Science.gov

Sample records for heterogeneous geological formations

  1. Dynamic effective properties of heterogeneous geological formations with spherical inclusions under periodic time variations

    NASA Astrophysics Data System (ADS)

    Rabinovich, A.; Dagan, G.; Miloh, T.

    2013-04-01

    In unsteady groundwater flow (or similar processes of heat/electrical conduction), the heterogeneous medium structure is characterized by two random properties, the conductivity K and the specific storativity S. The average head field ⟨H ⟩and the associated effective properties Kef, Sef are determined for a layer with a periodic head drop between boundaries, such that H is periodic in time, and a medium made up of a matrix with a dilute concentration of spherical inclusions. In the common quasi-steady approximation, Kef is equal to the classical steady solution while Sef = SA, the arithmetic mean. We derive expressions for the frequency dependent Kef, Sef, which are generally complex, i.e., dynamic. The main result is the delineation of the ranges of the parameters: dimensionless frequency (ω) and contrasts of conductivity (κ) and storativity (s) between the matrix and the inclusions, for which dynamic effects are significant.

  2. Intermediate Scale Laboratory Testing to Understand Mechanisms of Capillary and Dissolution Trapping during Injection and Post-Injection of CO2 in Heterogeneous Geological Formations

    SciTech Connect

    Illangasekare, Tissa; Trevisan, Luca; Agartan, Elif; Mori, Hiroko; Vargas-Johnson, Javier; Gonzalez-Nicolas, Ana; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin

    2015-03-31

    Carbon Capture and Storage (CCS) represents a technology aimed to reduce atmospheric loading of CO2 from power plants and heavy industries by injecting it into deep geological formations, such as saline aquifers. A number of trapping mechanisms contribute to effective and secure storage of the injected CO2 in supercritical fluid phase (scCO2) in the formation over the long term. The primary trapping mechanisms are structural, residual, dissolution and mineralization. Knowledge gaps exist on how the heterogeneity of the formation manifested at all scales from the pore to the site scales affects trapping and parameterization of contributing mechanisms in models. An experimental and modeling study was conducted to fill these knowledge gaps. Experimental investigation of fundamental processes and mechanisms in field settings is not possible as it is not feasible to fully characterize the geologic heterogeneity at all relevant scales and gathering data on migration, trapping and dissolution of scCO2. Laboratory experiments using scCO2 under ambient conditions are also not feasible as it is technically challenging and cost prohibitive to develop large, two- or three-dimensional test systems with controlled high pressures to keep the scCO2 as a liquid. Hence, an innovative approach that used surrogate fluids in place of scCO2 and formation brine in multi-scale, synthetic aquifers test systems ranging in scales from centimeter to meter scale developed used. New modeling algorithms were developed to capture the processes controlled by the formation heterogeneity, and they were tested using the data from the laboratory test systems. The results and findings are expected to contribute toward better conceptual models, future improvements to DOE numerical codes, more accurate assessment of storage capacities, and optimized placement strategies. This report presents the experimental and modeling methods

  3. Formation evaluation: Geological procedures

    SciTech Connect

    Whittaker, A.

    1985-01-01

    This volume goes beyond a discussion of petroleum geology and the techniques of hydrocarbon (oil and gas) logging as a reservoir evaluation tool. It provides the logging geologist with a review of geological techniques and classification systems that will ensure the maximum development of communicable geological information. Contents include: 1. Introduction--cuttings recovery, cutting sampling, core sampling, rock classification; 2. Detrital rocks--classification, description; 3. Carbonate rocks--classification, description; 4. Chemical rocks-introduction, siliceous rocks, ferruginous rocks, aluminous rocks, phosphatic rocks, aluminous rocks, carbonaceous rocks; 5. Igneous and metamorpbic rocks; Appendix; References and Index.

  4. Heterogeneity and Scaling in Geologic Media

    SciTech Connect

    Gregory N. Boitnott; Gilles Y. Bussod; Paul N. Hagin; Stephen R. Brown

    2005-04-18

    to a different and more accurate description of a heterogeneous system, when compared to a more traditional upscaling approach that combines averaging and the application of core-based models. This may be of particular significance in bio-remediation studies where the link between microorganism activity and mesoscale flow through geologic structures, resides in the integration of multiscale processes.

  5. Numerical Modelling of Geological Heterogeneity - Implications for CO2 Geological Storage

    NASA Astrophysics Data System (ADS)

    Hermanson, J. L.; Kirste, D. M.

    2012-12-01

    different rock types are varied within reasonable ranges and grid spacing is refined to determine the sensitivity of the models to grid size. Variations between simulations are used to determine the differences in the partitioning of CO2 between its various storage mechanisms, and whether the differences are reflective of heterogeneities in the real system or attributed to numerical error. Initial results indicate that variations in certain parameters are more significant than others in terms of the movement and partitioning of CO2 into its various storage mechanisms. Variations in horizontal to vertical permeability contrasts, and residual liquid and gas saturation have significant impacts on the flow path of CO2 through the system, and therefore the amount of CO2 that becomes trapped residually within the pore spaces or dissolves into the formation brine. Gradual changes in heterogeneity do not seem to alter the results significantly in comparison to discrete changes, indicating that modelling heterogeneities as discrete bodies is an adequate assumption. Results imply that certain geological heterogeneities and associated parameters require more accurate representation then others when considering how CO2 will be stored within the subsurface. Although finer grid sizes increases the numerical accuracy of simulations, acute grid refinement may not be required for all purposes.

  6. Anomalous transport in weakly heterogeneous geological porous media

    NASA Astrophysics Data System (ADS)

    Wang, Yan

    2013-03-01

    Anomalous transport is found to be ubiquitous in complex geological formations and it has a paramount impact on petroleum engineering and groundwater sciences. This process can be well described by the continuous time random walk (CTRW) model, in which the probability density function w(t) of a particle's transition time t follows a power law for large t: w(t)˜t-1-α (0<α<2). In this work, based on the CTRW theory, a semifractional advection-diffusion equation is proposed to model the anomalous transport for 1<α<2, which is, as evidenced by field and numerical experiments, possibly the typical situation for many complex geological porous media with weakly heterogeneous microstructures.

  7. Method of fracturing a geological formation

    DOEpatents

    Johnson, James O.

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  8. Experimental study on effects of geologic heterogeneity in enhancing dissolution trapping of supercritical CO2

    NASA Astrophysics Data System (ADS)

    Agartan, Elif; Trevisan, Luca; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin; Illangasekare, Tissa H.

    2015-03-01

    Dissolution trapping is one of the primary mechanisms that enhance the storage security of supercritical carbon dioxide (scCO2) in saline geologic formations. When scCO2 dissolves in formation brine produces an aqueous solution that is denser than formation brine, which leads to convective mixing driven by gravitational instabilities. Convective mixing can enhance the dissolution of CO2 and thus it can contribute to stable trapping of dissolved CO2. However, in the presence of geologic heterogeneities, diffusive mixing may also contribute to dissolution trapping. The effects of heterogeneity on mixing and its contribution to stable trapping are not well understood. The goal of this experimental study is to investigate the effects of geologic heterogeneity on mixing and stable trapping of dissolved CO2. Homogeneous and heterogeneous media experiments were conducted in a two-dimensional test tank with various packing configurations using surrogates for scCO2 (water) and brine (propylene glycol) under ambient pressure and temperature conditions. The results show that the density-driven flow in heterogeneous formations may not always cause significant convective mixing especially in layered systems containing low-permeability zones. In homogeneous formations, density-driven fingering enhances both storage in the deeper parts of the formation and contact between the host rock and dissolved CO2 for the potential mineralization. On the other hand, for layered systems, dissolved CO2 becomes immobilized in low-permeability zones with low-diffusion rates, which reduces the risk of leakage through any fault or fracture. Both cases contribute to the permanence of the dissolved plume in the formation.

  9. Petroleum geology of formation waters

    SciTech Connect

    Billo, S.M.

    1996-06-01

    Some researchers have argued that most petroleum traps are hydrostatic and the potentiometric surface is a level plane, whereas others have emphasized the importance of hydrodynamic traps and that the potentiometric surface slopes. The Salt Creek oil field, Wyoming is a prime example of the large, anticlinal traps that has produced over 500 million barrels of oil, and was located by a large oil seep over the trap. The structure has five producing zones, all sandstones in the Cretaceous and the Sundance sand (Jurassic). Each has a separate oil-water contact and a transition zone, indicating a lack of permeable interconnection. The multiple oil-water contacts dip northward in pact with the hydraulic gradient of the region. The slope of the potentiometric surface determines whether the water is in a state of static or dynamic equilibrium. A hydrodynamic condition is usually dependent on the topography of the surface and/or the geology of the region. Knowledge of subsurface waters can help in the discovery and seismic mapping of hydrocarbon reservoirs through valuation of possible changes imposed on the waters in the presence of hydrocarbons; by recognition of changes related to conducive development of traps; and eventually by defining condition of origin and migration of oil and gas.

  10. Simulation of Seismic Tunnel Detection Experiments in Heterogeneous Geological Media

    NASA Astrophysics Data System (ADS)

    Sherman, C. S.; Glaser, S. D.; Rector, J.

    2013-12-01

    Detecting covert tunnels and other underground openings is an important yet challenging problem for geophysicists, especially where geological heterogeneity is pronounced. A number of geophysical methods have been employed to solve this problem, each with varying degrees of success. We focus on the near-surface seismic techniques of surface wave backscattering, surface wave attenuation tomography, body wave diffraction imaging, and resonant imaging. We use the elastodynamic wave propagation code E3D to simulate tunnel detection experiments completed at this site for a range of synthetic fractal velocity models. The Black Diamond mine, located near Pittsburg California, is used for the field test of our analysis. Our results show that for the relatively low-frequency surface wave attenuation and backscattering methods, the maximum detectable tunnel depth in a homogenous medium is approximately equal to the wavelength of the probing Rayleigh wave. The higher-frequency body wave diffraction and resonant imaging techniques are able to locate tunnels at greater depths, but require more sophisticated analysis and are prone to greater attenuation losses. As is expected, for large values of heterogeneity amplitude, ɛ, the percent standard deviation from the mean velocity model, the average observed surface wave attenuation signal decreases and the maximum detectable tunnel depth decreases. However, for moderate values of heterogeneity amplitude (ɛ < 3%), the average surface wave attenuation signal increases and the maximum detectable tunnel depth increases. For the body wave diffraction and resonant imaging experiments, as ɛ increases the complexity of the observed signal increases, resulting in more difficult processing and interpretation. The additional scattering attenuation tends to degrade the signals significantly due to their reliance on lower amplitude and higher frequency waves.

  11. Adaptable formations utilizing heterogeneous unmanned systems

    NASA Astrophysics Data System (ADS)

    Barnes, Laura E.; Garcia, Richard; Fields, MaryAnne; Valavanis, Kimon

    2009-05-01

    This paper addresses the problem of controlling and coordinating heterogeneous unmanned systems required to move as a group while maintaining formation. We propose a strategy to coordinate groups of unmanned ground vehicles (UGVs) with one or more unmanned aerial vehicles (UAVs). UAVs can be utilized in one of two ways: (1) as alpha robots to guide the UGVs; and (2) as beta robots to surround the UGVs and adapt accordingly. In the first approach, the UAV guides a swarm of UGVs controlling their overall formation. In the second approach, the UGVs guide the UAVs controlling their formation. The unmanned systems are brought into a formation utilizing artificial potential fields generated from normal and sigmoid functions. These functions control the overall swarm geometry. Nonlinear limiting functions are defined to provide tighter swarm control by modifying and adjusting a set of control variables forcing the swarm to behave according to set constraints. Formations derived are subsets of elliptical curves but can be generalized to any curvilinear shape. Both approaches are demonstrated in simulation and experimentally. To demonstrate the second approach in simulation, a swarm of forty UAVs is utilized in a convoy protection mission. As a convoy of UGVs travels, UAVs dynamically and intelligently adapt their formation in order to protect the convoy of vehicles as it moves. Experimental results are presented to demonstrate the approach using a fully autonomous group of three UGVs and a single UAV helicopter for coordination.

  12. Geologic Study of the Coso Formation

    SciTech Connect

    D. L. Kamola; J. D. Walker

    1999-12-01

    There have been great advances in the last 20 years in understanding the volcanic, structural, geophysical, and petrologic development of the Coso Range and Coso geothermal field. These studies have provided a wealth of knowledge concerning the geology of the area, including general structural characteristics and kinematic history. One element missing from this dataset was an understanding of the sedimentology and stratigraphy of well-exposed Cenozoic sedimentary strata - the Coso Formation. A detailed sedimentation and tectonics study of the Coso Formation was undertaken to provide a more complete picture of the development of the Basin and Range province in this area. Detailed mapping and depositional analysis distinguishes separate northern and southern depocenters, each with its own accommodation and depositional history. While strata in both depocenters is disrupted by faults, these faults show modest displacement, and the intensity and magnitude of faulting does no t record significant extension. For this reason, the extension between the Sierran and Coso blocks is interpreted as minor in comparison to range bounding faults in adjacent areas of the Basin and Range.

  13. Constructing Hydraulic Barriers in Deep Geologic Formations

    SciTech Connect

    Carter, E.E.; Carter, P.E.; Cooper, D.C.

    2008-07-01

    Many construction methods have been developed to create hydraulic barriers to depths of 30 to 50 meters, but few have been proposed for depths on the order of 500 meters. For these deep hydraulic barriers, most methods are potentially feasible for soil but not for hard rock. In the course of researching methods of isolating large subterranean blocks of oil shale, the authors have developed a wax thermal permeation method for constructing hydraulic barriers in rock to depths of over 500 meters in competent or even fractured rock as well as soil. The technology is similar to freeze wall methods, but produces a permanent barrier; and is potentially applicable in both dry and water saturated formations. Like freeze wall barriers, the wax thermal permeation method utilizes a large number of vertical or horizontal boreholes around the perimeter to be contained. However, instead of cooling the boreholes, they are heated. After heating these boreholes, a specially formulated molten wax based grout is pumped into the boreholes where it seals fractures and also permeates radially outward to form a series of columns of wax-impregnated rock. Rows of overlapping columns can then form a durable hydraulic barrier. These barriers can also be angled above a geologic repository to help prevent influx of water due to atypical rainfall events. Applications of the technique to constructing containment structures around existing shallow waste burial sites and water shutoff for mining are also described. (authors)

  14. Radon potential, geologic formations, and lung cancer risk

    PubMed Central

    Hahn, Ellen J.; Gokun, Yevgeniya; Andrews, William M.; Overfield, Bethany L.; Robertson, Heather; Wiggins, Amanda; Rayens, Mary Kay

    2015-01-01

    Objective Exposure to radon is associated with approximately 10% of U.S. lung cancer cases. Geologic rock units have varying concentrations of uranium, producing fluctuating amounts of radon. This exploratory study examined the spatial and statistical associations between radon values and geological formations to illustrate potential population-level lung cancer risk from radon exposure. Method This was a secondary data analysis of observed radon values collected in 1987 from homes (N = 309) in Kentucky and geologic rock formation data from the Kentucky Geological Survey. Radon value locations were plotted on digital geologic maps using ArcGIS and linked to specific geologic map units. Each map unit represented a package of different types of rock (e.g., limestone and/or shale). Log-transformed radon values and geologic formation categories were compared using one-way analysis of variance. Results Observed radon levels varied significantly by geologic formation category. Of the 14 geologic formation categories in north central Kentucky, four were associated with median radon levels, ranging from 8.10 to 2.75 pCi/L. Conclusion Radon potential maps that account for geologic factors and observed radon values may be superior to using observed radon values only. Knowing radon-prone areas could help target population-based lung cancer prevention interventions given the inequities that exist related to radon. PMID:26844090

  15. Are geological media homogeneous or heterogeneous for neutron investigations?

    PubMed

    Woźnicka, U; Drozdowicz, K; Gabańska, B; Krynicka, E; Igielski, A

    2003-01-01

    The thermal neutron absorption cross section of a heterogeneous material is lower than that of the corresponding homogeneous one which contains the same components. When rock materials are investigated the sample usually contains grains which create heterogeneity. The heterogeneity effect depends on the mass contribution of highly and low-absorbing centers, on the ratio of their absorption cross sections, and on their sizes. An influence of the granulation of silicon and diabase samples on the absorption cross section measured with Czubek's method has been experimentally investigated. A 20% underestimation of the absorption cross section has been observed for diabase grains of sizes from 6.3 to 12.8 mm. PMID:12485675

  16. A Laboratory Study of Heterogeneity and Scaling in Geologic Media

    NASA Astrophysics Data System (ADS)

    Brown, S.; Boitnott, G.; Bussod, G.; Hagan, P.

    2004-05-01

    In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. We are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been characterizing the heterogeneity of a bench-size Berea sandstone block. Berea Sandstone has long been regarded as a laboratory standard in rock properties studies, owing to its uniformity and ``typical'' physical properties. We find

  17. Solute transport in heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Demmy, George Gary, Jr.

    1999-10-01

    This work quantifies relationships between the spatial, or Eulerian, distribution of the properties of a chemically and physically heterogeneous porous medium and those as observed along the natural, or Lagrangian, trajectories that a fluid particle traces in a steady and irrotational flow. From these relationships, expressions that relate the transport of solutes through the porous medium along the natural trajectories to the aforementioned Eulerian distributions are developed. The effects of injection mode upon global measures of transport as reflected by the temporal moments of breakthrough curves and spatial moments of a solute plume are developed. The coupled effects of correlation of a linear equilibrium sorption to the underlying log hydraulic conductivity field and injection mode on the evolving temporal moments of mass breakthrough curve and the coupled effects of correlation of a first-order decay coefficient and injection mode upon the spatial moments of a solute plume are examined.

  18. Experimental Investigation of CO2 Trapping and Leakage Mechanisms in Deep Geologic Formations for Model Improvement

    NASA Astrophysics Data System (ADS)

    Illangasekare, T. H.; Trevisan, L.; Agartan, E.; Vargas-Johnson, J.; Plampin, M. R.; Pini, R.; Pawar, R.; Cihan, A.; Birkholzer, J. T.; Zhou, Q.

    2014-12-01

    A fundamental and a comprehensive understanding of trapping and leakage processes will be of value to develop strategies for efficient and secure storage of CO2 in deep geologic formations and assess environmental and ecological risks associated with potential leakage. It is our contention that to make observations and collect data to obtain a fundamental understanding of how the natural formation heterogeneity manifested at all scales affects trapping is highly challenging or impossible to obtain in real field settings in deep geologic formations. A test scale intermediary between small laboratory columns and field scales that is referred to as "intermediate scale" provides an attractive alternative to investigate these processes under controlled conditions in the laboratory. Heterogeneities at all needed test scales can be designed using soils with known properties and experiments can be conducted under controlled conditions to obtain accurate data. Conducting intermediate scale laboratory experiments under ambient pressure and temperature conditions to understand the processes that occur in deep formations with very higher pressures and drastically different temperatures pose many challenges. This paper presents the approaches that were used to conduct multi-scale experiments from column to intermediate scale to understand the factors that contribute to capillary and dissolution trapping using surrogate fluids for supercritical CO2 and saline water combination. In addition, experiments were conducted in soil columns and two-dimensional tanks to study the effects of formation heterogeneity on CO2 gas evolution during leakage of water with dissolved CO2. The results from these experiments are presented to show how the new insights have helped to improve the conceptual understanding of effects of heterogeneity on CO2 trapping and leakage. This understanding has helped to improve numerical models that can be used to better engineer CO2 storage systems for permanence

  19. Ukranian program of radioactive waste disposal in geological formations

    SciTech Connect

    Khrushchov, D.P.; Pavlovsky, M.A.; Starodoumov, V.M.

    1996-12-01

    On the initiative of State Committee on Nuclear Power Utilization the purposeful investigations in the frames of interinstitutional program `isolation of radioactive waste in geologic formations` has been started in 1998. A preparatory stage of R&D program has been completed.

  20. The Suitable Geological Formations for Spent Fuel Disposal in Romania

    SciTech Connect

    Marunteanu, C.; Ionita, G.; Durdun, I.

    2007-07-01

    Using the experience in the field of advanced countries and formerly Romanian program data, ANDRAD, the agency responsible for the disposal of radioactive wastes, started the program for spent fuel disposal in deep geological formations with a documentary analysis at the national scale. The potential geological formations properly characterized elsewhere in the world: salt, clay, volcanic tuff, granite and crystalline rocks,. are all present in Romania. Using general or specific selection criteria, we presently consider the following two areas for candidate geological formations: 1. Clay formations in two areas in the western part of Romania: (1) The Pannonian basin Socodor - Zarand, where the clay formation is 3000 m thick, with many bentonitic strata and undisturbed structure, and (2) The Eocene Red Clay on the Somes River, extending 1200 m below the surface. They both need a large investigation program in order to establish and select the required homogeneous, dry and undisturbed zones at a suitable depth. 2. Old platform green schist formations, low metamorphosed, quartz and feldspar rich rocks, in the Central Dobrogea structural unit, not far from Cernavoda NPP (30 km average distance), 3000 m thick and including many homogeneous, fine granular, undisturbed, up to 300 m thick layers. (authors)

  1. Oceanic crust recycling and the formation of lower mantle heterogeneity

    NASA Astrophysics Data System (ADS)

    van Keken, Peter E.; Ritsema, Jeroen; Haugland, Sam; Goes, Saskia; Kaneshima, Satoshi

    2016-04-01

    The Earth's lower mantle is heterogeneous at multiple scales as demonstrated for example by the degree-2 distribution of LLSVPs seen in global tomography and widespread distribution of small scale heterogeneity as seen in seismic scattering. The origin of this heterogeneity is generally attributed to leftovers from Earth's formation, the recycling of oceanic crust, or a combination thereof. Here we will explore the consequences of long-term oceanic crust extraction and recycling by plate tectonics. We use geodynamical models of mantle convection that simulate plates in an energetically consistent manner. The recycling of oceanic crust over the age of the Earth produces persistent lower mantle heterogeneity while the upper mantle tends to be significantly more homogeneous. We quantitatively compare the predicted heterogeneity to that of the present day Earth by tomographic filtering of the geodynamical models and comparison with S40RTS. We also predict the scattering characteristics from S-P conversions and compare these to global scattering observations. The geophysical comparison shows that lower mantle heterogeneity is likely dominated by long-term oceanic crust recycling. The models also demonstrate reasonable agreement with the geochemically observed spread between HIMU-EM1-DMM in ocean island basalts as well as the long-term gradual depletion of the upper mantle as observed in Lu-Hf systematics.

  2. Geological pattern formation by growth and dissolution in aqueous systems

    SciTech Connect

    Paul Meakin

    2010-03-01

    Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the seasons was critically important to early human society, and Halley’s prediction of the return of the comet that bears his name is still considered to be a scientific milestone. Spatial patterns have also attracted attention because of their aesthetic appeal, which depends in subtle ways on a combination of regularity and irregularity. In recent decades, rapid growth in the capabilities of digital computers has facilitated the simulation of pattern formation processes, and computer simulations have become an important tool for evaluating theoretical concepts and for scientific discovery. Computer technology in combination with other technologies such as high resolution digital cameras, scanning microprobes (atomic force microscopy AFM), confocal microscopy, and scanning tunneling microscopy (STM), for example) has facilitated the quantitative characterization of patterns over a wide range of scales and has enabled rapid advances in our ability to understand the links between large scale pattern formation and microscopic processes. The ability to quantitatively characterize patterns is important because it enables a more rigorous comparison between the predictions of computer models and real world patterns and their formation.In some cases, the idea that patterns with a high degree of regularity have simple origins appears to be justified, but in other cases, such as the formation of almost perfectly circular stone rings due to freeze-thaw cycles simple patterns appear to be the consequence of quite complex processes. In other cases, it has been shown that

  3. Applying Seismic Methods to National Security Problems: Matched Field Processing With Geological Heterogeneity

    SciTech Connect

    Myers, S; Larsen, S; Wagoner, J; Henderer, B; McCallen, D; Trebes, J; Harben, P; Harris, D

    2003-10-29

    Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization of full three-dimensional (3D) finite difference modeling, as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project, in support of LLNL's national-security mission, benefits the U.S. military and intelligence community. Fiscal year (FY) 2003 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and analysis. The E3D code was enhanced to include topographic effects. Codes were developed to implement the Karhunen-Loeve (K-L) statistical methodology for generating geological heterogeneity that can be utilized in E3D modeling. The matched field processing methodology applied to vehicle tracking and based on a field calibration to characterize geological heterogeneity was tested and successfully demonstrated in a tank tracking experiment at the Nevada Test Site. A three-seismic-array vehicle tracking testbed was installed on site

  4. Experimental study of heterogeneity-induced capillary trapping in the context of leakage from geologic carbon sequestration sites

    NASA Astrophysics Data System (ADS)

    Liang, B.; Clarens, A. F.

    2014-12-01

    Leakage of CO2 from geologic carbon sequestration sites could undermine the long-term goal of reducing emissions to the atmosphere. Despite this, leakage processes, especially the vertical transport of gases through geologic formations overlaying target repositories, are poorly characterized. The goal of this work was to experimentally assess how sub-basin scale heterogeneity in overlaying formations could reduce CO2 leakage. High-pressure columns packed with sand and glass beads of different sizes were used to create a capillary barrier, which is an analog of low-permeability inter-beds. Transport of the resulting plume was recorded in real time using electrical resistivity. The effect of pressure, temperature, permeability, surface wettability, and CO2 flow rate were all assessed. Real-time monitoring and quantification of CO2 saturation suggests that capillary heterogeneity trapping is primarily controlled by permeability contrast, pressure, temperature and water/CO2 wettability on mineral surfaces. The amount of trapping was considerably enhanced when permeability contrasted increased, showing a good agreement with equilibrium capillary pressure - saturation analysis in the literature. Temperature and pressure controlled experiments demonstrated the sensitivity of capillary trapping to geothermal and pressure gradient. Wettability alterations also increased initial trapping when more CO2-philic materials is presented and a much greater increase in residual trapping (defined as 10 pore volume water re-imbibition). Variation of leakage rate was not shown to result in significant difference in the overall saturation values, but the stability of the trapped plume was reduced at high CO2 injection rates. These results suggest that local capillary trapping could contribute to secondary trapping and slow the buoyancy-driven rise of CO2. These measurements could have important implications for minimizing risk associated with leakage from carbon sequestration sites.

  5. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2012-02-01

    The microbial diversity in subsurface sediments at the Hanford Site's 300 Area in southeastern Washington State was investigated by analyzing 21 samples recovered from depths that ranged from 9 to 52 m. Approximately 8000 non-chimeric Bacterial and Archaeal 16S rRNA gene sequences were analyzed across geological strata that contain a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units, defined at the 97% identity level). Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (based upon Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic transition zone, richness was about 325 and declined to less than 50 in the deeper reduced zones. The Bacterial community in the oxic Hanford and Ringold Formations contained members of 9 major well-recognized phyla as well 30 as unusually high proportions of 3 candidate divisions (GAL15, NC10, and SPAM). The deeper Ringold strata were characterized by low OTU richness and a very high preponderance (ca. 90%) of Proteobacteria. The study has greatly expanded the intralineage phylogenetic diversity within some major divisions. These subsurface sediments have been shown to contain a large number of phylogenetically novel microbes, with substantial heterogeneities between sediment samples from the same geological formation.

  6. Large-scale characterization of geologic formations for CO2 injection using Compressed State Kalman Filter

    NASA Astrophysics Data System (ADS)

    Kokkinaki, A.; Li, J. Y.; Zhou, Q.; Birkholzer, J. T.; Kitanidis, P. K.

    2014-12-01

    Carbon dioxide (CO2) storage in deep geologic formations is gaining ground as a potential measure for climate change mitigation. Such storage projects typically operate at large scales (~km), but their performance is often governed by smaller-scale (~m) heterogeneities. The large domain sizes prohibit detailed site characterization and dense monitoring networks, leading to predictions of CO2 migration and trapping based on rough geologic models that cannot capture preferential flow. Kalman Filtering can be used to improve these prior models by assimilating available monitoring data, thereby tracking system performance and reducing prediction uncertainty. However, for large systems with fine discretization, the number of unknowns is in the order of tens of thousands or more, in which case the textbook version of the Kalman Filter has prohibitively expensive computation and storage costs. We present the Compressed State Kalman Filter (CSKF) that can be effectively used for systems with a large number of unknowns to estimate the underlying heterogeneity and to predict the state of interest (e.g., pressure and CO2 saturation). The algorithm's computational efficiency is achieved by using a low-rank approximation of the covariance matrix, as well as a Jacobian-free approach. We demonstrate the estimation and computational performance of our method in a typical CO2 storage scenario with a spatially sparse monitoring network, but with multiple datasets obtained before and during CO2 injection. Our data assimilation framework provides an efficient and practical way to characterize geological formations intended for CO2 injection and storage using monitoring data commonly collected in field applications, as well as to quantify the reduction in uncertainty brought by different types of monitoring data.

  7. Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Final report

    SciTech Connect

    Menzie, D.E.

    1995-05-01

    The main objective of this research project is to investigate dispersion as a method of quantifying geological characterization and defining reservoir heterogeneity in order to enhance crude oil recovery. The dispersion of flow of a reservoir rock (dispersion coefficient and dispersivity) was identified as one of the physical properties of a reservoir rock by measuring the mixing of two miscible fluids, one displacing the other in a porous medium. A rock was 100% saturated with a resident fluid and displaced by a miscible fluid of equal viscosity and equal density. Some specific experiments were performed with unequal densities. Produced fluid was analyzed by refractometer, nuclear reaction, electrical conductivity and X-ray scan. Several physical and flow characteristics were measured on the sand rock sample in order to establish correlations with the measured dispersion property. Absolute permeability, effective porosity, relative permeability, capillary pressure, the heterogeneity factor and electrical conductivity were used to better understand the flow system. Linear, transverse, 2-D and 3-D dispersions were measured and used to characterize the rock heterogeneity of the flow system. A new system of measuring dispersion was developed using a gas displacing gas system in a porous medium. An attempt was also made to determine the dispersion property of an actual reservoir from present day well log data on a producing well. 275 refs., 102 figs., 17 tabs.

  8. Geology of the Biwabik Iron Formation and Duluth Complex.

    PubMed

    Jirsa, Mark A; Miller, James D; Morey, G B

    2008-10-01

    The Biwabik Iron Formation is a approximately 1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by approximately 1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. PMID:17997209

  9. Geology of the Biwabik Iron Formation and Duluth Complex

    USGS Publications Warehouse

    Jirsa, M.A.; Miller, J.D., Jr.; Morey, G.B.

    2008-01-01

    The Biwabik Iron Formation is a ???1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by ???1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. ?? 2007 Elsevier Inc. All rights reserved.

  10. Evaluation of a method for designing sealing plugs for HLW geological disposal facilities, taking into account the heterogeneous characteristics of the geological environment

    SciTech Connect

    Suyama, Yasuhiro; Yanagizawa, Koichi; Toida, Masaru

    2007-07-01

    In order to ensure that a repository for the geological disposal of HLW is isolated from the human environment, underground excavations, including pits and tunnels, must be properly sealed. Effective sealing requires that these excavations are backfilled, and that the Excavation Damage or Disturbed Zone (EDZ), which includes preferential flow paths, must be intersected by sealing plugs. Methods for constructing a full-scale sealing plug and their influence on plug performance were evaluated and confirmed by a Tunnel Sealing Experiment (TSX). This experiment was carried out by an international partnership of the Japan Nuclear Cycle Development Institute (JNC) and Atomic Energy of Canada Limited (AECL). However certain specific roles of the scaling plugs at the scale of the whole repository were not studied. There remain issues to be clarified, notably the effectiveness of sealing plugs in a geological environment with heterogeneous characteristics and the resulting influences of the heterogeneities in performance assessment. Focusing on a geological environment with spatially heterogeneous characteristics, the authors have developed a method for designing the sealing plugs, based on a concept of 'primarily design for closure, secondarily design for construction'. Though the proposed method for designing sealing plugs has presently been developed only at a conceptual level, it indicates the possibility of establishing a repository even in a strongly heterogeneous geological environment that may have been considered previously to be inappropriate for a repository. (authors)

  11. Photoacoustic Signal Formation in Heterogeneous Multilayer Systems with Piezoelectric Detection

    NASA Astrophysics Data System (ADS)

    Isaiev, Mykola; Andrusenko, Dmytro; Tytarenko, Alona; Kuzmich, Andrey; Lysenko, Vladimir; Burbelo, Roman

    2014-12-01

    A new efficient model describing photoacoustic (PA) signal formation with piezoelectric detection is reported. Multilayer sandwich-like systems: heterogeneous studied structure—buffer layer—piezoelectric transducers are considered. In these systems, the buffer layer is used for spatial redistribution of thermoelastic force moments generated in the investigated structure. Thus, mechanical properties of this layer play a crucial role to ensure perfect control of the detected voltage formed on a piezoelectric transducer by contribution of different regions of the studied structure. In particular, formation of the voltage signal strongly depends on the point at which the thermoelastic source is applied. Therefore, use of relatively simple linear Green's functions introduced in frames of the Kirchhoff-Love theory is chosen as an efficient approach for the PA signal description. Moreover, excellent agreement between the theoretical model and measured results obtained on a heterogeneous "porous silicon-bulk Si substrate" structure is stated. Furthermore, resolving of the inverse problem with fitting of the experimental curves by the developed model allows reliable evaluation of the thermal conductivity of the nanostructured porous silicon layer.

  12. Acid-catalyzed Heterogeneous Reactions in SOA Formation

    NASA Astrophysics Data System (ADS)

    Ng, N.; Keywood, M.; Varutbangkul, V.; Gao, S.; Loewer, E.; Surratt, J.; Richard, F. C.; John, S. H.

    2003-12-01

    The importance of heterogeneous reactions in secondary organic aerosol (SOA) formation has recently excited a great deal of interest in the aerosol community. Jang and Kamens (2001) showed enhanced aerosol yield from aldehydes, which can be produced by atmospheric photochemical reactions, in the presence of acidic seed. They suggest that the carbonyl functional groups of the aldehydes further react in the aerosol phase via hydration, polymerization, and hemiacetal/acetal formation with alcohols at an accelerated rate in the presence of acid. Jang et al. (2003) demonstrated similar results using a flow reactor and Czoschke et al. (in press) qualitatively showed increased yields for isoprene and alpha-pinene ozonolysis in the presence of acidic seed. While these findings are intriguing and important, the conditions under which the experiments were carried out were atmospherically unrealistic. A series of SOA formation experiments have been carried out in the Caltech Indoor Chamber Facility, which is comprised of dual 28 m3 FEP Teflon chambers, with the flexibility to carry out both dark ozonolysis and photochemical OH oxidation reactions. Cycloheptene and alpha-pinene were oxidized in the presence of neutral seed under dry (<10% RH) and humid (50% RH) conditions and in the presence of acidic seed under humid (50% RH) conditions. The SOA yields for these experiments will be presented, and the extent of the influence of acid-catalyzed reactions on SOA yield will be discussed. Reference List 1. Cocker, D. R. III. and R. C. Flagan and J. H. Seinfeld, State-of-the-art chamber facility for studying atmospheric aerosol chemistry, Environmental Science and Technology, 35, 2594-2601, 2001. 2. Czoschke, N. M., M. Jang, and R. M. Kamens, Effect of acid seed on biogenic sceondary organic aerosol growth, Atmospheric Environment, In press. 3. Jang, M., S. Lee, and R. M. Kamens, Organic aerosol growth by acid-catalyzed heterogeneous reactions of octanal in a flow reactor

  13. The Influence of Geologic Heterogeneity on Groundwater Salinity and Aquifer-Ocean Exchange on the Scale of the Continental Shelf

    NASA Astrophysics Data System (ADS)

    Michael, H. A.; Scott, K. C.; Koneshloo, M.; Khan, M. R.; Katie, L.

