from such complex reservoir systems.

  8. Increasing Waterflood Reserves in the Wilmington Oil Field Through Reservoir Characterization and Reservoir Management

    SciTech Connect

    Chris Phillips; Dan Moos; Don Clarke; John Nguyen; Kwasi Tagbor; Roy Koerner; Scott Walker

    1997-04-10

    This project is intended to increase recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs. Transferring technology so that it can be applied in other sections of the Wilmington Field and by operators in other slope and basin reservoirs is a primary component of the project.

  9. Accurate maser positions for MALT-45

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2013-10-01

    MALT-45 is an untargeted survey, mapping the Galactic plane in CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. After obtaining images from the survey, a number of masers were detected, but without accurate positions. This project seeks to resolve each maser and its environment, with the ultimate goal of placing the Class I methanol maser into a timeline of high mass star formation.

  10. Accurate maser positions for MALT-45

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2013-04-01

    MALT-45 is an untargeted survey, mapping the Galactic plane in CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. After obtaining images from the survey, a number of masers were detected, but without accurate positions. This project seeks to resolve each maser and its environment, with the ultimate goal of placing the Class I methanol maser into a timeline of high mass star formation.

  11. 3D seismic studies of unconventional reservoirs, Badger Basin Wyoming; and Viking Group Turbidite systems, Norwegian Block 35/11, northern North Sea

    NASA Astrophysics Data System (ADS)

    Buggenhagen, John Edmund

    By integrating geologic and geophysical interpretations it is possible to form an accurate, high resolution, 3D model of the subsurface. The primary purpose of this model is to characterize heterogeneities within a potential reservoir and locate anomalous zones that correspond to potential high-quality reservoir intervals. Individual techniques used to create the final reservoir model include 3D seismic fault and horizon mapping, continuity analysis, and detailed velocity modeling from seismic stacking velocity analysis. The final model is centered around geologic interpretations from well log and core analysis. The methodology described above for Badger Basin was successful in identifying a regional abnormal underpressured compartment and locating a "sweet spot" corresponding to the best know production in the field. Integrating all of these interpretations confirmed previous analysis and has significantly reduced the uncertainty of the reservoir model for the Frontier Formation in Badger Basin. If this model was available prior to drilling the field it could have been more efficiently and cost effectively produced. The final proposed model for the Upper Jurassic Turbidites systems in Norwegian Block 35/11 suggests the presence of both axially and transversely transported turbidite systems within the elongated, fault-controlled sub-basins that developed during Late Jurassic extension. These systems appear to be sourced from the same updip depositional system, most likely from an Upper Jurassic Sognefjord Formation equivalent system. Detailed descriptions of these systems show that the architecture and shape of the turbidite systems vary greatly with respect to local tectonic setting. Comparison of the axial and transverse systems shows that although the two systems have the same transport and depositional elements, and were sourced from the same system, each has a different architecture. The axial turbidite system is represented by thinner, low width/length ratio

  12. Accurate Molecular Polarizabilities Based on Continuum Electrostatics

    PubMed Central

    Truchon, Jean-François; Nicholls, Anthony; Iftimie, Radu I.; Roux, Benoît; Bayly, Christopher I.

    2013-01-01

    A novel approach for representing the intramolecular polarizability as a continuum dielectric is introduced to account for molecular electronic polarization. It is shown, using a finite-difference solution to the Poisson equation, that the Electronic Polarization from Internal Continuum (EPIC) model yields accurate gas-phase molecular polarizability tensors for a test set of 98 challenging molecules composed of heteroaromatics, alkanes and diatomics. The electronic polarization originates from a high intramolecular dielectric that produces polarizabilities consistent with B3LYP/aug-cc-pVTZ and experimental values when surrounded by vacuum dielectric. In contrast to other approaches to model electronic polarization, this simple model avoids the polarizability catastrophe and accurately calculates molecular anisotropy with the use of very few fitted parameters and without resorting to auxiliary sites or anisotropic atomic centers. On average, the unsigned error in the average polarizability and anisotropy compared to B3LYP are 2% and 5%, respectively. The correlation between the polarizability components from B3LYP and this approach lead to a R2 of 0.990 and a slope of 0.999. Even the F2 anisotropy, shown to be a difficult case for existing polarizability models, can be reproduced within 2% error. In addition to providing new parameters for a rapid method directly applicable to the calculation of polarizabilities, this work extends the widely used Poisson equation to areas where accurate molecular polarizabilities matter. PMID:23646034

  13. Reservoir characterization and enhanced oil recovery research. Annual report, September 1988--August 1989

    SciTech Connect

    Lake, L.W.; Pope, G.A.; Schechter, R.S.

    1992-03-01

    The research in this annual report falls into three tasks each dealing with a different aspect of enhanced oil recovery. The first task strives to develop procedures for accurately modeling reservoirs for use as input to numerical simulation flow models. This action describes how we have used a detail characterization of an outcrop to provide insights into what features are important to fluid flow modeling. The second task deals with scaling-up and modeling chemical and solvent EOR processes. In a sense this task is the natural extension of task 1 and, in fact, one of the subtasks uses many of the same statistical procedures for insight into the effects of viscous fingering and heterogeneity. The final task involves surfactants and their interactions with carbon dioxide and reservoir minerals. This research deals primarily with phenomena observed when aqueous surfactant solutions are injected into oil reservoirs.

  14. 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.

  15. Structurally controlled and aligned tight gas reservoir compartmentalization in the San Juan and Piceance Basins

    SciTech Connect

    Decker, A.D.; Kuuskraa, V.A.; Klawitter, A.L.

    1995-10-01

    Recurrent basement faulting is the primary controlling mechanism for aligning and compartmentalizing upper Cretaceous aged tight gas reservoirs of the San Juan and Piceance Basins. Northwest trending structural lineaments that formed in conjunction with the Uncompahgre Highlands have profoundly influenced sedimentation trends and created boundaries for gas migration; sealing and compartmentalizing sedimentary packages in both basins. Fractures which formed over the structural lineaments provide permeability pathways which allowing gas recovery from otherwise tight gas reservoirs. Structural alignments and associated reservoir compartments have been accurately targeted by integrating advanced remote sensing imagery, high resolution aeromagnetics, seismic interpretation, stratigraphic mapping and dynamic structural modelling. This unifying methodology is a powerful tool for exploration geologists and is also a systematic approach to tight gas resource assessment in frontier basins.

  16. Next generation oil reservoir simulations

    SciTech Connect

    Joubert, W.

    1996-04-01

    This paper describes a collaborative effort between Amoco Production Company, Los Alamos National Laboratory and Cray Research Inc. to develop a next-generation massively parallel oil reservoir simulation code. The simulator, code-named Falcon, enables highly detailed simulations to be performed on a range of platforms such as the Cray T3D and T3E. The code is currently being used by Amoco to perform a sophisticated field study using multiple geostatistical realizations on a scale of 2-5 million grid blocks and 1000-2000 wells. In this paper we discuss the nature of this collaborative effort, the software design and engineering aspects of the code, parallelization experiences, and performance studies. The code will be marketed to the oil industry by a third-party independent software vendor in mid-1996.

  17. Rodent reservoirs of future zoonotic diseases.

    PubMed

    Han, Barbara A; Schmidt, John Paul; Bowden, Sarah E; Drake, John M

    2015-06-01

    The increasing frequency of zoonotic disease events underscores a need to develop forecasting tools toward a more preemptive approach to outbreak investigation. We apply machine learning to data describing the traits and zoonotic pathogen diversity of the most speciose group of mammals, the rodents, which also comprise a disproportionate number of zoonotic disease reservoirs. Our models predict reservoir status in this group with over 90% accuracy, identifying species with high probabilities of harboring undiscovered zoonotic pathogens based on trait profiles that may serve as rules of thumb to distinguish reservoirs from nonreservoir species. Key predictors of zoonotic reservoirs include biogeographical properties, such as range size, as well as intrinsic host traits associated with lifetime reproductive output. Predicted hotspots of novel rodent reservoir diversity occur in the Middle East and Central Asia and the Midwestern United States.

  18. 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.

  19. 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.

  20. Geological aspects of model construction for well placement optimization in a mixed fluvio-aeolian reservoir, UKCS

    SciTech Connect

    Hern, C.Y.; Lewis, J.J.M.; Seifert, D.; Steel, N.C.T.