    2015-12-01

    Exchange of water between aquifers and the ocean critically affects the quality of coastal groundwater resources and modifies ocean chemistry on both short and long timescales. Fresh groundwater has been shown to exist far offshore, and this is a potential future resource. However, controls on the origin of offshore freshened groundwater and the timescale over which it responds to hydrologic change are not well known. Further, high rates of saline groundwater discharge have been observed directly nearshore and with tracers across continental shelves, but the physical explanation for these large fluxes is not well established. Steady-state variable-density groundwater flow and solute transport simulations incorporating geostatistically-generated distributions of aquifer lithology were performed to explore the role of geologic heterogeneity in large-scale coastal groundwater flow and solute transport processes. Results indicate that heterogeneity critically affects both salinity distributions and aquifer-ocean exchange. The position, size, and variability of the mixing zone are influenced by the shore-perpendicular connectivity of the geologic structure. Submarine groundwater discharge extends further offshore and is more highly variable in heterogeneous relative to equivalent homogeneous simulations, and this effect increases with connectivity. The circulation of saline groundwater is consistently higher in heterogeneous simulations relative to homogeneous regardless of aquifer connectivity, increasing up to several orders of magnitude. These simulations suggest that heterogeneous aquifers with high geologic connectivity can result in significant volumes of freshened groundwater accompanied by fresh and saline discharge tens to hundreds of kilometers offshore along the continental shelf, even under present-day equilibrium conditions. The complicated flow fields and salinity distributions resulting from geologic heterogeneity contribute to high rates of saline

  14. Estimation of hydrologic properties of heterogeneous geologic media with an inverse method based on iterated function systems

    SciTech Connect

    Doughty, C.A.

    1996-05-01

    The hydrologic properties of heterogeneous geologic media are estimated by simultaneously inverting multiple observations from well-test data. A set of pressure transients observed during one or more interference tests is compared to the corresponding values obtained by numerically simulating the tests using a mathematical model. The parameters of the mathematical model are varied and the simulation repeated until a satisfactory match to the observed pressure transients is obtained, at which point the model parameters are accepted as providing a possible representation of the hydrologic property distribution. Restricting the search to parameters that represent fractal hydrologic property distributions can improve the inversion process. Far fewer parameters are needed to describe heterogeneity with a fractal geometry, improving the efficiency and robustness of the inversion. Additionally, each parameter set produces a hydrologic property distribution with a hierarchical structure, which mimics the multiple scales of heterogeneity often seen in natural geological media. Application of the IFS inverse method to synthetic interference-test data shows that the method reproduces the synthetic heterogeneity successfully for idealized heterogeneities, for geologically-realistic heterogeneities, and when the pressure data includes noise.

  15. Elastic and plastic effects on heterogeneous nucleation and nanowire formation

    NASA Astrophysics Data System (ADS)

    Boussinot, G.; Schulz, R.; Hüter, C.; Brener, E. A.; Spatschek, R.

    2014-02-01

    We investigate theoretically the effects of elastic and plastic deformations on heterogeneous nucleation and nanowire formation. In the first case, the influence of the confinement of the critical nucleus between two parallel misfitting substrates is investigated using scaling arguments. We present phase diagrams giving the nature of the nucleation regime as a function of the driving force and the degree of confinement. We complement this analytical study by amplitude equations simulations. In the second case, the influence of a screw dislocation inside a nanowire on the development of the morphological surface instability of the wire, related to the Rayleigh-Plateau instability, is examined. Here the screw dislocation provokes a torsion of the wire known as Eshelby twist. Numerical calculations using the finite element method and the amplitude equations are performed to support analytical investigations. It is shown that the screw dislocation promotes the Rayleigh-Plateau instability.

  16. Sulfuric Acid Monohydrate: Formation and Heterogeneous Chemistry in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Zhang, Renyi; Leu, Ming-Taun; Keyser, Leon F.

    1995-01-01

    We have investigated some thermodynamic properties (i.e., freezing/melting points) and heterogeneous chemistry of sulfuric acid monohydrate (SAM, H2SO4.H2O), using a fast flow reactor coupled to a quadrupole mass spectrometer. The freezing point observations of thin liquid sulfuric acid films show that for acid contents between 75 and 85 wt % the monohydrate crystallizes readily at temperatures between 220 and 240 K on a glass substrate. Once formed, SAM can be thermodynamically stable in the H2O partial pressure range of (1-4) x 10(exp -4) torr and in the temperature range of 220-240 K. For a constant H2O partial pressure, lowering the temperature causes SAM to melt when the temperature and water partial pressure conditions are out of its stability regime. The reaction probability measurements indicate that the hydrolysis of N2O5 is significantly suppressed owing to the formation of crystalline SAM: The reaction probability on water-rich SAM (with higher relative humidity, or RH) is of the order of 10(exp -3) at 210 K and decreases by more than an order of magnitude for the acid-rich form (with lower RH). The hydrolysis rate of ClONO2 on water-rich SAM is even smaller, of the order of 10(exp -4) at 195 K. These reported values on crystalline SAM are much smaller than those on liquid solutions. No enhancement of these reactions is observed in the presence of HCl vapor at the stratospheric concentrations. In addition, Brunauer, Emmett, and Teller analysis of gas adsorption isotherms and photomicrography have been performed to characterize the surface roughness and porosities of the SAM substrate. The results suggest the possible formation of SAM in some regions of the middle- or low-latitude stratosphere and, consequently, much slower heterogeneous reactions on the frozen aerosols.

  17. Determining resistivity of a geological formation using circuitry located within a borehole casing

    DOEpatents

    Vail III, William Banning

    2006-01-17

    Geological formation resistivity is determined. Circuitry is located within the borehole casing that is adjacent to the geological formation. The circuitry can measure one or more voltages across two or more voltage measurement electrodes associated with the borehole casing. The measured voltages are used by a processor to determine the resistivity of the geological formation. A common mode signal can also be reduced using the circuitry.

  18. Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

    SciTech Connect

    Brown, Stephen R.

    2003-06-01

    Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones Stephen Brown, Gregory Boitnott, and Martin Smith New England Research In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. With the exception of the acoustic velocity, we are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been

  19. Influence of tile-drainage on groundwater flow and nitrate transport in heterogeneous geological materials

    NASA Astrophysics Data System (ADS)

    De Schepper, G.; Therrien, R.; Refsgaard, J.

    2012-12-01

    Subsurface drainage is a common agricultural practice in poorly drained production fields to guarantee the productivity of crops and to reduce flooding risks. The impact of shallow tile-drainage networks on groundwater flow patterns and associated nitrate transport from the surface needs to be quantified for adequate agricultural management. A challenge is to represent tile-drain networks in numerical models, at the field scale, while accounting for the influence of subsurface heterogeneities on flow and transport. A numerical model of a tile-drainage system has been developed with the fully integrated HydroGeoSphere model for the Lillebaek agricultural catchment, Denmark. The Lillebaek catchment is an experimental study area where hydraulic heads, stream and drain discharges, as well as groundwater and surface water nitrate concentrations are regularly measured. This catchment includes various tile-drainage networks that are monitored on a daily basis; the one we have been focusing on is about 5 ha within a 34 ha model domain. The Lillebaek catchment subsurface is made of about 30 m thick Quaternary deposits which consist of a local sandy aquifer with upper and lower clayey till units, confining the aquifer in the upper part. The main modelling objective is to assess the influence of tile drains on the water flow pattern within the confining clayey till unit with and on the nitrate reduction zone depth, also known as the redox-interface, while accounting for local geological heterogeneities. Using the national-scale geological model for Denmark combined with available local data, a hydrogeological model at field scale has been generated. A proper representation of the tile-drains geometry is essential to calibrate and validate the water flow model associated with nitrate transport. HydroGeoSphere can represent drains directly into a model as one-dimensional features, which however requires a very fine mesh discretization that limits the size of the simulation

  20. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting

    NASA Astrophysics Data System (ADS)

    Fogg, Graham E.; Noyes, Charles D.; Carle, Steven F.

    Information on sediment texture and spatial continuity are inherent to sedimentary depositional facies descriptions, which are therefore potentially good predictors of spatially varying hydraulic conductivity (K). Analysis of complex alluvial heterogeneity in Livermore Valley, California, USA, using relatively abundant core descriptions and field pumping-test data, demonstrates a depositional-facies approach to characterization of subsurface heterogeneity. Conventional textural classifications of the core show a poor correlation with K; however, further refinement of the textural classifications into channel, levee, debris-flow, and flood-plain depositional facies reveals a systematic framework for spatial modeling of K. This geologic framework shows that most of the system is composed of very low-K flood-plain materials, and that the K measurements predominantly represent the other, higher-K facies. Joint interpretation of both the K and geologic data shows that spatial distribution of K in this system could not be adequately modeled without geologic data and analysis. Furthermore, it appears that K should not be assumed to be log-normally distributed, except perhaps within each facies. Markov chain modeling of transition probability, representing spatial correlation within and among the facies, captures the relevant geologic features while highlighting a new approach for statistical characterization of hydrofacies spatial variability. The presence of fining-upward facies sequences, cross correlation between facies, as well as other geologic attributes captured by the Markov chains provoke questions about the suitability of conventional geostatistical approaches based on variograms or covariances for modeling geologic heterogeneity. Résumé Les informations sur la texture des sédiments et leur continuité spatiale font partie des descriptions de faciès sédimentaires de dépôt. Par conséquent, ces descriptions sont d'excellents prédicteurs potentiels des

  1. A workflow for transferring heterogeneous complex geological models to consistent finite element models and application to a deep geothermal reservoir operation

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Bauer, Sebastian

    2016-04-01

    Geological models are the prerequisite of exploring possible use of the subsurface and evaluating induced impacts. Subsurface geological models often show strong complexity in geometry and hydraulic connectivity because of their heterogeneous nature. In order to model that complexity, the corner point grid approach has been applied by geologists for decades. The corner point grid utilizes a set of hexahedral blocks to represent geological formations. Due to the appearance of eroded geological layers, some edges of those blocks may be collapsed and the blocks thus degenerate. This leads to the inconsistency and the impossibility of using the corner point grid directly with a finite element based simulator. Therefore, in this study, we introduce a workflow for transferring heterogeneous geological models to consistent finite element models. In the corner point grid, the hexahedral blocks without collapsed edges are converted to hexahedral elements directly. But if they degenerate, each block is divided into prism, pyramid and tetrahedral elements based on individual degenerated situation. This approach consistently converts any degenerated corner point grid to a consistent hybrid finite element mesh. Along with the above converting scheme, the corresponding heterogeneous geological data, e.g. permeability and porosity, can be transferred as well. Moreover, well trajectories designed in the corner point grid can be resampled to the nodes in the finite element mesh, which represents the location for source terms along the well path. As a proof of concept, we implement the workflow in the framework of transferring models from Petrel to the finite element OpenGeoSys simulator. As application scenario we choose a deep geothermal reservoir operation in the North German Basin. A well doublet is defined in a saline aquifer in the Rhaetian formation, which has a depth of roughly 4000 m. The geometric model shows all kinds of degenerated blocks due to eroded layers and the

  2. Study of heterogeneity loss in upscaling of geological maps by introducing a cluster-based heterogeneity number

    NASA Astrophysics Data System (ADS)

    Ganjeh-Ghazvini, Mostafa; Masihi, Mohsen; Baghalha, Morteza

    2015-10-01

    The prediction of flow behavior in porous media can provide useful insights into the mechanisms involved in CO2 sequestration, petroleum engineering and hydrology. The multi-phase flow is usually simulated by solving the governing equations over an efficient model. The geostatistical (or fine grid) models are rarely used for simulation purposes because they have too many cells. A common approach is to coarsen a fine gird realization by an upscaling method. Although upscaling can speed up the flow simulation, it neglects the fine scale heterogeneity. The heterogeneity loss reduces the accuracy of simulation results. In this paper, the relation between heterogeneity loss during upscaling and accuracy of flow simulation is studied. A realization is divided into some clusters. Every cluster consists of a number of neighboring cells whose permeability values belong to a pre-known interval. The concept of coefficient of variation is applied to define the intra-cluster and inter-cluster heterogeneity numbers. These numbers are then calculated for some fine grid and corresponding upscaled models. The heterogeneous fine grid models are generated by the process of fractional Brownian motion. After simulating water-oil displacement in both fine and coarse models, the relation between flow performance error and heterogeneity loss is investigated. An upper limit for the degree of coarsening is also suggested according to this relation.

  3. Geology

    SciTech Connect

    Reidel, Stephen P.

    2008-01-17

    This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  4. Comparison of Publically Available Methodologies for Development of Geologic Storage Estimates for Carbon Dioxide in Saline Formations

    NASA Astrophysics Data System (ADS)

    Goodman, A.; Strazisar, B. R.; Guthrie, G. D.; Bromhal, G.

    2012-12-01

    High-level estimates of CO2 storage potential at the national, regional, and basin scale are required to assess the potential for carbon capture, utilization, and storage (CCUS) technologies to reduce CO2 emissions for application to saline formations. Both private and public entities worldwide rely on CO2 storage potential estimates for broad energy-related government policy and business decisions. High-level estimates of CO2 geologic storage potential, however, have a high degree of uncertainty because the assessments rely on simplifying assumptions due to the deficiency or absence of data from the subsurface associated with areas of potential storage in saline formations and the natural heterogeneity of geologic formations in general, resulting in undefined rock properties. As site characterization progresses to individual CO2 storage sites, additional site-specific data will likely be collected and analyzed that will allow for the refinement of high-level CO2 storage resource estimates and development of CO2 storage capacities. Until such detailed characterization can be documented, dependable high-level CO2 storage estimates are essential to ensure successful widespread deployment of CCUS technologies. Initiatives for assessing CO2 geologic storage potential have been conducted since 1993. Although dependable high-level CO2 storage estimates are essential to ensure successful deployment of CCUS technologies, it is difficult to assess the uncertainty of these estimates without knowing how the current methodologies targeted at high-level CO2 storage resource estimates for saline formations compare to one another. In this study, we compare high-level CO2 methodologies for development of geologic storage estimates for CO2 in saline formations to assess the uncertainty associated with various methodologies. The methodologies applied are listed as follows: (1) U.S. DOE Methodology: Development of Geologic Storage Potential for Carbon Dioxide at the National and

  5. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting

    NASA Astrophysics Data System (ADS)

    Fogg, Graham E.; Noyes, Charles D.; Carle, Steven F.

    Information on sediment texture and spatial continuity are inherent to sedimentary depositional facies descriptions, which are therefore potentially good predictors of spatially varying hydraulic conductivity (K). Analysis of complex alluvial heterogeneity in Livermore Valley, California, USA, using relatively abundant core descriptions and field pumping-test data, demonstrates a depositional-facies approach to characterization of subsurface heterogeneity. Conventional textural classifications of the core show a poor correlation with K; however, further refinement of the textural classifications into channel, levee, debris-flow, and flood-plain depositional facies reveals a systematic framework for spatial modeling of K. This geologic framework shows that most of the system is composed of very low-K flood-plain materials, and that the K measurements predominantly represent the other, higher-K facies. Joint interpretation of both the K and geologic data shows that spatial distribution of K in this system could not be adequately modeled without geologic data and analysis. Furthermore, it appears that K should not be assumed to be log-normally distributed, except perhaps within each facies. Markov chain modeling of transition probability, representing spatial correlation within and among the facies, captures the relevant geologic features while highlighting a new approach for statistical characterization of hydrofacies spatial variability. The presence of fining-upward facies sequences, cross correlation between facies, as well as other geologic attributes captured by the Markov chains provoke questions about the suitability of conventional geostatistical approaches based on variograms or covariances for modeling geologic heterogeneity. Résumé Les informations sur la texture des sédiments et leur continuité spatiale font partie des descriptions de faciès sédimentaires de dépôt. Par conséquent, ces descriptions sont d'excellents prédicteurs potentiels des

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

    SciTech Connect

    Mancini, E.A.

    1990-01-01

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

  7. Quantification of rock heterogeneities by structural geological field studies combined with laboratory analyses

    NASA Astrophysics Data System (ADS)

    Reyer, Dorothea; Afsar, Filiz; Philipp, Sonja

    2013-04-01

    Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical in sedimentary successions. The knowledge of in-situ mechanical rock properties is crucial for a better understanding of processes such as fracturing and fluid transport in fractured reservoirs. To estimate in situ rock properties at different depths it is important to understand how rocks from outcrops differ from rocks at depth, for example due to alteration and removal of the overburden load. We aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses of outcrop samples and drill-cores. The field studies focus on 1) fault zone infrastructure and 2) host rock fracture systems in two different study areas with different lithologies, the North German and the Bristol Channel Basin. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems. The field studies are complemented by systematic sampling to obtain the parameters Young's modulus, compressive and tensile strengths and elastic strain energy (also referred to as destruction work) from which we estimate rock and fracture toughnesses. The results show that in rocks with distinctive layering fractures are often restricted to individual layers, that is, stratabound. The probability of arrest seems to depend on the stiffness contrast between two single layers as well as on the thickness of the softer layer. The results also show that there are clear differences between fault zones in the different lithologies in terms of damage zone thicknesses and fracture system parameters. The results of laboratory analyses show that the mechanical properties vary considerably and for many samples there are clear directional differences. That is, samples taken perpendicular to layering commonly have higher stiffnesses and strengths than those taken parallel to layering. We combine the results of

  8. Statistical characterisation and stochastic parameterisation of sedimentary geological formations on their reaction capacity for sustainable groundwater quality management

    NASA Astrophysics Data System (ADS)

    Griffioen, J.; Vermooten, S.; Keijzer, T.; Bakr, M.; Valstar, J.

    2012-04-01

    The fate of contaminants in groundwater aquifers is determined by the buffering capacity of those aquifers together with the composition of inflowing groundwater. A nationwide characterisation of the environmental geochemistry of the shallow subsurface (down to 30 m below surface) has been started in the Netherlands. This covers: 1. the reaction capacity of sediments as buffer for contamination, and 2. typical elemental composition of geological formations and the association between trace elements and major minerals. For this purpose, the Netherlands is subdivided into 27 so-called geotop regions each having a unique geological build-up of the shallow subsurface. Here, four types are recognised based on vertical hydrogeological build-up. The regions are statistically characterised on their geochemical composition using combinations of lithological class and geological formation as strata. The statistical data are subsequently coupled with a geological voxel model of the subsurface to stochastically parameterise the geological units on reaction capacity. This combined approach will be illustrated for the Dutch province Zeeland. Reaction capacity is considered as a series of geochemical characteristics that control acid/base condition, redox condition and sorption capacity. Five primary reaction capacity variables are characterised: 1. pyrite, 2. non-pyrite, reactive iron (oxides, siderite and glauconite), 3. clay fraction, 4. organic matter and 5. Ca-carbonate. Important reaction capacity variables that are determined by more than one solid compound are also deduced: 1. potential reduction capacity (PRC) by pyrite and organic matter, 2. cation-exchange capacity (CEC) by organic matter and clay content, 3. carbonate buffering upon pyrite oxidation (CPBO) by carbonate and pyrite. A statistical investigation of several hunderds of sediment analyses is performed that provides the geochemical properties of the sediments. Here, classification based on sedimentary facies

  9. Approaches to identifying reservoir heterogeneity and reserve growth opportunities from subsurface data: The Oficina Formation, Budare field, Venezuela

    SciTech Connect

    Hamilton, D.S.; Raeuchle, S.K.; Holtz, M.H.

    1997-08-01

    We applied an integrated geologic, geophysical, and engineering approach devised to identify heterogeneities in the subsurface that might lead to reserve growth opportunities in our analysis of the Oficina Formation at Budare field, Venezuela. The approach involves 4 key steps: (1) Determine geologic reservoir architecture; (2) Investigate trends in reservoir fluid flow; (3) Integrate fluid flow trends with reservoir architecture; and (4) Estimate original oil-in-place, residual oil saturation, and remaining mobile oil, to identify opportunities for reserve growth. There are three main oil-producing reservoirs in the Oficina Formation that were deposited in a bed-load fluvial system, an incised valley-fill, and a barrier-strandplain system. Reservoir continuity is complex because, in addition to lateral facies variability, the major Oficina depositional systems were internally subdivided by high-frequency stratigraphic surfaces. These surfaces define times of intermittent lacustrine and marine flooding events that punctuated the fluvial and marginal marine sedimentation, respectively. Syn and post depositional faulting further disrupted reservoir continuity. Trends in fluid flow established from initial fluid levels, response to recompletion workovers, and pressure depletion data demonstrated barriers to lateral and vertical fluid flow caused by a combination of reservoir facies pinchout, flooding shale markers, and the faults. Considerable reserve growth potential exists at Budare field because the reservoir units are highly compartment by the depositional heterogeneity and structural complexity. Numerous reserve growth opportunities were identified in attics updip of existing production, in untapped or incompletely drained compartments, and in field extensions.

  10. Geology, compositional heterogeneities, and geochemical origin of the Yacheng gas field, Qiongdongnan Basin, South China Sea

    SciTech Connect

    Hao, F.; Li, S.; Sun, Y.; Zhang, Q.

    1998-07-01

    The Yacheng gas field is located in the footwall of the No. 1 fault, the boundary fault between the Yinggehai and Qiongdongnan basins. All strata are normally pressured in the gas field except for the Meishan Formation. The Meishan Formation is overpressured near the No. 1 fault in the gas field and in the adjacent Yinggehai Basin. An obvious thermal anomaly occurs below 3600 m in the gas field. This anomaly, characterized by an abrupt increase in drill-stem test and fluid-inclusion homogenization temperatures, vitrinite reflectance (R{sub o}), and Rock-Eval T{sub max}, and by an abnormally low temperature/R{sub o}/T{sub max} gradient, diminishes away from the Yinggehai Basin. The gases and condensates have abnormally high aromatic hydrocarbon contents and show obvious heterogeneities. Away from the No. 1 fault, the C{sub 2+} hydrocarbon content and C{sub 2+}/{Sigma}C{sub n} increase; carbon dioxide content decreases; {delta}{sup 13}C values for methane, ethane, and carbon dioxide become lighter; the heptane and isoheptane values decrease; and the relative contents of aromatic hydrocarbons, both in C{sub 6}/C{sub 7} light hydrocarbons and in the condensates, decrease. The gas field was charged from both the Qiongdongnan and the Yinggehai basins. Hydrocarbons sourced from the Qiongdongnan Basin have relatively low maturities, whereas hydrocarbons from the Yinggehai Basin have relatively higher maturities and seem to have been in association with hydrothermal fluids. The hydrothermal fluids from the Yinggehai Basin, in which methane, ethane, carbon dioxide, and especially aromatic hydrocarbons dissolved under the high-temperature and high-pressure subsurface conditions, migrated along the No. 1 fault and caused the abnormally high concentration of aromatic hydrocarbons, as well as the thermal anomalies in the gas field, especially near the No. 1 fault.

  11. Nitrate reduction in geologically heterogeneous catchments--a framework for assessing the scale of predictive capability of hydrological models.

    PubMed

    Refsgaard, Jens Christian; Auken, Esben; Bamberg, Charlotte A; Christensen, Britt S B; Clausen, Thomas; Dalgaard, Esben; Effersø, Flemming; Ernstsen, Vibeke; Gertz, Flemming; Hansen, Anne Lausten; He, Xin; Jacobsen, Brian H; Jensen, Karsten Høgh; Jørgensen, Flemming; Jørgensen, Lisbeth Flindt; Koch, Julian; Nilsson, Bertel; Petersen, Christian; De Schepper, Guillaume; Schamper, Cyril; Sørensen, Kurt I; Therrien, Rene; Thirup, Christian; Viezzoli, Andrea

    2014-01-15

    In order to fulfil the requirements of the EU Water Framework Directive nitrate load from agricultural areas to surface water in Denmark needs to be reduced by about 40%. The regulations imposed until now have been uniform, i.e. the same restrictions for all areas independent of the subsurface conditions. Studies have shown that on a national basis about 2/3 of the nitrate leaching from the root zone is reduced naturally, through denitrification, in the subsurface before reaching the streams. Therefore, it is more cost-effective to identify robust areas, where nitrate leaching through the root zone is reduced in the saturated zone before reaching the streams, and vulnerable areas, where no subsurface reduction takes place, and then only impose regulations/restrictions on the vulnerable areas. Distributed hydrological models can make predictions at grid scale, i.e. at much smaller scale than the entire catchment. However, as distributed models often do not include local scale hydrogeological heterogeneities, they are typically not able to make accurate predictions at scales smaller than they are calibrated. We present a framework for assessing nitrate reduction in the subsurface and for assessing at which spatial scales modelling tools have predictive capabilities. A new instrument has been developed for airborne geophysical measurements, Mini-SkyTEM, dedicated to identifying geological structures and heterogeneities with horizontal and lateral resolutions of 30-50 m and 2m, respectively, in the upper 30 m. The geological heterogeneity and uncertainty are further analysed by use of the geostatistical software TProGS by generating stochastic geological realisations that are soft conditioned against the geophysical data. Finally, the flow paths within the catchment are simulated by use of the MIKE SHE hydrological modelling system for each of the geological models generated by TProGS and the prediction uncertainty is characterised by the variance between the

  12. Estimation of hydrologic properties of heterogeneous geologic media with an inverse method based on iterated function systems

    SciTech Connect

    Doughty, C

    1995-12-01

    The highly heterogeneous nature of most geologic media, coupled with the restricted view of the subsurface available through boreholes, makes it difficult to determine the spatial distribution of subsurface hydrologic properties. Without such a description one cannot predict how fluid flow or solute transport will occur through permeable geologic media, and these predictions are critically needed to address many important environmental problems, including toxic chemical spills, leaking underground storage tanks, and long-term radioactive waste isolation. A common concern of these problems is the possible existence of high-permeability pathways connecting the problem to the biosphere. An understanding of flow and transport behavior is also necessary to optimize energy extraction from petroleum or geothermal reservoirs, where identifying low-permeability barriers that compartmentalize reservoirs and hamper efficient resource utilization is a key problem. The present work describes the development and application of a new inverse method for determining the spatial distribution of hydrologic properties (permeability and specific storage) in heterogeneous geologic media, using pressure transients from interference well tests. The method employs fractal concepts to improve efficiency and reliability. It is applicable to any sort of heterogeneous geologic medium in which wells communicate with each other, whether it be porous, fractured, or a combination thereof. Application to field data from a shallow aquifer at Kesterson Reservoir agrees well with an independent analysis using traditional well-test analysis methods. Application to a series of interference tests conducted at the Gypsy Pilot Site produces a detailed picture of the subsurface, which compares favorably with cross-well seismic imaging studies. 53 refs.

  13. High Performance Simulation of Environmental Tracers in Heterogeneous Formations

    NASA Astrophysics Data System (ADS)

    Gardner, P.; Hammond, G. E.; Lichtner, P. C.; Arnold, B. W.

    2013-12-01

    Environmental tracers provide information on fluid flux, yielding important information for use in groundwater studies. Currently environmental tracer interpretation has been limited by computational expense. Here we use a scalable, massively parallel, flow and reactive transport code PFLOTRAN to simulate the concentrations of 3H, 3He, CFC-11, CFC-12, CFC-113, SF6, 39Ar, 81Kr , 4He and the mean groundwater age in 2D and 3D heterogeneous fields on grids with an excess of 10 million nodes. We utilize this computational platform to simulate the spatial distribution of environmental tracer concentration, tracer derived ages and modeled mean ground water age in heterogeneous aquifers. Modeled concentrations are then used to calculate tracer derived ages. The deviation of the tracer derived age distribution from the true groundwater age distribution increases with increasing heterogeneity of the system. The separation between the apparent age derived from different tracers also increases with increasing system heterogeneity. Age distributions in 3D aquifers differ significantly from 2D simulations with similar spatial statistics. The addition of the 3rd dimension increases connectivity, decreasing mean age and reducing age variability. High performance computation allows for investigation of tracer and groundwater age spatial distribution in unprecedented detail, providing a foundation for the next generation of environmental tracer interpretation.

  14. The Effects of Realistic Geological Heterogeneity on Seismic Modeling: Applications in Shear Wave Generation and Near-Surface Tunnel Detection

    NASA Astrophysics Data System (ADS)

    Sherman, Christopher Scott

    Naturally occurring geologic heterogeneity is an important, but often overlooked, aspect of seismic wave propagation. This dissertation presents a strategy for modeling the effects of heterogeneity using a combination of geostatistics and Finite Difference simulation. In the first chapter, I discuss my motivations for studying geologic heterogeneity and seis- mic wave propagation. Models based upon fractal statistics are powerful tools in geophysics for modeling heterogeneity. The important features of these fractal models are illustrated using borehole log data from an oil well and geomorphological observations from a site in Death Valley, California. A large part of the computational work presented in this disserta- tion was completed using the Finite Difference Code E3D. I discuss the Python-based user interface for E3D and the computational strategies for working with heterogeneous models developed over the course of this research. The second chapter explores a phenomenon observed for wave propagation in heteroge- neous media - the generation of unexpected shear wave phases in the near-source region. In spite of their popularity amongst seismic researchers, approximate methods for modeling wave propagation in these media, such as the Born and Rytov methods or Radiative Trans- fer Theory, are incapable of explaining these shear waves. This is primarily due to these method's assumptions regarding the coupling of near-source terms with the heterogeneities and mode conversion. To determine the source of these shear waves, I generate a suite of 3D synthetic heterogeneous fractal geologic models and use E3D to simulate the wave propaga- tion for a vertical point force on the surface of the models. I also present a methodology for calculating the effective source radiation patterns from the models. The numerical results show that, due to a combination of mode conversion and coupling with near-source hetero- geneity, shear wave energy on the order of 10% of the

  15. Volcanic rises on Venus: Geology, formation, and sequence of evolution

    NASA Technical Reports Server (NTRS)

    Senske, D. A.; Stofan, E. R.; Bindschadler, D. L.; Smrekar, S. E.

    1993-01-01

    Large centers of volcanism on Venus are concentrated primarily in the equatorial region of the planet and are associated with regional topographic rises. Analysis of both radar images and geophysical data suggest that these uplands are sites of mantle upwelling. Magellan radar imaging provides a globally contiguous data set from which the geology of these regions is evaluated and compared. In addition, high resolution gravity data currently being collected provide a basis to assess the relationship between these uplands and processes in the planet's interior. Studies of the geology of the three largest volcanic highlands (Beta Regio, Atla Regio, Western Eistla Regio) show them to be distinct, having a range of volcanic and tectonic characteristics. In addition to these large areas, a number of smaller uplands are identified and are being analyzed (Bell Regio, Imdr Regio, Dione Regio (Ushas, Innini, and Hathor Montes), and Themis Regio). To understand better the mechanisms by which these volcanic rises form and evolve, we assess their geologic and geophysical characteristics.

  16. Integration of geology, geostatistics, well logs and pressure data to model a heterogeneous supergiant field in Iran

    SciTech Connect

    Samimi, B.; Bagherpour, H.; Nioc, A.

    1995-08-01

    The geological reservoir study of the supergiant Ahwaz field significantly improved the history matching process in many aspects, particularly the development of a geostatistical model which allowed a sound basis for changes and by delivering much needed accurate estimates of grid block vertical permeabilities. The geostatistical reservoir evaluation was facilitated by using the Heresim package and litho-stratigraphic zonations for the entire field. For each of the geological zones, 3-dimensional electrolithofacies and petrophysical property distributions (realizations) were treated which captured the heterogeneities which significantly affected fluid flow. However, as this level of heterogeneity was at a significantly smaller scale than the flow simulation grid blocks, a scaling up effort was needed to derive the effective flow properties of the blocks (porosity, horizontal and vertical permeability, and water saturation). The properties relating to the static reservoir description were accurately derived by using stream tube techniques developed in-house whereas, the relative permeabilities of the grid block were derived by dynamic pseudo relative permeability techniques. The prediction of vertical and lateral communication and water encroachment was facilitated by a close integration of pressure, saturation data, geostatistical modelling and sedimentological studies of the depositional environments and paleocurrents. The nature of reservoir barriers and baffles varied both vertically and laterally in this heterogeneous reservoir. Maps showing differences in pressure between zones after years of production served as a guide to integrating the static geological studies to the dynamic behaviour of each of the 16 reservoir zones. The use of deep wells being drilled to a deeper reservoir provided data to better understand the sweep efficiency and the continuity of barriers and baffles.

  17. Modeling CO2 distribution in a heterogeneous sandstone reservoir: the Johansen Formation, northern North Sea

    NASA Astrophysics Data System (ADS)

    Sundal, Anja; Miri, Rohaldin; Petter Nystuen, Johan; Dypvik, Henning; Aagaard, Per

    2013-04-01

    The last few years there has been broad attention towards finding permanent storage options for CO2. The Norwegian continental margin holds great potential for storage in saline aquifers. Common for many of these reservoir candidates, however, is that geological data are sparse relative to thoroughly mapped hydrocarbon reservoirs in the region. Scenario modeling provides a method for estimating reservoir performances for potential CO2 storage sites and for testing injection strategies. This approach is particularly useful in the evaluation of uncertainties related to reservoir properties and geometry. In this study we have tested the effect of geological heterogeneities in the Johansen Formation, which is a laterally extensive sandstone and saline aquifer at burial depths of 2 - 4 km, proposed as a suitable candidate for CO2 storage by Norwegian authorities. The central parts of the Johansen Formation are underlying the operating hydrocarbon field Troll. In order not to interfere with ongoing gas production, a potential CO2 injection well should be located at a safe distance from the gas reservoir, which consequently implies areas presently without well control. From 3D seismic data, prediction of spatial extent of sandstone is possible to a certain degree, whereas intra-reservoir flow baffles such as draping mudstone beds and calcite cemented layers are below seismic resolution. The number and lateral extent of flow baffles, as well as porosity- and permeability distributions are dependent of sedimentary facies and diagenesis. The interpretation of depositional environment and burial history is thus of crucial importance. A suite of scenario models was established for a potential injection area south of the Troll field. The model grids where made in Petrel based on our interpretations of seismic data, wire line logs, core and cuttings samples. Using Eclipse 300 the distribution of CO2 is modeled for different geological settings; with and without the presence of

  18. AStudy of the Relationship of Geological Formation to the Norm.

    SciTech Connect

    Bursh, T.P.; Derald Chriss

    1997-07-08

    Naturally Occurring Radioactive Materials (NORM) is a common and costly contaminant of produced waters associated with natural gas production and exploration. One way of combating this problem is by identifying the problem beforehand. Our approach to this problem involves development of NORM prediction capabilities based on the geological environment. During the eleventh quarter of this project, emphasis again remained on two major tasks; identifying new sampling sites and seeking approval for final project revisions. In light of the delays experienced, the project has been granted a one year extension, and a revision is currently under review.

  19. Study of effects of formation heterogeneity of carbon dioxide gas migration using a two-dimensional intermediate scale

    NASA Astrophysics Data System (ADS)

    Lassen, R. N.; Sakaki, T.; Plampin, M. R.; Pawar, R. J.; Jensen, K. H.; Sonnenborg, T.; Illangasekare, T. H.

    2011-12-01

    An important issue that needs attention in designing effective storage schemes for storage of CO2 in deep geologic formations is the assessment of risk of potential leakage. Leaking gas threatening the surface and groundwater sources and vegetation. In our research group, we have conducted experiments in soil columns to obtain a fundamental understanding of formation of gas and its migration. The results of these experiments demonstrated that a number of factors that include pressure gradients, temperature and formation heterogeneity, among others controls these processes. As a first step to upscale these findings from one-dimensional columns to multidimensional field settings, a set of experiments were conducted in a two-dimensional tank. The experiments are designed specifically to further improve our understanding of the effects of geologic heterogeneity on gas leakage. A two-dimensional tall tank with dimensions of 2.44m (H) x 0.41m (W) x 0.08m (D) was constructed. The tank was instrumented with 18 soil moisture sensors to measure the gas fraction and eight of which also measures temperature and electrical conductivity (EC). Pressure in the water phase was also measured at eight elevations along the length of the tank. The tank was packed with two test sands with known hydraulic and retention characteristics in a staggered pattern. The permeability of the coarser sand is roughly four times higher than that of the finer sand. There is no significant difference in porosity between the two sands. To simulate leakage from storage, gas-phase CO2 was injected at the bottom of the tank at a pressure of 35-70 kPa for durations changing from 6-24 hours. Soil moisture, EC, temperature, and water pressure were monitored during the experiment. It was observed that the gas phase CO2 first developed a preferential pathway mainly through the coarse soil. The data gathered from the pressure probes showed a significant pressure build-up during the gas injection, and a slow

  20. Formation Buffering Potential Pertaining to Geological Storage of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Ellis, B. R.; Peters, C. A.; Buschkuehle, M.

    2007-12-01

    One promising strategy for decreasing CO2 emissions to the atmosphere is carbon capture and storage in deep saline formations. Modeling efforts and the experimental measurements that support these efforts are critical to determining the fate of injected CO2. The focus of this work is CO2-water-rock interactions as they pertain to formation buffering potential. PHREEQC was used to model pH evolution in siliciclastic and carbonate rocks after simulated injection of CO2. The initial mineral and formation water compositions were determined from analysis of core samples and brines from several formations in the Alberta sedimentary basin in western Canada. Simulation parameters correspond to injection conditions of 50°C, CO2 pressure of 100 bar and high ionic strength. Results indicate that the carbonate formations have a higher buffering potential relative to siliciclastic formations. Considerable variability of acid-catalyzed reactions among formations with similar mineralogical compositions was also observed. To assess the effect of grain coating by clay minerals, a comparative simulation was performed with kaolinite as the dominant mineral in contact with the pore fluids. Results from this simulation showed a pronounced retardation in pH buffering reaction kinetics. This emphasizes the importance for differentiating between mineral abundance and accessibility in model calculations when clay coatings may obscure contact between pore fluids and potentially reactive minerals.

  1. Modeling solute advection coupled with sorption kinetics in heterogeneous formations

    NASA Astrophysics Data System (ADS)

    Selroos, Jan-Olof; Cvetkovic, Vladimir

    1992-05-01

    A method for coupling sorption kinetics and solute advection in particle-tracking models is proposed; this method is efficient for the case where sorption rate coefficients can be assumed constant field scale parameters. A simulation example of reactive solute advection in two-dimensional heterogeneous porous media is presented. The effect of sorption kinetics on solute advection is investigated. Nonequilibrium effects are exhibited as enhanced tailing in the solute breakthrough. Because high variability in the hydraulic conductivity also yields enhanced tailing, the nonequilibrium effect is more pronounced for the case of low variability. Moreover, it may be difficult to distinguish cases of low variability with nonequilibrium sorption from cases of high variability with equilibrium sorption. A comparison of Monte Carlo ensemble results is made with an analytical model for the mass arrival of kinetically sorbing solute in heterogeneous porous media obtained using first-order perturbation. The comparison indicates that the analytical model provides reasonable approximations of the expected solute breakthrough if the variance of the natural logarithm of the hydraulic conductivity is smaller than 1.

  2. Permafrost on Mars: distribution, formation, and geological role

    NASA Technical Reports Server (NTRS)

    Nummedal, D.

    1984-01-01

    The morphology of channels, valleys, chaotic and fretted terrains and many smaller features on Mars is consistent with the hypothesis that localized deterioration of thick layers of ice-rich permafrost was a dominant geologic process on the Martian surface. Such ground ice deterioration gave rise to large-scale mass movement, including sliding, slumping and sediment gravity flowage, perhaps also catastropic floods. In contrast to Earth, such mass movement processes on Mars lack effective competition from erosion by surface runoff. Therefore, Martian features due to mass movement grew to reach immense size without being greatly modified by secondary erosional processes. The Viking Mission to Mars in 1976 provided adequate measurements of the relevant physical parameters to constrain models for Martian permafrost.

  3. Use and Features of Basalt Formations for Geologic Sequestration

    SciTech Connect

    McGrail, B. Peter; Ho, Anita M.; Reidel, Steve P.; Schaef, Herbert T.

    2003-01-01

    Extrusive lava flows of basalt are a potential host medium for geologic sequestration of anthropogenic CO2. Flood basalts and other large igneous provinces occur worldwide near population and power-producing centers and could securely sequester a significant fraction of global CO2 emissions. We describe the location, extent, and general physical and chemical characteristics of large igneous provinces that satisfy requirements as a good host medium for CO2 sequestration. Most lava flows have vesicular flow tops and bottoms as well as interflow zones that are porous and permeable and serve as regional aquifers. Additionally, basalt is iron-rich, and, under the proper conditions of groundwater pH, temperature, and pressure, injected CO2 will react with iron released from dissolution of primary minerals in the basalt to form stable ferrous carbonate minerals. Conversion of CO2 gas into a solid form was confirmed in laboratory experiments with supercritical CO2 in contact with basalt samples from Washington state.

  4. Geology

    NASA Technical Reports Server (NTRS)

    Stewart, R. K.; Sabins, F. F., Jr.; Rowan, L. C.; Short, N. M.

    1975-01-01

    Papers from private industry reporting applications of remote sensing to oil and gas exploration were presented. Digitally processed LANDSAT images were successfully employed in several geologic interpretations. A growing interest in digital image processing among the geologic user community was shown. The papers covered a wide geographic range and a wide technical and application range. Topics included: (1) oil and gas exploration, by use of radar and multisensor studies as well as by use of LANDSAT imagery or LANDSAT digital data, (2) mineral exploration, by mapping from LANDSAT and Skylab imagery and by LANDSAT digital processing, (3) geothermal energy studies with Skylab imagery, (4) environmental and engineering geology, by use of radar or LANDSAT and Skylab imagery, (5) regional mapping and interpretation, and digital and spectral methods.

  5. Bacterial interactions and transport in geological formation of alumino-silica clays.

    PubMed

    Vu, Kien; Yang, Guang; Wang, Boya; Tawfiq, Kamal; Chen, Gang

    2015-01-01

    Bacterial transport in the subsurface is controlled by their interactions with the surrounding environment, which are determined by the surface properties of the geological formation and bacterial surfaces. In this research, surface thermodynamic properties of Escherichia coli and the geological formation of alumino-silica clays were characterized based on contact angle measurements, which were utilized to quantify the distance-dependent interactions between E. coli and the geological formation according to the traditional and extended Derjaguin, Landau, Verwey and Overbeek (DLVO) theory. E. coli attachment to alumino-silica clays was evaluated in laboratory columns under saturated and steady-state flow conditions. E. coli deposition coefficient and desorption coefficient were simulated using convection-dispersion transport models against E. coli breakthrough curves, which were then linked to interactions between E. coli and the geological formation. It was discovered that E. coli deposition was controlled by the long-ranged electrostatic interaction and E. coli desorption was attributed to the short-ranged Lifshitz-van der Waals and Lewis acid-base interactions. E. coli transport in three layers of different alumino-silica clays was further examined and the breakthrough curve was simulated using E. coli deposition coefficient and desorption coefficient obtained from their individual column experiments. The well-fitted simulation confirmed that E. coli transport observations were interaction-dependent phenomena between E. coli and the geological formation. PMID:25437062

  6. A Standard-Driven Data Dictionary for Data Harmonization of Heterogeneous Datasets in Urban Geological Information Systems

    NASA Astrophysics Data System (ADS)

    Liu, G.; Wu, C.; Li, X.; Song, P.

    2013-12-01

    The 3D urban geological information system has been a major part of the national urban geological survey project of China Geological Survey in recent years. Large amount of multi-source and multi-subject data are to be stored in the urban geological databases. There are various models and vocabularies drafted and applied by industrial companies in urban geological data. The issues such as duplicate and ambiguous definition of terms and different coding structure increase the difficulty of information sharing and data integration. To solve this problem, we proposed a national standard-driven information classification and coding method to effectively store and integrate urban geological data, and we applied the data dictionary technology to achieve structural and standard data storage. The overall purpose of this work is to set up a common data platform to provide information sharing service. Research progresses are as follows: (1) A unified classification and coding method for multi-source data based on national standards. Underlying national standards include GB 9649-88 for geology and GB/T 13923-2006 for geography. Current industrial models are compared with national standards to build a mapping table. The attributes of various urban geological data entity models are reduced to several categories according to their application phases and domains. Then a logical data model is set up as a standard format to design data file structures for a relational database. (2) A multi-level data dictionary for data standardization constraint. Three levels of data dictionary are designed: model data dictionary is used to manage system database files and enhance maintenance of the whole database system; attribute dictionary organizes fields used in database tables; term and code dictionary is applied to provide a standard for urban information system by adopting appropriate classification and coding methods; comprehensive data dictionary manages system operation and security. (3

  7. River-aquifer interactions, geologic heterogeneity, and low-flow management

    USGS Publications Warehouse

    Fleckenstein, J.H.; Niswonger, R.G.; Fogg, G.E.

    2006-01-01

    Low river flows are commonly controlled by river-aquifer exchange, the magnitude of which is governed by hydraulic properties of both aquifer and aquitard materials beneath the river. Low flows are often important ecologically. Numerical simulations were used to assess how textural heterogeneity of an alluvial system influences river seepage and low flows. The Cosumnes River in California was used as a test case. Declining fall flows in the Cosumnes River have threatened Chinook salmon runs. A ground water-surface water model for the lower river basin was developed, which incorporates detailed geostatistical simulations of aquifer heterogeneity. Six different realizations of heterogeneity and a homogenous model were run for a 3-year period. Net annual seepage from the river was found to be similar among the models. However, spatial distribution of seepage along the channel, water table configuration and the level of local connection, and disconnection between the river and aquifer showed strong variations among the different heterogeneous models. Most importantly, the heterogeneous models suggest that river seepage losses can be reduced by local reconnections, even when the regional water table remains well below the riverbed. The percentage of river channel responsible for 50% of total river seepage ranged from 10% to 26% in the heterogeneous models as opposed to 23% in the homogeneous model. Differences in seepage between the models resulted in up to 13 d difference in the number of days the river was open for salmon migration during the critical fall months in one given year. Copyright ?? 2006 The Author(s).

  8. Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    2009-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

  9. Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    2010-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

  10. Numerical study on the impacts of heterogeneous reactions on ozone formation in the Beijing urban area

    NASA Astrophysics Data System (ADS)

    Xu, Jun; Zhang, Yuanhang; Wang, Wei

    2006-12-01

    The air quality model CMAQ-MADRID (Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution) was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.

  11. Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

    SciTech Connect

    Stephen R. Brown; Gregory Boitnott; Gilles Y. Bussod; Paul Hagin

    2005-12-13

    In building models of the subsurface, it is generally acknowledged that the required properties are rarely known or observed at the scale of the model elements. Typically they are constrained by measurements or observations made at other scales such as smaller scale core measurements or larger scale wellbore or field tests. As a result, model parameters contain a certain level of uncertainty even in the best of cases. These values typically require adjustment to fit field observations through a process commonly referred to as calibration. The characterization of flow and transport in the vadose and saturated zones, requires a detailed knowledge of subsurface structures, flow paths, and hydrophysical properties. We have constructed a methodology and workflow that use fine-scale measurements of heterogeneity to constrain physically based models for upscaling geophysical and hydrological properties. The methodology provides a means to assign hydrophysical properties at scales more appropriate to field applications, while preserving a physical influence of fine scale heterogeneities. We start by describing millimeter-scale physical properties measurements made on the surface of a sample. Combining physical properties maps and measured parameters with effective medium models, we show that these fine-scale heterogeneities can cause saturation dependent anisotropy in several properties such as electrical conductivity, relative permeability and velocity. Finally, we demonstrate that traditional upscaling of multiphase properties such as capillary pressure leads to inaccuracies that can be avoided by employing upscaling that explicitly incorporates fine-scale heterogeneity. This methodology provides a more accurate interpretation and representation of the subsurface for both environmental and fossil fuel reservoir applications, and can be extended to the study of surface damage in man made structures such as concrete. Realistic hydrologic, geophysical and hydrochemical

  12. Fundamental Study on the Dynamics of Heterogeneity-Enhanced CO2 Gas Evolution in the Shallow Subsurface During Possible Leakage from Deep Geologic Storage Sites

    NASA Astrophysics Data System (ADS)

    Plampin, M. R.; Lassen, R. N.; Sakaki, T.; Pawar, R.; Jensen, K.; Illangasekare, T. H.

    2013-12-01

    A concern for geologic carbon sequestration is the potential for CO2 stored in deep geologic formations to leak upward into shallow freshwater aquifers where it can have potentially detrimental impacts to the environment and human health. Understanding the mechanisms of CO2 exsolution, migration and accumulation (collectively referred to as 'gas evolution') in the shallow subsurface is critical to predict and mitigate the environmental impacts. During leakage, CO2 can move either as free-phase or as a dissolved component of formation brine. CO2 dissolved in brine may travel upward into shallow freshwater systems, and the gas may be released from solution. In the shallow aquifer, the exsolved gas may accumulate near interfaces between soil types, and/or create flow paths that allow the gas to escape through the vadose zone to the atmosphere. The process of gas evolution in the shallow subsurface is controlled by various factors, including temperature, dissolved CO2 concentration, water pressure, background water flow rate, and geologic heterogeneity. However, the conditions under which heterogeneity controls gas phase evolution have not yet been precisely defined and can therefore not yet be incorporated into models used for environmental risk assessment. The primary goal of this study is to conduct controlled laboratory experiments to help fill this knowledge gap. With this as a goal, a series of intermediate-scale laboratory experiments were conducted to observe CO2 gas evolution in porous media at multiple scales. Deionized water was saturated with dissolved CO2 gas under a specified pressure (the saturation pressure) before being injected at a constant volumetric flow rate into the bottom of a 1.7 meter-tall by 5.7 centimeter-diameter column or a 2.4 meter-tall by 40 centimeter-wide column that were both filled with sand in various heterogeneous packing configurations. Both test systems were initially saturated with fresh water and instrumented with soil

  13. CO2 leakage risk in 3D heterogeneous formations

    NASA Astrophysics Data System (ADS)

    Hou, Z.; Murray, C. J.; Rockhold, M. L.

    2011-12-01

    In this study we use a stochastic sensitivity analysis framework to evaluate the impact of 3D spatial heterogeneity in permeability on CO2 leakage risk. The leakage is defined as the total mass of CO2 moving into the overburden through the caprock-overburden interface, in both gaseous and liquid (dissolved) phases. The entropy-based framework has the ability to quantify the uncertainty associated with the input parameters/factors in the form of prior pdfs (probability density functions). Effective sampling of the prior pdfs enables us to explore the parameter space and systematically evaluate the individual and combined effects of the factors/parameters of interest on CO2 leakage risk. The parameters that are considered in the study include: mean, variance, and horizontal to vertical spatial anisotropy ratio for caprock permeability, and those same parameters for reservoir permeability. Given the sampled spatial variogram parameters, multiple realizations of permeability fields were generated using GSLIB subroutines. For each permeability field, a numerical simulator STOMP (water-salt-CO2-energy operational mode) is used to simulate the CO2 migration within the reservoir and caprock up to 50 years after injection. Due to intensive computational demand, a scalable version simulator, eSTOMP, is run on the Jaguar supercomputer. We then perform statistical analyses and summarize the relationships between the parameters of interest (mean/variance/anisotropy ratio of caprock/reservoir permeability) and CO2 leakage ratio. We will also present the effects of those parameters on CO2 plume radius and reservoir injectivity.

  14. Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

    SciTech Connect

    Ababou, R.

    1991-08-01

    This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs.

  15. Geology and hydrogeology of the Dammam Formation in Kuwait

    NASA Astrophysics Data System (ADS)

    Al-Awadi, E.; Mukhopadhyay, A.; Al-Senafy, M. N.

    The Dammam Formation of Middle Eocene age is one of the major aquifers containing useable brackish water in Kuwait. Apart from the paleokarst zone at the top, the Dammam Formation in Kuwait consists of 150-200m of dolomitized limestone that is subdivided into three members, on the basis of lithology and biofacies. The upper member consists of friable chalky dolomicrite and dolomite. The middle member is mainly laminated biomicrite and biodolomicrite. The lower member is nummulitic limestone with interlayered shale toward the base. Geophysical markers conform to these subdivisions. Core analyses indicate that the upper member is the most porous and permeable of the three units, as confirmed by the distribution of lost-circulation zones. The quality of water in the aquifer deteriorates toward the north and east. A potentiometric-head difference exists between the Dammam Formation and the unconformably overlying Kuwait Group; this difference is maintained by the presence of an intervening aquitard. Résumé La formation de Damman, d'âge Éocène moyen, est l'un des principaux aquifères du Koweit, contenant de l'eau saumâtre utilisable. A part dans sa partie supérieure où existe un paléokarst, la formation de Damman au Koweit est constituée par 150 à 200m de calcaires dolomitisés, divisés en trois unités sur la base de leur lithologie et de biofaciès. L'unité supérieure est formée d'une dolomicrite crayeuse et friable et d'une dolomie. L'unité médiane est pour l'essentiel une biomicrite laminée et une biodolomicrite. L'unité inférieure est un calcaire nummulitique avec des intercalations argileuses vers la base. Les marqueurs géophysiques sont conformes à ces subdivisions. Les analyses de carottes montrent que l'unité supérieure est la plus poreuse et la plus perméable des trois. La répartition des zones d'écoulement souterrain confirment ces données. La qualité de l'eau dans l'aquifère se dégrade en direction du nord et de l'est. Une

  16. A note on the orientation of the macrodispersion tensor in partially saturated heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Russo, David; Hadad, Avichay; Laufer, Asher

    The general situation in which the mean gradient vector, J, is not necessarily aligned in a direction perpendicular to the bedding of a partially saturated heterogeneous formation, is considered. Previous results of first-order analyses, based on a stochastic continuum presentation of unsaturated flow and a general Lagrangian description of the transport 15 and standard tensor transformation relationships, were used to evaluate the orientation of the principal axes of the asymptotic macrodispersion tensor as a function of the inclination of J, and to assess its impact on solute spreading in partially saturated heterogeneous formations of three-dimensional anisotropic structure. The main results obtained in this study suggest that under unsaturated flow, for given statistics of the formation properties and given mean water saturation, and when the inclination of J is relatively small, coarse-textured soil material with negligibly small capillary forces may compensate for the enhanced lateral displacement (in the same direction as that of J relative to the longitudinal axis of the formation heterogeneity) and the enhanced lateral spreading of the solute plume due to increasing anisotropy (smaller e = I yv/I yh where Iyv and Iyh are the correlation length scales of log-unsaturated conductivity in the vertical (longitudinal) and horizontal directions, respectively). On the other hand, when the inclination of J is relatively large, such soil material may enhance lateral displacement of the solute plume in a direction opposite to that of J relative to the longitudinal axis of the formation heterogeneity.

  17. Thermal state and complex geology of a heterogeneous salty crust of Jupiter's satellite, Europa

    NASA Astrophysics Data System (ADS)

    Prieto-Ballesteros, Olga; Kargel, Jeffrey S.

    2005-01-01

    The complex geology of Europa is evidenced by many tectonic and cryomagmatic resurfacing structures, some of which are "painted" into a more visible expression by exogenic alteration processes acting on the principal endogenic cryopetrology. The surface materials emplaced and affected by this activity are mainly composed of water ice in some areas, but in other places there are other minerals involved. Non-ice minerals are visually recognized by their low albedo and reddish color either when first emplaced or, more likely, after alteration by Europan weathering processes, especially sublimation and alteration by ionizing radiation. While red chromophoric material could be due to endogenic production of solid sulfur allotropes or other compounds, most likely the red substance is an impurity produced by radiation alteration of hydrated sulfate salts or sulphuric acid of mainly internal origin. If the non-ice red materials or their precursors have a source in the satellite interior, and if they are not merely trace contaminants, then they can play an important role in the evolution of the icy crust, including structural differentiation and the internal dynamics. Here we assume that these substances are major components of Europa's cryo/hydrosphere, as some models have predicted they should be. If this is an accurate assumption, then these substances should not be neglected in physical, chemical, and biological models of Europa, even if major uncertainties remain as to the exact identity, abundance, and distribution of the non-ice materials. The physical chemical properties of the ice-associated materials will contribute to the physical state of the crust today and in the geological past. In order to model the influence of them on the thermal state and the geology, we have determined the thermal properties of the hydrated salts. Our new lab data reveal very low thermal conductivities for hydrated salts compared to water ice. Lower conductivities of salty ice would

  18. Thermal state and complex geology of a heterogeneous salty crust of Jupiter's satellite, Europa

    USGS Publications Warehouse

    Prieto-Ballesteros, O.; Kargel, J.S.

    2005-01-01

    The complex geology of Europa is evidenced by many tectonic and cryomagmatic resurfacing structures, some of which are "painted" into a more visible expression by exogenic alteration processes acting on the principal endogenic cryopetrology. The surface materials emplaced and affected by this activity are mainly composed of water ice in some areas, but in other places there are other minerals involved. Non-ice minerals are visually recognized by their low albedo and reddish color either when first emplaced or, more likely, after alteration by Europan weathering processes, especially sublimation and alteration by ionizing radiation. While red chromophoric material could be due to endogenic production of solid sulfur allotropes or other compounds, most likely the red substance is an impurity produced by radiation alteration of hydrated sulfate salts or sulphuric acid of mainly internal origin. If the non-ice red materials or their precursors have a source in the satellite interior, and if they are not merely trace contaminants, then they can play an important role in the evolution of the icy crust, including structural differentiation and the internal dynamics. Here we assume that these substances are major components of Europa's cryo/hydrosphere, as some models have predicted they should be. If this is an accurate assumption, then these substances should not be neglected in physical, chemical, and biological models of Europa, even if major uncertainties remain as to the exact identity, abundance, and distribution of the non-ice materials. The physical chemical properties of the ice-associated materials will contribute to the physical state of the crust today and in the geological past. In order to model the influence of them on the thermal state and the geology, we have determined the thermal properties of the hydrated salts. Our new lab data reveal very low thermal conductivities for hydrated salts compared to water ice. Lower conductivities of salty ice would

  19. Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

    SciTech Connect

    Brown, Stephen R.

    2003-06-01

    The DOE National Laboratories have extensive environmental remediation and operations centers as well as research teams specializing in environmental problems. These organizations are concerned largely with pollution prevention, safe disposal of hazardous materials, polluted site identification and characterization, and cleanup of polluted sites. These organizations, and the private-industry subcontractors they hire, require state of the art tools and techniques for characterization and monitoring. Our research will contribute to this effort by providing descriptions of heterogeneities and scaling properties in the vadose and saturated zones with particular emphasis on flow and transport. This work will also provide an important link between some geophysical measurements and fluid transport characteristics.

  20. 1996 SPE annual technical conference and exhibition: Formation evaluation and reservoir geology

    SciTech Connect

    1996-12-31

    This document contains the Proceedings of the 1996 Society of Petroleum Engineers Annual Technical Conference and Exhibition, Formation Evaluation and Reservoir Geology section. Topics covered in this section include the evaluation of reservoir engineering and resource management techniques for oil and natural gas fields, data acquisition methods for reservoir characterization, description of problems and maintenance techniques for fluid flow in oil wells, and technology assessment of well logging instrumentation for formation evaluation and reservoir characterization.

  1. The Affect of Realistic Geologic Heterogeneity on Local and Regional P/S Amplitude Ratios Based on Numerical Simulations

    SciTech Connect

    Myers, S C; Wagoner, J L; Preston, L; Smith, K; Larsen, S C

    2005-07-11

    and geologic complexity in the upper crust strongly contributed to the generation of S-waves from the NPE shot. When either geologic heterogeneity or topography is removed from the model, simulated amplitudes of regional S-waves are diminished. We also find that deeper sources scatter less energy off of topography and upper-crustal structures, resulting in diminished S-wave amplitudes with increasing source depth.

  2. Modeling Heterogeneous CINO2 Formation, Chloride Availability, and Chlorine Cycling in Southeast Texas

    EPA Science Inventory

    Nitryl chloride (ClNO2) mixing ratios above 1 ppbv have been measured off the coast of Southeast Texas. ClNO2 formation, the result of heterogeneous N205 uptake on chloride-containing aerosols, has a significant impact on oxidant form...

  3. Geological study of uranium potential of the Kingston Peak Formation, Death Valley Region, California

    SciTech Connect

    Carlisle, D.; Kettler, R.M.; Swanson, S.C.

    1980-09-01

    The results of a geological survey of the Kingston Peak Formation on the western slope of the Panamint Range near Death Valley are discussed. The geology of the Panamint mountains was mapped on topographic base maps of the Telescope Peak and Manly Peak quadrangles. Radiometric suveys of the area were conducted using gamma ray spectrometers. Samples of the conglomerate were analyzed using delayed neutron, neutron activation, atomic absorption, and LECO analysis. It is concluded that uranium mineralization in the Favorable Submember is significant and further exploration is warranted. The monazite-fenotime related uranium and thorium mineralization in the Mountain Girl quartz pebble conglomerate is of no economic interest. (DMC)

  4. Geological conditions of the time of formation of impact craters on Pai-Khoi

    NASA Astrophysics Data System (ADS)

    Mashchak, M. S.

    Present-day ideas on the time of formation of the Kara and Ust-Kara astroblemes are presented, and the main features of the geological structure of Phai-Khoi (the region where these structures are located) are described. Based on an analysis of the geological conditions, a large complex of fossil fauna and diatomaceous algae, and radiological dating of tagamites and impact glasses, it is shown that the craters were formed on the Cretaceous-Paleogene boundary about 66-67 million years ago.

  5. Formation evaluation and reservoir geology. 1995 SPE annual technical conference and exhibition

    SciTech Connect

    1995-12-31

    This document contains the proceedings of the Annual Technical Conference and Exhibition of the Society of Petroleum Engineers which was held on October 22-25, 1995 in Dallas, Texas. This volume contains the presentations regarding Formation Evaluation and Reservoir Geology. The topics covered in these presentations include: resource management and reservoir engineering of oil, natural gas and gas condensate fields, magnetic, electrical, and seismic surveys of reservoir rock, mathematical models and computerized simulation of fluid flow in reservoir rock, geochemistry of reservoir fluids, and enhanced recovery of oil and natural gas using waterflooding and other secondary recovery methods. Team approaches to reservoir characterization using geology, geophysics, and petroleum engineering are also described.

  6. Geologic Observations and Numerical Modeling: A Combined Approach to Understanding Crater and Basin Formation and Structure

    NASA Astrophysics Data System (ADS)

    Potter, R. W. K.; Head, J. W., III

    2014-12-01

    Impact cratering is a fundamental geological process throughout the Solar System. The Moon is an ideal location to document the impact cratering process due to the number and excellent state of preservation of large craters and basins, and the wide range of geological, geophysical, topographic, mineralogic, remote sensing and returned sample data. Despite the number and excellent preservation state of many large complex craters and basins, their formation and the origin of their structural features and the stages in their evolution remain contentious. To more comprehensively document the final stage of lunar impact basin formation, we have compiled detailed topographic, geological and mineralogic maps of several type examples of peak-ring and multi-ring basins, including the Orientale basin. These data include the mineralogic characteristics of basin ring structures and assist in the interpretation of the target stratigraphy, and the depth of origin of basin rings. Data for the current structure of basins is compared to numerical model outputs of basin-forming impacts, which track formation to the conclusion of dynamic processes (2 to 3 hours after impact). We use the Orientale basin as an example and provide combined correlations and interpretations that assign rings to various stages in the numerical models, and compare these candidates to crustal stratigraphy, with the ultimate aim of producing a consistent model for large crater/basin formation. The shock physics code iSALE is used to numerically model the basin-scale impacts. Constitutive equations and equations of state for materials analogous to the lunar crust (gabbroic anorthosite) and mantle (dunite) are used. Aspects of the numerically-produced lunar basins (e.g., material distribution and accumulated stress) are compared and contrasted to remote observations and geological maps of the Orientale rings and geological units, including ejecta and impact melt deposits.

  7. A Highly Efficient Heterogenized Iridium Complex for the Catalytic Hydrogenation of Carbon Dioxide to Formate.

    PubMed

    Park, Kwangho; Gunasekar, Gunniya Hariyanandam; Prakash, Natarajan; Jung, Kwang-Deog; Yoon, Sungho

    2015-10-26

    A heterogenized catalyst on a highly porous covalent triazine framework was synthesized and characterized to have a coordination environment similar to that of its homogeneous counterpart. The catalyst efficiently converted CO2 into formate through hydrogenation with a turnover number of 5000 after 2 h and an initial turnover frequency of up to 5300 h(-1) ; both of these values are the highest reported to date for a heterogeneous catalyst, which makes it attractive toward industrial application. Furthermore, the synthesized catalyst was found to be stable in air and was recycled by simple filtration without significant loss of catalytic activity. PMID:26493515

  8. Risk Assessment of Geologic Formation Sequestration in The Rocky Mountain Region, USA

    SciTech Connect

    Lee, Si-Yong; McPherson, Brian

    2013-08-01

    The purpose of this report is to describe the outcome of a targeted risk assessment of a candidate geologic sequestration site in the Rocky Mountain region of the USA. Specifically, a major goal of the probabilistic risk assessment was to quantify the possible spatiotemporal responses for Area of Review (AoR) and injection-induced pressure buildup associated with carbon dioxide (CO₂) injection into the subsurface. Because of the computational expense of a conventional Monte Carlo approach, especially given the likely uncertainties in model parameters, we applied a response surface method for probabilistic risk assessment of geologic CO₂ storage in the Permo-Penn Weber formation at a potential CCS site in Craig, Colorado. A site-specific aquifer model was built for the numerical simulation based on a regional geologic model.

  9. The digital geologic map of Colorado in ARC/INFO format

    USGS Publications Warehouse

    Green, Gregory N.

    1992-01-01

    This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

  10. The digital geologic map of Colorado in ARC/INFO format, Part A. Documentation

    USGS Publications Warehouse

    Green, Gregory N.

    1992-01-01

    This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

  11. Comparison of methods for geologic storage of carbon dioxide in saline formations

    SciTech Connect

    Goodman, Angela L.; Bromhal, Grant S.; Strazisar, Brian; Rodosta, Traci D.; Guthrie, William J.; Allen, Douglas E.; Guthrie, George D.

    2013-01-01

    Preliminary estimates of CO{sub 2} storage potential in geologic formations provide critical information related to Carbon Capture, Utilization, and Storage (CCUS) technologies to mitigate CO{sub 2} emissions. Currently multiple methods to estimate CO{sub 2} storage and multiple storage estimates for saline formations have been published, leading to potential uncertainty when comparing estimates from different studies. In this work, carbon dioxide storage estimates are compared by applying several commonly used methods to general saline formation data sets to assess the impact that the choice of method has on the results. Specifically, six CO{sub 2} storage methods were applied to thirteen saline formation data sets which were based on formations across the United States with adaptations to provide the geologic inputs required by each method. Methods applied include those by (1) international efforts – the Carbon Sequestration Leadership Forum (Bachu et al., 2007); (2) United States government agencies – U.S. Department of Energy – National Energy Technology Laboratory (US-DOE-NETL, 2012) and United States Geological Survey (Brennan et al., 2010); and (3) the peer-reviewed scientific community – Szulczewski et al. (2012) and Zhou et al. (2008). A statistical analysis of the estimates generated by multiple methods revealed that assessments of CO{sub 2} storage potential made at the prospective level were often statistically indistinguishable from each other, implying that the differences in methodologies are small with respect to the uncertainties in the geologic properties of storage rock in the absence of detailed site-specific characterization.

  12. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, III, William B.

    1991-01-01

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas present. Lithological characteristics of the formation such as the pressence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes.

  13. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, W.B. III.

    1991-08-27

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into the formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes. 48 figures.

  14. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, W.B. III.

    1989-11-21

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes. 48 figs.

  15. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

    DOEpatents

    Vail, III, William B.

    1989-01-01

    Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes.

  16. Evaluation of the geological relationships to gas hydrate formation and stability

    SciTech Connect

    Not Available

    1986-01-01

    Although there are many publications pertaining to gas hydrates, their formation and stability in various geological conditions are poorly known. Therefore, for the same reasons and because of the very broad scope of our research, limited amount and extremely dispersed information, the study regions are very large. Moreover, almost without exception the geological environments controlling gas hydrates formation and stability of the studied regions are very complex. The regions studied (completed and partially completed - total 17 locations) during the reporting period, particularly the Gulf of Mexico and the Middle America Trench, are the most important in this entire research project. In the past, both of these regions have been extensively studied, the presence of gas hydrates confirmed and samples recovered. In our investigation it was necessary not only to review all previous data and interpretations, but to do a thorough analysis of the basins, and a critical evaluation of an previously reported and publicly available but not published information.