    1996-12-31

    The cost-effective development of small fields requires a thorough description of the reservoir with a strong focus on the estimation of uncertainty. In this example, 3-D reservoir models are used to define and risk optimum well trajectories in a complex, mixed fluvio-aeolian gas reservoir. Emphasis is placed on the definition and quantification of those geological factors that affect the integrity of the hybrid stochastic-deterministic reservoir model. Sequential Indicator Simulation (SIS) models conditioned to well data were constructed for target zones. Construction of geologically realistic models required identification of genetic units, an understanding of their spatial distribution and assignation of appropriate dimensions. These objectives were achieved by an integration of probe-permeametry and sedimentology data on reservoir core, and the derivation of relevant genetic unit architectures from analogous sequences at outcrop. Assignation of appropriate sizes depends on the similarity between the outcrop analogue and the subsurface reservoir. Similarity was assessed by comparison of facies types, their proportions, the vertical association of facies, types of fluvio-aeolian interaction, the size of depositional systems and general depositional environment. Outcrop data were compared to reservoir observations and sub-sampled to eliminate unrepresentative elements. The SIS models generated with this data were {open_quote}pin-cushioned{close_quote} with over 100,000 numerical {open_quotes}wells{close_quotes} of varying azimuth, length, inclination and elevation. Much improved decision support was provided through a statistical definition of the {open_quote}optimum{close_quote} well trajectory.

  1. Geological aspects of model construction for well placement optimization in a mixed fluvio-aeolian reservoir, UKCS

    SciTech Connect

    Hern, C.Y.; Lewis, J.J.M.; Seifert, D. ); Steel, N.C.T. )

    1996-01-01

    The cost-effective development of small fields requires a thorough description of the reservoir with a strong focus on the estimation of uncertainty. In this example, 3-D reservoir models are used to define and risk optimum well trajectories in a complex, mixed fluvio-aeolian gas reservoir. Emphasis is placed on the definition and quantification of those geological factors that affect the integrity of the hybrid stochastic-deterministic reservoir model. Sequential Indicator Simulation (SIS) models conditioned to well data were constructed for target zones. Construction of geologically realistic models required identification of genetic units, an understanding of their spatial distribution and assignation of appropriate dimensions. These objectives were achieved by an integration of probe-permeametry and sedimentology data on reservoir core, and the derivation of relevant genetic unit architectures from analogous sequences at outcrop. Assignation of appropriate sizes depends on the similarity between the outcrop analogue and the subsurface reservoir. Similarity was assessed by comparison of facies types, their proportions, the vertical association of facies, types of fluvio-aeolian interaction, the size of depositional systems and general depositional environment. Outcrop data were compared to reservoir observations and sub-sampled to eliminate unrepresentative elements. The SIS models generated with this data were [open quote]pin-cushioned[close quote] with over 100,000 numerical [open quotes]wells[close quotes] of varying azimuth, length, inclination and elevation. Much improved decision support was provided through a statistical definition of the [open quote]optimum[close quote] well trajectory.

  2. Trophic classification of Tennessee Valley area reservoirs derived from LANDSAT multispectral scanner data. [Alabama, Georgia, Kentucky, Tennessee, and North Carolina

    NASA Technical Reports Server (NTRS)

    Meinert, D. L.; Malone, D. L.; Voss, A. W. (Principal Investigator); Scarpace, F. L.

    1980-01-01

    LANDSAT MSS data from four different dates were extracted from computer tapes using a semiautomated digital data handling and analysis system. Reservoirs were extracted from the surrounding land matrix by using a Band 7 density level slice of 3; and descriptive statistics to include mean, variance, and ratio between bands for each of the four bands were calculated. Significant correlations ( 0.80) were identified between the MSS statistics and many trophic indicators from ground truth water quality data collected at 35 reservoirs in the greater Tennessee Valley region. Regression models were developed which gave significant estimates of each reservoir's trophic state as defined by its trophic state index and explained in all four LANDSAT frames at least 85 percent of the variability in the data. To illustrate the spatial variations within reservoirs as well as the relative variations between reservoirs, a table look up elliptical classification was used in conjunction with each reservoir's trophic state index to classify each reservoir on a pixel by pixel basis and produce color coded thematic representations.

  3. The Potosi Reservoir Model 2013

    SciTech Connect

    Adushita, Yasmin; Smith, Valerie; Leetaru, Hannes

    2014-09-30

    As a part of a larger project co-funded by the United States Department of Energy (US DOE) to evaluate the potential of formations within the Cambro-Ordovician strata above the Mt. Simon as potential targets for carbon sequestration in the Illinois and Michigan Basins, the Illinois Clean Coal Institute (ICCI) requested Schlumberger to evaluate the potential injectivity and carbon dioxide (CO2) plume size of the Cambrian Potosi Formation. The evaluation of this formation was accomplished using wireline data, core data, pressure data, and seismic data from the US DOE-funded Illinois Basin–Decatur Project (IBDP) being conducted by the Midwest Geological Sequestration Consortium in Macon County, Illinois. In 2010, technical performance evaluations on the Cambrian Potosi Formation were performed through reservoir modeling. The data included formation tops from mud logs, well logs from the VW1 and the CCS1 wells, structural and stratigraphic formation from three dimensional (3D) seismic data, and field data from several waste water injection wells for Potosi Formation. Intention was for two million tons per annum (MTPA) of CO2 to be injected for 20 years. In the preceding, the 2010 Potosi heterogeneous model (referred to as the "Potosi Dynamic Model 2010" in this topical report) was re-run using a new injection scenario; 3.2 MTPA for 30 years. The extent of the Potosi Dynamic Model 2010, however, appeared too small for the new injection target. It was not sufficiently large enough to accommodate the evolution of the plume. The new model, Potosi Dynamic Model 2013a, was built by extending the Potosi Dynamic Model 2010 grid to 30 miles x 30 miles (48.3km x48.3km), while preserving all property modeling workflows and layering. This model was retained as the base case of Potosi Dynamic Model 2013a. The Potosi reservoir model was updated to take into account the new data from the verification well VW2 which was drilled in 2012. The new porosity and permeability modeling was

  4. 9. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING SOUTHWEST, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING SOUTHWEST, SHOWING CHAIN-LINK FENCE IN FOREGROUND AND FOUNDATION STRUCTURE IN THE MIDDLE OF RESERVOIR BASIN - Portland Reservoir No. 2, 6007 Southeast Division Street, Portland, Multnomah County, OR

  5. 10. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW LOOKING EAST FROM PICACHO RESERVOIR INLET CHANNEL - San Carlos Irrigation Project, Marin Canal, Amhurst-Hayden Dam to Picacho Reservoir, Coolidge, Pinal County, AZ

  6. 13. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING EAST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING EAST FROM NORTHWEST CORNER OF RESERVOIR. POST OF ORIGINAL FENCE IS IN FOREGROUND - Portland Reservoir No. 2, 6007 Southeast Division Street, Portland, Multnomah County, OR

  7. The Obtaining of Oil from an Oil Reservoir.

    ERIC Educational Resources Information Center

    Dawe, R. A.

    1979-01-01

    Discusses the mechanics of how an actual oil reservoir works and provides some technical background in physics. An experiment which simulates an oil reservoir and demonstrates quantitatively all the basic concepts of oil reservoir rock properties is also presented. (HM)

  8. High Frequency QRS ECG Accurately Detects Cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian; Poulin, Gregory; Moser, Daniel R.; Delgado, Reynolds

    2005-01-01

    High frequency (HF, 150-250 Hz) analysis over the entire QRS interval of the ECG is more sensitive than conventional ECG for detecting myocardial ischemia. However, the accuracy of HF QRS ECG for detecting cardiomyopathy is unknown. We obtained simultaneous resting conventional and HF QRS 12-lead ECGs in 66 patients with cardiomyopathy (EF = 23.2 plus or minus 6.l%, mean plus or minus SD) and in 66 age- and gender-matched healthy controls using PC-based ECG software recently developed at NASA. The single most accurate ECG parameter for detecting cardiomyopathy was an HF QRS morphological score that takes into consideration the total number and severity of reduced amplitude zones (RAZs) present plus the clustering of RAZs together in contiguous leads. This RAZ score had an area under the receiver operator curve (ROC) of 0.91, and was 88% sensitive, 82% specific and 85% accurate for identifying cardiomyopathy at optimum score cut-off of 140 points. Although conventional ECG parameters such as the QRS and QTc intervals were also significantly longer in patients than controls (P less than 0.001, BBBs excluded), these conventional parameters were less accurate (area under the ROC = 0.77 and 0.77, respectively) than HF QRS morphological parameters for identifying underlying cardiomyopathy. The total amplitude of the HF QRS complexes, as measured by summed root mean square voltages (RMSVs), also differed between patients and controls (33.8 plus or minus 11.5 vs. 41.5 plus or minus 13.6 mV, respectively, P less than 0.003), but this parameter was even less accurate in distinguishing the two groups (area under ROC = 0.67) than the HF QRS morphologic and conventional ECG parameters. Diagnostic accuracy was optimal (86%) when the RAZ score from the HF QRS ECG and the QTc interval from the conventional ECG were used simultaneously with cut-offs of greater than or equal to 40 points and greater than or equal to 445 ms, respectively. In conclusion 12-lead HF QRS ECG employing

  9. Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs

    SciTech Connect

    Watney, W.L.