  17. Methods and apparatus for measurement of the resistivity of geological formations from within cased boreholes

    DOEpatents

    Vail, W.B. III.

    1989-04-11

    Methods and apparatus are disclosed which allow measurement of the resistivity of a geological formation through borehole casing which may be surrounded by brine saturated cement. A.C. current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. The A.C. voltage difference is measured between two additional vertically disposed electrodes on the interior of the casing which provides a measure of the resistivity of the geological formation. A calibration and nulling procedure is presented which minimizes the influence of variations in the thickness of the casing. The procedure also minimizes the influence of inaccurate placements of the additional vertically disposed electrodes. 3 figs.

  18. Methods and apparatus for measurement of the resistivity of geological formations from within cased boreholes

    DOEpatents

    Vail, III, William B.

    1989-01-01

    Methods and apparatus are disclosed which allow measurement of the resistivity of a geological formation through borehole casing which may be surrounded by brine saturated cement. A.C. current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. The A.C. voltage difference is measured between two additional vertically disposed electrodes on the interior of the casing which provides a measure of the resistivity of the geological formation. A calibration and nulling procedure is presented which minimizes the influence of variations in the thickness of the casing. The procedure also minimizes the influence of inaccurate placements of the additional vertically disposed electrodes.

  19. Method for Controlling a Producing Zone of a Well in a Geological Formation

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)

    2005-01-01

    System and methods for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.

  20. Method for controlling a producing zone of a well in a geological formation

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)

    2005-01-01

    System and methods for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.

  1. Evaluation of Displacement and Pore Pressure change Due to the Injections of Fluid in Geological Formations and Mineralization

    NASA Astrophysics Data System (ADS)

    Chang, C.; Hsu, K.

    2011-12-01

    Cap rock plays an important role in the geological sequestration of carbon dioxide capture and storage. It indicates the effectiveness of the storage formation and controls the leakance of carbon dioxide and serves the need for geological repair and restoration. In this study, analytical solutions were devived based on the poroelastic theory. The effects of properties geological formation and mineralization were investigated on the change of pore pressure and the displacement of caprock. The results can be used for monitoring the geological sequestration of carbon dioxide.

  2. Experiences with the Application of Services Oriented Approaches to the Federation of Heterogeneous Geologic Data Resources

    NASA Astrophysics Data System (ADS)

    Cervato, C.; Fils, D.; Bohling, G.; Diver, P.; Greer, D.; Reed, J.; Tang, X.

    2006-12-01

    The federation of databases is not a new endeavor. Great strides have been made e.g. in the health and astrophysics communities. Reviews of those successes indicate that they have been able to leverage off key cross-community core concepts. In its simplest implementation, a federation of databases with identical base schemas that can be extended to address individual efforts, is relatively easy to accomplish. Efforts of groups like the Open Geospatial Consortium have shown methods to geospatially relate data between different sources. We present here a summary of CHRONOS's (http://www.chronos.org) experience with highly heterogeneous data. Our experience with the federation of very diverse databases shows that the wide variety of encoding options for items like locality, time scale, taxon ID, and other key parameters makes it difficult to effectively join data across them. However, the response to this is not to develop one large, monolithic database, which will suffer growth pains due to social, national, and operational issues, but rather to systematically develop the architecture that will enable cross-resource (database, repository, tool, interface) interaction. CHRONOS has accomplished the major hurdle of federating small IT database efforts with service-oriented and XML-based approaches. The application of easy-to-use procedures that allow groups of all sizes to implement and experiment with searches across various databases and to use externally created tools is vital. We are sharing with the geoinformatics community the difficulties with application frameworks, user authentication, standards compliance, and data storage encountered in setting up web sites and portals for various science initiatives (e.g., ANDRILL, EARTHTIME). The ability to incorporate CHRONOS data, services, and tools into the existing framework of a group is crucial to the development of a model that supports and extends the vitality of the small- to medium-sized research effort that is

  3. Estimation of Geologic Storage Capacity of Carbon Dioxide in the Bukpyeong Basin, Korea Using Integrated Three-Dimensional Geologic Formation Modeling and Thermo-Hydrological Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kihm, J.; Park, S.; SNU CO2 GEO-SEQ TEAM

    2011-12-01

    A conventional method, which was suggested by NETL (2007), has been widely used for estimating the geologic storage capacity of carbon dioxide in sedimentary basins. Because of its simple procedure, it has been straightforwardly applied to even spatially very complicate sedimentary basins. Thus, the results from the conventional method are often not accurate and reliable because it can not consider spatial distributions of fluid conditions and carbon dioxide properties, which are not uniform but variable within sedimentary basins. To overcome this limit of the conventional method, a new method, which can consider such spatially variable distributions of fluid conditions and carbon dioxide properties within sedimentary basins, is suggested and applied in this study. In this new method, a three-dimensional geologic formation model of a target sedimentary basin is first established and discretized into volume elements. The fluid conditions (i.e., pressure, temperature, and salt concentration) within each element are then obtained by performing thermo-hydrological numerical modeling. The carbon dioxide properties (i.e., phase, density, dynamic viscosity, and solubility to groundwater) within each element are then calculated from thermodynamic database under corresponding fluid conditions. Finally, the geologic storage capacity of carbon dioxide with in each element is estimated using the corresponding carbon dioxide properties as well as porosity and element volume, and that within the whole sedimentary basin is determined by summation over all elements. This new method is applied to the Bukpyeong Basin, which is one of the prospective offshore sedimentary basins for geologic storage of carbon dioxide in Korea. A three-dimensional geologic formation model of the Bukpyeong Basin is first established considering the elevation data of the boundaries between the geologic formations obtained from seismic survey and geologic maps at the sea floor surface. This geologic

  4. The Impact of Geologic Heterogeneity on CO2 Injection with Simultaneous Brine Extraction and Economic Uncertainty for Large-Scale CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Kobos, P. H.; Heath, J. E.; Roach, J. D.; McKenna, S. A.; Dewers, T. A.; Gutierrez, K.

    2011-12-01

    Performance assessment of CO2 sequestration opportunities at the scale of the United States presents challenges for coping with geologic and economic uncertainties. Inaccurate estimation of suitable flow properties could result in drilling wells in parts of a formation that could not physically accommodate the needed injection rates and storage volumes. Data paucity and heterogeneity in geologic properties necessitates probabilistic approaches for estimating CO2 injection and simultaneous brine extraction rates (for beneficial use such as power-plant cooling or pressure management) and associated costs. We present an Integrated Assessment Model (IAM) that assesses CO2 injection rates with or without simultaneous brine extraction for the saline reservoirs identified in the National Carbon Sequestration Database (NatCarb). We have linked NatCarb reservoirs to injectivity rock types. We define these rock types quantitatively by probability distribution functions (PDFs) of permeability and porosity, and spatial correlation models. Thus, IAM has flexibility in calculating CO2 injectivity and brine productivity while coping with heterogeneity, and then determining the uncertainty in well-associated costs. For computational efficiency, IAM performs injectivity and productivity calculations with analytical solutions that have been validated by numerical simulation and comparison to available field data. The solutions incorporate spatially varying properties through PDFs that are based on upscaling of geostatistical realizations of the injectivity rock types. A key method of the geostatistics is linear coregionalization, which defines the linear relationship between porosity and log permeability with a specified correlation coefficient, r, of the regression while maintaining the spatial correlation of each variable. The major finding is high sensitivity of well-associated costs to permeability. Error in field prediction of an order of magnitude in permeability may be the

  5. Intrinsic formation of nanocrystalline neptunium dioxide under neutral aqueous conditions relevant to deep geological repositories.

    PubMed

    Husar, Richard; Hübner, René; Hennig, Christoph; Martin, Philippe M; Chollet, Mélanie; Weiss, Stephan; Stumpf, Thorsten; Zänker, Harald; Ikeda-Ohno, Atsushi

    2015-01-25

    The dilution of aqueous neptunium carbonate complexes induces the intrinsic formation of nanocrystalline neptunium dioxide (NpO2) particles, which are characterised by UV/Vis and X-ray absorption spectroscopies and transmission electron microscopy. This new route of nanocrystalline NpO2 formation could be a potential scenario for the environmental transport of radionuclides from the waste repository (i.e. under near-field alkaline conditions) to the geological environment (i.e. under far-field neutral conditions). PMID:25479067

  6. A methodology for the geological and numerical modelling of CO2 storage in deep saline formations

    NASA Astrophysics Data System (ADS)

    Guandalini, R.; Moia, F.; Ciampa, G.; Cangiano, C.

    2009-04-01

    Several technological options have been proposed to stabilize and reduce the atmospheric concentrations of CO2 among which the most promising are the CCS technologies. The remedy proposed for large stationary CO2 sources as thermoelectric power plants is to separate the flue gas, capturing CO2 and to store it into deep subsurface geological formations. In order to support the identification of potential CO2 storage reservoirs in Italy, the project "Identification of Italian CO2 geological storage sites", financed by the Ministry of Economic Development with the Research Fund for the Italian Electrical System under the Contract Agreement established with the Ministry Decree of march 23, 2006, has been completed in 2008. The project involves all the aspects related to the selection of potential storage sites, each carried out in a proper task. The first task has been devoted to the data collection of more than 6800 wells, and their organization into a geological data base supported by GIS, of which 1911 contain information about the nature and the thickness of geological formations, the presence of fresh, saline or brackish water, brine, gas and oil, the underground temperature, the seismic velocity and electric resistance of geological materials from different logs, the permeability, porosity and geochemical characteristics. The goal of the second task was the set up of a numerical modelling integrated tool, that is the in order to allow the analysis of a potential site in terms of the storage capacity, both from solubility and mineral trapping points of view, in terms of risk assessment and long-term storage of CO2. This tool includes a fluid dynamic module, a chemical module and a module linking a geomechanical simulator. Acquirement of geological data, definition of simulation parameter, run control and final result analysis can be performed by a properly developed graphic user interface, fully integrated and calculation platform independent. The project is then

  7. Numerical evaluation of apparent transport parameters from forced-gradient tracer tests in statistically anisotropic heterogeneous formations

    NASA Astrophysics Data System (ADS)

    Pedretti, D.; Fernandez-Garcia, D.; Bolster, D.; Sanchez-Vila, X.; Benson, D.

    2012-04-01

    For risk assessment and adequate decision making regarding remediation strategies in contaminated aquifers, solute fate in the subsurface must be modeled correctly. In practical situations, hydrodynamic transport parameters are obtained by fitting procedures, that aim to mathematically reproduce solute breakthrough (BTC) observed in the field during tracer tests. In recent years, several methods have been proposed (curve-types, moments, nonlocal formulations) but none of them combine the two main characteristic effects of convergent flow tracer tests (which are the most used tests in the practice): the intrinsic non-stationarity of the convergent flow to a well and the ubiquitous multiscale hydraulic heterogeneity of geological formations. These two effects separately have been accounted for by a lot of methods that appear to work well. Here, we investigate both effects at the same time via numerical analysis. We focus on the influence that measurable statistical properties of the aquifers (such as the variance and the statistical geometry of correlation scales) have on the shape of BTCs measured at the pumping well during convergent flow tracer tests. We built synthetic multigaussian 3D fields of heterogeneous hydraulic conductivity fields with variable statistics. A well is located in the center of the domain to reproduce a forced gradient towards it. Constant-head values are imposed on the boundaries of the domains, which have 251x251x100 cells. Injections of solutes take place by releasing particles at different distances from the well and using a random walk particle tracking scheme with constant local coefficient of dispersivity. The results show that BTCs partially display the typical anomalous behavior that has been commonly referred to as the effect of heterogeneity and connectivity (early and late arrival times of solute differ from the one predicted by local formulations). Among the most salient features, the behaviors of BTCs after the peak (the slope

  8. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2011-11-29

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington State (USA) was investigated by analyzing samples recovered from depths of 9 to 52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analyzed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units at the 97% identity level), respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (ca. 90%) of Proteobacteria. The Bacterial community in the oxic sediments contained not only members of 9 well-recognized phyla but also an unusually high proportion of 3 candidate divisions (GAL15, NC10, and SPAM). Additionally, novel phylogenetic orders were identified within the Delta-proteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site.

  9. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site.

    PubMed

    Lin, Xueju; Kennedy, David; Fredrickson, Jim; Bjornstad, Bruce; Konopka, Allan

    2012-02-01

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington state (USA) was investigated by analysing 21 samples recovered from depths of 9-52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analysed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (operational taxonomic units at the 97% identity level) respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (> 700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (c. 90%) of Proteobacteria. The bacterial community in the oxic sediments contained not only members of nine well-recognized phyla but also an unusually high proportion of three candidate divisions (GAL15, NC10 and SPAM). Additionally, 13 novel phylogenetic orders were identified within the Deltaproteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site. PMID:22122741

  10. Heterogeneous Chemistry of Carbonyls and Alcohols With Sulfuric Acid: Implications for Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Levitt, N.; Zhang, R.

    2006-12-01

    Recent environmental chamber studies have suggested that acid-catalyzed particle-phase reactions of organic carbonyls lead to multifold increases in secondary organic aerosol (SOA) mass and acid-catalyzed reactions between alcohols and aldehydes in the condensed phase lead to the formation of hemiacetals and acetals, also enhancing secondary organic aerosol growth. The kinetics and mechanism of the heterogeneous chemistry of carbonyls and alcohols with sulfuric acid, however, remain largely uncertain. In this talk, we present measurements of heterogeneous uptake of several carbonyls and alcohols on liquid H2SO4 in a wide range of acid concentrations and temperatures. The results indicate that uptake of larger carbonyls is explained by aldol condensation. For small dicarbonyls, heterogeneous reactions are shown to decrease with acidity and involve negligible formation of sulfate esters. Hydration and polymerization likely explain the measured uptake of such small dicarbonyls on H2SO4 and the measurements do not support an acid- catalyzed uptake. Atmospheric implications from our findings will be discussed.

  11. Characterization of the Geologic Setting of Recurring Slope Lineae: Constraints on Their Formation Mechanism

    NASA Astrophysics Data System (ADS)

    Watkins, J.; Ojha, L.; Reith, R. C.; Yin, A.

    2013-12-01

    Recurring Slope Lineae (RSL) are seasonal, low albedo features that originate at the base of bedrock outcrops and extend down steep, equator-facing, mid-latitude and equatorial rocky slopes of Mars. They exhibit progressive growth in the downslope direction during warm seasons, diverting around topographic obstacles, and fade during cold seasons. Slopes containing RSL appear to be sites of geologically very recent activity, including 'fresh' impact craters and active mass wasting, and are also associated with numerous small channels and bright fans. Based on their seasonal growth and strong dependency on latitude and slope aspect, RSL formation has been attributed to the seepage and downslope transport of a salt-bearing (briny), water-based liquid (potentially melted) through porous regolith near the surface. The seepage of this liquid wets and thus darkens the RSL surface, and evaporates once seasonal flow ceases. However, the source of this water, and an active recharge mechanism to maintain this source over even short geological timescales, are not currently understood. Subsurface groundwater is one possible source for the amount of liquid required to fill pore spaces between particles and create a hydraulic gradient to initiate and maintain water flow to the surface. Preexisting structural inhomogeneities, including faults, fractures, and joints, may act as conduits for subsurface fluid migration, supporting groundwater exploitation of routes of increased permeability. To investigate this fault-controlled brine flow hypothesis, morphological mapping of RSL slope surfaces is performed. Preliminary analysis of these geologic settings suggests a spatial correlation between RSL sites and fault related morphology, including linear features and offsets, transtensional features, sub parallel zones, and multiple styles of brittle deformation. This detailed, systematic study characterizing the geologic context of all confirmed RSL sites as well as of observed locations

  12. Role of geomechanically grown fractures on dispersive transport in heterogeneous geological formations.

    PubMed

    Nick, H M; Paluszny, A; Blunt, M J; Matthai, S K

    2011-11-01

    A second order in space accurate implicit scheme for time-dependent advection-dispersion equations and a discrete fracture propagation model are employed to model solute transport in porous media. We study the impact of the fractures on mass transport and dispersion. To model flow and transport, pressure and transport equations are integrated using a finite-element, node-centered finite-volume approach. Fracture geometries are incrementally developed from a random distributions of material flaws using an adoptive geomechanical finite-element model that also produces fracture aperture distributions. This quasistatic propagation assumes a linear elastic rock matrix, and crack propagation is governed by a subcritical crack growth failure criterion. Fracture propagation, intersection, and closure are handled geometrically. The flow and transport simulations are separately conducted for a range of fracture densities that are generated by the geomechanical finite-element model. These computations show that the most influential parameters for solute transport in fractured porous media are as follows: fracture density and fracture-matrix flux ratio that is influenced by matrix permeability. Using an equivalent fracture aperture size, computed on the basis of equivalent permeability of the system, we also obtain an acceptable prediction of the macrodispersion of poorly interconnected fracture networks. The results hold for fractures at relatively low density. PMID:22181492

  13. Formation of HCN+ in Heterogeneous Reactions of N2+ and N+ with Surface Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Harnisch, Martina; Keim, Alan; Scheier, Paul; Herman, Zdenek

    2013-10-01

    A significant increase of the ion yield at m/z 27 in collisions of low-energy ions of N2+ and N+ with hydrocarbon-covered room-temperature or heated surfaces of tungsten, carbon-fiber composite, and beryllium, not observed in analogous collisions of Ar+, is ascribed to the formation of HCN+ in heterogeneous reactions between N2+ or N+ and surface hydrocarbons. The formation of HCN+ in the reaction with N+ indicated an exothermic reaction with no activation barrier, likely to occur even at very low collision energies. In the reaction with N2+, the formation of HCN+ was observed to a different degree on these room-temperature and heated (150 and 300 °C) surfaces at incident energies above about 50 eV. This finding suggested an activation barrier or reaction endothermicity of the heterogeneous reaction of about 3-3.5 eV. The main process in N2+ or N+ interaction with the surfaces is ion neutralization; the probability of forming the reaction product HCN+ was very roughly estimated for both N2+ and N+ ions to about one in 104 collisions with the surfaces.

  14. Geologic factors controlling CO2 storage capacity and permanence: case studies based on experience with heterogeneity in oil and gas reservoirs applied to CO2 storage

    NASA Astrophysics Data System (ADS)

    Ambrose, W. A.; Lakshminarasimhan, S.; Holtz, M. H.; Núñez-López, V.; Hovorka, S. D.; Duncan, I.

    2008-06-01

    A variety of structural and stratigraphic factors control geological heterogeneity, inferred to influence both sequestration capacity and effectiveness, as well as seal capacity. Structural heterogeneity factors include faults, folds, and fracture intensity. Stratigraphic heterogeneity is primarily controlled by the geometry of depositional facies and sandbody continuity, which controls permeability structure. The permeability structure, in turn, has implications for CO2 injectivity and near-term migration pathways, whereas the long-term sequestration capacity can be inferred from the production history. Examples of Gulf Coast oil and gas reservoirs with differing styles of stratigraphic heterogeneity demonstrate the impact of facies variability on fluid flow and CO2 sequestration potential. Beach and barrier-island deposits in West Ranch field in southeast Texas are homogeneous and continuous. In contrast, Seeligson and Stratton fields in south Texas, examples of major heterogeneity in fluvial systems, are composed of discontinuous, channel-fill sandstones confined to narrow, sinuous belts. These heterogeneous deposits contain limited compartments for potential CO2 storage, although CO2 sequestration effectiveness may be enhanced by the high number of intraformational shale beds. These field examples demonstrate that areas for CO2 storage can be optimized by assessing sites for enhanced oil and gas recovery in mature hydrocarbon provinces.

  15. Physical Constraints on Geologic CO2 Sequestration in Low-Volume Basalt Formations

    SciTech Connect

    Ryan M. Pollyea; Jerry P. Fairley; Robert K. Podgorney; Travis L. McLing

    2014-03-01

    Deep basalt formations within large igneous provinces have been proposed as target reservoirs for carbon capture and sequestration on the basis of favorable CO2-water-rock reaction kinetics that suggest carbonate mineralization rates on the order of 102–103 d. Although these results are encouraging, there exists much uncertainty surrounding the influence of fracture-controlled reservoir heterogeneity on commercial-scale CO2 injections in basalt formations. This work investigates the physical response of a low-volume basalt reservoir to commercial-scale CO2 injections using a Monte Carlo numerical modeling experiment such that model variability is solely a function of spatially distributed reservoir heterogeneity. Fifty equally probable reservoirs are simulated using properties inferred from the deep eastern Snake River Plain aquifer in southeast Idaho, and CO2 injections are modeled within each reservoir for 20 yr at a constant mass rate of 21.6 kg s–1. Results from this work suggest that (1) formation injectivity is generally favorable, although injection pressures in excess of the fracture gradient were observed in 4% of the simulations; (2) for an extensional stress regime (as exists within the eastern Snake River Plain), shear failure is theoretically possible for optimally oriented fractures if Sh is less than or equal to 0.70SV; and (3) low-volume basalt reservoirs exhibit sufficient CO2 confinement potential over a 20 yr injection program to accommodate mineral trapping rates suggested in the literature.

  16. Method of detecting leakage from geologic formations used to sequester CO.sub.2

    SciTech Connect

    White, Curt; Wells, Arthur; Diehl, J. Rodney; Strazisar, Brian

    2010-04-27

    The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

  17. Paleogene mammals from the Iwaki Formation in Japan: Their implications for the geologic age and paleobiogeography of this formation

    NASA Astrophysics Data System (ADS)

    Tsubamoto, Takehisa; Koda, Yoshiki; Hasegawa, Yoshikazu; Nabana, Satoshi; Tomida, Yukimitsu

    2015-08-01

    The mammalian fauna and geologic age of the Iwaki Formation of the Paleogene Shiramizu Group (Iwaki, southern Fukushima, northeastern Japan) are reviewed and previously undescribed specimens are described. The Iwaki mammalian fauna consists of three artiodactyl species: Bothriogenys sp. cf. B. hui (Anthracotheriidae), Entelodon gobiensis (Entelodontidae), and cf. Notomeryx sp. (Ruminantia). These three genera indicate an Ergilian Asian Land Mamma Age (=late Eocene [Priabonian] equivalent) correlation for the Iwaki Formation, demonstrating that the Eocene-Oligocene boundary exists within the Shiramizu Group. These three genera have never co-occurred in a single formation, although in Asia they have been recorded only in the late Eocene. In Asia, Bothriogenys has been recorded in the southern and middle regions, Entelodon has been mostly recorded in the northern and middle regions with one exception from the southern region, and Notomeryx has been recorded in the southern region. The co-occurrence of these three genera in the Iwaki Formation implies that Bothriogenys, Entelodon, and perhaps also Notomeryx can be useful late Eocene indicators in terrestrial eastern Asia. It also suggests that the Iwaki mammalian fauna is paleobiogeographically located between the northern and southern late Eocene faunas of eastern Asia, showing some faunal mixture. The Iwaki fauna is also unique in comprising diverse faunas of marine sharks and seashore birds together with terrestrial mammals. The Iwaki vertebrate fauna is key for reconstructing the faunas of the eastern coastal margin of the Asian Continent during the late Eocene.

  18. Impacts of transport mechanisms and plume history on tailing of sorbing plumes in heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Maghrebi, Mahdi; Jankovic, Igor; Allen-King, Richelle M.; Rabideau, Alan J.; Kalinovich, Indra; Weissmann, Gary S.

    2014-11-01

    This work investigated the impacts of permeability and sorption heterogeneity on contaminant transport in groundwater using simulation experiments designed to elucidate the causes of tailing. The effects of advection, diffusion and sorption mechanisms and plume history were explored. A simple conceptual model consisting of a single inclusion (heterogeneity) of uniform hydraulic conductivity K and sorption distribution coefficient Kd was adopted. The 3D inclusion, shaped as a horizontal oblate ellipsoid of variable thickness, was placed in a homogeneous anisotropic background of different hydraulic conductivity and sorption distribution coefficient. The background represents average K and Kd of a heterogeneous porous formation. A closed-form analytic flow solution for uniform flow past the inclusion was coupled with a numerical transport solution to simulate contaminant migration for a wide range of transport parameters and two distinct source conditions. Over 2600 numerical simulations were performed in parallel. Transport results were presented in terms of travel time distributions at a control plane downstream of the inclusion and used to quantify tailing for a wide range of transport parameters, in order to separate advection-dominated from diffusion-dominated transport regime and to investigate effects of inclusion shape, diffusion, sorption and plume history on tailing.

  19. Modeling heterogeneous ClNO 2 formation, chloride availability, and chlorine cycling in Southeast Texas

    NASA Astrophysics Data System (ADS)

    Simon, H.; Kimura, Y.; McGaughey, G.; Allen, D. T.; Brown, S. S.; Coffman, D.; Dibb, J.; Osthoff, H. D.; Quinn, P.; Roberts, J. M.; Yarwood, G.; Kemball-Cook, S.; Byun, D.; Lee, D.

    2010-12-01

    Nitryl Chloride (ClNO 2) mixing ratios above 1 ppbv have been measured off the coast of Southeast Texas. ClNO 2 formation, the result of heterogeneous N 2O 5 uptake on chloride-containing aerosols, has a significant impact on oxidant formation for the Houston area. This work reports on the modeling of ClNO 2 formation and describes the sensitivity of ClNO 2 formation to key parameters. Model sensitivity analyses found that: (1) Chloride availability limits the formation of nitryl chloride at ground level but not aloft; (2) When excess particulate chloride was assumed to be present at ground level through sea salt, ClNO 2 concentrations increased in some locations by a factor of 13, as compared to cases where sea salt chloride was assumed to be limited; (3) Inland formation of ClNO 2 seems feasible based on chloride availability and could have a large impact on total ClNO 2 formed in the region; and (4) ClNO 2 formation is quite sensitive to the assumed yield of ClNO 2 from N 2O 5 uptake. These results demonstrate that there is a need for further field studies to better understand the geographic extent of ClNO 2 formation and the atmospheric conditions which control partitioning of chloride into the particle phase. In addition, this work examined the role of ClNO 2 in the cycling of chlorine between chloride and reactive chlorine radicals. The modeling indicated that the majority of reactive chlorine in Texas along the Gulf coast is cycled through ClNO 2, demonstrating the importance of including ClNO 2 into photochemical models for this region.

  20. Geologic framework of the Jurassic (Oxfordian) Smackover Formation the Alabama coastal waters area

    SciTech Connect

    Tew, B.H.; Mancini, E.A. ); Mink R.M.; Mann, S.D. ); Mancini, E.A.

    1993-09-01

    The Jurassic (Oxfordian) Smackover Formation is a prolific hydrocarbon-producing geologic unit in the onshore Gulf of Mexico area, including southwest Alabama. However, no Smackover strata containing commercial accumulations of oil or gas have thus far been discovered in the Alabama state coastal waters area (ACW). This study of the regional geologic framework of the Smackover Formation was done to characterize the unit in the ACW and to compare strata in the ACW with productive Smackover intervals in the onshore area. In the study area, the Smackover Formation was deposited on a highly modified carbonate associated with pre-Smackover topographic features. In the onshore Alabama, north of the Wiggins arch complex, an inner ramp developed in the area of the Mississippi interior salt basin and the Manila and Conecuh embayments. South of the Wiggins arch complex in extreme southern onshore Alabama and in the ACW, an outer ramp formed that was characterized by a much thicker Smackover section. In the outer ramp setting, four lithofacies associations are recognized: lower, middle, and upper outer ramp lithofacies (ORL) and the coastal dolostone lithofacies. The coastal dolostone lithofacies accounts for most of the reservoir-grade porosity in the outer ramp setting. The lower, middle, and upper ORL, for the most part, are nonporous. Volumetrically, intercrystalline porosity is the most important pore type in the coastal dolostone lithofacies. Numerous data in the ACW area indicate that halokinesis has created structural conditions favorable for accumulation and entrapment of oil and gas in the outer ramp lithofacies of the Smackover. Prolific hydrocarbon source rocks are present in the ACW, as evidenced by the significant natural gas accumulations in the Norphlet Formation. To date, however, reservoir quality rocks of the coastal dolostone lithofacies coincident with favorable structural conditions have not been encountered in the ACW.

  1. Conformational Heterogeneity of Bax Helix 9 Dimer for Apoptotic Pore Formation

    NASA Astrophysics Data System (ADS)

    Liao, Chenyi; Zhang, Zhi; Kale, Justin; Andrews, David W.; Lin, Jialing; Li, Jianing

    2016-07-01

    Helix α9 of Bax protein can dimerize in the mitochondrial outer membrane (MOM) and lead to apoptotic pores. However, it remains unclear how different conformations of the dimer contribute to the pore formation on the molecular level. Thus we have investigated various conformational states of the α9 dimer in a MOM model — using computer simulations supplemented with site-specific mutagenesis and crosslinking of the α9 helices. Our data not only confirmed the critical membrane environment for the α9 stability and dimerization, but also revealed the distinct lipid-binding preference of the dimer in different conformational states. In our proposed pathway, a crucial iso-parallel dimer that mediates the conformational transition was discovered computationally and validated experimentally. The corroborating evidence from simulations and experiments suggests that, helix α9 assists Bax activation via the dimer heterogeneity and interactions with specific MOM lipids, which eventually facilitate proteolipidic pore formation in apoptosis regulation.

  2. Conformational Heterogeneity of Bax Helix 9 Dimer for Apoptotic Pore Formation

    PubMed Central

    Liao, Chenyi; Zhang, Zhi; Kale, Justin; Andrews, David W.; Lin, Jialing; Li, Jianing

    2016-01-01

    Helix α9 of Bax protein can dimerize in the mitochondrial outer membrane (MOM) and lead to apoptotic pores. However, it remains unclear how different conformations of the dimer contribute to the pore formation on the molecular level. Thus we have investigated various conformational states of the α9 dimer in a MOM model — using computer simulations supplemented with site-specific mutagenesis and crosslinking of the α9 helices. Our data not only confirmed the critical membrane environment for the α9 stability and dimerization, but also revealed the distinct lipid-binding preference of the dimer in different conformational states. In our proposed pathway, a crucial iso-parallel dimer that mediates the conformational transition was discovered computationally and validated experimentally. The corroborating evidence from simulations and experiments suggests that, helix α9 assists Bax activation via the dimer heterogeneity and interactions with specific MOM lipids, which eventually facilitate proteolipidic pore formation in apoptosis regulation. PMID:27381287

  3. Conformational Heterogeneity of Bax Helix 9 Dimer for Apoptotic Pore Formation.

    PubMed

    Liao, Chenyi; Zhang, Zhi; Kale, Justin; Andrews, David W; Lin, Jialing; Li, Jianing

    2016-01-01

    Helix α9 of Bax protein can dimerize in the mitochondrial outer membrane (MOM) and lead to apoptotic pores. However, it remains unclear how different conformations of the dimer contribute to the pore formation on the molecular level. Thus we have investigated various conformational states of the α9 dimer in a MOM model - using computer simulations supplemented with site-specific mutagenesis and crosslinking of the α9 helices. Our data not only confirmed the critical membrane environment for the α9 stability and dimerization, but also revealed the distinct lipid-binding preference of the dimer in different conformational states. In our proposed pathway, a crucial iso-parallel dimer that mediates the conformational transition was discovered computationally and validated experimentally. The corroborating evidence from simulations and experiments suggests that, helix α9 assists Bax activation via the dimer heterogeneity and interactions with specific MOM lipids, which eventually facilitate proteolipidic pore formation in apoptosis regulation. PMID:27381287

  4. An effect of CO2 leakage from deep geological formations on the quality of shallow aquifers

    NASA Astrophysics Data System (ADS)

    Wang, Sookyun; Nam, Ji Eun

    2013-04-01

    Injection of CO2 into deep geological formations is a promising technique for Sequestration of large amount of CO2. If some fraction of the stored CO2 were to leak and reach shallow groundwater aquifers, however, it would lead to geochemical alteration that could have detrimental effects on the water quality. A series of experiments were performed on dissolution kinetics of a trace metal, galena, to evaluate the change in groundwater pH and the enhanced dissolution as carbon dioxide introduces into the aquifer. The conventional rate law was applied to obtain reaction parameters on dissolution kinetics for further modeling studies. The results from batch experiments and kinetic analysis were applied to develop a 1D mathematical model to simulate the fate and transport of dissolved trace metals in shallow aquifers. Results show that CO2 dissolution in groundwater aquifers can solubilize trace metals to levels that exceed drinking water standards. This approach allows for a reasonable assessment of the risks on tha quality of freshwater aquifers due to the escape of CO2 from deep geological formations.

  5. Heterogeneous Formation of Polar Stratospheric Clouds- Part 1: Nucleation of Nitric Acid Trihydrate (NAT)

    NASA Technical Reports Server (NTRS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooss, J.-U.; Peter, T.

    2013-01-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  6. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-09-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  7. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-03-01

    Satellite based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarisation (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled the thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed PSCs very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  8. Crustal rheological strength heterogeneities control the formation of continental plateau margins

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Zhu, Bojing; Yang, Xiaolin

    2015-08-01

    The margins bordering the Tibetan Plateau show two end-member morphologies in topographic gradient: steep margins and low-gradient margins. To investigate the formation mechanism of convergent intracontinental plateau margins, we conduct 2D numerical experiments to simulate crustal deformation process across plateau margins. Our numerical experiments demonstrate that heterogeneities in crustal rheological strength control significantly the formation of plateau margins when subjected to crustal convergence. A very steep margin is the result of crustal convergence between plateau with weak lower crust and foreland basin with strong lower crust. By contrast, a low-gradient margin could result from crustal convergence between plateau and foreland with less strength contrast. This finding suggests that the diversity in topographic gradient along the Tibetan Plateau borders reflects heterogeneities in crustal rheological strength across the plateau margins. Steep gradient at the margins indicate large crustal rheological strength contrasts between the weak ductile lower crust of the Tibetan Plateau and its strong surrounding foreland basins, like the Sichuan Basin, the Tarim Basin and the Qaidam Basin. Beneath these steep margins the horizontal flow of the Tibetan ductile lower crust is inhibited and forced to extrude to support escarpments. Low-gradient at the margins indicate less crustal strength variations between the plateau and outer forelands, like at the northeastern and southeastern margins, where they might be outlets for the weak ductile Tibetan lower crust to flow away from the plateau.