    1992-01-01

    The objectives of this research are to: (1) assist producers in locating and producing petroleum not currently being produced because of technological problems or the inability to identify details of reservoir compartmentalization (2) to decrease risk in field development, (3) accelerate the retrieval and analysis of baseline geoscience information for initial reservoir description. The interdisciplinary data sought in this research will be used to resolve specific problems in correlation of strata and to establish the mechanisms responsible for the Upper Pennsylvanian stratigraphic architecture in the Midcontinent. The data will better constrain ancillary problems related to the validation of depositional sequence and subsequence correlation, subsidence patterns, sedimentation rates, sea-level changes, and the relationship of sedimentary sequences to basement terrains. The geoscientific information, including data from field studies, surface and near-surface reservoir analogues, and regional data base development, will also be used for development of geologic computer process-based simulation models tailored to specific depositional sequences for use in improving prediction of reservoir characteristics. Accomplishments for this quarter are described for the following tasks: depositional sequence characterization; computer modeling; and reservoir development, prediction, and play potential. 11 figs.

  10. INTELLIGENT COMPUTING SYSTEM FOR RESERVOIR ANALYSIS AND RISK ASSESSMENT OF THE RED RIVER FORMATION

    SciTech Connect

    Kenneth D. Luff

    2002-09-30

    Integrated software has been written that comprises the tool kit for the Intelligent Computing System (ICS). Luff Exploration Company is applying these tools for analysis of carbonate reservoirs in the southern Williston Basin. The integrated software programs are designed to be used by small team consisting of an engineer, geologist and geophysicist. The software tools are flexible and robust, allowing application in many environments for hydrocarbon reservoirs. Keystone elements of the software tools include clustering and neural-network techniques. The tools are used to transform seismic attribute data to reservoir characteristics such as storage (phi-h), probable oil-water contacts, structural depths and structural growth history. When these reservoir characteristics are combined with neural network or fuzzy logic solvers, they can provide a more complete description of the reservoir. This leads to better estimates of hydrocarbons in place, areal limits and potential for infill or step-out drilling. These tools were developed and tested using seismic, geologic and well data from the Red River Play in Bowman County, North Dakota and Harding County, South Dakota. The geologic setting for the Red River Formation is shallow-shelf carbonate at a depth from 8000 to 10,000 ft.

  11. INTELLIGENT COMPUTING SYSTEM FOR RESERVOIR ANALYSIS AND RISK ASSESSMENT OF THE RED RIVER FORMATION

    SciTech Connect

    Kenneth D. Luff

    2002-06-30

    Integrated software has been written that comprises the tool kit for the Intelligent Computing System (ICS). Luff Exploration Company is applying these tools for analysis of carbonate reservoirs in the southern Williston Basin. The integrated software programs are designed to be used by small team consisting of an engineer, geologist and geophysicist. The software tools are flexible and robust, allowing application in many environments for hydrocarbon reservoirs. Keystone elements of the software tools include clustering and neural-network techniques. The tools are used to transform seismic attribute data to reservoir characteristics such as storage (phi-h), probable oil-water contacts, structural depths and structural growth history. When these reservoir characteristics are combined with neural network or fuzzy logic solvers, they can provide a more complete description of the reservoir. This leads to better estimates of hydrocarbons in place, areal limits and potential for infill or step-out drilling. These tools were developed and tested using seismic, geologic and well data from the Red River Play in Bowman County, North Dakota and Harding County, South Dakota. The geologic setting for the Red River Formation is shallow-shelf carbonate at a depth from 8000 to 10,000 ft.

  12. 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.

  13. Direction and Description

    NASA Astrophysics Data System (ADS)

    Ben-Menahem, Yemima

    This paper deals with the dependence of directionality in the course of events-or our claims concerning such directionality-on the modes of description we use in speaking of the events in question. I argue that criteria of similarity and individuation play a crucial role in assessments of directionality. This is an extension of Davidson's claim regarding the difference between causal and explanatory contexts. The argument is based on a characterisation of notions of necessity and contingency that differ from their modal logic counterparts on the one hand, and from causality and chance on the other. I show that some types of directionality are perfectly compatible with both determinism and indeterminism at the microscopic level, and that there is no likelihood of, or advantage to, reducing such directionality to other laws or causal processes.

  14. Symmetrical gait descriptions

    NASA Astrophysics Data System (ADS)

    Dunajewski, Adam; Dusza, Jacek J.; Rosado Muñoz, Alfredo

    2014-11-01

    The article presents a proposal for the description of human gait as a periodic and symmetric process. Firstly, the data for researches was obtained in the Laboratory of Group SATI in the School of Engineering of University of Valencia. Then, the periodical model - Mean Double Step (MDS) was made. Finally, on the basis of MDS, the symmetrical models - Left Mean Double Step and Right Mean Double Step (LMDS and RMDS) could be created. The method of various functional extensions was used. Symmetrical gait models can be used to calculate the coefficients of asymmetry at any time or phase of the gait. In this way it is possible to create asymmetry, function which better describes human gait dysfunction. The paper also describes an algorithm for calculating symmetric models, and shows exemplary results based on the experimental data.

  15. Task Description Language

    NASA Technical Reports Server (NTRS)

    Simmons, Reid; Apfelbaum, David

    2005-01-01

    Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

  16. Description of Jet Breakup

    NASA Technical Reports Server (NTRS)

    Papageorgiou, Demetrios T.

    1996-01-01

    In this article we review recent results on the breakup of cylindrical jets of a Newtonian fluid. Capillary forces provide the main driving mechanism and our interest is in the description of the flow as the jet pinches to form drops. The approach is to describe such topological singularities by constructing local (in time and space) similarity solutions from the governing equations. This is described for breakup according to the Euler, Stokes or Navier-Stokes equations. It is found that slender jet theories can be applied when viscosity is present, but for inviscid jets the local shape of the jet at breakup is most likely of a non-slender geometry. Systems of one-dimensional models of the governing equations are solved numerically in order to illustrate these differences.

  17. Geological characterisation of complex reservoirs using 3D seismic: Case studies

    NASA Astrophysics Data System (ADS)

    Benaissa, Zahia; Benaïssa, Abdelkader; Seghir Baghaoui, Mohamed; Bendali, Mohamed; Chami, Adel; Khelifi Touhami, Médina; Ouadfeul, Sid Ali; Boudella, Amar

    2014-05-01

    3D seismic allows getting a set of numerous closely-spaced seismic lines that provide a high spatially sampled measure of subsurface reflectivity. It leads to an accurate interpretation of seismic reflection data, which is one of the most important stages of a successful hydrocarbons exploration, especially in the reservoirs characterised by complex geological setting. We present here two case studies pertaining to two Algerian hydrocarbon fields. Considering the positive results obtained from 2D seismic interpretation, several wells were drilled. Some of them have proved dry, due certainly to inaccurate seismic interpretation because of non standard geological context. For the first case, the high quality of the 3D seismic data allowed to reveal, on all the inlines and crosslines, the existence of paleovalleys under the top of the Ordovician (unit IV) reservoir. The mapping of these paleovalleys clearly showed that the dry well, contrary to the other wells, was implanted outside paleovalleys. This fact was confirmed by the analysis of well data. The second case study concerns the problem of andesitic eruptive deposits on the top of the Ordovician reservoir, which condition the geometry and continuity of this reservoir and cause uncertainties in the mapping of the Hercynian unconformity. Well data associated with 3D seismic response shows that eruptive deposits generate high impedance anomaly because of the high density and velocity of andesites. We used this information to interpret these eruptive rocks as being responsible of high impedance anomalies, inside the Ordovician reservoir, on the impedance volume generated from the 3D seismic data. A 3D extraction of the anomalies allowed an accurate localisation of the andesites. So, it appears, according to these two case studies, that for an efficient recovery of hydrocarbons, we have to rely, first of all, on an accurate seismic interpretation before we use microscopic measurements. 3D seismic, once again, remains

  18. YUCCA MOUNTAIN SITE DESCRIPTION

    SciTech Connect

    A.M. Simmons

    2004-04-16

    The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.

  19. Effect of sporadic destratification, seasonal overturn and artificial mixing on CH4 emissions at the surface of a subtropical hydroelectric reservoir (Nam Theun 2 Reservoir, Lao PDR)

    NASA Astrophysics Data System (ADS)

    Guérin, F.; Deshmukh, C.; Labat, D.; Pighini, S.; Vongkhamsao, A.; Guédant, P.; Rode, W.; Godon, A.; Chanudet, V.; Descloux, S.; Serça, D.