  9. Lithofacies and cyclicity of the Yates Formation, Permian basin: Implications for reservoir heterogeneity

    SciTech Connect

    Borer, J.M.; Harris, P.M. )

    1991-04-01

    Siliciclastics of the Yates Formation (Permian, upper Guadalupian) are significant hydrocarbon reservoirs in the US Permian basin. Subsurface and outcrop data show that the most porous lithofacies occur in a clastic-dominated middle shelf and that evaporitic inner shelf and carbonate outer shelf equivalents are mostly nonporous. Lithofacies relations and much of the heterogeneity in Yates reservoirs are related to the stacking of depositional sequences (i.e., siliciclastic-carbonate alternations and sandstone-argillaceous siltstone alternations) in response to three orders of orbitally forced, low-amplitude, eustatic variation. In general, siliciclastics dominated the Yates shelf during lowstand parts of asymmetric, 400-k.y. sea level fluctuations, whereas carbonates were deposited during sea level highstands. The character and position of sand depocenters on the Yates shelf during these lowstands were controlled by a longer duration third-order sea level variation. Shorter duration cycles controlled the heterogeneity within the 400-k.y. depositional sequences. The variation in cycle packaging, lithology, and reservoir quality between the Central Basin platform and Northwest shelf may be a response of eustatic variation on parts of the shelf with different slopes or subsidence profiles. The lithofacies described from the Yates Formation and the deposition model proposed to explain the stratigraphy may be valuable as analogs in other basins containing mixed siliciclastic-carbonate settings.

  10. Modeling the effects of geological heterogeneity and metamorphic dehydration on slow slip and shallow deformation in subduction zones

    NASA Astrophysics Data System (ADS)

    Skarbek, Robert M.

    Slow slip and tectonic tremor in subduction zones take place at depths (˜20 - 50 km) where there is abundant evidence for distributed shear over broad zones (˜10 - 103 m) composed of rocks with marked differences in mechanical properties and for near lithostatic pore pressures along the plate interface where the main source of fluids must be attributed to chemical dehydration reactions. In Chapter II, I model quasi-dynamic rupture along faults composed of material mixtures characterized by different rate-and-state-dependent frictional properties to determine the parameter regime capable of producing slow slip in an idealized subduction zone setting. Keeping other parameters fixed, the relative proportions of velocity-weakening (VW) and velocity-strengthening (VS) materials control the sliding character (stable, slow, or dynamic) along the fault. The stability boundary between slow and dynamic is accurately described by linear analysis of a double spring-slider system with VW and VS blocks. In Chapter III, I model viscoelastic compaction of material subducting through the slow slip and tremor zone in the presence of pressure and temperature-dependent dehydration reactions. A dehydration fluid source is included using 1) a generalized basalt dehydration reaction in subducting oceanic crust or 2) a general nonlinear kinetic reaction rate law parameterized for an antigorite dehydration reaction. Pore pressures in excess of lithostatic values are a robust feature of simulations that employ parameters consistent with the geometry of the Cascadia subduction margin. Simulations that include viscous deformation uniformly generate traveling porosity waves that transport increased fluid pressures within the slow slip region. Slow slip and tremor also occur in shallow (< 10 km depth) accretionary prism sections of subduction zones. In Chapter IV, I examine how geologic heterogeneities affect the mechanics of accretionary prisms in subduction zones by showing how spatial

  11. Formation and evolution of Lakshmi Planum, Venus: Assessment of models using observations from geological mapping

    NASA Astrophysics Data System (ADS)

    Ivanov, M. A.; Head, J. W.

    2008-12-01

    Detailed geological analysis of the Lakshmi Planum region of western Ishtar Terra results in the establishment of the sequence of major events during the formation and evolution of western Ishtar Terra, an important and somewhat unique area on Venus characterized by a raised volcanic plateau surrounded by distinctive folded mountain belts, such as Maxwell Montes. These mapping results and the stratigraphic and structural relationships provide a basis for addressing the complicated problem of Lakshmi Planum formation and for testing the suite of models previously proposed to explain this structure. We review and classify previous models of formation for western Ishtar Terra into "downwelling" models (generally involving convergence and underthrusting) and "upwelling" models (generally involving plume-like upwelling and divergence). The interpreted nature of units and the sequence of events derived from geological mapping are in contrast to the predictions of the divergent models. The major contradictions are as follows: (1) The very likely presence of an ancient (craton-like) tessera massif in the core of Lakshmi, which is inconsistent with the model of formation of Lakshmi due to rise and collapse of a mantle diapir; (2) The absence of rift zones in the interior of Lakshmi that are predicted by the divergent models; (3) The apparent migration of volcanic activity toward the center of Lakshmi, whereas divergent models predict the opposite trend; (4) The abrupt cessation of ridges of the mountain ranges at the edge of Lakshmi Planum and propagation of these ridges over hundreds of kilometers outside Lakshmi; the divergent models predict the opposite progression in the development of major contractional features. In contrast, convergent models of formation and evolution of Lakshmi Planum appear to be more consistent with the observations and explain this structure by collision and underthrusting/subduction of lower-lying plains with the elevated and rigid block of

  12. Heterogeneous reactions of glyoxal on mineral particles: A new avenue for oligomers and organosulfate formation

    NASA Astrophysics Data System (ADS)

    Shen, Xiaoli; Wu, Huihui; Zhao, Yue; Huang, Dao; Huang, Liubin; Chen, Zhongming

    2016-04-01

    Glyoxal (GL) plays a crucial role in the formation of secondary organic aerosols (SOA), because it is highly water soluble and capable of oligomerization. This is the first study to describe irreversible heterogeneous reactions of GL on clean and acidic gas-aged SiO2, α-Al2O3, and CaCO3 particles, as models of real mineral particles, at various relative humidity and without irradiation and gas phase oxidants. A series of products, including oligomers, organosulfates, and organic acids, which contribute to SOA formation, were produced. GL uptake on SO2-aged α-Al2O3 enabled the oxidation of surface S(IV) to S(VI). The presence of adsorbed water on particles favored GL uptake and the formation of oligomers and organosulfate, but it suppressed organic acid formation. In addition, the aging process enhanced the positive effect of adsorbed water on GL uptake. These findings will further our understanding of the GL sink and SOA sources in the atmosphere.

  13. Psychoeducation in an Outpatient Setting--Designing a Heterogeneous Format for a Heterogeneous Population of Juvenile Delinquents.

    ERIC Educational Resources Information Center

    Carpenter, Patricia; Sugrue, Dennis P.

    1984-01-01

    Describes the G.I.T. (Getting It Together) program, a heterogeneous delinquent treatment program combining affective education and social skills training. Delinquents with immature personalities or neurotic features appeared to benefit more from the program than those with characterological disorders. (JAC)

  14. Effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events

    SciTech Connect

    Quan, Jiannong; Liu, Yangang; Liu, Quan; Li, Xia; Gao, Yang; Jia, Xingcan; Sheng, Jiujiang

    2015-09-30

    In this study, the effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events was investigated by analysis of comprehensive measurements of aerosol composition and concentrations [e.g., particular matters (PM2.5), nitrate (NO3), sulfate (SO4), ammonium (NH4)], gas-phase precursors [e.g., nitrogen oxides (NOx), sulfur dioxide (SO2), and ozone (O3)], and relevant meteorological parameters [e.g., visibility and relative humidity (RH)]. The measurements were conducted in Beijing, China from Sep. 07, 2012 to Jan. 16, 2013. The results show that the conversion ratios of N from NOx to nitrate (Nratio) and S from SO2 to sulfate (Sratio) both significantly increased in haze events, suggesting enhanced conversions from NOx and SO2 to their corresponding particle phases in the late haze period. Further analysis shows that Nratio and Sratio increased with increasing RH, with Nratio and Sratio being only 0.04 and 0.03, respectively, when RH < 40%, and increasing up to 0.16 and 0.12 when RH reached 60–80%, respectively. The enhanced conversion ratios of N and S in the late haze period is likely due to heterogeneous aqueous reactions, because solar radiation and thus the photochemical capacity are reduced by the increases in aerosols and RH. This point was further affirmed by the relationships of Nratio and Sratio to O3: the conversion ratios increase with decreasing O3 concentration when O3 concentration is lower than <15 ppb but increased with increasing O3 when O3 concentration is higher than 15 ppb. The results suggest that heterogeneous aqueous reactions likely changed aerosols and their precursors during the haze events: in the beginning of haze events, the precursor gases accumulated quickly

  15. Effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events

    DOE PAGESBeta

    Quan, Jiannong; Liu, Yangang; Liu, Quan; Li, Xia; Gao, Yang; Jia, Xingcan; Sheng, Jiujiang

    2015-09-30

    In this study, the effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events was investigated by analysis of comprehensive measurements of aerosol composition and concentrations [e.g., particular matters (PM2.5), nitrate (NO3), sulfate (SO4), ammonium (NH4)], gas-phase precursors [e.g., nitrogen oxides (NOx), sulfur dioxide (SO2), and ozone (O3)], and relevant meteorological parameters [e.g., visibility and relative humidity (RH)]. The measurements were conducted in Beijing, China from Sep. 07, 2012 to Jan. 16, 2013. The results show that the conversion ratios of N from NOx to nitrate (Nratio) and S from SO2 to sulfate (Sratio) bothmore » significantly increased in haze events, suggesting enhanced conversions from NOx and SO2 to their corresponding particle phases in the late haze period. Further analysis shows that Nratio and Sratio increased with increasing RH, with Nratio and Sratio being only 0.04 and 0.03, respectively, when RH < 40%, and increasing up to 0.16 and 0.12 when RH reached 60–80%, respectively. The enhanced conversion ratios of N and S in the late haze period is likely due to heterogeneous aqueous reactions, because solar radiation and thus the photochemical capacity are reduced by the increases in aerosols and RH. This point was further affirmed by the relationships of Nratio and Sratio to O3: the conversion ratios increase with decreasing O3 concentration when O3 concentration is lower than <15 ppb but increased with increasing O3 when O3 concentration is higher than 15 ppb. The results suggest that heterogeneous aqueous reactions likely changed aerosols and their precursors during the haze events: in the beginning of haze events, the precursor gases accumulated quickly due to high emission and low reaction rate; the occurrence of heterogeneous aqueous reactions in the late haze period, together with the accumulated high concentrations of precursor gases such as SO2 and NOx, accelerated the

  16. Geologic setting, petrophysical characteristics, and regional heterogeneity patterns of the Smackover in southwest Alabama. Draft topical report on Subtasks 2 and 3

    SciTech Connect

    Kopaska-Merkel, D.C.; Mann, S.D.; Tew, B.H.

    1992-06-01

    This is the draft topical report on Subtasks 2 and 3 of DOE contract number DE-FG22-89BC14425, entitled ``Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity.`` This volume constitutes the final report on Subtask 3, which had as its primary goal the geological modeling of reservoir heterogeneity in Smackover reservoirs of southwest Alabama. This goal was interpreted to include a thorough analysis of Smackover reservoirs, which was required for an understanding of Smackover reservoir heterogeneity. This report is divided into six sections (including this brief introduction). Section two, entitled ``Geologic setting,`` presents a concise summary of Jurassic paleogeography, structural setting, and stratigraphy in southwest Alabama. This section also includes a brief review of sedimentologic characteristics and stratigraphic framework of the Smackover, and a summary of the diagenetic processes that strongly affected Smackover reservoirs in Alabama. Section three, entitled ``Analytical methods,`` summarizes all nonroutine aspects of the analytical procedures used in this project. The major topics are thin-section description, analysis of commercial porosity and permeability data, capillary-pressure analysis, and field characterization. ``Smackover reservoir characteristics`` are described in section four, which begins with a general summary of the petrographic characteristics of porous and permeable Smackover strata. This is followed by a more-detailed petrophysical description of Smackover reservoirs.

  17. Formation of Small Gas Phase Carbonyls from Heterogeneous Oxidation of Polyunsaturated Fatty Acids (PUFA)

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Zhao, R.; Lee, A.; Gao, S.; Abbatt, J.

    2011-12-01

    Fatty acids (FAs) are emitted into the atmosphere from gas and diesel powered vehicles, cooking, plants, and marine biota. Field measurements have suggested that FAs, including polyunsaturated fatty acids (PUFA), could make up an important contribution to the organic fraction of atmospheric aerosols. Due to the existence of carbon-carbon double bonds in their molecules, PUFA are believed to be highly reactive towards atmospheric oxidants such as OH and NO3 radicals and ozone, which will contribute to aerosol hygroscopicity and cloud condensation nuclei activity. Previous work from our group has shown that small carbonyls formed from the heterogeneous reaction of linoleic acid (LA) thin films with gas-phase O3. It is known that the formation of small carbonyls in the atmosphere is not only relevant to the atmospheric budget of volatile organic compounds but also to secondary organic aerosol formation. In the present study, using an online proton transfer reaction mass spectrometry (PTR-MS) and off-line gas chromatography-mass spectrometry (GC-MS) we again investigated carbonyl formation from the same reaction system, i.e. the heterogeneous ozonolysis of LA film. In addition to the previously reported carbonyls, malondialdehyde (MDA), a source of reactive oxygen species that is mutagenic, has been identified as a product for the first time. Small dicarbonyls, e.g. glyoxal, are expected to be formed from the further oxidation of MDA. In this presentation, the gas-phase chemistry of MDA with OH radicals using a newly built Teflon chamber in our group will also be presented.

  18. Contaminant tailing in highly heterogeneous porous formations: Sensitivity on model selection and material properties

    NASA Astrophysics Data System (ADS)

    Maghrebi, Mahdi; Jankovic, Igor; Weissmann, Gary S.; Matott, L. Shawn; Allen-King, Richelle M.; Rabideau, Alan J.

    2015-12-01

    Coupled impacts of slow advection, diffusion and sorption were investigated using two heterogeneity models that differ in structure and in the mathematical framework that was used to simulate flow and transport and to quantify contaminant tailing. Both models were built using data from a highly heterogeneous exposure of the Borden Aquifer at a site located 2 km north-west of the Stanford-Waterloo experimental site at Canadian Forces Base Borden, Ontario, Canada. The inclusions-based model used a simplified representation of the different materials found at the site, while the second model was based on transitional probability geostatistics of the formation. These two models were used to investigate sensitivity of contaminant tailing on model selection and on geometric and material properties. While simulations were based on data collected at Borden, models were exercised beyond the geometric and material properties that characterize the site. Various realizations have identified very low conductive silty clay, found at volume fraction of 23.4%, as the material with dominant influence on tailing, and vertical diffusion in and out of low conductive units, affected by sorption, as the dominant transport mechanism causing tailing. The two models yielded almost identical transport results when vertical correlation lengths of silty clay were matched. Several practical implications relevant for characterization of low conductive units were identified and briefly discussed.

  19. Travel time approach to kinetically sorbing solute by diverging radial flows through heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Severino, Gerardo; de Bartolo, Samuele; Toraldo, Gerardo; Srinivasan, Gowri; Viswanathan, Hari

    2012-12-01

    Diverging radial flow takes place in a heterogeneous porous medium where the log conductivity Y = ln K is modeled as a stationary random space function (RSF). The flow is steady, and is generated by a fully penetrating well. A linearly sorbing solute is injected through the well envelope, and we aim at computing the average flux concentration (breakthrough curve). A relatively simple solution for this difficult problem is achieved by adopting, similar to Indelman and Dagan (1999), a few simplifying assumptions: (i) a thick aquifer of large horizontal extent, (ii) mildly heterogeneous medium, (iii) strongly anisotropic formation, and (iv) large Peclet number. By introducing an appropriate Lagrangian framework, three-dimensional transport is mapped onto a one-dimensional domain (τ, t) where τ and t represent the fluid travel and current time, respectively. Central for this approach is the probability density function of the RSF τthat is derived consistently with the adopted assumptions stated above. Based on this, it is shown that the travel time can be regarded as a Gaussian random variable only in the far field. The breakthrough curves are analyzed to assess the impact of the hydraulic as well as reactive parameters. Finally, the travel time approach is tested against a forced-gradient transport experiment and shows good agreement.

  20. Diagenesis of sandstones at shale contacts and diagenetic heterogeneity, Frio Formation, Texas

    SciTech Connect

    Sullivan, K.B.; McBride, E.F. )

    1991-01-01

    Diagenetic trends near sandstone/shale contacts were studied in 12 cored sequences from four wells between depths of 5200 and 15,700 ft (1585 and 4785 m) to evaluate the heterogeneity of diagenetic processes on a local scale and to evaluate the hypothesis that reactive aqueous fluids and components for cements in sandstones were derived from adjacent shales. The only evidence suggesting that diagenetic components in sandstones were derived from immediately adjacent shales is an increase in chlorite cement in sandstones toward contacts with shale beds for two of three contacts appropriate for study. Secondary pores and cements of quartz, carbonate, and kaolinite do not correlate with proximity to shale beds, but have a preference for sandstones that had relatively high initial porosities and permeabilities. Thus, the flux of formation water and probably long-distance transportation of diagenetic components were more important influences on reservoir quality of sandstones than was the local availability of components. Multiple regression of 22 independent variables indicates that the best predictors of secondary porosity are kaolinite cement and intergranular porosity. Sandstone sequences are extremely heterogeneous in the distribution of total thin section porosity, secondary porosity, and quartz and carbonate cements; in addition, they have significant variations in the abundance of kaolinite and chlorite cements. Mass balance calculations for silica and aluminum indicate silica was imported to and aluminum was exported from the sandstones.

  1. Evaluating Variable Switching and Flash Methods in Modeling Carbon Sequestration in Deep Geologic Formations using PFLOTRAN

    SciTech Connect

    Lu, Chuan; Lichtner, Peter; Hammond, Glenn; Mills, Richard T

    2010-01-01

    PFLOTRAN a massively parallel computer code for modeling coupled hydro-thermal-chemical processes in variably saturated, non-isothermal porous media is applied to sequestration of supercritical CO{sub 2} in deep geologic formations. Two different methods of solution to the governing partial differential equations are implemented referred to as variable switching and the flash approach. Variable switching entails choosing the independent variables according to the set of phases present in a control volume, whereas in the flash approach a persistent set of variables are used through the calculation. The features and performance of the two approaches are described and contrasted in regard to stability and convergence, flexibility of choice of solver, and scaling behavior.

  2. Sudbury project (University of Muenster-Ontario Geological Survey): Petrology, chemistry, and origin of breccia formations

    NASA Technical Reports Server (NTRS)

    Stoeffler, D.; Deutsch, A.; Avermann, M.; Brockmeyer, P.; Lakomy, R.; Mueller-Mohr, V.

    1992-01-01

    Within the Sudbury Project of the University of Muenster and the Ontario Geological Survey special emphasis was put on the breccia formations exposed at the Sudbury structure (SS) because of their crucial role for the impact hypothesis. They were mapped and sampled in selected areas of the north, east, and south ranges of the SS. The relative stratigraphic positions of these units are summarized. Selected samples were analyzed by optical microscopy, SEM, microprobe, XRF and INAA, Rb-Sr and SM-Nd-isotope geochemistry, and carbon isotope analysis. The results of petrographic and chemical analysis for those stratigraphic units that were considered the main structural elements of a large impact basin are summarized.

  3. BIGFLOW: A numerical code for simulating flow in variably saturated, heterogeneous geologic media. Theory and user`s manaual, Version 1.1

    SciTech Connect

    Ababou, R.; Bagtzoglou, A.C.

    1993-06-01

    This report documents BIGFLOW 1.1, a numerical code for simulating flow in variably saturated heterogeneous geologic media. It contains the underlying mathematical and numerical models, test problems, benchmarks, and applications of the BIGFLOW code. The BIGFLOW software package is composed of a simulation and an interactive data processing code (DATAFLOW). The simulation code solves linear and nonlinear porous media flow equations based on Darcy`s law, appropriately generalized to account for 3D, deterministic, or random heterogeneity. A modified Picard Scheme is used for linearizing unsaturated flow equations, and preconditioned iterative methods are used for solving the resulting matrix systems. The data processor (DATAFLOW) allows interactive data entry, manipulation, and analysis of 3D datasets. The report contains analyses of computational performance carried out using Cray-2 and Cray-Y/MP8 supercomputers. Benchmark tests include comparisons with other independently developed codes, such as PORFLOW and CMVSFS, and with analytical or semi-analytical solutions.

  4. Heterogeneous-nucleation and glass-formation studies of 56Ga2O3-44CaO

    NASA Technical Reports Server (NTRS)

    Ethridge, Edwin C.; Curreri, Peter A.; Pline, David

    1987-01-01

    Glass formation and heterogeneous crystallization are described for the reluctant-glass-forming 56Ga2O3-44CaO eutectic composition. The times and temperatures for nucleation at various cooling rates and experimental conditions were measured and empirical continuous-cooling-crystallization boundaries were constructed for various heterogeneous nucleation processes. A definition for an empirical critical cooling rate to form a glass from reluctant borderline glass formers is proposed, i.e., the cooling rate that results in glass formation in 95 percent of the quenching experiments.

  5. Geology and geochemistry of the La Luna Formation type sections in the Maracaibo basin, Venezuela

    SciTech Connect

    Baptista, N.; Scherer, W.

    1996-08-01

    The Upper Cretaceous La Luna Formation is the most important source rock of hydrocarbons in Western Venezuela. Curiously enough it has two type sections, the formation was first defined in 1926 in Perija on the western flank of the Maracaibo basin; 30 years later the La Aguada, Chejende and Timbetes members were defined 260 km toward the east, on the shelf of the basin. The purpose of this study is to compare these sections and to define the vertical and horizontal variability of geological and geochemical characteristics that might have influenced the generation of hydrocarbons. The study consisted of detailed, bed level sampling, macroscopic sedimentary descriptions, petrography of 168 thin sections with 40 variables recorded in a statistical data matrix for determination of lithomicrofacies, as well as geochemical analysis of total organic carbon (TOC), visual kerogen, Rock-Eval pyrolysis and gas chromatography. The western type section is characterized by alternating thinly laminated and massive bedded limestones. Thermally immature, amorphous organic matter of marine origin is abundant in this section; TOC values range from 0.23% to 8.56%, generally increasing toward the top. Hydrogen index values range from 327 to 1078, indicating good to excellent oil generating potential. The eastern type sections have a higher level of thermal maturity; they show increasing amounts of clastic material, less authigenic minerals and abundant Favreina sp crab fecal pellets. The mainly terrestrially derived organic matter concentrations are considerably less, ranging from 0.07 to 3.39, again increasing toward the top of the section.

  6. Seasonal variability of heterogeneous ice formation in stratiform clouds over the Amazon Basin

    NASA Astrophysics Data System (ADS)

    Seifert, Patric; Kunz, Clara; Baars, Holger; Ansmann, Albert; Bühl, Johannes; Senf, Fabian; Engelmann, Ronny; Althausen, Dietrich; Artaxo, Paulo

    2015-07-01

    Based on 11 months of polarization lidar observations in the Amazon Basin near Manaus, Brazil (2.3°S, 60°W), the relationship between temperature and heterogeneous ice formation efficiency in stratiform clouds was evaluated in the cloud top temperature range between -40 and 0°C. Between -30 and 0°C, ice-containing clouds are a factor of 1.5 to 2 more frequent during the dry season. Free-tropospheric aerosol backscatter profiles revealed a twofold to tenfold increase in aerosol load during the dry season and a Monitoring Atmospheric Composition and Climate—Interim Implementation reanalysis data set implies that the aerosol composition during the dry season is strongly influenced by biomass burning aerosol, whereas other components such as mineral dust do not vary strongly between the seasons. The injection of smoke accompanied by the likely dispersion of biological material, soil dust, or ash particles was identified as a possible source for the increased ice formation efficiency during the dry season.

  7. Reactive Tracer Techniques to Quantitatively Monitor Carbon Dioxide Storage in Geologic Formations

    NASA Astrophysics Data System (ADS)

    Matter, J. M.; Carson, C.; Stute, M.; Broecker, W. S.

    2012-12-01

    Injection of CO2 into geologic storage reservoirs induces fluid-rock reactions that may lead to the mineralization of the injected CO2. The long-term safety of geologic CO2 storage is, therefore, determined by in situ CO2-fluid-rock reactions. Currently existing monitoring and verification techniques for CO2 storage are insufficient to characterize the solubility and reactivity of the injected CO2, and to establish a mass balance of the stored CO2. Dissolved and chemically transformed CO2 thus avoid detection. We developed and are testing a new reactive tracer technique for quantitative monitoring and detection of dissolved and chemically transformed CO2 in geologic storage reservoirs. The technique involves tagging the injected carbon with radiocarbon (14C). Carbon-14 is a naturally occurring radioisotope produced by cosmic radiation and made artificially by 14N neutron capture. The ambient concentration is very low with a 14C/12C ratio of 10-12. The concentration of 14C in deep geologic formations and fossil fuels is at least two orders of magnitude lower. This makes 14C an ideal quantitative tracer for tagging underground injections of anthropogenic CO2. We are testing the feasibility of this tracer technique at the CarbFix pilot injection site in Iceland, where approximately 2,000 tons of CO2 dissolved in water are currently injected into a deep basalt aquifer. The injected CO2 is tagged with 14C by dynamically adding calibrated amounts of H14CO3 solution to the injection stream. The target concentration is 12 Bq/kg of injected water, which results in a 14C activity that is 5 times enriched compared to the 1850 background. In addition to 14C as a reactive tracer, trifluormethylsulphur pentafluoride (SF5CF3) and sulfurhexafluoride (SF6) are used as conservative tracers to monitor the transport of the injected CO2 in the subsurface. Fluid samples are collected for tracer analysis from the injection and monitoring wells on a regular basis. Results show a fast

  8. Assessment of potential radionuclide transport in site-specific geologic formations

    SciTech Connect

    Dosch, R.G.

    1980-08-01

    Associated with the development of deep, geologic repositories for nuclear waste isolation is a need for safety assessments of the potential for nuclide migration. Frequently used in estimating migration rates is a parameter generally known as a distribution coefficient, K/sub d/, which describes the distribution of a radionuclide between a solid (rock) and a liquid (groundwater) phase. This report is intended to emphasize that the use of K/sub d/ must be coupled with a knowledge of the geology and release scenarios applicable to a repository. Selected K/sub d/ values involving rock samples from groundwater/brine simulants typical of two potential repository sites, WIPP and NTS, are used to illustrate this concern. Experimental parameters used in K/sub d/ measurements including nuclide concentration, site sampling/rock composition, and liquid-to-solid ratios are discussed. The solubility of U(VI) in WIPP brine/groundwater was addressed in order to assess the potential contribution of this phenomena to K/sub d/ values. Understanding mehanisms of sorption of radionuclides on rocks would lead to a better predictive capability. Sorption is attributed to the presence of trace constituents (often unidentified) in rocks. An attempt was made to determine if this applied to WIPP dolomite rocks by comparing sorption behavior of the natural material with that of a synthetic dolomite prepared in the laboratory with reagent grade chemicals. The results were inconclusive. The results of a study of Tc sorption by an argillite sample from the Calico Hills formation at NTS under ambient laboratory conditions were more conclusive. The Tc sorption was found to be associated with elemental carbon. Available evidence points to a reduction mechanism leading to the apparent sorption of Tc on the solid phase.

  9. Geology and hydrocarbon reservoir potential of the Pituil and Barreal Formations, Calingasta Valley, western Argentina

    SciTech Connect

    Janks, J.S. ); Lopez-Gamundi, O.R.; Siegele, P.K. )

    1990-05-01

    The Calingasta basin is one of the north-south-trending intermontane basins informally known as the Bolsones. The stratigraphy consists of lower Paleozoic metamorphic basement overlain by sediments and volcanics of upper Paleozoic through Cenozoic age. Three distinct geological provinces are recognized within the Bolsones region: Sierras Pampeanas, Precordillera, and Cordillera Frontal. Outcrop samples from the Permian Pituil and Triassic Barreal formations from the Tamberias region of the Sierras Pampeanas province were analyzed to determine the composition, porosity type, and diagenetic modification. The Pituil formation is a shallow marine sequence overlying Carboniferous glaciomarine sediments. They grade eastward into nonmarine lacustrine, deltaic, and fluvial sandstones. The rocks are fine- to medium-grained litharenites with porosities of 6-10 %. Diagenetic modifications include quartz overgrowths, unstable grain dissolution, carbonate cements, pyrite, and kaolinite. Triassic deposits occur on the western flank of the Precordillera, overlying a basement of volcanics and metasedimentary rocks. The Triassic sediments can be several hundreds of meters thick; deposition occurred in fluvial to lacustrine environments. These clastic sediments are considered to be northern extensions of the hydrocarbon-productive sediments in the Cuyo basin. The Barreal formation ranges from clay-rich lithic wackes and shales to conglomeratic, volcaniclastic litharenites and sublitharenites. Framework grains consist of quartz, feldspars, rock fragments, and, rarely, glass shards. Cements include zeolites, carbonates, chalcedony, pyrite, and clays. Tuffs are found at certain intervals within the section; alteration to iron-rich smectite is common. Reservoir potential is highly variable. Porosities range from as low as 5% to greater than 25%.

  10. Geology of the Molina Member of the Wasatch Formation, Piceance Basin, Colorado

    SciTech Connect

    Lorenz, J.; Nadon, G.; LaFreniere, L.

    1996-06-01

    The Molina Member of the Wasatch Formation has been cored in order to assess the presence/absence and character of microbial communities in the deep subsurface. Geological study of the Molina Member was undertaken in support of the microbiological tasks of this project, for the purposes of characterizing the host strata and of assessing the potential for post-depositional introduction of microbes into the strata. The Molina Member comprises a sandy fluvial unit within a formation dominated by mudstones. Sandy to conglomeratic deposits of braided and meandering fluvial systems are present on the western and eastern margins of the basin respectively, although the physical and temporal equivalence of these systems cannot be proven. Distal braided facies of planar-horizontal bedded sandstones are recognized on the western margin of the basin. Natural fractures are present in all Molina sandstones, commonly as apparent shear pairs. Core from the 1-M-18 well contains natural fractures similar to those found in outcrops, and has sedimentological affinities to the meandering systems of the eastern margin of the basin. The hydrologic framework of the Molina, and thus any potential post-depositional introduction of microbes into the formation, should have been controlled by approximately east-west flow through the natural fracture system, the geometries and extent of the sandstones in which the fractures occur, and hydraulic gradient. Migration to the well site, from outcropping recharge areas at the edge of the basin, could have started as early as 40 million years ago if the cored strata are connected to the eastern sedimentary system.

  11. Supercritical fluid behavior at nanoscale interfaces: implications for CO2 sequestration in geologic formations

    SciTech Connect

    Cole, David R; Chialvo, Ariel A; Rother, Gernot; Vlcek, L.; Cummings, Peter T

    2010-01-01

    Injection of CO2 into subsurface geologic formations has been identified as a key strategy for mitigating the impact of anthropogenic emissions of CO2. A key aspect of this process is the prevention of leakage from the host formation by an effective cap or seal rock which has low porosity and permeability characteristics. Shales comprise the majority of cap rocks encountered in subsurface injection sites with pore sizes typically less than 100 nm and whose surface chemistries are dominated by quartz (SiO2) and clays. We report the behavior of pure CO2 interacting with simple substrates, i.e. SiO2 and mica, that act as proxies for more complex mineralogical systems. Modeling of small-angle neutron scattering (SANS) data taken from CO2- silica aerogel (95% porosity; 6 nm pores) interactions indicates the presence of fluid depletion for conditions above the critical density. A theoretical framework, i.e. integral equation approximation (IEA), is presented that describes the fundamental behavior of near-critical adsorption onto a non-confining substrate that is consistent with SANS experimental results. Structural and dynamic behavior for supercritical CO2 interaction in K-mica slit pores was assessed by classical molecular dynamics (CMD). These results indicate the development of distinct layers of CO2 within slit pores, reduced mobility by one to two orders of magnitudes compared to bulk CO2 depending on pore size and formation of bonds between CO2 oxygens and H from mica hydroxyls. Analysis of simple, well-characterized fluid-substrate systems can provide details on the thermodynamic, structural and dynamic properties of CO2 at conditions relevant to sequestration.

  12. 3rd hand smoking; heterogeneous oxidation of nicotine and secondary aerosol formation in the indoor environment

    NASA Astrophysics Data System (ADS)

    Petrick, Lauren; Dubowski, Yael

    2010-05-01

    Tobacco smoking is well known as a significant source of primary indoor air pollutants. However, only recently has it been recognized that the impact of Tobacco smoking may continue even after the cigarette has been extinguished (i.e., third hand smoke) due to the effect of indoor surfaces. These surfaces may affect the fate of tobacco smoke in the form of secondary reactions and pollutants, including secondary organic aerosol (SOA) formation. Fourier Transform Infrared spectrometry with Attenuated Total Reflection (FTIR-ATR) in tandem with a Scanning Mobility Particle Sizing (SMPS) system was used to monitor the ozonation of cellulose sorbed nicotine and resulting SOA formation. SOA formation began at onset of ozone introduction ([O3] = 60 ± 5 ppb) with a size distribution of dp ≤ 25 nm, and was determined to be a result of heterogeneous reaction (opposed to homogeneous). SOA yield from reacted surface nicotine was on the order of 10 %. Simultaneous to SOA monitoring, FTIR-ATR spectra showed surface changes in the nicotine film as the reaction progressed, revealing a pseudo first-order surface reaction rate of 0.0026 ± 0.0008 min-1. Identified surface oxidation products included: cotinine, myosmine, methylnicotinamide and nicotyrine. Surface reaction rate was found to be partially inhibited at high relative humidity. Given the toxicity of some of the identified products (e.g., cotinine has shown potential mutagenicity and teratogenicity) and that small particles may contribute to adverse health effects, the present study indicates that exposure to 3rd hand smoke ozonation products may pose additional health risks.

  13. A Study of Geological Formation on Different Sites in Batu Pahat, Malaysia Based On HVSR Method Using Microtremor Measurement

    NASA Astrophysics Data System (ADS)

    Noor, M. A. M.; Madun, A.; Kamarudin, A. F.; Daud, M. E.

    2016-07-01

    Geological formation is a one of information need to know during site reconnaissance. Conventional method like borehole has been known is very accurate to identify the formation of geology of a site. However, the problem of this technique is very expensive and not economical for large area. In the last decade, microtremor measurement has been introduced as an alternative technique and widely used in the geological formation study. Therefore, the aim in this study is to determine the geological formation underneath of surface in Batu Pahat district using microtremor measurement. There are two parameters have been carried out from microtremor measurement in term of natural frequency and HVSR curves images. Microtremor measurements are done conducted at 15 sites surrounding of Batu Pahat. Horizontal to vertical spectral ratio (HVSR) method was used for analyzing microtermor measurement data, to determine the natural frequency and also HVSR curves image. In this study, values of natural frequencies are used to classify the soil types with range in the between 0.93 to 5.35 Hz, meanwhile the pattern of HVSR curve images has been shown exists a few groups of soil types surrounding Batu Pahat district. Hence, microtremor measurement indirectly can be used as a one technique to add value in the site reconnaissance in the future.

  14. Geologic and hydrogeologic characteristics of the Ogallala Formation and White River Group, Belvoir Ranch near Cheyenne, Laramie County, Wyoming

    USGS Publications Warehouse

    Bartos, Timothy T.; Diehl, Sharon F.; Hallberg, Laura L.; Webster, Daniel M.