    2015-07-01

    Inland waters in general and specifically freshwater reservoirs are recognized as source of CH4 to the atmosphere. Although the diffusion at the air-water interface is the most studied pathway, its spatial and temporal variations are poorly documented. We measured fortnightly CH4 concentrations and physico-chemical parameters at nine stations in a subtropical monomictic reservoir which was flooded in 2008 (Nam Theun 2 Reservoir, Lao PDR). Based on these results, we quantified CH4 storage in the water column and diffusive fluxes from June 2009 to December 2012. We also compared emissions with aerobic methane oxidation calculated from Deshmukh et al. (2015). In this monomictic reservoir, the seasonal variations of CH4 concentration and storage were highly dependant of the thermal stratification. Hypolimnic CH4 concentration and CH4 storage reached their maximum in the warm dry season (WD) when the reservoir was stratified. They decreased during the warm wet (WW) season and reached its minimum after the reservoir overturned in the cool dry season (CD). The sharp decreases of the CH4 storage were concomitant with sporadic extreme diffusive fluxes (up to 200 mmol m-2 d-1). These hot moments of emissions occurred mostly in the inflow region in the WW season and during the overturn in the CD season in the area of the reservoir that has the highest CH4 storage. Although they corresponded to less than 10 % of the observations, these CH4 extreme emissions (> 5 mmol m-2 d-1) contributed up to 50 % of total annual emissions by diffusion. Based on our fortnightly monitoring, we determined that accurate estimation of the emissions can be determined from measurements made at least at a monthly frequency. During the transition between the WD and WW seasons, a new hotspot of emissions was identified upstream of the water intake where diffusive fluxes peaked at 600 mmol m-2 d-1 in 2010 down to 200 mmol m-2 d-1 in 2012. In the CD season, diffusive fluxes from this area were the

  20. MHD coal-fired flow facility baseline water-quality study. Woods Reservoir, May 1979-April 1980

    SciTech Connect

    Cooper, J.

    1980-12-01

    The Department of Energy (DOE) Magnetohydrodynamics (MHD) Coal-Fired Flow Facility (CFFF) is located on Woods Reservoir at The University of Tennessee Space Institute (UTSI). Part of the role of UTSI, as participants in the DOE program, is to document environmental aspects of coal-fired MHD. In early 1979, prior to operation of the CFFF, a water quality program was initiated to establish baseline conditions for the reservoir. The study was designed to provide an accurate assessment of water quality which could be used as a basis for comparison to evaluate the impact, if any, of the plant operation on the aquatic environment. Results of a one year baseline study of water quality on Woods Reservoir are presented in this report. The key findings are that this reservoir is a eutrophic lake. Its predominant ions are calcium and bicarbonate and its pH is circumneutral.

  1. 5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES TO LEFT MIDDLE GROUND OF PICTURE. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  2. Assessing water reservoir management and development in Northern Vietnam

    NASA Astrophysics Data System (ADS)

    Pianosi, F.; Quach, X.; Castelletti, A.; Soncini-Sessa, R.

    2012-04-01

    In many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this work we use multi-objective deterministic and stochastic optimization to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam), focusing on the major controllable infrastructure in the basin, the HoaBinh reservoir on the Da River. We first provide a general and mathematical description of the socio economic and physical system of the Red River Basin, including the three main objectives of hydropower production, flood control, and water supply, and using conceptual and data-driven modeling tools. Then, we analyze the historical operation of the HoaBinh reservoir and explore re-operation options corresponding to different tradeoffs among the three main objectives, using Multi-Objective Genetic Algorithm. Results show that there exist several operating policies that prove Pareto-dominant over the historical one, that is, they can improve all three management objectives simultaneously. However, while the improvement is rather significant with respect to hydropower production and water supply, it is much more limited in terms of flood control. To understand whether this is due to structural constraints (insufficient storing capacity) or to the imperfect information system (uncertainty in forecasting future flows and thus anticipate floods), we assessed the infrastructural system potential by application of Deterministic Dynamic Programming. Results show that the current operation can only be relatively improved by advanced optimization

  3. Sedimentology and diagenesis of misoa C-2 reservoir, VLE-305/326 area, block V, Lamar Field, Maracaibe Lake, Venezuela

    SciTech Connect

    Cabrera de Casas, L.; Chacartegui, F. )

    1993-02-01

    The main purpose of this study was to characterize the Upper Eocene C-2 reservoir using sedimentological, petrophysical and biostratigraphic parameters. The reservoir quality was evaluated by defining its physical attributes, geometry, areal distribution and orientation, from facies analysis of sedimentary units identified in core samples. In evaluating the sedimentary features of the Misoa C-2 reservoir in VLE 305/326 area, Block V, Lamar Field, Maracaibo Lake, 2,000' of cores from five wells (named VLe-339, VLE-720, VLE -723, VLe-754, LPG-1211) were analyzed. The sedimentary sequence studied represents upper-middle deltaic plain deposits with no marine influence. These deposits were identified as interdistributary channels, crevasse splays and interdistributary bays deposited in a northward prograding system. Seven sedimentary facies were defined from the physical, chemical and biological features observed in all cores. These facies were petrophysically and petrographically characterized then grouped in six sedimentary units which were then correlated over the entire area. One hundred well logs were correlated using sedimentological criteria. Finally, four flow units were identified in the reservoir using the sedimentological parameters, petrophysical data and production behavior. A surface trend analysis program utilizing thickness values resulted in contours, trends, residuals and isometry maps of each unit with a generalized southwest-northeast trend orientation. It was determined that facies distribution in the units controls the reservoir quality. These results are the main input into reservoir simulation. An accurate reservoir modeling is needed to prepare for optimizing secondary oil recovery.

  4. Accurately Mapping M31's Microlensing Population

    NASA Astrophysics Data System (ADS)

    Crotts, Arlin

    2004-07-01

    We propose to augment an existing microlensing survey of M31 with source identifications provided by a modest amount of ACS {and WFPC2 parallel} observations to yield an accurate measurement of the masses responsible for microlensing in M31, and presumably much of its dark matter. The main benefit of these data is the determination of the physical {or "einstein"} timescale of each microlensing event, rather than an effective {"FWHM"} timescale, allowing masses to be determined more than twice as accurately as without HST data. The einstein timescale is the ratio of the lensing cross-sectional radius and relative velocities. Velocities are known from kinematics, and the cross-section is directly proportional to the {unknown} lensing mass. We cannot easily measure these quantities without knowing the amplification, hence the baseline magnitude, which requires the resolution of HST to find the source star. This makes a crucial difference because M31 lens m ass determinations can be more accurate than those towards the Magellanic Clouds through our Galaxy's halo {for the same number of microlensing events} due to the better constrained geometry in the M31 microlensing situation. Furthermore, our larger survey, just completed, should yield at least 100 M31 microlensing events, more than any Magellanic survey. A small amount of ACS+WFPC2 imaging will deliver the potential of this large database {about 350 nights}. For the whole survey {and a delta-function mass distribution} the mass error should approach only about 15%, or about 6% error in slope for a power-law distribution. These results will better allow us to pinpoint the lens halo fraction, and the shape of the halo lens spatial distribution, and allow generalization/comparison of the nature of halo dark matter in spiral galaxies. In addition, we will be able to establish the baseline magnitude for about 50, 000 variable stars, as well as measure an unprecedentedly deta iled color-magnitude diagram and luminosity

  5. Accurate upwind methods for the Euler equations

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1993-01-01

    A new class of piecewise linear methods for the numerical solution of the one-dimensional Euler equations of gas dynamics is presented. These methods are uniformly second-order accurate, and can be considered as extensions of Godunov's scheme. With an appropriate definition of monotonicity preservation for the case of linear convection, it can be shown that they preserve monotonicity. Similar to Van Leer's MUSCL scheme, they consist of two key steps: a reconstruction step followed by an upwind step. For the reconstruction step, a monotonicity constraint that preserves uniform second-order accuracy is introduced. Computational efficiency is enhanced by devising a criterion that detects the 'smooth' part of the data where the constraint is redundant. The concept and coding of the constraint are simplified by the use of the median function. A slope steepening technique, which has no effect at smooth regions and can resolve a contact discontinuity in four cells, is described. As for the upwind step, existing and new methods are applied in a manner slightly different from those in the literature. These methods are derived by approximating the Euler equations via linearization and diagonalization. At a 'smooth' interface, Harten, Lax, and Van Leer's one intermediate state model is employed. A modification for this model that can resolve contact discontinuities is presented. Near a discontinuity, either this modified model or a more accurate one, namely, Roe's flux-difference splitting. is used. The current presentation of Roe's method, via the conceptually simple flux-vector splitting, not only establishes a connection between the two splittings, but also leads to an admissibility correction with no conditional statement, and an efficient approximation to Osher's approximate Riemann solver. These reconstruction and upwind steps result in schemes that are uniformly second-order accurate and economical at smooth regions, and yield high resolution at discontinuities.