    2014-01-01

    The geologic and hydrogeologic characteristics of Tertiary lithostratigraphic units (Ogallala Formation and White River Group) that typically compose or underlie the High Plains aquifer system in southeastern Wyoming were described physically and chemically, and evaluated at a location on the Belvoir Ranch in Laramie County, Wyoming. On the basis of this characterization and evaluation, three Tertiary lithostratigraphic units were identified using physical and chemical characteristics determined during this study and previous studies, and these three units were determined to be correlative with three identified hydrogeologic units composing the groundwater system at the study site—a high-yielding aquifer composed of the entire saturated thickness of the heterogeneous and coarse-grained fluvial sediments assigned to the Ogallala Formation (Ogallala aquifer); an underlying confining unit composed primarily of very fine-grained volcaniclastic sediments and mudrocks assigned to the Brule Formation of the White River Group and some additional underlying sediments that belong to either the Brule or Chadron Formation, or both (Brule confining unit); and an underlying low-yielding aquifer composed primarily of poorly sorted fluvial sediments assigned to the Chadron Formation of the White River Group (Chadron aquifer). Despite widely varying sediment heterogeneity and consolidation, some limited hydraulic connection throughout the full vertical extent of the Ogallala aquifer was indicated but not conclusively proven by interpretation of similar chemical and isotopic characteristics, modern apparent groundwater ages, and similar hydraulic-head responses measured continuously in two Ogallala aquifer monitoring wells installed for this study at two different widely separated (83 feet) depth intervals. Additional work beyond the scope of this study, such as aquifer tests, would be required to conclusively determine hydraulic connection within the Ogallala aquifer. Groundwater

  15. Geologically Controlled Isotope-Time Patterns Reveal Early Differentiation and Crust Formation Processes

    NASA Astrophysics Data System (ADS)

    Bennett, V. C.; Nutman, A. P.

    2014-12-01

    The mechanisms of continental crust production and evolution in the early Earth remain controversial, as are questions of the relative roles of early differentiation versus subsequent tectonic procssing in creating Earth's chemical signatures. Here we present geologic observations integrated with whole rock major, trace element and Sm-Nd isotopic signatures and combined with U-Pb and Lu-Hf isotopic compositions of zircon populations from the same rocks, from the most extensive early rock record comprising the 3.9 Ga to 3.6 Ga terranes of southwest Greenland. These data reveal repeated patterns of formation of juvenile TTG crust and associated mafic and ultramafic rocks in convergent margin settings followed by formation of more evolved granites [1]. Our new zircon Lu-Hf data from rare 3.6-3.7 Ga tonalites within the Itsaq Gneiss Complex, obtained from single component, non-migmatitic gneisses with simple zircon populations, limited within sample Hf isotopic variability and accurate U-Pb ages, now document extraction of juvenile tonalites from a near chondritic mantle source between 3.9 Ga and 3.6 Ga. The more evolved, granitic rocks in each area show slightly negative initial ɛHf in accord with crustal reworking of the older (3.8-3.9 Ga) gniesses. There is no evidence for Hadean material in the sources of the granitoids. The Hf isotope-time patterns are consistent with juvenile crust production from a mantle source that experienced only modest amounts of prior crustal extraction. They are distinct from those predicted by reprocessing of an enriched Hadean mafic crust, as has been proposed for this region [2] and for the source of the Hadean Jack Hills zircons [3]. The well-documented, time decreasing, positive 142Nd anomalies [e.g., 4] from these rocks are further evidence of crustal derivation from a convecting mantle source, rather than reworking of an enriched mafic lithosphere. The 143Nd isotopic -time patterns are more complex, reflecting the interplay

  16. Process and device for injecting a liquid agent used for treating a geological formation in the vicinity of a well bore traversing this formation

    SciTech Connect

    Colonna, J.; Fitremann, Jm.; Genin, R.; Sarda, Jp.

    1984-02-14

    A technique is disclosed for liquid treating a geological formation. It comprises spraying the liquid with a pressurized carrier gas, using a spraying pipe whose length and diameter are adjusted as a function of the pressure prevailing at the level of the formation and of the characteristics of the injected liquid and the pressurized carrier gas, so that the size of the liquid droplets at the outlet of the spraying pipe has a narrow range of distribution about a single preselected value.

  17. A dynamic flow simulation code benchmark study addressing the highly heterogeneous properties of the Stuttgart formation at the Ketzin pilot site

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; Class, Holger; Görke, Uwe-Jens; Norden, Ben; Kolditz, Olaf; Kühn, Michael; Walter, Lena; Wang, Wenqing; Zehner, Björn

    2013-04-01

    CO2 injection at the Ketzin pilot site located in Eastern Germany (Brandenburg) about 25 km west of Berlin is undertaken since June 2008 with a scheduled total amount of about 70,000 t CO2 to be injected into the saline aquifer represented by the Stuttgart Formation at a depth of 630 m to 650 m until the end of August 2013. The Stuttgart Formation is of fluvial origin determined by high-permeablity sandstone channels embedded in a floodplain facies of low permeability indicating a highly heterogeneous distribution of reservoir properties as facies distribution, porosity and permeability relevant for dynamic flow simulations. Following the dynamic modelling activities discussed by Kempka et al. (2010), a revised geological model allowed us to history match CO2 arrival times in the observation wells and reservoir pressure with a good agreement (Martens et al., 2012). Consequently, the validated reservoir model of the Stuttgart Formation at the Ketzin pilot site enabled us to predict the development of reservoir pressure and the CO2 plume migration in the storage formation by dynamic flow simulations. A benchmark study of industrial (ECLIPSE 100 as well as ECLIPSE 300 CO2STORE and GASWAT) and scientific dynamic flow simulations codes (TOUGH2-MP/ECO2N, OpenGeoSys and DuMuX) was initiated to address and compare the simulator capabilities considering a highly complex reservoir model. Hence, our dynamic flow simulations take into account different properties of the geological model such as significant variation of porosity and permeability in the Stuttgart Formation as well as structural geological features implemented in the geological model such as seven major faults located at the top of the Ketzin anticline. Integration of the geological model into reservoir models suitable for the different dynamic flow simulators applied demonstrated that a direct conversion of reservoir model discretization between Finite Volume and Finite Element flow simulators is not feasible

  18. Mercury's hollows: Constraints on formation and composition from analysis of geological setting and spectral reflectance

    NASA Astrophysics Data System (ADS)

    Blewett, David T.; Vaughan, William M.; Xiao, Zhiyong; Chabot, Nancy L.; Denevi, Brett W.; Ernst, Carolyn M.; Helbert, JöRn; D'Amore, Mario; Maturilli, Alessandro; Head, James W.; Solomon, Sean C.

    2013-05-01

    unique to Mercury, hollows are shallow, flat-floored irregular depressions notable for their relatively high reflectance and characteristic color. Here we document the range of geological settings in which hollows occur. Most are associated with impact structures (simple bowl-shaped craters to multiring basins, and ranging from Kuiperian to Calorian in age). Hollows are found in the low-reflectance material global color unit and in low-reflectance blue plains, but they appear to be absent from high-reflectance red plains. Hollows may occur preferentially on equator- or hot-pole-facing slopes, implying that their formation is linked to solar heating. Evidence suggests that hollows form because of loss of volatile material. We describe hypotheses for the origin of the volatiles and for how such loss proceeds. Intense space weathering and solar heating are likely contributors to the loss of volatiles; contact heating by melts could promote the formation of hollows in some locations. Lunar Ina-type depressions differ from hollows on Mercury in a number of characteristics, so it is unclear if they represent a good analog. We also use MESSENGER multispectral images to characterize a variety of surfaces on Mercury, including hollows, within a framework defined by laboratory spectra for analog minerals and lunar samples. Data from MESSENGER's X-Ray Spectrometer indicate that the planet's surface contains up to 4% sulfur. We conclude that nanophase or microphase sulfide minerals could contribute to the low reflectance of the low-reflectance material relative to average surface material. Hollows may owe their relatively high reflectance to destruction of the darkening agent (sulfides), the presence of alteration minerals, and/or physical differences in particle size, texture, or scattering behavior.

  19. Nuclear Waste Disposal in Deep Geological Formations: What are the Major Remaining Scientific Issues?

    SciTech Connect

    Toulhoat, Pierre

    2007-07-01

    For more than thirty years, considerable efforts have been carried out in order to evaluate the possibility of disposing of high level wastes in deep geological formations. Different rock types have been examined, such as water-under-saturated tuffs (USA), granites or crystalline rocks (Canada, Sweden, and Finland), clays (France, Belgium, and Switzerland), rock-salt (Germany). Deep clays and granites, (provided that the most fractured zones are avoided in the second case) are considered to fulfill most allocated functions, either on short term (reversibility) or long term. Chemically reducing conditions favor the immobilization of actinides and most fission products by precipitation, co-precipitation and sorption. If oxidizing conditions prevail, the safety demonstration will mostly rely on the performance of artificial confinement systems. Rock-salt offers limited performance considering the issue of reversibility, which is now perceived as essential, mostly for ethical and sociological reasons. However, several issues would deserve additional research programs, and as a first priority, a clear description of time/space succession of processes during the evolution of the repository. This will allow a better representation of coupled processes in performance assessment, such as the influence of gases (H{sub 2}) generated by corrosion, on the long term dynamics of the re-saturation. Geochemical interactions between the host formation and the engineered systems (packages + barriers) are still insufficiently described. Additional gains in performance could be obtained when taking into account processes such as isotopic exchange. Imaginative solutions, employing ceramic- carbon composite materials could be proposed to replace heavy and gas-generating overpacks, or to accommodate the small but probably significant amount of 'ultimate' wastes that will be inevitably produced by Generation IV reactor systems. (author)

  20. Flow and Transport in Highly Heterogeneous Porous Formations: Numerical Experiments Performed Using the Analytic Element Method

    NASA Astrophysics Data System (ADS)

    Jankovic, I.

    2002-05-01

    can be used to infer the effective conductivity of the medium. As many as 100,000 inhomogeneities are placed inside the domain for 2D simulations. Simulations in 3D were limited to 50,000 inclusions. A large number of simulations was conducted on a massively parallel supercomputer cluster at the Center for Computational Research, University at Buffalo. Simulations range from mildly heterogeneous formations to highly heterogeneous formations (variance of the logarithm of conductivity equal to 10) and from sparsely populated systems to systems where inhomogeneities cover 95% of the volume. Particles are released and tracked inside the core of constant mean velocity. Following the particle tracking, various medium, flow, and transport statistics are computed. These include: spatial moments of particle positions, probability density function of hydraulic conductivity and each component of velocity, their two-point covariance function in the direction of flow and normal to it, covariance of Lagrangean velocities, and probability density function of travel times to various break-through locations. Following the analytic nature of the flow solution, all the results are presented in dimensionless forms. For example, the dispersion coefficients are made dimensionless with respect to the mean velocity and size of inhomogeneities. Detailed results will be presented and compared to well known first-order results and the results that are based on simple approximate transport solutions of Aldo Fiori.

  1. Microbial characterization of basalt formation waters targeted for geological carbon sequestration.

    PubMed

    Lavalleur, Heather J; Colwell, Frederick S

    2013-07-01

    Geological carbon sequestration in basalts is a promising solution to mitigate carbon emissions into the Earth's atmosphere. The Wallula pilot well in Eastern Washington State, USA provides an opportunity to investigate how native microbial communities in basalts are affected by the injection of supercritical carbon dioxide into deep, alkaline formation waters of the Columbia River Basalt Group. Our objective was to characterize the microbial communities at five depth intervals in the Wallula pilot well prior to CO2 injection to establish a baseline community for comparison after the CO2 is injected. Microbial communities were examined using quantitative polymerase chain reaction to enumerate bacterial cells and 454 pyrosequencing to compare and contrast the diversity of the native microbial communities. The deepest depth sampled contained the greatest amount of bacterial biomass, as well as the highest bacterial diversity. The shallowest depth sampled harbored the greatest archaeal diversity. Pyrosequencing revealed the well to be dominated by the Proteobacteria, Firmicutes, and Actinobacteria, with microorganisms related to hydrogen oxidizers (Hydrogenophaga), methylotrophs (Methylotenera), methanotrophs (Methylomonas), iron reducers (Geoalkalibacter), sulfur oxidizers (Thiovirga), and methanogens (Methermicocccus). Thus, the Wallula pilot well is composed of a unique microbial community in which hydrogen and single-carbon compounds may play a significant role in sustaining the deep biosphere. PMID:23418786

  2. Geologic reservoir model for the Triassic Doig Formation, northeast British Columbia, Canada

    SciTech Connect

    Moslow, T.F. ); Munroe, H.D. )

    1991-03-01

    A subsurface investigation of the mid-Triassic Doig formation in northeastern British Columbia documented two main reservoir facies. Both are a product of mass movement and sediment gravity flow processes on a progradational, tectonically active continental shelf margin. Substrate instability was likely a product of sediment loading, perhaps in concert with seismic activity. Sedimentary facies and reservoir parameters were determined from analysis of approximately 150 cores and 900 well logs. Laterally discontinuous Doig sandstones are up to 60 m thick and trend northeasterly within the study area. The main reservoir facies are incised density flow deposits and laterally extensive slump deposits. Reservoir quality within these sands is extremely variable with porosity ranging from less than 5% to 15%. In core, these deposits consist of moderately well sorted, very fine grained sandstones with no vertical grain size variation. The best production to date is in the Buick Creek field with initial flows of 346 BOPD. The slump deposits are thinner and tend to be more elongate parallel to paleoshoreline. These sands were subject to some wave or current reworking. Modern analogs where similar processes and products of deposition are known to occur include the Gulf of Alaska continental shelf and the Fraser River Delta slope. Doig sandstones usually are enclosed in fine-grained shelf deposits that provide a good stratigraphic trapping mechanism. Successful development of Doig reservoirs must incorporate geologic modes that assist in understanding the complex and highly variable reservoir quality of sandstones units.

  3. Petrophysical properties and geology of selected intervals in the Frio Formation, Stratton field, South Texas for modeling interwell seismic logging response

    SciTech Connect

    Collier, H.A.; Parra, J.O.

    1996-09-01

    Seismic or continuity logging consists of locating a seismic source in one borehole near or in a low-velocity layer and deploying a detector array in a second borehole. Detection of guided waves transmitted between the two wells indicates bed connectivity. The guided wave signatures are either leaky modes or normal modes (or both). The technique has numerous applications in various types of heterogeneous geological environments, including many Gulf Coast gas reservoirs. It can be used to determine the continuity of beds between wells, estimate and locate variations in the thickness of beds, and estimate the average rock physical properties of the beds. Stratton field was selected as the Gulf-Coast-gas-play type field for a project to model interwell seismic logging responses. Stratton is a mature gas field located in the south Texas Gulf Coast, about 30 miles southwest of Corpus Christi. It encompasses over 120,000 acres in portions of Kleberg, Nueces, and Jim Wells counties. Stratton is one of 29 fields in the Frio Formation fluvial-deltaic lay associated with the Vicksburg fault zone along the Texas Gulf Coast Basin. This poster presentation explains the technique of interwell seismic logging, documents the petrophysical properties and geology of intervals in the upper and middle Frio, and presents the results of the forward modeling tests.

  4. Formation of environmentally persistent free radicals from the heterogeneous reaction of ozone and polycyclic aromatic compounds.

    PubMed

    Borrowman, Cuyler K; Zhou, Shouming; Burrow, Timothy E; Abbatt, Jonathan P D

    2016-01-01

    In the 1980s long-lived radical species were identified in cigarette tar. Since then, environmentally persistent free radicals (EPFRs) have been observed in ambient particulate matter, and have been generated in particulate matter generated from internal combustion engines. For the first time, we measure in situ the formation and decay of EPFRs through the heterogeneous reaction of ozone and several polycyclic aromatic compounds (PAC). Solid anthracene (ANT), pyrene (PY), benzo[a]pyrene (BAP), benzo[ghi]perylene (BGHIP), 1,4-naphthoquinone (1,4NQ), and 9,10-anthraquinone (AQ) were reacted with gas-phase ozone in a flow system placed in the active cavity of an electron paramagnetic resonance (EPR) spectrometer, and the formation of radicals was measured on the timescale of tens of minutes at ambient levels of ozone down to 30 ppb. For most substrates the net radical production is initially rapid, slows at intermediate times, and is followed by a slow decay. For oxidized solid BAP, radical signal persists for many days in the absence of ozone. To evaluate the effect of substrate phase, the solid PAHs were also dissolved in squalane, an organic oil inert to ozone, which yielded a much higher maximum radical concentration and faster radical decay when exposed to ozone. With higher mobility, reactants were apparently able to more easily diffuse and react with each other, yielding the higher radical concentrations. The EPR spectra exhibit three radicals types, two of which have been assigned to semiquinone species and one to a PAH-derived, carbon-centered radical. Although our system uses levels of PAC not typically found in the environment it is worth noting that the amounts of radical formed, on the order of 10(18) radicals per g, are comparable to those observed in ambient particulate matter. PMID:26603953

  5. Adsorption of binary gas mixtures in heterogeneous carbon predicted by density functional theory: on the formation of adsorption azeotropes.

    PubMed

    Ritter, James A; Pan, Huanhua; Balbuena, Perla B

    2010-09-01

    Classical density functional theory (DFT) was used to predict the adsorption of nine different binary gas mixtures in a heterogeneous BPL activated carbon with a known pore size distribution (PSD) and in single, homogeneous, slit-shaped carbon pores of different sizes. By comparing the heterogeneous results with those obtained from the ideal adsorbed solution theory and with those obtained in the homogeneous carbon, it was determined that adsorption nonideality and adsorption azeotropes are caused by the coupled effects of differences in the molecular size of the components in a gas mixture and only slight differences in the pore sizes of a heterogeneous adsorbent. For many binary gas mixtures, selectivity was found to be a strong function of pore size. As the width of a homogeneous pore increases slightly, the selectivity for two different sized adsorbates may change from being greater than unity to less than unity. This change in selectivity can be accompanied by the formation of an adsorption azeotrope when this same binary mixture is adsorbed in a heterogeneous adsorbent with a PSD, like in BPL activated carbon. These results also showed that the selectivity exhibited by a heterogeneous adsorbent can be dominated by a small number of pores that are very selective toward one of the components in the gas mixture, leading to adsorption azeotrope formation in extreme cases. PMID:20712330

  6. Diagenetic controls on reservoir heterogeneity in Cretaceous Mishrif Formation in Zeta-1 well, offshore Dubai

    SciTech Connect

    Videtich, P.E.; McLimans, R.K.; Frank, H.J.

    1989-03-01

    The Zeta-1 well tested a thickened lens of the Cretaceous Mishrif Formation located east of Fateh field in offshore Dubai, United Arab Emirates. Initial petrographic study of Mishrif core showed it to be a homogeneous, mollusk-rudist packstone that apparently underwent similar diagenesis throughout. However, geochemical analyses of the ore identified a horizon where sharp changes in the elemental and stable carbon isotope compositions occur. The authors interpret those changes to be due to a discontinuity that divides the packstone into upper and lower units. There is a marked change in porosity coincident with the discontinuity from 13% in the lower unit to 24% in the upper unit. Evidence for oil migration at Zeta-1 is retained in the form of oil fluid inclusions trapped within calcite cements. However, oil inclusions are found only in cements near or above the discontinuity. This suggests that oil migration was confined to the upper packstone, whereas cementation continued unrestricted in the lower packstone, resulting in diminished porosity. The lack of an updip seal is the apparent reason why commercial quantities of oil did not accumulate at Zeta-1. Geothermometry studies of fluid inclusions entrapped in late blocky calcite spar that occludes much of the porosity indicate that the cement originated at depth from a high-density brine, consistent with the above scenario. Thus, the heterogeneity in the reservoir rock is related to early diagenesis, controlled in part by the discontinuity, deep burial cementation, and migration of oil.

  7. Transport of sorbing solutes in randomly heterogeneous formations: Spatial moments, macrodispersion, and parameter uncertainty

    SciTech Connect

    Andricevic, R.

    1993-06-01

    Expressions for the spatial moments and macrodispersion tensor for sorbing solutes in heterogeneous formations were presented using a probabilistic model of a fluid residence time coupled with the particle position analysis. The fluid residence time was defined as a fraction of the actual time during which the particle stayed in the mobile fluid phase of the aquifer. The fluid residence time is a random variable whose variability comes as a result of the non-equilibrium sorption properties. The sorbing solute was assumed to be governed with first-order linear kinetics. The closed-form expressions were based on the stationarity in the kinetic process and on the first-order approximation in the hydraulic conductivity field and in the fluid residence time. The non-equilibrium effects were presented as a function of the spatial variability in hydraulic conductivity and temporal variability in the fluid residence time. The importance of the non-equilibrium processes in the field scale was found to be dependent on reaction rates, retardation factor, mean velocity, and on variance and correlation scale of the hydraulic conductivity. The time needed to reach the asymptotic macrodispersivity is dependent on the degree of non-equilibrium processes and distribution coefficient. The impact from the uncertainty in parameters upon the spatial moments was examined and compared with the organic tracer used in the Borden field experiment.

  8. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation

    SciTech Connect

    Matter, J.; Chandran, K.

    2013-05-31

    Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is produced and used. Various carbon capture and storage (CCS) technologies are currently being developed, but unfortunately little is known regarding the fundamental characteristics of CO{sub 2}-mineral reactions to allow a viable in-situ carbon mineralization that would provide the most permanent and safe storage of geologically-injected CO{sub 2}. The ultimate goal of this research project was to develop a microbial and chemical enhancement scheme for in-situ carbon mineralization in geologic formations in order to achieve long-term stability of injected CO{sub 2}. Thermodynamic and kinetic studies of CO{sub 2}-mineral-brine systems were systematically performed to develop the in-situ mineral carbonation process that utilizes organic acids produced by a microbial reactor. The major participants in the project are three faculty members and their graduate and undergraduate students at the School of Engineering and Applied Science and at the Lamont-Doherty Earth Observatory at Columbia University: Alissa Park in Earth and Environmental Engineering & Chemical Engineering (PI), Juerg Matter in Earth and Environmental Science (Co-PI), and Kartik Chandran in Earth and Environmental Engineering (Co-PI). Two graduate students, Huangjing Zhao and Edris Taher, were trained as a part of this project as well as a number of graduate students and undergraduate students who participated part-time. Edris Taher received his MS degree in 2012 and Huangjing Zhao will defend his PhD on Jan. 15th, 2014. The interdisciplinary training provided by this project was valuable to those students who are entering into the workforce in the United States. Furthermore, the findings from this study were and will be published in referred journals to disseminate the results. The list of the papers is given at

  9. A workflow for handling heterogeneous 3D models with the TOUGH2 family of codes: Applications to numerical modeling of CO 2 geological storage

    NASA Astrophysics Data System (ADS)

    Audigane, Pascal; Chiaberge, Christophe; Mathurin, Frédéric; Lions, Julie; Picot-Colbeaux, Géraldine

    2011-04-01

    This paper is addressed to the TOUGH2 user community. It presents a new tool for handling simulations run with the TOUGH2 code with specific application to CO 2 geological storage. This tool is composed of separate FORTRAN subroutines (or modules) that can be run independently, using input and output files in ASCII format for TOUGH2. These modules have been developed specifically for modeling of carbon dioxide geological storage and their use with TOUGH2 and the Equation of State module ECO2N, dedicated to CO 2-water-salt mixture systems, with TOUGHREACT, which is an adaptation of TOUGH2 with ECO2N and geochemical fluid-rock interactions, and with TOUGH2 and the EOS7C module dedicated to CO 2-CH 4 gas mixture is described. The objective is to save time for the pre-processing, execution and visualization of complex geometry for geological system representation. The workflow is rapid and user-friendly and future implementation to other TOUGH2 EOS modules for other contexts (e.g. nuclear waste disposal, geothermal production) is straightforward. Three examples are shown for validation: (i) leakage of CO 2 up through an abandoned well; (ii) 3D reactive transport modeling of CO 2 in a sandy aquifer formation in the Sleipner gas Field, (North Sea, Norway); and (iii) an estimation of enhanced gas recovery technology using CO 2 as the injected and stored gas to produce methane in the K12B Gas Field (North Sea, Denmark).

  10. Source/Sink Matching for U.S. Ethanol Plants and Candidate Deep Geologic Carbon Dioxide Storage Formations

    SciTech Connect

    Dahowski, Robert T.; Dooley, James J.

    2008-09-18

    This report presents data on the 140 existing and 74 planned ethanol production facilities and their proximity to candidate deep geologic storage formations. Half of the existing ethanol plants and 64% of the planned units sit directly atop a candidate geologic storage reservoir. While 70% of the existing and 97% of the planned units are within 100 miles of at least one candidate deep geologic storage reservoir. As a percent of the total CO2 emissions from these facilities, 92% of the exiting units CO2 and 97% of the planned units CO2 emissions are accounted for by facilities that are within 100 miles of at least one potential CO2 storage reservoir.

  11. New geological aspects for freshwater seepage and formation in Eckernförde Bay, western Baltic

    NASA Astrophysics Data System (ADS)

    Jensen, Jørn B.; Kuijpers, Antoon; Bennike, Ole; Laier, Troels; Werner, Friedrich

    2002-10-01

    The subsurface geology relevant to the submarine freshwater seepage in Eckernförde Bay has been investigated using shallow seismic instruments and vibrocoring. Detailed surveying revealed that the pockmarks are aligned like pearls on a string or densely clustered in furrow-like structures depending on the glacial and postglacial setting of the underlying strata. Two possible aquifers have been verified: The older Miocene sand aquifer is partly sealed by a till unit forming the central part of the Mittelgrund. The younger aquifer consists of a mixture of glacial till and meltwater sediments partly sealed by till and partly by lateglacial galciolacustrine silt and clay sediments. The investigations imply that connections exist between the aquifers and that groundwater leakage takes place in the marginal zones of the bay due to thinning and coarsening of the sediment composition of the lateglacial seal. Within the seepage areas, the pockmarks are restricted to areas covered by unconsolidated Holocene mud of low thickness' that are easy to penetrate by artesian groundwater. Macrofossil studies and AMS 14C dating of the lateglacial and Holocene units reveal that the Mittelgrund shoal of glacial origin has been modified by coastal processes and formation of cuspate foreland deposits during the subsequent palaeo-lake phases of 15-20 m below the present sea level (b.s.l.). The lake phases correlate in time with the regional Baltic Ice Lake highstand about 10,000 14C years BP and the Ancylus Lake highstand about 9200 14C years BP. This means that local contemporary lakes existed or the western margin of the regional lakes can be moved considerably further west than expected hitherto. In the earliest phase of the Littorina Sea transgression, the Mittelgrund shoal was exposed to coastal erosion once more before the final drowning and the initiation of mud sedimentation in the surrounding basins took place.

  12. Geologic constraints on kinematic models and age of formation of the Amerasia Basin of the Arctic

    NASA Astrophysics Data System (ADS)

    Miller, E. L.

    2015-12-01

    A wealth of new geologic and geophysical data now exist for the Amerasia Basin, but the details of its age and the nature/kinematics of events that resulted in its formation remain elusive. Basement rock ages, detrital zircon signatures of sedimentary rocks, and sediment dispersal systems have been used to show how parts of the southern margin(s) of the Amerasia Basin (Arctic Alaska-Chukotka, AAC) match their rifted margin counterparts on the Eurasia and Canada side of the Amerasia Basin. Thus we know the approximate finite translations needed to restore the paleogeography of the Arctic, but not the kinematics involved. Important features of the Amerasia Basin that need to be explained in a model for its opening are the age and extent of the high Arctic LIP, the linearity of the strip of continental crust represented by the Lomonosov Ridge, its right angle intersection with the Canadian Arctic margin, and the directional fault patterns mapped bathymetrically and seismically across the Alpha-Lomonosov Ridge and surrounding seafloor. Across AAC, post-Early Cretaceous oroclinal bends provide insight into strike-slip components of deformation involved in opening of the Amerasia Basin: The Chukchi syntax offsets the Brooks Range in a right-lateral sense from Wrangel Island along the Herald Arch; right-lateral motion of Arctic Alaska with respect to the Chukchi Borderland during opening of the Canada Basin; right-lateral shear in Chukotka during 100 Ma magmatism; the tight bend in the northern Verkhoyansk, result of Cretaceous right-lateral shear. The land-based relationships imply a post-Early Cretaceous, younger than Barremian (~130 Ma) age for onset of magmatism and extension related to rifting and formation of the Amerasia Basin. At least two stages of extension are documented, with older E-W extension characterizing the longitude of the New Siberian Islands to Pevek, Russian Arctic, (ca.125 Ma to 100 Ma), with younger N-S extension superimposed on this system (ca

  13. Integration of Sedimentology,Petrophysics and Statistics for Characterizing the Reservoir Heterogeneity of the Late Ordovician Sarah Formation, Central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    El-Deek, Islam; Abdullatif, Osman; Korvin, Gabor; Al-Ramadan, Khalid

    2014-05-01

    The first glaciogenic event in the Arabian Peninsula is represented by the Late Ordovician Sarah Formation. Sarah Formation is outcropping in areas of central and northern Arabia bordering the Arabian Shield, while it occupies several sub-basinal areas in the subsurface. The glacio-fluvial Sarah Formation is considered as an important tight gas reservoir target. This study uses the outcrop analog of the Sarah Formation to characterize the reservoir heterogeneity of the paleovalleys based on sedimentological, petrophysical, and statistical approaches. Facies types and architectural elements were identified within several paleovalleys of the Sarah Formation. The study indicated variability in texture, composition, sandstone type, facies, geometry and architecture at outcrop scale. Outcrop relationships also showed vertical and lateral facies change with other Paleozoic formations. The integration of field and laboratory data helped identifying the heterogeneity within Sarah paleovalleys. The reservoir quality trends in the Sarah Formation show variations that might be due to the controls of facies, depositional environments, and paleogeography. Three measures of heterogeneity were applied on the petrophysical data for various paleovalleys of the Sarah Formation. Those measures are: the coefficient of variation, Dykstra-Parsons, and Lorenz coefficients.The coefficient of variation values indicate extremely heterogeneous distribution. Dykstra-Parsons coefficient values suggest very to extremely heterogeneous reservoirs. Lorenz coefficients show good correlation with Dykstra-Parsons coefficient for Sarah paleovalleys. The studied heterogeneity measures indicate that Sarah paleovalleys represent very to extremely heterogeneous reservoirs.

  14. Exploring the nitrous acid (HONO) formation mechanism in winter Beijing: direct emissions and heterogeneous production in urban and suburban areas.

    PubMed

    Tong, Shengrui; Hou, Siqi; Zhang, Ying; Chu, Biwu; Liu, Yongchun; He, Hong; Zhao, Pusheng; Ge, Maofa

    2016-07-18

    Continuous measurements of nitrous acid (HONO) were performed from December 12 to December 22, 2015 in both urban and suburban areas of Beijing to study the formation mechanism of HONO. The measurement campaign in both sites included a clean-haze-clean transformation process. HONO concentrations showed similar variations in the two sites, while they were always higher in the urban area. Moreover, correlations of HONO with NOx, NO2, NO, PM2.5 and relative humidity (RH) were studied to explore possible HONO formation pathways, and the contributions of direct emissions, heterogeneous reactions, and homogeneous reactions were also calculated. This showed that HONO in urban and suburban areas underwent totally different formation procedures, which were affected by meteorological conditions, PM2.5 concentrations, direct emissions, homogeneous reactions and heterogeneous reactions. PM2.5 concentrations and RH would influence the NO2 conversion efficiency. Heterogeneous reactions of NO2 were more efficient in suburban areas and in clean periods while direct emissions and homogeneous reactions contributed more in urban areas and in polluted periods when the concentrations of NOx and NO were at a high level. PMID:27081740

  15. Laboratory investigations of the effects of geologic heterogeneity on groundwater salinization and flush-out times from a tsunami-like event

    NASA Astrophysics Data System (ADS)

    Vithanage, M.; Engesgaard, P.; Jensen, K. H.; Illangasekare, T. H.; Obeysekera, J.