  6. Accurate measurement of unsteady state fluid temperature

    NASA Astrophysics Data System (ADS)

    Jaremkiewicz, Magdalena

    2016-07-01

    In this paper, two accurate methods for determining the transient fluid temperature were presented. Measurements were conducted for boiling water since its temperature is known. At the beginning the thermometers are at the ambient temperature and next they are immediately immersed into saturated water. The measurements were carried out with two thermometers of different construction but with the same housing outer diameter equal to 15 mm. One of them is a K-type industrial thermometer widely available commercially. The temperature indicated by the thermometer was corrected considering the thermometers as the first or second order inertia devices. The new design of a thermometer was proposed and also used to measure the temperature of boiling water. Its characteristic feature is a cylinder-shaped housing with the sheath thermocouple located in its center. The temperature of the fluid was determined based on measurements taken in the axis of the solid cylindrical element (housing) using the inverse space marching method. Measurements of the transient temperature of the air flowing through the wind tunnel using the same thermometers were also carried out. The proposed measurement technique provides more accurate results compared with measurements using industrial thermometers in conjunction with simple temperature correction using the inertial thermometer model of the first or second order. By comparing the results, it was demonstrated that the new thermometer allows obtaining the fluid temperature much faster and with higher accuracy in comparison to the industrial thermometer. Accurate measurements of the fast changing fluid temperature are possible due to the low inertia thermometer and fast space marching method applied for solving the inverse heat conduction problem.

  7. Application of Artificial Intelligence to Reservoir Characterization - An Interdisciplinary Approach

    SciTech Connect

    Kelkar, B.G.; Gamble, R.F.; Kerr, D.R.; Thompson, L.G.; Shenoi, S.

    2000-01-12

    The primary goal of this project is to develop a user-friendly computer program to integrate geological and engineering information using Artificial Intelligence (AI) methodology. The project is restricted to fluvially dominated deltaic environments. The static information used in constructing the reservoir description includes well core and log data. Using the well core and the log data, the program identifies the marker beds, and the type of sand facies, and in turn, develops correlation's between wells. Using the correlation's and sand facies, the program is able to generate multiple realizations of sand facies and petrophysical properties at interwell locations using geostatistical techniques. The generated petrophysical properties are used as input in the next step where the production data are honored. By adjusting the petrophysical properties, the match between the simulated and the observed production rates is obtained.

  8. New law requires 'medically accurate' lesson plans.

    PubMed

    1999-09-17

    The California Legislature has passed a bill requiring all textbooks and materials used to teach about AIDS be medically accurate and objective. Statements made within the curriculum must be supported by research conducted in compliance with scientific methods, and published in peer-reviewed journals. Some of the current lesson plans were found to contain scientifically unsupported and biased information. In addition, the bill requires material to be "free of racial, ethnic, or gender biases." The legislation is supported by a wide range of interests, but opposed by the California Right to Life Education Fund, because they believe it discredits abstinence-only material.

  9. Accurate density functional thermochemistry for larger molecules.

    SciTech Connect

    Raghavachari, K.; Stefanov, B. B.; Curtiss, L. A.; Lucent Tech.

    1997-06-20

    Density functional methods are combined with isodesmic bond separation reaction energies to yield accurate thermochemistry for larger molecules. Seven different density functionals are assessed for the evaluation of heats of formation, Delta H 0 (298 K), for a test set of 40 molecules composed of H, C, O and N. The use of bond separation energies results in a dramatic improvement in the accuracy of all the density functionals. The B3-LYP functional has the smallest mean absolute deviation from experiment (1.5 kcal mol/f).

  10. New law requires 'medically accurate' lesson plans.

    PubMed

    1999-09-17

    The California Legislature has passed a bill requiring all textbooks and materials used to teach about AIDS be medically accurate and objective. Statements made within the curriculum must be supported by research conducted in compliance with scientific methods, and published in peer-reviewed journals. Some of the current lesson plans were found to contain scientifically unsupported and biased information. In addition, the bill requires material to be "free of racial, ethnic, or gender biases." The legislation is supported by a wide range of interests, but opposed by the California Right to Life Education Fund, because they believe it discredits abstinence-only material. PMID:11366835

  11. Universality: Accurate Checks in Dyson's Hierarchical Model

    NASA Astrophysics Data System (ADS)

    Godina, J. J.; Meurice, Y.; Oktay, M. B.

    2003-06-01

    In this talk we present high-accuracy calculations of the susceptibility near βc for Dyson's hierarchical model in D = 3. Using linear fitting, we estimate the leading (γ) and subleading (Δ) exponents. Independent estimates are obtained by calculating the first two eigenvalues of the linearized renormalization group transformation. We found γ = 1.29914073 ± 10 -8 and, Δ = 0.4259469 ± 10-7 independently of the choice of local integration measure (Ising or Landau-Ginzburg). After a suitable rescaling, the approximate fixed points for a large class of local measure coincide accurately with a fixed point constructed by Koch and Wittwer.

  12. Top-Down, Intelligent Reservoir Model

    NASA Astrophysics Data System (ADS)

    Mohaghegh, Shahab

    2010-05-01

    Conventional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir that is populated with the best available petrophysical and geophysical information at the time of development. Engineering fluid flow principles are added and solved numerically so as to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery. Top-Down, Intelligent Reservoir Modeling approaches the reservoir simulation and modeling from an opposite angle by attempting to build a realization of the reservoir starting with the measured well production behavior (history). The production history is augmented by core, log, well test and seismic data in order to increase the accuracy of the Top-Down modeling technique. Although not intended as a substitute for the conventional reservoir simulation of large, complex fields, this novel approach to reservoir modeling can be used as an alternative (at a fraction of the cost) to conventional reservoir simulation and modeling in cases where performing conventional modeling is cost (and man-power) prohibitive. In cases where a conventional model of a reservoir already exists, Top-Down modeling should be considered as a compliment to, rather than a competition for the conventional technique, to provide an independent look at the data coming from the reservoir/wells for optimum development strategy and recovery enhancement. Top-Down, Intelligent Reservoir Modeling starts with well-known reservoir engineering techniques such as Decline Curve Analysis, Type Curve Matching, History Matching using single well numerical reservoir simulation, Volumetric Reserve Estimation and calculation of Recovery Factors for all the wells (individually) in the field. Using statistical techniques multiple Production Indicators (3, 6, and 9 months cum

  13. Development of luminescent bacteria as tracers for geological reservoir characterization

    SciTech Connect

    King, J.W.

    1991-10-01

    Bioluminescent cultures were acquired and tested for use as biological tracers for reservoir characterization by small independent oil companies. Initially these bacterial cultures were fastidious to work with, but when we finally determined their critical growth parameters simple test variations were developed that could be routinely accomplished. The intensity of their luminescence is easily distinguished by the human eye and requires no sophisticated technical knowledge or instrumentation. Cultures were received from culture banks and collected from marine environments. In our laboratory they were screened using the criteria of optimum growth and luminescence. Three stock cultures proved to grow profusely even when variations were made in nutrient additions, salts, and temperature. These three selected cultures were not inhibited when introduced to formations and formation waters and were not overgrown by other bacteria. Cultures isolated from the Gulf of Mexico were overgrown by indigenous bacteria and therefore, they were eliminated from further screening and adaption. Experiments were performed according to three major task descriptions: 1. Establish growth and luminescencing limitations of selected bacteria in various media, varying salt concentration and temperature. 2. Adapt cultures to formation waters. 3. Determine transport limitations of bioluminescent bacteria through representative reservoir cores. 19 refs., 5 figs., 7 tabs.

  14. Reservoir technology research at the INEL

    SciTech Connect

    Renner, J.L.; Shook, G.M.; Faulder, D.D.

    1996-05-01

    Reservoir engineering research at INEL was aimed at developing a better understanding of The Geysers and developing better tools with which to study flow in fractured geothermal reservoirs in general. Two specific topics were studies in the last year: matrix fracture interactions and decline curve analysis. A third project, revisiting the behavior of the `high-temperature reservoir` (HTR), was started near the end of 1995. These projects are being conducted in collaboration with other researchers and/or private industry. For example, our HTR studies are motivated in part because of new isotopic analyses conducted elsewhere (Walters et al., in preparation). The ultimate goal of these projects is to improve predictive capabilities and reservoir management practices and to extend the commercial life of The Geysers. In addition to conducting engineering research for the Reservoir Technology Program, INEL also continued to assist the Geothermal Technology Organization (GTO) with the development and execution of cooperative research projects. In support of the overall mission of the Reservoir Technology program, INEL also entered into a broad program of subcontracts with industrial groups and universities. These programs support the Reservoir Technology mission by providing support for research topics considered particularly important by the geothermal industry. The GTO projects are summarized below.

  15. Dissolved methane in Indian freshwater reservoirs.

    PubMed

    Narvenkar, G; Naqvi, S W A; Kurian, S; Shenoy, D M; Pratihary, A K; Naik, H; Patil, S; Sarkar, A; Gauns, M

    2013-08-01

    Emission of methane (CH4), a potent greenhouse gas, from tropical reservoirs is of interest because such reservoirs experience conducive conditions for CH4 production through anaerobic microbial activities. It has been suggested that Indian reservoirs have the potential to emit as much as 33.5 MT of CH4 per annum to the atmosphere. However, this estimate is based on assumptions rather than actual measurements. We present here the first data on dissolved CH4 concentrations from eight freshwater reservoirs in India, most of which experience seasonal anaerobic conditions and CH4 buildup in the hypolimnia. However, strong stratification prevents the CH4-rich subsurface layers to ventilate CH4 directly to the atmosphere, and surface water CH4 concentrations in these reservoirs are generally quite low (0.0028-0.305 μM). Moreover, only in two small reservoirs substantial CH4 accumulation occurred at depths shallower than the level where water is used for power generation and irrigation, and in the only case where measurements were made in the outflowing water, CH4 concentrations were quite low. In conjunction with short periods of CH4 accumulation and generally lower concentrations than previously assumed, our study implies that CH4 emission from Indian reservoirs has been greatly overestimated. PMID:23397538

  16. Seismic modeling of fluvial reservoirs in outcrop

    SciTech Connect

    Campbell, E. )

    1993-09-01

    Three-dimensional (3-D) seismics and concomitant improvements in processing techniques have increased the amount of reservoir-scale information that can be obtained from the seismic waveform reaching the surface. However, the geological significance of these seismic events remains unclear. The seismic modeling of reservoir formations in outcrops allows analogs to be drawn to the seismic response of reservoirs at depth. Previous outcrop modeling studies are mostly high-frequency approximations, suitable for large-scale geometrical imaging but unsuitable for imaging lateral variations in lithology and geometry of bodies that lie on or below the [open quotes]visual[close quotes] resolution of the seismic tool. This study examines finite-difference seismic modeling of Tertiary, fluvial-sandstone bodies in outcrop from central Spain. The outcrops were well known from reservoir characterization studies, easily accessible, and well exposed. Outcrop geometry was converted into a finite-difference grid, with density and velocity values coming from measurements of cores and blocks from each of the lithologies. Synthetic traces were generated. The traces were then processed in the conventional manner. Full solution of the wave equation allows all wave types to be modeled, e.g., diffraction sand multiples. Models were generated to simulate reservoir conditions at the surface and at depth. Seismic wave-forms could then be related back to reservoir characteristics. Seismic modeling of reservoir sands in outcrop can aid in the interpretation of such bodies at depth. Seismic modeling of reservoirs is a low-cost interpretation tool that may aid field development by delineation of reservoirs in area of complex sedimentology where surface analogs exist.

  17. Accurate shear measurement with faint sources

    SciTech Connect

    Zhang, Jun; Foucaud, Sebastien; Luo, Wentao E-mail: walt@shao.ac.cn

    2015-01-01

    For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be measured accurately in Fourier space in the presence of background noise and finite pixel size, without assumptions on the morphologies of galaxy and PSF. The remaining major source of error is source Poisson noise, due to the finiteness of source photon number. This problem is particularly important for faint galaxies in space-based weak lensing measurements, and for ground-based images of short exposure times. In this work, we propose a simple and rigorous way of removing the shear bias from the source Poisson noise. Our noise treatment can be generalized for images made of multiple exposures through MultiDrizzle. This is demonstrated with the SDSS and COSMOS/ACS data. With a large ensemble of mock galaxy images of unrestricted morphologies, we show that our shear measurement method can achieve sub-percent level accuracy even for images of signal-to-noise ratio less than 5 in general, making it the most promising technique for cosmic shear measurement in the ongoing and upcoming large scale galaxy surveys.

  18. Accurate determination of characteristic relative permeability curves

    NASA Astrophysics Data System (ADS)

    Krause, Michael H.; Benson, Sally M.

    2015-09-01

    A recently developed technique to accurately characterize sub-core scale heterogeneity is applied to investigate the factors responsible for flowrate-dependent effective relative permeability curves measured on core samples in the laboratory. The dependency of laboratory measured relative permeability on flowrate has long been both supported and challenged by a number of investigators. Studies have shown that this apparent flowrate dependency is a result of both sub-core scale heterogeneity and outlet boundary effects. However this has only been demonstrated numerically for highly simplified models of porous media. In this paper, flowrate dependency of effective relative permeability is demonstrated using two rock cores, a Berea Sandstone and a heterogeneous sandstone from the Otway Basin Pilot Project in Australia. Numerical simulations of steady-state coreflooding experiments are conducted at a number of injection rates using a single set of input characteristic relative permeability curves. Effective relative permeability is then calculated from the simulation data using standard interpretation methods for calculating relative permeability from steady-state tests. Results show that simplified approaches may be used to determine flowrate-independent characteristic relative permeability provided flow rate is sufficiently high, and the core heterogeneity is relatively low. It is also shown that characteristic relative permeability can be determined at any typical flowrate, and even for geologically complex models, when using accurate three-dimensional models.

  19. How Accurately can we Calculate Thermal Systems?

    SciTech Connect

    Cullen, D; Blomquist, R N; Dean, C; Heinrichs, D; Kalugin, M A; Lee, M; Lee, Y; MacFarlan, R; Nagaya, Y; Trkov, A

    2004-04-20

    I would like to determine how accurately a variety of neutron transport code packages (code and cross section libraries) can calculate simple integral parameters, such as K{sub eff}, for systems that are sensitive to thermal neutron scattering. Since we will only consider theoretical systems, we cannot really determine absolute accuracy compared to any real system. Therefore rather than accuracy, it would be more precise to say that I would like to determine the spread in answers that we obtain from a variety of code packages. This spread should serve as an excellent indicator of how accurately we can really model and calculate such systems today. Hopefully, eventually this will lead to improvements in both our codes and the thermal scattering models that they use in the future. In order to accomplish this I propose a number of extremely simple systems that involve thermal neutron scattering that can be easily modeled and calculated by a variety of neutron transport codes. These are theoretical systems designed to emphasize the effects of thermal scattering, since that is what we are interested in studying. I have attempted to keep these systems very simple, and yet at the same time they include most, if not all, of the important thermal scattering effects encountered in a large, water-moderated, uranium fueled thermal system, i.e., our typical thermal reactors.

  20. Accurate Stellar Parameters for Exoplanet Host Stars

    NASA Astrophysics Data System (ADS)

    Brewer, John Michael; Fischer, Debra; Basu, Sarbani; Valenti, Jeff A.

    2015-01-01

    A large impedement to our understanding of planet formation is obtaining a clear picture of planet radii and densities. Although determining precise ratios between planet and stellar host are relatively easy, determining accurate stellar parameters is still a difficult and costly undertaking. High resolution spectral analysis has traditionally yielded precise values for some stellar parameters but stars in common between catalogs from different authors or analyzed using different techniques often show offsets far in excess of their uncertainties. Most analyses now use some external constraint, when available, to break observed degeneracies between surface gravity, effective temperature, and metallicity which can otherwise lead to correlated errors in results. However, these external constraints are impossible to obtain for all stars and can require more costly observations than the initial high resolution spectra. We demonstrate that these discrepencies can be mitigated by use of a larger line list that has carefully tuned atomic line data. We use an iterative modeling technique that does not require external constraints. We compare the surface gravity obtained with our spectral synthesis modeling to asteroseismically determined values for 42 Kepler stars. Our analysis agrees well with only a 0.048 dex offset and an rms scatter of 0.05 dex. Such accurate stellar gravities can reduce the primary source of uncertainty in radii by almost an order of magnitude over unconstrained spectral analysis.

  1. Benchmark data base for accurate van der Waals interaction in inorganic fragments

    NASA Astrophysics Data System (ADS)

    Brndiar, Jan; Stich, Ivan

    2012-02-01

    A range of inorganic materials, such as Sb, As, P, S, Se are built from van der Waals (vdW) interacting units forming the crystals, which neither the standard DFT GGA description as well as cheap quantum chemistry methods, such as MP2, do not describe correctly. We use this data base, for which have performed ultra accurate CCSD(T) calculations in complete basis set limit, to test the alternative approximate theories, such as Grimme [1], Langreth-Lundqvist [2], and Tkachenko-Scheffler [3]. While none of these theories gives entirely correct description, Grimme consistently provides more accurate results than Langreth-Lundqvist, which tend to overestimate the distances and underestimate the interaction energies for this set of systems. Contrary Tkachenko-Scheffler appear to yield surprisingly accurate and computationally cheap and convenient description applicable also for systems with appreciable charge transfer. [4pt] [1] S. Grimme, J. Comp. Chem. 27, 1787 (2006) [0pt] [2] K. Lee, et al., Phys. Rev. B 82 081101 (R) (2010) [0pt] [3] Tkachenko and M. Scheffler Phys. Rev. Lett. 102 073005 (2009).