    2012-08-01

    This intermediate scale laboratory experimental study was designed to improve the conceptual understanding of aquifer flushing time associated with diffuse saltwater contamination of coastal aquifers due to a tsunami-like event. The motivation comes from field observations made after the tsunami in December, 2004 in South Asia. The focus is on the role and effects of heterogeneity on flushing effectiveness. A scheme that combines experimentation in a 4.8 m long laboratory tank and numerical modeling was used. To demonstrate the effects of geologic heterogeneity, plume migration and flushing times were analyzed in both homogeneous and layered media and under different boundary conditions (ambient flow, saltwater infiltration rate, freshwater recharge). Saltwater and freshwater infiltrations imitate the results of the groundwater salinization from the tsunami and freshening from the monsoon rainfall. The saltwater plume behavior was monitored both through visual observations (digital photography) of the dyed salt water and using measurements taken from several electrical conductivity sensors installed through the tank walls. The variable-density, three dimensional code HST3D was used to simulate the tank experiments and understand the fate and movement of the saltwater plume under field conditions. The results from the tank experiments and modeling demonstrated that macro-scale heterogeneity significantly influenced the migration patterns and flushing times of diffuse saltwater contamination. Ambient flow had a direct influence on total flush-out time, and heterogeneity impacted flush-out times for the top part of the tank and total flush-out times. The presence of a continuous low-permeability layer caused a 40% increase in complete flush-out time due to the slower flow of salt water in the low-permeability layer. When a relatively small opening was introduced in the low-permeability layer, salt water migrated quickly into a higher-permeable layer below causing a

  16. Effect of crustal heterogeneities and effective rock strength on the formation of HP and UHP rocks.

    NASA Astrophysics Data System (ADS)

    Reuber, Georg; Kaus, Boris; Schmalholz, Stefan; White, Richard

    2015-04-01

    The formation of high pressure and ultra-high pressure rocks has been controversially discussed in recent years. Most existing petrological interpretations assume that pressure in the Earth is lithostatic and therefore HP and UHP rocks have to come from great depth, which usually involves going down a subduction channel and being exhumed again. Yet, an alternative explanation points out that pressure in the lithosphere is often non-lithostatic and can be either smaller or larger than lithostatic as a function of location and time. Whether this effect is tectonically significant or not depends on the magnitude of non-lithostatic pressure, and as a result a number of researchers have recently performed numerical simulations to address this. Somewhat disturbingly, they obtained widely differing results with some claiming that overpressures as large as a GPa can occur (Schmalholz et al. 2014), whereas others show that overpressures of exhumed rocks are generally less than 20% and thus insignificant (Li et al. 2010; Burov et al. 2014). In order to understand where these discrepancies come from, we reproduce the simulations of Li et al (2010) of a typical subduction and collision scenario, using an independently developed numerical code (MVEP2). For the same model setup and parameters, we confirm the earlier results of Li et al. (2010) and obtain no more than ~20% overpressure in exhumed rocks of the subduction channel. Yet, a critical assumption in their models is that the subducted crust is laterally homogeneous and that it has a low effective friction angle that is less than 7o. The friction angle of (dry) rocks is experimentally well-constrained to be around 30o, and low effective friction angles require, for example, high-fluid pressures. Whereas high fluid pressures might exist in the sediment-rich upper crust, they are likely to be much lower or absent in the lower crust from which melt has been extracted or in rocks that underwent a previous orogenic cycle. In a

  17. Effect of pattern formation on C and N turnover heterogeneity in initial soils

    NASA Astrophysics Data System (ADS)

    Schaaf, Wolfgang; Zimmermann, Claudia

    2013-04-01

    The formation of vegetation patterns and hydrological processes, among others, result in soil heterogeneity in newly exposed land surfaces. We studied the effect of these developling structures on carbon and nitrogen trunover in soils of the artificial catchment Chicken Creek (Schaaf et al. 2011, 2012). Substrates with different physical and geochemical properties in combination with different labelled plant litter materials were studied in a microcosm experiment over a period of 80 weeks. Main objectives of the microcosm experiment were to determine the transformation processes of C and N from litter decomposition within the gaseous, liquid and solid phase, the interaction with mineral surfaces and its role for the establishment of biogeochemical cycles. The microcosm experiments were established in a climate chamber at constant 10 °C. In total, 48 soil columns (diameter: 14.4 cm; height: 30 cm) were filled with two different quaternary substrates (sand and loamy sand) representing the textural variation within the catchment at a bulk density of 1.4-1.5 g cm-3. The columns were automatically irrigated with artificial rainwater four times a day with 6.6 ml each (corresponding to 600 mm yr-1). The gaseous phase in the headspace of the microcosms was analyzed continuously for CO2 and N2O concentrations. C and N transformation processes were studied using 13C and 15N labelled litter of two different plant species occurring at the catchment (Lotus corniculatus, Calamagrostis epigejos) that was incorporated into the microcosm surface. By including litter from species with wide distribution within the catchment and soil substrates representing the main variation types of the sediments used for catchment construction we were able to characterize the general function of these sub-patches within the catchment with respect to litter decomposition, soil solution composition, DOC and nutrient leaching, and impact on the mineral soil phase. The results suggest that initial

  18. Structural and dynamical heterogeneities in PVA films induced by evaporation during the formation process

    NASA Astrophysics Data System (ADS)

    Ghoshal, Sushanta; Denner, Paul; Stapf, Siegfried; Mattea, Carlos

    2011-10-01

    Microscopic dynamical studies were performed on poly(vinyl alcohol) in aqueous solution by means of NMR microimaging and relaxation techniques. The study indicates a spatial heterogeneity in the molecular dynamics, observed at different heights during evaporation of the solvent. In the advanced stage of the drying process, the microscopic arrangement of the polymer chains during their solidification is influenced by this dynamic heterogeneity and determines the final structure of the film. X-ray diffractometry of the film in its final state confirmed the structural heterogeneity identified by the NMR. This suggests that crystallization of the polymer from the evaporated solution is enhanced on the side of the film where evaporation takes place.

  19. Evidence for Regional Basin Formation in Early Post-Tessera Venus History: Geology of the Lavinia Planitia Area (V55)

    NASA Technical Reports Server (NTRS)

    Head, J. W.; Ivanov, M. A.

    1995-01-01

    On Venus, global topography shows the presence of highs and lows including regional highly deformed plateaus (tesserae), broad rifted volcanic rises, linear lows flanking uplands, and more equidimensional lowlands (e.g. Lavinia and Atalanta planitiae) Each of these terrain types on Venus has relatively distinctive characteristics, but origins are uncertain in terms of mode of formation, time of formation, and potential evolutionary links. There is a high level of uncertainty about the formation and evolution of lowlands on Venus. We have undertaken the mapping of a specific lowlands region of Venus to address several of these major questions. Using geologic mapping we have tried to establish: What is the sequence of events in the formation and evolution of large-scale equidimensional basins on Venus? When do the compressional features typical of basin interiors occur? What is the total volume of lava that occurs in the basins and is this similar to other non-basin areas? How much subsidence and downwarping has occurred after the last major plains units? WE have undertaken an analysis of the geology of the V55 Lavinia Planitia quadrangle in order to address many of these issues and we report on the results here.

  20. Assessment of the Geologic Carbon Dioxide Storage Resources of the Clinton, Medina, and Tuscarora Formations in the Appalachian Basin

    NASA Astrophysics Data System (ADS)

    Doolan, C.

    2013-12-01

    The U.S. Geological Survey (USGS) has completed an assessment of the geologic carbon dioxide (CO2) storage potential within the Appalachian Basin. This assessment was performed as part of the USGS national assessment of geologic CO2 storage resources in which individual sedimentary basins are divided into storage assessment units (SAUs) based on geologic characteristics such as lithology, porosity, permeability, reservoir depth, formation water salinity, and the presence of a regional sealing formation. This study focuses on the assessment of the Clinton, Medina and Tuscarora Formations storage assessment unit (SAU) that covers an area of 48.9 million acres in eastern Kentucky and Ohio, West Virginia, northern and western Pennsylvania, and southwestern New York. The areal extent of the SAU is defined on the western boundary by the 100 foot isopach contour of the combined Rochester and Rose Hill Shales that acts as the regional sealing formation and is defined by the 3,000 foot depth to top contour of the Clinton and Tuscarora Formations elsewhere. Depth-to-top and isopach contours were derived from IHS Energy Group, 2011 data for over 25,000 unique boreholes located throughout the area of the SAU. The Clinton, Medina and Tuscarora Formations SAU is composed of the porous intervals of the Lower to Middle Silurian strata that is bounded by the underlying Ordovician age Queenston Shale, and the overlying Silurian age Rochester and Rose Hill Shales. Porous intervals were deposited in a variety of wave and tidal dominated environments as a result of a Lower Silurian shoreline that prograded southeast to northwest. Porous units in the Tuscarora Formation in southwestern and central Pennsylvania and West Virginia are predominantly fine to medium grained sands of alluvial plain facies and those of the Clinton and Medina Formations in southwestern New York, northeastern Pennsylvania, eastern Ohio and northeastern Kentucky are typically fine grained quartzarenites deposited

  1. Spatial changes of seismic attenuation and multiscale geological heterogeneity in the Baikal rift and surroundings from analysis of coda waves

    NASA Astrophysics Data System (ADS)

    Dobrynina, Anna A.; Sankov, Vladimir A.; Chechelnitsky, Vladimir V.; Déverchère, Jacques

    2016-04-01

    The Baikal rift system is undergoing an active tectonic deformation expressed by a high level of seismic activity. This deformation leads to physical and mechanical changes of crustal properties which can be investigated by the seismic quality factor and its frequency dependence. Using a single backscattering model, a seismic quality-factor (QC), a frequency parameter (n) and an attenuation coefficient (δ) have been estimated by analyzing coda waves of 274 local earthquakes of the Baikal rift system for nineteen lapse time windows (W) from 10 to 100 s every 5 s and for six central frequencies (0.3, 0.75, 1.5, 3, 6 and 12 Hz). The average QC value increases with the frequency and lapse time window from 46 ± 52 (at 0.75 Hz) to 502 ± 109 (at 12 Hz) for W = 10 s and from 114 ± 49 (at 0.3 Hz) to 1865 ± 679 (at 12 Hz) for W = 100 s. The values of QC(f) and δ were estimated for the whole Baikal rift system and for separate tectonic blocks: the stable Siberian Platform, main rift basins, spurs and uplifts. Along the rift system, the Q0-value (QC-factor at the frequency f = 1 Hz) varies within 72-109 and the frequency parameter n ranges from 0.87 to 1.22, whereas Q0 is 134 and n is 0.48 for the stable Siberian Platform. Vertical variations of attenuation reveal that sharp changes of δ and n are confined to the velocity discontinuities. The comparison of lateral variations of seismic wave attenuation and geological and geophysical characteristics of the Baikal rift system shows that attenuation is correlated with both seismic activity and heat flow and in a lesser degree with the surface fault density and the age of the crust. Seismic wave attenuation found across the main shear zones of the south-western Baikal rift (Main Sayan strike-slip fault zone and Tunka, Obruchev and Primorsky normal faults) is increased by more than 25-60% compared to the neighboring areas.

  2. Heterogeneity of the North Atlantic oceanic lithosphere based on integrated analysis of GOCE satellite gravity and geological data

    NASA Astrophysics Data System (ADS)

    Barantseva, Olga; Artemieva, Irina; Thybo, Hans; Herceg, Matija

    2015-04-01

    constrained by numerous published seismic profiles and potential-field models across the Norwegian off-shore crust (e.g. Breivik et al., 2005, 2007). The results demonstrate the presence of strong gravity and density heterogeneity of the upper mantle in the North Atlantic region. In particular, there is a sharp contrast at the continent-ocean transition, which also allows for recognising mantle gravity anomalies associated with continental fragments and with anomalous oceanic lithosphere.

  3. Heterogeneous Catalysis.

    ERIC Educational Resources Information Center

    Miranda, R.

    1989-01-01

    Described is a heterogeneous catalysis course which has elements of materials processing embedded in the classical format of catalytic mechanisms and surface chemistry. A course outline and list of examples of recent review papers written by students are provided. (MVL)

  4. The Enigmatic Longevity of Granular Materials on Mars: The Case for Geologically Episodic Dune Formation

    NASA Technical Reports Server (NTRS)

    Marshall, J.

    1999-01-01

    Martian sand dunes are concentrated in vast sand seas in the circumpolar belt of the planet's northern hemisphere, but they are also pervasive over the whole planet. Their occurrence is to be expected on a super-arid planetary surface subjected to boundary layer drag from a continually active atmosphere. Whilst their occurrence is to be expected, their survival is enigmatic. But the enigma only arises if the martian system is considered similar to Earth's --where sand is moved highly frequently, more or less on a seasonal basis. Experimentally it is readily demonstrated that active sand will soon wear down to small grains and eventually diminish to below the critical sand size required to sustain dune formation. According to conventional wisdom, sand moves at higher speeds on Mars than on Earth, and if it were to move as frequently as it does on Earth, then the dune-forming sand population should have long since disappeared, given the great longevity of the martian aeolian system (Sagan coined the term "kamikaze" grains to express this disappearance). No supply of sand could keep pace with this depletion, especially in light of the fact that Mars does not have very active weathering, nor significant crustal differentiation. On Earth, plate tectonics, magmatic activity, and general crustal differentiation over geological time have produced great concentrations of quartz crystals in the continental crustal masses. Not only are these quartz grains chemically and mechanically resilient, they are about the right size for being transported by either wind or water. Add to this, the geologically recent contribution of glacial grinding, and it is easy to see why there are dune field on Earth. So what are the martian dunes composed of, and how does the material survive the eons of attrition? In addition to experimental demonstrations of sand comminution in laboratory aeolian simulations, the problem can be approached from first principles. Sagan showed that by simple

  5. Numerical Study of Artificial Seal Formation to Remedy Leakage from Geological CO2 Storage Reservoirs

    NASA Astrophysics Data System (ADS)

    Ito, T.; Tanaka, H.; Xu, T.

    2011-12-01

    In the Carbon dioxide Capture and Storage (CCS), the CO2 is captured from emission source and stored into geological reservoirs at a depth below 800 m. The injected CO2 is less dense than water, and as a result, it tends to migrate upward. For trapping to inhibit the upward migration of CO2, the reservoirs should be covered with a sufficiently impermeable seal, i.e. caprock. However, the caprock may contain imperfections such as faults and fractures which will play a role of a high permeability path to arise leakage of the injected CO2 from the reservoirs. Pressurization with the injected CO2 can create fissures that may transmit CO2 through the caprock (Zoback and Zinke, 2002). Preparing for such risk of CO2 leakage through pre-existing and/or induced fractures, the International Energy Agency (IEA) has pointed out the importance of establishing a ready-to-use strategy for remediation of leakage from CO2 storage reservoirs (IEA, 2007). As one possibility to realize the strategy, we have proposed a concept to use an aqueous solution (Ito et al., 2006). The solution will have a sufficiently-low viscosity for passing through even small aperture, and it will not impact formation permeability as long as the solution is left as it is. When the solution encounters dissolved CO2, precipitation will occur due to chemical reaction. As a result, the permeability will be reduced by filling the pores and fractures in the rocks with the precipitates. In the present study, we demonstrated first this idea through laboratory experiments simulating subsurface condition at 1000 m deep, i.e. 10 MPa and 40 deg. C, and using a silicate solution reacting with CO2. In this case, the solution - CO2 reaction will produce precipitates of amorphous silica. The results of laboratory experiments show that the present method led to a 99 % permeability reduction in a glass-bead artificial rock even its initially-high permeability of few darcy. Such reduction of permeability was reproduced

  6. Spatial heterogeneity of uranium isotope variations in a Phanerozoic, epicontintental black shale (Hushpuckney Shale, Swope Formation)

    NASA Astrophysics Data System (ADS)

    Herrmann, A. D.; Gordon, G. W.; Romaniello, S. J.; Algeo, T. J.; Anbar, A. D.

    2012-12-01

    It has recently been shown that substantial variations in the 238U/235U ratio exist in nature. The isotopic composition of seawater is ultimately driven by the relative sizes and isotopic signatures of the major sources and sinks. Rivers are the major sources of uranium to the ocean, and reducing sediments (mainly anoxic and suboxic sediments) are the major sinks. Under reducing conditions heavy uranium isotopes are sequestered preferentially. Because of the long residence time of uranium in the global ocean, and the relatively large fractionation during removal of uranium under reducing conditions, it has been suggested that the isotope composition of seawater might reflect changes in the redox state of the ocean and that such changes might be mirrored in black shales. Here we present uranium isotope variations of a Pennsylvanian black shale (Hushpuckney Shale; Swope Formation) from two cores from the same depositional basin (Late Paleozoic Midcontinent Sea; LPMS) to test whether global marine redox conditions can be determined from a single section in epicontinental settings. If uranium isotopes in epicontinental black shales can be used to quantify changes in redox changes of the global ocean, then contemporaneous black shales sections should have the same isotope trends and magnitudes. The Hushpuckney shale is one of several cyclothem core intervals that were deposited over large areas (tens of thousands of square kilometers) on continental crust during early transgression in response to the deglaciation of large icesheets in the southern hemisphere. The two cores investigated for this study represent a transect through the LPMS from close to the open ocean (SE Kansas) towards the shoreline (Iowa). The Hushpuckney shale can be easily identified and correlated in these two cores. Thus, it offers an excellent opportunity to test whether the uranium isotopic composition is similar across the basin and how much local redox conditions can play a role in faithfully

  7. Geophysical investigation for the evaluation of the long-time safety of repositories and underground disposals in deep geological formations

    NASA Astrophysics Data System (ADS)

    Just, A.; Salinar Group

    2003-04-01

    The performance assessment of underground disposal facilities is an indispensable premise to ensure that repositories fulfil the requirements for permanent and safe disposal of hazardous waste. The geological barrier is supposed to be a virtually impermeable host formation like rock salt. The efficiency of the barrier is endangered by the presence of risk zones such as faults or fractures particularly with regard to water-bearing host rocks. Thus the evaluation of the long-time safety of the geological barrier has to be carried out with a minimum of invasion of the future host formation and a maximum of spatial coverage and resolution. Especially geophysical methods are suitable to investigate the geological barrier due to their non-destructive character and spatial information content. Three research projects supported by the German Federal Ministry of Education and Research (BMBF) are engaged in the design and enhancement of a complex geophysical measuring and evaluation system for the investigation of problem zones of the geological barrier in rock salt. The benefit of the combination of high-performance geophysical measuring techniques as seismics, DC-geoelectrics, ground penetrating radar (GPR), electromagnetics and sonar together with strong knowledge of regional salt geology is to increase essentially the reliability of the interpretation of underground measurements. The measuring methods and interpretation tools for host rock characterisation were applied, developed and improved in a flat salt seam structure of an inoperative salt mine in the Lower Harz region. The joint interpretation of the underground geophysical measurements revealed a by-then unknown wet zone, which was tectonically affected. With the scope of refining the complex geophysical measuring and evaluation system and transferring the precedingly acquired experiences to another type of host formation, an operating potassium salt mine in the vicinity of Hannover/Germany was chosen as a new

  8. Formation and Evolution of Lakshmi Planum (V-7), Venus: Assessment of Models using Observations from Geological Mapping

    NASA Technical Reports Server (NTRS)

    Ivanov, M. A.; Head, James W.

    2008-01-01

    Lakshmi Planum is a high-standing plateau (3.5-4.5 km above MPR) surrounded by the highest mountain ranges on Venus. Lakshmi represents a unique type of elevated region different from dome-shaped and rifted rises and tessera-bearing crustal plateaus. The unique characteristics of Lakshmi suggest that it formed by an unusual combination of processes and played an important role in Venus geologic history. Lakshmi was studied with Venera-15/16 and Magellan data, resulting in two classes of models, divergent and convergent, to explain its unusual topographic and morphologic characteristics. Divergent models explain Lakshmi as a site of mantle upwelling due to rising and subsequent collapse of a mantle diapir; such models explain emplacement of a lava plateau inside Lakshmi and, in some circumstances, formation of the mountain ranges. The convergent models consider Lakshmi as a locus of mantle downwelling, convergence, underthrusting, and possible subduction. Key features in these models are the mountain ranges, high topography of Lakshmi interior, and the large volcanic centers in the plateau center. These divergent and convergent models entail principally different mechanisms of formation and suggest different geodynamic regimes on Venus. Almost all models make either explicit or implicit predictions about the type and sequence of major events during formation and evolution of Lakshmi and thus detailed geological mapping can be used to test them. Here we present the results of such geological mapping (the V-7 quadrangle, 50-75degN, 300-360degE; scale 1:5M) that allows testing the proposed models for Lakshmi.

  9. Aspherical structural heterogeneity within the uppermost inner core: Insights into the hemispherical boundaries and core formation

    NASA Astrophysics Data System (ADS)

    Miller, Meghan S.; Niu, Fenglin; Vanacore, Elizabeth A.

    2013-10-01

    Lateral heterogeneities at the top of the inner core are investigated using earthquakes that occurred in Indonesia and southeast Asia and were recorded in the southeastern Caribbean. Using seismic observations of attenuation and seismic velocity, we were able to constrain the characteristics of the boundary between the inner and outer core to further investigate the dynamics and evolution of the Earth’s core. Our seismic observations from core phases confirm that the outermost inner core is asymmetrically heterogeneous and we are able to further constrain the morphology and physical properties of this layer. Comparison of data from earthquakes with ray paths traversing from east to the west versus those with ray paths from west to east allow us to map the aspherical heterogeneity of the boundary layer and specifically image the boundary between the proposed quasi-eastern and western hemispheres of the inner core. The variation of differential travel times between PKPdf and PKPbc, attenuation in terms of Q factor, and latitudinal changes for both of these observations, can be attributed to localized heterogeneity at the quasi-hemispherical boundaries of the inner core. We constrain the change in the thickness of outermost core boundary layer from 100 to 250 km within a distance of a few 10s of kilometers at 45°E ± 2°, for the western boundary, with an overall P-wave velocity decrease in the western hemisphere of 0.5% and increase of 0.5% in the eastern hemisphere. We constrain the eastern boundary at latitudes greater than 45°N to 173°E ± 4° with an overall P-wave velocity decrease in the western hemisphere of 1.0% in the uppermost 200 km of the inner core. The eastern boundary at equatorial latitudes is constrained to a region <170°E with a western hemisphere with a 0.5% drop in P-wave velocity in the uppermost 250 km.

  10. Formation of double glass in binary mixtures of anisotropic particles: Dynamic heterogeneities in rotations and displacements

    NASA Astrophysics Data System (ADS)

    Takae, Kyohei; Onuki, Akira

    2013-10-01

    We study glass behavior in a mixture of elliptic and circular particles in two dimensions at low temperatures using an orientation-dependent Lennard-Jones potential. The ellipses have a mild aspect ratio (˜1.2) and tend to align at low temperatures, while the circular particles play the role of impurities disturbing the ellipse orientations at a concentration of 20%. These impurities have a size smaller than that of the ellipses and attract them in the homeotropic alignment. As a result, the coordination number around each impurity is mostly 5 or 4 in glassy states. We realize double glass, where both the orientations and the positions are disordered but still hold mesoscopic order. We find a strong heterogeneity in the flip motions of the ellipses, which sensitively depends on the impurity clustering. In our model, a small fraction of the ellipses still undergo flip motions relatively rapidly even at low temperatures. In contrast, the nonflip rotations (with angle changes not close to ±π) are mainly caused by the cooperative configuration changes involving many particles. Then, there arises a long-time heterogeneity in the nonflip rotations closely correlated with the dynamic heterogeneity in displacements.

  11. Formation of double glass in binary mixtures of anisotropic particles: dynamic heterogeneities in rotations and displacements.

    PubMed

    Takae, Kyohei; Onuki, Akira

    2013-10-01

    We study glass behavior in a mixture of elliptic and circular particles in two dimensions at low temperatures using an orientation-dependent Lennard-Jones potential. The ellipses have a mild aspect ratio (∼1.2) and tend to align at low temperatures, while the circular particles play the role of impurities disturbing the ellipse orientations at a concentration of 20%. These impurities have a size smaller than that of the ellipses and attract them in the homeotropic alignment. As a result, the coordination number around each impurity is mostly 5 or 4 in glassy states. We realize double glass, where both the orientations and the positions are disordered but still hold mesoscopic order. We find a strong heterogeneity in the flip motions of the ellipses, which sensitively depends on the impurity clustering. In our model, a small fraction of the ellipses still undergo flip motions relatively rapidly even at low temperatures. In contrast, the nonflip rotations (with angle changes not close to ±π) are mainly caused by the cooperative configuration changes involving many particles. Then, there arises a long-time heterogeneity in the nonflip rotations closely correlated with the dynamic heterogeneity in displacements. PMID:24229182

  12. Organosulfate Formation through the Heterogeneous Reaction of Sulfur Dioxide with Unsaturated Fatty Acids and Long-Chain Alkenes.

    PubMed

    Passananti, Monica; Kong, Lingdong; Shang, Jing; Dupart, Yoan; Perrier, Sébastien; Chen, Jianmin; Donaldson, D James; George, Christian

    2016-08-22

    The heterogeneous reaction between SO2 and unsaturated compounds results in the efficient production of organosulfates for several fatty acids and long-chain alkenes. The presence of an acid group, the physical state of the reactants (solid or liquid), the nature of the double bond (cis, trans, terminal), and the use of light irradiation all have an impact on the reaction rate. The reaction was investigated using different set-ups (coated flow tube, aerosol flow tube, and diffuse reflectance infrared Fourier transform cell). The reaction products were identified by high-resolution mass spectrometry and the impact of this reaction on organosulfate formation in the atmosphere is discussed. PMID:27458109

  13. Heterogeneous chemistry: a mechanism missing in current models to explain secondary inorganic aerosol formation during the January 2013 haze episode in North China

    NASA Astrophysics Data System (ADS)

    Zheng, B.; Zhang, Q.; Zhang, Y.; He, K. B.; Wang, K.; Zheng, G. J.; Duan, F. K.; Ma, Y. L.; Kimoto, T.

    2014-06-01

    Severe regional haze pollution events occurred in eastern and central China in January 2013, which had adverse effects on the environment and public health. Extremely high levels of particulate matter with aerodynamic diameter of 2.5 μm or less (PM2.5) with dominant components of sulfate and nitrate are responsible for the haze pollution. Although heterogeneous chemistry is thought to play an important role in the production of sulfate and nitrate during haze episodes, few studies have comprehensively evaluated the effect of heterogeneous chemistry on haze formation in China by using the 3-D models due to of a lack of treatments for heterogeneous reactions in most climate and chemical transport models. In this work, the offline-coupled WRF-CMAQ model with newly added heterogeneous reactions is applied to East Asia to evaluate the impacts of heterogeneous chemistry and the meteorological anomaly during January 2013 on regional haze formation. The revised CMAQ with heterogeneous chemistry not only captures the magnitude and temporal variation of sulfate and nitrate, but also reproduces the enhancement of relative contribution of sulfate and nitrate to PM2.5 mass from clean days to polluted haze days. These results indicate the significant role of heterogeneous chemistry in regional haze formation and improve the understanding of the haze formation mechanisms during the January 2013 episode.

  14. Geology of East Egypt greenstone field in Neoproterozoic isoand arc: Reconstruction of Iron formation sedimentary environment.

    NASA Astrophysics Data System (ADS)

    Kiyokawa, S.; Suzuki, T.

    2015-12-01

    Geology of East Egypt greenstone-granit belt which is northern part of Nubia shield was identified neoproterozoic island arc amalgamated sections. There are several iron formation within these greenstone belt. Age data shows this iron formation may be overlaped during 700 Ma Snowball period, how ever, there is no detail report of well preserved ice related evidences. We now started detail field work for identified tectonic reconstruction, original stratigraphy around Iron formation and sedimentary environment during the iron formation sedimentation area. East Egyptian shield was divided three geology, Proterozoic greenstone complex, 700-600 Granitic domes and cover sequence (Hammamet Group). We focus three area to identified sedimentary environment of iron sedimentation. Along the north-south trend of Wadi EL Dabban area are, we named Wadi branch as West site is RW-0 ~ 12, East site is RE-0 ~ 12 from north to south. Northern area is structurally moderate, southern portion is north dipping. Southern portion was intruded by granite and several place contain granitic dikes. Northeast to eastern area are identified younger sedimentary sequence (Hammamat Group) which is unconformablly overlay on the other iron formation bearing greenstone belt. Structurally these area is divided four units. Wadi was divided by right-lateral strike-ship fault. The displacement are more than 3 km. Also north dipping faults are identified.East-West trend fault are divided two units. It is divided NE, SE, NW and NS units.SW unit is most well preserved thick sequence of the Iron formation. SW unit is well preserved iron formation sequence within thick volcaniclastics. This unit mostly north dipping around 40-60 degree. Structural repetition in not well understand. Reconstract stratigraphy in this unit is at least 4000m in thickness. 5 member is identified in this sequence. Several thin iron formations are observed with in pillow lava and volcaniclastic sequence. These very thick

  15. Formation Of Antifriction And Wear-Proof Coatings By Heterogeneous Arc Plasma

    NASA Astrophysics Data System (ADS)

    Smyaglikov, I. P.; Chubrik, N. I.; Kuznechik, O. O.; Minko, D. V.

    2010-07-01

    Formation of coatings of the various functionality on electrode-detail while injecting of metal particles in plasma flow of short argon arc is considered. The possibility of formation both antifriction and wear-proof dense coatings, which have a metallurgical bond with a base, is shown.

  16. Pore size and pore throat types in a heterogeneous dolostone reservoir, Devonian Grosmont formation, western Canada sedimentary basin

    SciTech Connect

    Luo, P.; Machel, H. G.

    1995-11-01

    The Devonian Grosmont Formation in northeastern Alberta, Canada, is a giant heavy-oil reservoir. The main reservoir rocks are dolomitized and karstified platform and ramp carbonates, and the best reservoir facies occur in the upper Grosmont (UGM) units 3 and 2. In these units, reservoir properties are highly heterogeneous. Hand specimen, thin section, UV, and SEM petrography, as well as grading scales, mercury capillary pressure curve analysis, and statistics, have been used to characterize reservoir heterogeneity. Our investigation led to a new pore size classification for carbonate reservoirs; this new classification has four pore sizes: microporosity (pore diameters <1 {mu}m), mesoporosity (pore diameters 1-1000 {mu}m), macroporosity (pore diameters 1-256 mm), and megaporosity (pore diameters >256 mm). A combination of microscopic observations and capillary pressure curve characteristics led to the recognition of four pore throat texture types on the microporosity scale, and to five types on the mesoporosity scale. Microporosity pore types include (1) intracrystal dissolution porosity, (2) pervasive intercrystal and intracrystal dissolution porosity, (3) intergranular and/or intercrystal porosity in grainstones, and (4) primary or solution microporosity in mud matrix (only in limestones). Mesoporosity pore types include (1) intercrystal porosity, (2) solution-enhanced intercrystal porosity, (3) oversized porosity, (4) intragranular solution porosity, and (5) intergranular solution porosity. Some of these types are homogeneous (e.g., non-fabric selective dissolution porosity and intercrystal primary porosity), whereas others are heterogeneous. Generally, hydrocarbon recovery efficiency is good in the homogeneous pore throat types, but poor in the heterogeneous types.

  17. Integrated radionuclide transport model for a high-level waste repository in water-saturated geologic formations

    SciTech Connect

    Ahn, J.

    1998-01-01

    Presented are results of a mathematical analysis on radionuclide transport in parallel planar fractures in water-saturated geologic formations integrated with the source term model, where precipitation of hardly soluble species at the waste-form alteration location and subsequent radionuclide transport in the engineered barriers are considered. Radioactive decay chains of an arbitrary length are considered. A computer code has been developed based on the analytical solutions. With a transport distance of 100 m through the natural barrier, a four-orders-of-magnitude reduction in the total hazard is observed. Thus, the importance of the region in the vicinity of the engineered barriers in the context of the safety assessment can be pointed out. Because the region is disturbed by repository construction, further analysis must be performed by taking into account differing geochemical, hydrological, and mechanical properties from those in the undisturbed host rock. Because the major contributors in the host rock are the decay daughters of minor actinides, recovery of minor actinides reduces the total hazard evaluated at the exit of the geosphere. However, the radiological hazard would be reduced much more effectively by the 100-m-thick geologic formation around the repository than by even a 99% recovery of the actinides.

  18. Multiscale heterogeneity characterization of tidal channel, tidal delta and foreshore facies, Almond Formation outcrops, Rock Springs uplift, Wyoming

    SciTech Connect

    Schatzinger, R.A.; Tomutsa, L.

    1997-08-01

    In order to accurately predict fluid flow within a reservoir, variability in the rock properties at all scales relevant to the specific depositional environment needs to be taken into account. The present work describes rock variability at scales from hundreds of meters (facies level) to millimeters (laminae) based on outcrop studies of the Almond Formation. Tidal channel, tidal delta and foreshore facies were sampled on the eastern flank of the Rock Springs uplift, southeast of Rock Springs, Wyoming. The Almond Fm. was deposited as part of a mesotidal Upper Cretaceous transgressive systems tract within the greater Green River Basin. Bedding style, lithology, lateral extent of beds of bedsets, bed thickness, amount and distribution of depositional clay matrix, bioturbation and grain sorting provide controls on sandstone properties that may vary more than an order of magnitude within and between depositional facies in outcrops of the Almond Formation. These features can be mapped on the scale of an outcrop. The products of diagenesis such as the relative timing of carbonate cement, scale of cemented zones, continuity of cemented zones, selectively leached framework grains, lateral variability of compaction of sedimentary rock fragments, and the resultant pore structure play an equally important, although less predictable role in determining rock property heterogeneity. A knowledge of the spatial distribution of the products of diagenesis such as calcite cement or compaction is critical to modeling variation even within a single facies in the Almond Fin. because diagenesis can enhance or reduce primary (depositional) rock property heterogeneity. Application of outcrop heterogeneity models to the subsurface is greatly hindered by differences in diagenesis between the two settings. The measurements upon which this study is based were performed both on drilled outcrop plugs and on blocks.

  19. The impact of mantle heterogeneity on oceanic core complex formation, 12-16°N, Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Barnard, A.; Casey, J. F.; Chang, T.; Murton, B. J.

    2012-12-01

    The 12-16°N segment of the Mid-Atlantic Ridge has two fundamentally different modes of seafloor spreading: symmetric and asymmetric. The central part of this segment (~14°N) is characterized by continuous axial rift valleys flanked by normal faults with high length/displacement ratios. In contrast, crust that has spread asymmetrically within this segment features shorter fault scarp lengths, outward tilted surfaces, nodal basins, discontinuous neovolcanic zones and has a more irregular bathymetric character. Asymmetric spreading is a result of amagmatic tectonic extension and is accommodated by very-large-offset low-angle normal faults. These faults expose a complete section through the mafic crust to serpentinized mantle on the seafloor. Collectively, tectonic, magmatic and hydrothermal processes lead to the formation and character of oceanic core complexes. Dredged peridotites from this region are predominantly harzburgites. Electron microprobe analyses of accessory chromian spinel suggest at least 16 to 20% melt extraction preceded their exposure. However, it is difficult to reconcile the high melt volumes implied by the peridotite with thin, absent, and asymmetrically spreading crust. This evidence supports our prior suggestions that magma supply, and oceanic core complex formation, within these ridge segments is controlled by mantle heterogeneities. Heterogeneities may include, but are not limited to, garnet-pyroxenite sources that produce high volume melts and ultra-depleted mantle that produce little melt. Large segments of the mantle are likely receiving a free ride to the surface without significant melting in the region.

  20. Saharan dust and heterogeneous ice formation: Eleven years of cloud observations at a central European EARLINET site

    NASA Astrophysics Data System (ADS)

    Seifert, P.; Ansmann, A.; Mattis, I.; Wandinger, U.; Tesche, M.; Engelmann, R.; Müller, D.; PéRez, C.; Haustein, K.

    2010-10-01

    More than 2300 observed cloud layers were analyzed to investigate the impact of aged Saharan dust on heterogeneous ice formation. The observations were performed with a polarization/Raman lidar at the European Aerosol Research Lidar Network site of Leipzig, Germany (51.3°N, 12.4°E) from February 1997 to June 2008. The statistical analysis is based on lidar-derived information on cloud phase (liquid water, mixed phase, ice cloud) and cloud top height, cloud top temperature, and vertical profiles of dust mass concentration calculated with the Dust Regional Atmospheric Modeling system. Compared to dust-free air masses, a significantly higher amount of ice-containing clouds (25%-30% more) was observed for cloud top temperatures from -10°C to -20°C in air masses that contained mineral dust. The midlatitude lidar study is compared with our SAMUM lidar study of tropical stratiform clouds at Cape Verde in the winter of 2008. The comparison reveals that heterogeneous ice formation is much stronger over central Europe and starts at higher temperatures than over the tropical station. Possible reasons for the large difference are discussed.

  1. Chemical composition and geologic history of saline waters in Aux Vases and Cypress Formations, Illinois Basin

    USGS Publications Warehouse

    Demir, I.; Seyler, B.

    1999-01-01

    Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/mL of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.

  2. Geology, structure and age of the Nahuel Niyeu Formation in the Aguada Cecilio area, North Patagonian Massif, Argentina

    NASA Astrophysics Data System (ADS)

    Greco, Gerson A.; González, Pablo D.; González, Santiago N.; Sato, Ana M.; Basei, Miguel A. S.; Tassinari, Colombo C. G.; Sato, Kei; Varela, Ricardo; Llambías, Eduardo J.