  2. Dispersivity as an oil reservoir rock characteristic

    SciTech Connect

    Menzie, D.E.; Dutta, S.

    1989-12-01

    The main objective of this research project is to establish dispersivity, {alpha}{sub d}, as an oil reservoir rock characteristic and to use this reservoir rock property to enhance crude oil recovery. A second objective is to compare the dispersion coefficient and the dispersivity of various reservoir rocks with other rock characteristics such as: porosity, permeability, capillary pressure, and relative permeability. The dispersivity of a rock was identified by measuring the physical mixing of two miscible fluids, one displacing the other in a porous medium. 119 refs., 27 figs., 12 tabs.

  3. A Reservoir of Nitrate Beneath Desert Soils

    USGS Publications Warehouse

    Walvoord, M.A.; Phillips, F.M.; Stonestrom, D.A.; Evans, R.D.; Hartsough, P.C.; Newman, B.D.; Striegl, R.G.

    2003-01-01

    A large reservoir of bioavailable nitrogen (upto ???104 kilograms of nitrogen per hectare, as nitrate) has been previously overlooked in studies of global nitrogen distribution. The reservoir has been accumulating in subsoil zones of and regions throughout the Holocene. Consideration of the subsoil reservoir raises estimates of vadose-zone nitrogen inventories by 14 to 71% for warm deserts and arid shrublands worldwide and by 3 to 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation of nutrient dynamics in xeric ecosystems. Evidence that subsoil accumulations are readily mobilized raises concern about groundwater contamination after land-use or climate change.

  4. New closed system integral cesium reservoir

    NASA Astrophysics Data System (ADS)

    Rhee, Hyop S.; Britt, Edward J.; Kim, Kwang Y.; Kennel, Elliot B.

    Attention is given to the lead-cesium solution reservoir concept, according to which the cesium reservoir is in the form of a gas-buffered heat pipe, such that the cesium pressure will remain roughly constant over a wide range of input temperature flux. This concept carries fission gases from the cesium. Experimental data show that adequate cesium pressure control is facilitated by a lead-cesium solution at the collector operating temperature of the thermionic fuel elements (TFEs). If the performance and material compatibility issues are resolved, the lead-cesium reservoir could offer great benefits in terms of simplicity and reduction of TFE manufacturing costs.

  5. A reservoir of nitrate beneath desert soils.

    PubMed

    Walvoord, Michelle A; Phillips, Fred M; Stonestrom, David A; Evans, R Dave; Hartsough, Peter C; Newman, Brent D; Striegl, Robert G

    2003-11-01

    A large reservoir of bioavailable nitrogen (up to approximately 10(4) kilograms of nitrogen per hectare, as nitrate) has been previously overlooked in studies of global nitrogen distribution. The reservoir has been accumulating in subsoil zones of arid regions throughout the Holocene. Consideration of the subsoil reservoir raises estimates of vadose-zone nitrogen inventories by 14 to 71% for warm deserts and arid shrublands worldwide and by 3 to 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation of nutrient dynamics in xeric ecosystems. Evidence that subsoil accumulations are readily mobilized raises concern about groundwater contamination after land-use or climate change.

  6. Production-induced changes in reservoir geomechanics

    NASA Astrophysics Data System (ADS)

    Amoyedo, Sunday O.

    Sand production remains a source of concern in both conventional and heavy oil production. Porosity increase and changes in local stress magnitude, which often enhance permeability, have been associated with severe sanding. On the other hand, sand production has been linked to a large number of field incidences involving loss of well integrity, casing collapse and corrosion of down-hole systems. It also poses problems for separators and transport facilities. Numerous factors such as reservoir consolidation, well deviation angle through the reservoir, perforation size, grain size, capillary forces associated with water cut, flow rate and most importantly reservoir strain resulting from pore pressure depletion contribute to reservoir sanding. Understanding field-specific sand production patterns in mature fields and poorly consolidated reservoirs is vital in identifying sand-prone wells and guiding remedial activities. Reservoir strain analysis of Forties Field, located in the UK sector of the North Sea, shows that the magnitude of the production-induced strain, part of which is propagated to the base of the reservoir, is of the order of 0.2 %, which is significant enough to impact the geomechanical properties of the reservoir. Sand production analysis in the field shows that in addition to poor reservoir consolidation, a combined effect of repeated perforation, high well deviation, reservoir strain and high fluid flow rate have contributed significantly to reservoir sanding. Knowledge of reservoir saturation variation is vital for in-fill well drilling, while information on reservoir stress variation provides a useful guide for sand production management, casing design, injector placement and production management. Interpreting time-lapse difference is enhanced by decomposing time-lapse difference into saturation, pressure effects and changes in rock properties (e.g. porosity) especially in highly compacting reservoirs. Analyzing the stress and saturation

  7. Safety drain system for fluid reservoir

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

    2012-01-01

    A safety drain system includes a plurality of drain sections, each of which defines distinct fluid flow paths. At least a portion of the fluid flow paths commence at a side of the drain section that is in fluid communication with a reservoir's fluid. Each fluid flow path at the side communicating with the reservoir's fluid defines an opening having a smallest dimension not to exceed approximately one centimeter. The drain sections are distributed over at least one surface of the reservoir. A manifold is coupled to the drain sections.

  8. Simulation of Radon Transport in Geothermal Reservoirs

    SciTech Connect

    Semprini, Lewis; Kruger, Paul

    1983-12-15

    Numerical simulation of radon transport is a useful adjunct in the study of radon as an in situ tracer of hydrodynamic and thermodynamic numerical model has been developed to assist in the interpretation of field experiments. The model simulates transient response of radon concentration in wellhead geofluid as a function of prevailing reservoir conditions. The radon simulation model has been used to simulate radon concentration response during production drawdown and two flowrate transient tests in vapor-dominated systems. Comparison of model simulation with experimental data from field tests provides insight in the analysis of reservoir phenomena such as propagation of boiling fronts, and estimates of reservoir properties of porosity and permeability thickness.

  9. Incorporating teleconnection information into reservoir operating policies using Stochastic Dynamic Programming and a Hidden Markov Model

    NASA Astrophysics Data System (ADS)

    Turner, Sean; Galelli, Stefano; Wilcox, Karen

    2015-04-01

    Water reservoir systems are often affected by recurring large-scale ocean-atmospheric anomalies, known as teleconnections, that cause prolonged periods of climatological drought. Accurate forecasts of these events -- at lead times in the order of weeks and months -- may enable reservoir operators to take more effective release decisions to improve the performance of their systems. In practice this might mean a more reliable water supply system, a more profitable hydropower plant or a more sustainable environmental release policy. To this end, climate indices, which represent the oscillation of the ocean-atmospheric system, might be gainfully employed within reservoir operating models that adapt the reservoir operation as a function of the climate condition. This study develops a Stochastic Dynamic Programming (SDP) approach that can incorporate climate indices using a Hidden Markov Model. The model simulates the climatic regime as a hidden state following a Markov chain, with the state transitions driven by variation in climatic indices, such as the Southern Oscillation Index. Time series analysis of recorded streamflow data reveals the parameters of separate autoregressive models that describe the inflow to the reservoir under three representative climate states ("normal", "wet", "dry"). These models then define inflow transition probabilities for use in a classic SDP approach. The key advantage of the Hidden Markov Model is that it allows conditioning the operating policy not only on the reservoir storage and the antecedent inflow, but also on the climate condition, thus potentially allowing adaptability to a broader range of climate conditions. In practice, the reservoir operator would effect a water release tailored to a specific climate state based on available teleconnection data and forecasts. The approach is demonstrated on the operation of a realistic, stylised water reservoir with carry-over capacity in South-East Australia. Here teleconnections relating

  10. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 2: Supplemental Papers and Data Documentation.

    SciTech Connect

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmoids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator; northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  11. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 1, Final Report of Research.

    SciTech Connect

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program a measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmonids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator: northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  12. Microgravity Environment Description Handbook

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; McPherson, Kevin; Hrovat, Kenneth; Moskowitz, Milton; Rogers, Melissa J. B.; Reckart, Timothy

    1997-01-01

    The Microgravity Measurement and Analysis Project (MMAP) at the NASA Lewis Research Center (LeRC) manages the Space Acceleration Measurement System (SAMS) and the Orbital Acceleration Research Experiment (OARE) instruments to measure the microgravity environment on orbiting space laboratories. These laboratories include the Spacelab payloads on the shuttle, the SPACEHAB module on the shuttle, the middeck area of the shuttle, and Russia's Mir space station. Experiments are performed in these laboratories to investigate scientific principles in the near-absence of gravity. The microgravity environment desired for most experiments would have zero acceleration across all frequency bands or a true weightless condition. This is not possible due to the nature of spaceflight where there are numerous factors which introduce accelerations to the environment. This handbook presents an overview of the major microgravity environment disturbances of these laboratories. These disturbances are characterized by their source (where known), their magnitude, frequency and duration, and their effect on the microgravity environment. Each disturbance is characterized on a single page for ease in understanding the effect of a particular disturbance. The handbook also contains a brief description of each laboratory.

  13. CGL description revisited

    NASA Astrophysics Data System (ADS)

    Hunana, P.; Zank, G. P.; Goldstein, M. L.; Webb, G. M.; Adhikari, L.

    2016-03-01

    Solar wind observational studies have emphasized that the solar wind plasma data is bounded by the mirror and firehose instabilities, and it is often believed that these instabilities are of a purely kinetic nature. The simplest fluid model that generalizes magnetohydrodynamics with anisotropic temperatures is the Chew-Goldberger-Low model (CGL). Here we briefly revisit the CGL description and discuss its (otherwise well-documented) linear firehose and mirror instability thresholds; namely that the firehose instability threshold is identical to the one found from linear kinetic theory and that the mirror threshold contains a factor of 6 error. We consider a simple higher-order fluid model with time dependent heat flux equations and show that the mirror instability threshold is correctly reproduced. We also present fully nonlinear three-dimensional simulations of freely decaying turbulence for the Hall-CGL model with isothermal electrons. The spatial resolution of these simulations is 5123 and the formation of a spectral break in magnetic and velocity field spectra around the proton inertial length is found.

  14. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-07-01

    In fully-saturated rock and at ultrasonic frequencies, the microscopic squirt flow induced between the stiff and soft parts of the pore space by an elastic wave is responsible for velocity-frequency dispersion and attenuation. In the seismic frequency range, it is the macroscopic cross-flow between the stiffer and softer parts of the rock. We use the latter hypothesis to introduce simple approximate equations for velocity-frequency dispersion and attenuation in a fully water saturated reservoir. The equations are based on the assumption that in heterogeneous rock and at a very low frequency, the effective elastic modulus of the fully-saturated rock can be estimated by applying a fluid substitution procedure to the averaged (upscaled) dry frame whose effective porosity is the mean porosity and the effective elastic modulus is the Backus-average (geometric mean) of the individual dry-frame elastic moduli of parts of the rock. At a higher frequency, the effective elastic modulus of the saturated rock is the Backus-average of the individual fully-saturated-rock elastic moduli of parts of the rock. The difference between the effective elastic modulus calculated separately by these two methods determines the velocity-frequency dispersion. The corresponding attenuation is calculated from this dispersion by using (e.g.) the standard linear solid attenuation model.

  15. A coupled bubble plume-reservoir model for hypolimnetic oxygenation

    NASA Astrophysics Data System (ADS)

    Singleton, V. L.; Rueda, F. J.; Little, J. C.

    2010-12-01

    A model for a linear bubble plume used for hypolimnetic oxygenation was coupled with a three-dimensional hydrodynamic model to simulate the complex interaction between bubble plumes and the large-scale processes of transport and mixing. The coupled model accurately simulated the evolution of dissolved oxygen (DO) and temperature fields that occurred during two full-scale diffuser tests in a water supply reservoir. The prediction of asymmetric circulation cells laterally and longitudinally on both sides of the linear diffuser was due to the uneven reservoir bathymetry. Simulation of diffuser operation resulted in baroclinic pressure gradients, which caused vertical oscillations above the hypolimnion and contributed to distribution of plume detrainment upstream and downstream of the diffuser. On the basis of a first-order variance analysis, the largest source of uncertainty for both predicted DO and temperature was the model bathymetry, which accounted for about 90% of the overall uncertainty. Because the oxygen addition rate was 4 times the sediment oxygen uptake (SOU) rate, DO predictions were not sensitive to SOU. In addition to bathymetry, the momentum assigned to plume entrainment and detrainment is a significant source of uncertainty in the coupled model structure and appreciably affects the predicted intensity of mixing and lake circulation. For baseline runs, the entrainment and detrainment velocities were assumed to be half of the velocities through the flux face of the grid cells. Additional research on appropriate values of the plume detrainment momentum for the coupled model is required.

  16. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, R.S.

    1999-06-08

    This technical progress report describes work performed from October 1, 1998 through December 31, 1998, for the project, ''Using Chemicals to Optimize Conformance in Fractured Reservoirs.'' In our first task area, disproportionate permeability reduction, a literature survey and analysis are underway to identify options for reducing permeability to water much more than that to oil. In our second task area, we are encouraging the use of our recently developed software for sizing gelant treatments in hydraulically fractured production wells. In several field applications, we noted the importance of obtaining accurate values of the static reservoir pressure before using our program. In our third task area, we examined gel properties as they extruded through fractures. We found stable pressure gradients during injection of a large volume of a one-day-old Cr(III)-acetate-HPAM gel into a 0.04-in.-wide, four-ft-long fracture. This finding confirms that gel injection (under our specific circumstances) did not lead to continuously increasing pressure gradients and severely limited gel propagation. Our experiments also provided insights into the mechanism for gel propagation during extrusion through fractures.

  17. Robust numerical solution of the reservoir routing equation

    NASA Astrophysics Data System (ADS)

    Fiorentini, Marcello; Orlandini, Stefano

    2013-09-01

    The robustness of numerical methods for the solution of the reservoir routing equation is evaluated. The methods considered in this study are: (1) the Laurenson-Pilgrim method, (2) the fourth-order Runge-Kutta method, and (3) the fixed order Cash-Karp method. Method (1) is unable to handle nonmonotonic outflow rating curves. Method (2) is found to fail under critical conditions occurring, especially at the end of inflow recession limbs, when large time steps (greater than 12 min in this application) are used. Method (3) is computationally intensive and it does not solve the limitations of method (2). The limitations of method (2) can be efficiently overcome by reducing the time step in the critical phases of the simulation so as to ensure that water level remains inside the domains of the storage function and the outflow rating curve. The incorporation of a simple backstepping procedure implementing this control into the method (2) yields a robust and accurate reservoir routing method that can be safely used in distributed time-continuous catchment models.

  18. ENVIRONMENTAL AUDITING: An Integrated Approach to Reservoir Management: The Williston Reservoir Case Study.

    PubMed

    Baker; Young; Arocena

    2000-05-01

    / The management of industrial reservoirs for hydroelectric energy can cause severe impacts to surrounding communities. This study examines the generation of dust along the northern foreshore zones of Williston Reservoir in northern British Columbia. The dust is generated in the spring when the reservoir levels are low and impacts a relocated First Nations' village (Tsay Keh) at the north end of the reservoir. Data were gathered to provide an overview of the physical conditions that contribute to the dust problem, including a social survey, soil analysis, and vegetation inventory. The study provides a scoping method to assess a large-scale and complex problem with respect to dust management along a large reservoir. Methods for dust control include short- and long-term solutions that integrate the use of native vegetation along the foreshore zones of the reservoir.

  19. Thirteenth workshop on geothermal reservoir engineering: Proceedings

    SciTech Connect

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.; Cook, J.W.

    1988-01-21

    PREFACE The Thirteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 19-21, 1988. Although 1987 continued to be difficult for the domestic geothermal industry, world-wide activities continued to expand. Two invited presentations on mature geothermal systems were a keynote of the meeting. Malcolm Grant presented a detailed review of Wairakei, New Zealand and highlighted plans for new development. G. Neri summarized experience on flow rate decline and well test analysis in Larderello, Italy. Attendance continued to be high with 128 registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, New Zealand, Japan, Mexico and The Philippines. A discussion of future workshops produced a strong recommendation that the Stanford Workshop program continue for the future. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Four technical papers not presented at the Workshop are also published. In addition to these forty five technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was Gustavo Calderon from the Inter-American Development Bank. We thank him for sharing with the Workshop participants a description of the Bank???s operations in Costa Rica developing alternative energy resources, specifically Geothermal, to improve the country???s economic basis. His talk appears as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: J. Combs, G. T. Cole, J. Counsil, A. Drenick, H. Dykstra, K. Goyal, P. Muffler, K. Pruess, and S. K. Sanyal. The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Marilyn King, Pat Oto, Terri Ramey, Bronwyn Jones

  20. Filling the gaps: A robust description of adhesive birth-death-movement processes

    NASA Astrophysics Data System (ADS)

    Johnston, Stuart T.; Baker, Ruth E.; Simpson, Matthew J.

    2016-04-01

    Existing continuum descriptions of discrete adhesive birth-death-movement processes provide accurate predictions of the average discrete behavior for limited parameter regimes. Here we present an alternative continuum description in terms of the dynamics of groups of contiguous occupied and vacant lattice sites. Our method provides more accurate predictions, is valid in parameter regimes that could not be described by previous continuum descriptions, and provides information about the spatial clustering of occupied sites. Furthermore, we present a simple analytic approximation of the spatial clustering of occupied sites at late time, when the system reaches its steady-state configuration.