    2015-10-01

    The low-grade Nahuel Niyeu Formation in the Aguada Cecilio area (40°50‧S-65°53‧W) shows ultramafic to felsic metaigneous rocks forming a sill swarm intercalated in the metasedimentary sequence and a polyphase deformation which permit an integrated study of the magmatic and tectonometamorphic evolution of this geological unit. In this paper we present a geological characterization of the Nahuel Niyeu Formation in the Aguada Cecilio area combining mapping, structural and metamorphic analysis with a SHRIMP U-Pb age and geochemical data from the metaigneous rocks. The metasedimentary sequence consists of alternating metagreywackes and phyllites, and minor metasandstones and granule metaconglomerates. The sills are pre-kinematic intrusions and yielded one SHRIMP U-Pb, zircon crystallization age of 513.6 ± 3.3 Ma. Their injection occurred after consolidation of the sedimentary sequence. A syn-sedimentary volcanic activity is interpreted by a metaandesite lava flow interlayered in the metasedimentary sequence. Sedimentary and igneous protoliths of the Nahuel Niyeu Formation would have been formed in a continental margin basin associated with active magmatic arc during the Cambrian Epoch 2. Two main low-grade tectonometamorphic events affected the Nahuel Niyeu Formation, one during the Cambrian Epoch 2-Early Ordovician and the other probably in the late Permian at ˜260 Ma. Local late folds could belong to the final stages of the late Permian deformation or be even younger. In a regional context, the Nahuel Niyeu and El Jagüelito formations and Mina Gonzalito Complex show a comparable Cambrian-Ordovician evolution related to the Terra Australis Orogen in the south Gondwana margin. This evolution is also coeval with the late and early stages of the Pampean and Famatinian orogenies of Central Argentina, respectively. The late Permian event recorded in the Nahuel Niyeu Formation in Aguada Cecilio area is identified by comparable structures affecting the Mina Gonzalito

  3. Is it possible to use different data types and scales to reduce flow and transport uncertainty in natural heterogeneous formations? The experimental setup of the Settolo aquifer (Italy)

    NASA Astrophysics Data System (ADS)

    Camporese, M.; Salandin, P.; Darvini, G.; Durigon, R.; Pizzaia, P.

    2009-12-01

    The uncertainty characterizing the description of hydraulic properties of aquifers, together with those implied in the process modeling and measurement errors, can be successfully dealt with by stochastic approaches, which allow the interpretation and the prediction of flow and transport processes in natural heterogeneous formations. The practical application of these approaches still encounters many difficulties, mainly due to the need for a detailed hydrogeological characterization of the site and to the unsuitability of the models, sometimes related to simplistic schematizations when describing in random terms the aquifer and its processes. The need to describe the spatial joint probability distribution of the hydraulic properties at different scales demands a large amount of data, to be obtained by several in situ and laboratory measurements. Moreover, modeling of these processes is often limited by the hypotheses of statistical homogeneity of the flow field and ergodicity of the dispersive process. These approaches are not suitable for the cases of practical interest, where the finite domain is characterized by irregular shapes and the flow field can be highly non-homogeneous, due to the influence of the boundary conditions, the presence of localized pumpings or inflows, or the lack of spatial stationarity of the hydraulic conductivity. Such circumstances emerge clearly in the real case of Settolo, an alluvial phreatic aquifer in a piedmont area of Northeastern Italy, where the effects related to the variability of the geological structures crossed by paleo-riverbeds and characterized by different facies, to the interactions between watercourses and the aquifer, to the recharge linked to the precipitation, and to the correct interpretation of concentration measurements of solutes must be challenged for an effective protection and/or a sustainable exploitation of the water resources. For these reasons, a careful site characterization is in progress, with a

  4. Simulating Geologic Co-sequestration of Carbon Dioxide and Hydrogen Sulfide in a Basalt Formation

    SciTech Connect

    Bacon, Diana H.; Ramanathan, Ramya; Schaef, Herbert T.; McGrail, B. Peter

    2014-01-15

    Co-sequestered CO2 with H2S impurities could affect geologic storage, causing changes in pH and oxidation state that affect mineral dissolution and precipitation reactions and the mobility of metals present in the reservoir rocks. We have developed a variable component, non-isothermal simulator, STOMP-COMP (Water, Multiple Components, Salt and Energy), which simulates multiphase flow gas mixtures in deep saline reservoirs, and the resulting reactions with reservoir minerals. We use this simulator to model the co-injection of CO2 and H2S into brecciated basalt flow top. A 1000 metric ton injection of these supercritical fluids, with 99% CO2 and 1% H2S, is sequestered rapidly by solubility and mineral trapping. CO2 is trapped mainly as calcite within a few decades and H2S is trapped as pyrite within several years.

  5. Spatial niche formation but not malignant progression is a driving force for intratumoural heterogeneity

    PubMed Central

    Hoefflin, Rouven; Lahrmann, Bernd; Warsow, Gregor; Hübschmann, Daniel; Spath, Cathleen; Walter, Britta; Chen, Xin; Hofer, Luisa; Macher-Goeppinger, Stephan; Tolstov, Yanis; Korzeniewski, Nina; Duensing, Anette; Grüllich, Carsten; Jäger, Dirk; Perner, Sven; Schönberg, Gita; Nyarangi-Dix, Joanne; Isaac, Sanjay; Hatiboglu, Gencay; Teber, Dogu; Hadaschik, Boris; Pahernik, Sascha; Roth, Wilfried; Eils, Roland; Schlesner, Matthias; Sültmann, Holger; Hohenfellner, Markus; Grabe, Niels; Duensing, Stefan

    2016-01-01

    Intratumoural heterogeneity (ITH) is a major cause of cancer-associated lethality. Extensive genomic ITH has previously been reported in clear cell renal cell carcinoma (ccRCC). Here we address the question whether ITH increases with malignant progression and can hence be exploited as a prognostic marker. Unexpectedly, precision quantitative image analysis reveals that the degree of functional ITH is virtually identical between primary ccRCCs of the lowest stage and advanced, metastatic tumours. Functional ITH was found to show a stage-independent topological pattern with peak proliferative and signalling activities almost exclusively in the tumour periphery. Exome sequencing of matching peripheral and central primary tumour specimens reveals various region-specific mutations. However, these mutations cannot directly explain the zonal pattern suggesting a role of microenvironmental factors in shaping functional ITH. In conclusion, our results indicate that ITH is an early and general characteristic of malignant growth rather than a consequence of malignant progression. PMID:27291893

  6. A case of type I polar stratospheric cloud formation by heterogeneous nucleation

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Ferry, G. V.; Snetsinger, K. G.; Goodman, J.; Dye, J. E.; Baumgardner, D.; Gandrud, B. W.

    1992-01-01

    The NASA ER-2 aircraft flew on January 24, 1989, from Stavanger to Spitsbergen, Norway, at the 430-440 K potential temperature surface (19.2-19.8 km pressure altitude). Aerosols were sampled continuously by an optical particle counter (PMS-FSSP300) for concentration and size analyses, and during five 10-min intervals by four wire and one replicator impactor for concentration, size, composition, and phase analysis. During sampling, the air saturation of H2O with respect to ice changed from 20 to 100 percent, and of HNO3 with respect to nitric acid trihydrate (NAT) from subsaturation to supersaturation. Data from both instruments indicate a condensation of hydrochloric acid and, later, nitric acid on the background aerosol particles as the ambient temperature decreases along the flight track. This heterogeneous nucleation mechanism generates type I polar stratospheric cloud particles of 10-fold enhanced optical depth, which could play a role in stratospheric ozone depletion.

  7. Spatial niche formation but not malignant progression is a driving force for intratumoural heterogeneity.

    PubMed

    Hoefflin, Rouven; Lahrmann, Bernd; Warsow, Gregor; Hübschmann, Daniel; Spath, Cathleen; Walter, Britta; Chen, Xin; Hofer, Luisa; Macher-Goeppinger, Stephan; Tolstov, Yanis; Korzeniewski, Nina; Duensing, Anette; Grüllich, Carsten; Jäger, Dirk; Perner, Sven; Schönberg, Gita; Nyarangi-Dix, Joanne; Isaac, Sanjay; Hatiboglu, Gencay; Teber, Dogu; Hadaschik, Boris; Pahernik, Sascha; Roth, Wilfried; Eils, Roland; Schlesner, Matthias; Sültmann, Holger; Hohenfellner, Markus; Grabe, Niels; Duensing, Stefan

    2016-01-01

    Intratumoural heterogeneity (ITH) is a major cause of cancer-associated lethality. Extensive genomic ITH has previously been reported in clear cell renal cell carcinoma (ccRCC). Here we address the question whether ITH increases with malignant progression and can hence be exploited as a prognostic marker. Unexpectedly, precision quantitative image analysis reveals that the degree of functional ITH is virtually identical between primary ccRCCs of the lowest stage and advanced, metastatic tumours. Functional ITH was found to show a stage-independent topological pattern with peak proliferative and signalling activities almost exclusively in the tumour periphery. Exome sequencing of matching peripheral and central primary tumour specimens reveals various region-specific mutations. However, these mutations cannot directly explain the zonal pattern suggesting a role of microenvironmental factors in shaping functional ITH. In conclusion, our results indicate that ITH is an early and general characteristic of malignant growth rather than a consequence of malignant progression. PMID:27291893

  8. The formation and functional consequences of heterogeneous mitochondrial distributions in skeletal muscle.

    PubMed

    Pathi, B; Kinsey, S T; Howdeshell, M E; Priester, C; McNeill, R S; Locke, B R

    2012-06-01

    Diffusion plays a prominent role in governing both rates of aerobic metabolic fluxes and mitochondrial organization in muscle fibers. However, there is no mechanism to explain how the non-homogeneous mitochondrial distributions that are prevalent in skeletal muscle arise. We propose that spatially variable degradation with dependence on O(2) concentration, and spatially uniform signals for biogenesis, can account for observed distributions of mitochondria in a diversity of skeletal muscle. We used light and transmission electron microscopy and stereology to examine fiber size, capillarity and mitochondrial distribution in fish red and white muscle, fish white muscle that undergoes extreme hypertrophic growth, and four fiber types in mouse muscle. The observed distributions were compared with those generated using a coupled reaction-diffusion/cellular automata (CA) mathematical model of mitochondrial function. Reaction-diffusion analysis of metabolites such as oxygen, ATP, ADP and PCr involved in energy metabolism and mitochondrial function were considered. Coupled to the reaction-diffusion approach was a CA approach governing mitochondrial life cycles in response to the metabolic state of the fiber. The model results were consistent with the experimental observations and showed higher mitochondrial densities near the capillaries because of the sometimes steep gradients in oxygen. The present study found that selective removal of mitochondria in the presence of low prevailing local oxygen concentrations is likely the primary factor dictating the spatial heterogeneity of mitochondria in a diversity of fibers. The model results also suggest decreased diffusional constraints corresponding to the heterogeneous mitochondrial distribution assessed using the effectiveness factor, defined as the ratio of the reaction rate in the system with finite rates of diffusion to that in the absence of any diffusion limitation. Thus, the non-uniform distribution benefits the muscle

  9. The secondary formation of inorganic aerosols in the droplet mode through heterogeneous aqueous reactions under haze conditions

    NASA Astrophysics Data System (ADS)

    Wang, Xinfeng; Wang, Wenxing; Yang, Lingxiao; Gao, Xiaomei; Nie, Wei; Yu, Yangchun; Xu, Pengju; Zhou, Yang; Wang, Zhe

    2012-12-01

    Secondary inorganic aerosols play important roles in visibility reduction and in regional haze pollution. To investigate the characteristics of size distributions of secondary sulfates and nitrates as well as their formation mechanisms under hazes, size-resolved aerosols were collected using a Micro-Orifice Uniform Deposit Impactor (MOUDI) at an urban site in Jinan, China, in all four seasons (December 2007-October 2008). In haze episodes, the secondary sulfates and nitrates primarily formed in fine particles, with elevated concentration peaks in the droplet mode (0.56-1.8 μm). The fine sulfates and nitrates were completely neutralized by ammonia and existed in the forms of (NH4)2SO4 and NH4NO3, respectively. The secondary formation of sulfates, nitrates and ammonium (SNA) was found to be related to heterogeneous aqueous reactions and was largely dependent on the ambient humidity. With rising relative humidity, the droplet-mode SNA concentration, the ratio of droplet-mode SNA to the total SNA, the fraction of SNA in droplet-mode particles and the mass median aerodynamic diameter of SNA presented an exponential, logarithmic or linear increase. Two heavily polluted multi-day haze episodes in winter and summer were analyzed in detail. The secondary sulfates were linked to heterogeneous uptake of SO2 followed by the subsequent catalytic oxidation by oxygen together with iron and manganese in winter. The fine nitrate formation was strongly associated with the thermodynamic equilibrium among NH4NO3, gaseous HNO3 and NH3, and showed different temperature-dependences in winter and summer.

  10. Geologic structure and altitude of the top of the Minnelusa Formation, northeastern Black Hills, South Dakota

    USGS Publications Warehouse

    Peter, Kathy D.; Kyllonen, David P.; Mills, Kathy R.

    1988-01-01

    This map shows the altitude of the top of the Permian--and Pennsylvanian age Minnelusa Formation, the deepest aquifer in the northeastern Black Hills for which there is sufficient data available to construct a structural map. The Minnelusa Formation outcrops in the western part of the map area and is more than 3 ,600 ft below land surface in the northeastern corner of the area. The formation consists of interbedded sandstone, sandy dolomite and limestone, shale, siltstone, gypsum, and anhydrite. The upper beds are an aquifer and the lower beds are a confining or semi-confining unit. Small anticlines and synclines parallel the Minnelusa outcrop. Domal structures and peaks in the study area are the result of Tertiary-age intrusions. (USGS)

  11. Geological Sequestration of CO2 by Hydrous Carbonate Formation with Reclaimed Slag

    SciTech Connect

    Von L. Richards; Kent Peaslee; Jeffrey Smith

    2008-02-06

    The concept of this project is to develop a process that improves the kinetics of the hydrous carbonate formation reaction enabling steelmakers to directly remove CO2 from their furnace exhaust gas. It is proposed to bring the furnace exhaust stream containing CO2 in contact with reclaimed steelmaking slag in a reactor that has an environment near the unit activity of water resulting in the production of carbonates. The CO2 emissions from the plant would be reduced by the amount sequestered in the formation of carbonates. The main raw materials for the process are furnace exhaust gases and specially prepared slag.

  12. Inventory of Shale Formations in the US, Including Geologic, Hydrological, and Mechanical Characteristics

    SciTech Connect

    Dobson, Patrick; Houseworth, James

    2013-11-22

    The objective of this report is to build upon previous compilations of shale formations within many of the major sedimentary basins in the US by developing GIS data delineating isopach and structural depth maps for many of these units. These data are being incorporated into the LANL digital GIS database being developed for determining host rock distribution and depth/thickness parameters consistent with repository design. Methods were developed to assess hydrological and geomechanical properties and conditions for shale formations based on sonic velocity measurements.

  13. Coupling geothermal energy capture with carbon dioxide sequestration in naturally permeable, porous geologic formations -- a novel approach for expanding geothermal energy utilization

    NASA Astrophysics Data System (ADS)

    Randolph, Jimmy Bryan

    This thesis research presents a new method to harness geothermal energy by combining it with geologic carbon dioxide (CO2) sequestration. CO2 is injected into deep, naturally porous and permeable geologic formations. The geothermally heated CO2 is piped to the surface, used to produce electricity, and then returned to the subsurface. This new approach represents a radical shift in electric/heat power generation as it not only utilizes a renewable energy source but has a negative carbon footprint. This research explores the potential and applicability of the approach and related aspects of geologic fluid and heat flow.

  14. Phase 1 user instruction manual. A geological formation - drill string dynamic interaction finite element program (GEODYN)

    SciTech Connect

    Tinianow, M.A.; Rotelli, R.L. Jr.; Baird, J.A.

    1984-06-01

    User instructions for the GEODYN Interactive Finite Element Computer Program are presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit - Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates non-linear, time dependent, loading and boundary conditions.

  15. Geological formation - drill string dynamic interaction finite-element program (GEODYN). Phase 1. Theoretical description

    SciTech Connect

    Baird, J.A.; Apostal, M.C.; Rotelli, R.L. Jr.; Tinianow, M.A.; Wormley, D.N.

    1984-06-01

    The Theoretical Description for the GEODYN interactive finite-element computer program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates nonlinear, time-dependent, loading and boundary conditions.

  16. Evaluation of the geological relationships to gas hydrate formation and stability

    SciTech Connect

    Krason, J.; Finley, P.

    1988-01-01

    The summaries of regional basin analyses document that potentially economic accumulations of gas hydrates can be formed in both active and passive margin settings. The principal requirement for gas hydrate formation in either setting is abundant methane. Passive margin sediments with high sedimentation rates and sufficient sedimentary organic carbon can generate large quantities of biogenic methane for hydrate formation. Similarly, active margin locations near a terrigenous sediment source can also have high methane generation potential due to rapid burial of adequate amounts of sedimentary organic matter. Many active margins with evidence of gas hydrate presence correspond to areas subject to upwelling. Upwelling currents can enhance methane generation by increasing primary productivity and thus sedimentary organic carbon. Structural deformation of the marginal sediments at both active and passive sites can enhance gas hydrate formation by providing pathways for migration of both biogenic and thermogenic gas to the shallow gas hydrate stability zone. Additionally, conventional hydrocarbon traps may initially concentrate sufficient amounts of hydrocarbons for subsequent gas hydrate formation.

  17. Formation of fold and thrust belts on Venus due to horizontal shortening of a laterally heterogeneous lithosphere

    NASA Technical Reports Server (NTRS)

    Zuber, M. T.; Parmentier, E. M.; Neumann, G. A.

    1994-01-01

    An outstanding question relevant to understanding the tectonics of Venus is the mechanism of formation of fold and thrust belts, such as the mountain belts that surround Lakshmi Planum in western Ishtar Terra. These structures are typically long (hundreds of km) and narrow (many tens of km), and are often located at the margins of relatively high (km-scale) topographic rises. Previous studies have attempted to explain fold and thrust belts in various areas of Venus in the context of viscous and brittle wedge theory. However, while wedge theory can explain the change in elevation from the rise to the adjacent lowland, it fails to account for a fundamental aspect of the deformation, i.e., the topographic high at the edge of the rise. In this study we quantitatively explore the hypothesis that fold and thrust belt morphology on Venus can alternatively be explained by horizontal shortening of a lithosphere that is laterally heterogeneous, due either to a change in thickness of the lithosphere or the crust. Lateral heterogeneities in lithosphere structure may arise in response to thermal thinning or extensive faulting, while variations in crustal thickness may arise due to either spatially variable melting of mantle material or by horizontal shortening of the crust. In a variable thickness lithosphere or crust that is horizontally shortened, deformation will tend to localize in the vicinity of thickness heterogeneity, resulting in a higher component of dynamic topography there as compared to elsewhere in the shortening lithosphere. This mechanism may thus provide a simple explanation for the topographic high at the edge of the rise.

  18. Geology and hydrocarbon potential of Dawson Bay Formation carbonate unit (Middle Devonian), Williston basin, North Dakota

    SciTech Connect

    Pound, W.

    1988-07-01

    The Middle Devonian Dawson Bay Formation carbonate unit is present in the subsurface of North Dakota except where truncated by postdepositional erosion. The carbonate unit thickens from the erosional limit to a maximum thickness of 47.5 m (156 ft) in Renville County and reaches a maximum depth of 3798 m (12,460 ft) below the surface in McKenzie County. In North Dakota, a submarine hardground separates the carbonate unit from the underlying second red bed member of the Dawson Bay Formation. The upper contact with the Souris River Formation is conformable except in those areas where the Dawson Bay Formation was exposed to subaerial erosion prior to deposition of the Souris River sediments. The Dawson Bay carbonate unit is predominantly dolomitic and fossiliferous limestone or fossiliferous dolostone. The carbonate unit can be subdivided into five lithofacies on the basis of characteristic fossil fauna, flora, and other lithologic features. Lithofacies analysis of the Dawson Bay carbonates suggests a shallowing-upward succession of depositional environments and associated energy zones as follows: shallow epeiric sea (very low energy), stromatoporoid biostrome/bioherm (low energy), very shallow epeiric sea (very low energy), restricted shallow epeiric sea (extremely low energy), and shallow epeiric sea shoreline (variable energy). Eogenetic diagenesis includes color-mottling, dolomitization of micrite to microcrystalline dolomite with penecontemporaneous anhydrite replacement of cryptalgal mudstones and boundstones, cementation by sparry calcite, and vuggy porosity development. Mesogenetic diagenesis includes formation of mosaic dolomites, cementation by blocky equant calcite, neomorphism, pressure-solution, fracturing, halite cementation, and hydrocarbon emplacement.

  19. Effects on the mobility of metals from acidification caused by possible CO₂ leakage from sub-seabed geological formations.

    PubMed

    de Orte, Manoela Romanó; Sarmiento, Aguasanta M; Basallote, Maria Dolores; Rodríguez-Romero, Araceli; Riba, Inmaculada; Delvalls, Angel

    2014-02-01

    Carbon dioxide capture and storage (CCS) in submarine geological formations has been proposed as a mitigation measure for the prevention of global warming. However, leakage of CO2 to overlying sediments may occur over time, leading to various effects on ecosystems. Laboratory-scale experiments were performed, involving direct release of carbon dioxide into sediment, inside non-pressurized chambers, in order to provide data on the possible effects of CO2 leakage from geological storage sites on the fate of several metals. Marine sediments from three sites with different levels of contamination were sampled and submitted to acidification by means of CO2 injection. The experiment lasted 10 days and sediment samples were collected at the beginning and end of the experiment and pore water was extracted for metal analysis. The results revealed that mobility of metals from sediment to pore water depends on the site, metal and length of time exposed. Mobilization of the metals Al, Fe, Zn, Co, Pb and Cu increases with acidification, and this response generally increases with time of exposure to CO2 injection. The geochemical model applied suggests that acidification also influences the speciation of metals, transforming metals and metalloids, like As, into species much more toxic to biota. The data obtained from this study will be useful for calculating the potential risk of CCS activities to the marine environment. PMID:24144940

  20. Heterogeneous chemistry: a mechanism missing in current models to explain secondary inorganic aerosol formation during the January 2013 haze episode in North China

    NASA Astrophysics Data System (ADS)

    Zheng, B.; Zhang, Q.; Zhang, Y.; He, K. B.; Wang, K.; Zheng, G. J.; Duan, F. K.; Ma, Y. L.; Kimoto, T.

    2015-02-01

    Severe regional haze pollution events occurred in eastern and central China in January 2013, which had adverse effects on the environment and public health. Extremely high levels of particulate matter with aerodynamic diameter of 2.5 μm or less (PM2.5) with dominant components of sulfate and nitrate are responsible for the haze pollution. Although heterogeneous chemistry is thought to play an important role in the production of sulfate and nitrate during haze episodes, few studies have comprehensively evaluated the effect of heterogeneous chemistry on haze formation in China by using the 3-D models due to of a lack of treatments for heterogeneous reactions in most climate and chemical transport models. In this work, the WRF-CMAQ model with newly added heterogeneous reactions is applied to East Asia to evaluate the impacts of heterogeneous chemistry and the meteorological anomaly during January 2013 on regional haze formation. As the parameterization of heterogeneous reactions on different types of particles is not well established yet, we arbitrarily selected the uptake coefficients from reactions on dust particles and then conducted several sensitivity runs to find the value that can best match observations. The revised CMAQ with heterogeneous chemistry not only captures the magnitude and temporal variation of sulfate and nitrate, but also reproduces the enhancement of relative contribution of sulfate and nitrate to PM2.5 mass from clean days to polluted haze days. These results indicate the significant role of heterogeneous chemistry in regional haze formation and improve the understanding of the haze formation mechanisms during the January 2013 episode.

  1. Formation and Geological Sequestration of Uranium Nanoparticles in Deep Granitic Aquifer

    PubMed Central

    Suzuki, Yohey; Mukai, Hiroki; Ishimura, Toyoho; Yokoyama, Takaomi D.; Sakata, Shuhei; Hirata, Takafumi; Iwatsuki, Teruki; Mizuno, Takashi

    2016-01-01

    The stimulation of bacterial activities that convert hexavalent uranium, U(VI), to tetravalent uranium, U(IV), appears to be feasible for cost-effective remediation of contaminated aquifers. However, U(VI) reduction typically results in the precipitation of U(IV) particles less than 5 nanometers in diameter, except for environmental conditions enriched with iron. Because these tiny particles are mobile and susceptible to oxidative dissolution after the termination of nutrient injection, in situ bioremediation remains to be impractical. Here we show that U(IV) nanoparticles of coffinite (U(SiO4)1−x(OH)4x) formed in fracture-filling calcium carbonate in a granitic aquifer. In situ U-Pb isotope dating demonstrates that U(IV) nanoparticles have been sequestered in the calcium carbonate for at least 1 million years. As the microbiologically induced precipitation of calcium carbonate in aquifer systems worldwide is extremely common, we anticipate simultaneous stimulation of microbial activities for precipitation reactions of calcium carbonate and U(IV) nanoparticles, which leads to long-term sequestration of uranium and other radionuclides in contaminated aquifers and deep geological repositories. PMID:26948389

  2. Geologic Controls on the Growth of Petroleum Reserves

    USGS Publications Warehouse

    Fishman, Neil S.; Turner, Christine E.; Peterson, Fred; Dyman, Thaddeus S.; Cook, Troy

    2008-01-01

    The geologic characteristics of selected siliciclastic (largely sandstone) and carbonate (limestone and dolomite) reservoirs in North America (largely the continental United States) were investigated to improve our understanding of the role of geology in the growth of petroleum reserves. Reservoirs studied were deposited in (1) eolian environments (Jurassic Norphlet Formation of the Gulf Coast and Pennsylvanian-Permian Minnelusa Formation of the Powder River Basin), (2) interconnected fluvial, deltaic, and shallow marine environments (Oligocene Frio Formation of the Gulf Coast and the Pennsylvanian Morrow Formation of the Anadarko and Denver Basins), (3) deeper marine environments (Mississippian Barnett Shale of the Fort Worth Basin and Devonian-Mississippian Bakken Formation of the Williston Basin), (4) marine carbonate environments (Ordovician Ellenburger Group of the Permian Basin and Jurassic Smackover Formation of the Gulf of Mexico Basin), (5) a submarine fan environment (Permian Spraberry Formation of the Midland Basin), and (6) a fluvial environment (Paleocene-Eocene Wasatch Formation of the Uinta-Piceance Basin). The connection between an oil reservoir's production history and geology was also evaluated by studying production histories of wells in disparate reservoir categories and wells in a single formation containing two reservoir categories. This effort was undertaken to determine, in general, if different reservoir production heterogeneities could be quantified on the basis of gross geologic differences. It appears that reserve growth in existing fields is most predictable for those in which reservoir heterogeneity is low and thus production differs little between wells, probably owing to relatively homogeneous fluid flow. In fields in which reservoirs are highly heterogeneous, prediction of future growth from infill drilling is notably more difficult. In any case, success at linking heterogeneity to reserve growth depends on factors in addition to

  3. An aqueous rechargeable formate-based hydrogen battery driven by heterogeneous Pd catalysis.

    PubMed

    Bi, Qing-Yuan; Lin, Jian-Dong; Liu, Yong-Mei; Du, Xian-Long; Wang, Jian-Qiang; He, He-Yong; Cao, Yong

    2014-12-01

    The formate-based rechargeable hydrogen battery (RHB) promises high reversible capacity to meet the need for safe, reliable, and sustainable H2 storage used in fuel cell applications. Described herein is an additive-free RHB which is based on repetitive cycles operated between aqueous formate dehydrogenation (discharging) and bicarbonate hydrogenation (charging). Key to this truly efficient and durable H2 handling system is the use of highly strained Pd nanoparticles anchored on graphite oxide nanosheets as a robust and efficient solid catalyst, which can facilitate both the discharging and charging processes in a reversible and highly facile manner. Up to six repeated discharging/charging cycles can be performed without noticeable degradation in the storage capacity. PMID:25382034

  4. Microbial growth and biofilm formation in geologic media is detected with complex conductivity measurements

    NASA Astrophysics Data System (ADS)

    Davis, Caroline A.; Atekwana, Estella; Atekwana, Eliot; Slater, Lee D.; Rossbach, Silvia; Mormile, Melanie R.

    2006-09-01

    Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and biofilms to sand surfaces. We conclude that complex conductivity techniques, specifically imaginary conductivity measurements are a proxy indicator for microbial growth and biofilm formation in porous media. Our results have implications for microbial enhanced oil recovery, CO2 sequestration, bioremediation, and astrobiology studies.

  5. Local-heterogeneous responses and transient dynamics of cage breaking and formation in colloidal fluids

    NASA Astrophysics Data System (ADS)

    Nag, Preetom; Teramoto, Hiroshi; Li, Chun-Biu; Terdik, Joseph Z.; Scherer, Norbert F.; Komatsuzaki, Tamiki

    2014-09-01

    Quantifying the interactions in dense colloidal fluids requires a properly designed order parameter. We present a modified bond-orientational order parameter, bar{ψ }6, to avoid problems of the original definition of bond-orientational order parameter. The original bond-orientational order parameter can change discontinuously in time but our modified order parameter is free from the discontinuity and, thus, it is a suitable measure to quantify the dynamics of the bond-orientational ordering of the local surroundings. Here we analyze bar{ψ }6 in a dense driven monodisperse quasi-two-dimensional colloidal fluids where a single particle is optically trapped at the center. The perturbation by the trapped and driven particle alters the structure and dynamics of the neighboring particles. This perturbation disturbs the flow and causes spatial and temporal distortion of the bond-orientational configuration surrounding each particle. We investigate spatio-temporal behavior of bar{ψ }6 by a Wavelet transform that provides a time-frequency representation of the time series of bar{ψ }6. It is found that particles that have high power in frequencies corresponding to the inverse of the timescale of perturbation undergo distortions of their packing configurations that result in cage breaking and formation dynamics. To gain insight into the dynamic structure of cage breaking and formation of bond-orientational ordering, we compare the cage breaking and formation dynamics with the underlying dynamical structure identified by Lagrangian Coherent Structures (LCSs) estimated from the finite-time Lyapunov exponent (FTLE) field. The LCSs are moving separatrices that effectively divide the flow into distinct regions with different dynamical behavior. It is shown that the spatial distribution of the FTLE field and the power of particles in the wavelet transform have positive correlation, implying that LCSs provide a dynamic structure that dominates the dynamics of cage breaking and

  6. The geology and mechanics of formation of the Fort Rock Dome, Yavapai County, Arizona

    USGS Publications Warehouse

    Fuis, Gary S.

    1996-01-01

    The Fort Rock Dome, a craterlike structure in northern Arizona, is the erosional product of a circular domal uplift associated with a Precambrian shear zone exposed within the crater and with Tertiary volcanism. A section of Precambrian to Quaternary rocks is described, and two Tertiary units, the Crater Pasture Formation and the Fort Rock Creek Rhyodacite, are named. A mathematical model of the doming process is developed that is consistent with the history of the Fort Rock Dome.

  7. Modeling the formation of polar stratospheric clouds with allowance for kinetic and heterogeneous processes

    NASA Astrophysics Data System (ADS)

    Aloyan, A. E.; Yermakov, A. N.; Arutyunyan, V. O.

    2015-05-01

    A new mathematical model of global transport of multicomponent gaseous admixtures and aerosols in the atmosphere and the formation of polar stratospheric clouds (PSC) in both hemispheres has been constructed. Two types of PSCs are considered: type Ia, nitric acid trihydrate (NAT), and type Ib, supercooled ternary solutions of H2SO4/HNO3/H2O (STS). New equations are used to describe the variation in gas- and condensed-phase components on the basis of their thermodynamic properties. The formation of PSCs is coupled with sulfate aerosols generated in the upper troposphere and lower stratosphere, and with chemical and kinetic transformation processes (photochemistry, nucleation, condensation/evaporation, and coagulation). Using this coupled model, numerical experiments were performed to reproduce the spatial and temporal variability of PSCs in winter in both hemispheres. First, the formation of primary sulfate aerosols in the atmosphere is considered and then these aerosols are incorporated to the PSC model. The results of the numerical experiments are analyzed.

  8. Spatial Heterogeneity and Imperfect Mixing in Chemical Reactions: Visualization of Density-Driven Pattern Formation

    DOE PAGESBeta

    Sobel, Sabrina G.; Hastings, Harold M.; Testa, Matthew

    2009-01-01

    Imore » mperfect mixing is a concern in industrial processes, everyday processes (mixing paint, bread machines), and in understanding salt water-fresh water mixing in ecosystems. The effects of imperfect mixing become evident in the unstirred ferroin-catalyzed Belousov-Zhabotinsky reaction, the prototype for chemical pattern formation. Over time, waves of oxidation (high ferriin concentration, blue) propagate into a background of low ferriin concentration (red); their structure reflects in part the history of mixing in the reaction vessel. However, it may be difficult to separate mixing effects from reaction effects. We describe a simpler model system for visualizing density-driven pattern formation in an essentially unmixed chemical system: the reaction of pale yellow Fe 3 + with colorless SCN − to form the blood-red Fe ( SCN ) 2 + complex ion in aqueous solution. Careful addition of one drop of Fe ( NO 3 ) 3 to KSCN yields striped patterns after several minutes. The patterns appear reminiscent of Rayleigh-Taylor instabilities and convection rolls, arguing that pattern formation is caused by density-driven mixing.« less

  9. Studies of the formation, chemical reactivity, and properties of small clusters: Application to an understanding of aerosol formation and heterogeneous chemistry

    SciTech Connect

    Castleman, A.W. Jr.

    1990-01-01

    The small cluster program involves (1) studies of reactions related to formation and growth of heteromolecular clusters and their thermochemical properties, (2) studies of photoinitiated processes in clusters, (3) investigations related to heterogeneous reactions including the influence of reaction centers on the interconversion, and (4) theoretical calculations of properties, dynamics, and structure. A major thrust of the work during the past year has been devoted to a study of the role of ionization and the presence of ions on reactions and energetics. During the past few months, particular attention has been paid to systems having varying proton affinities. From the data, we can determine the influence of these values on the nature of the reactions and ascertain the ultimate chemical nature of the ionization center formed as a result of the reactions. 83 refs., 12 figs., 2 tabs.

  10. Leveraging Regional Exploration to Develop Geologic Framework for CO2 Storage in Deep Formations in Midwestern United States

    SciTech Connect

    Neeraj Gupta

    2009-09-30

    Ohio River Valley corridor in the Appalachian Basin, which underlies large concentrations of CO{sub 2} emission sources. In addition, some wells in the Michigan basin are included. Assessment of the geologic and petrophysical properties of zones of interest has been conducted. Although a large number of formations have been evaluated across the geologic column, the primary focus has been on evaluating the Cambrian sandstones (Mt. Simon, Rose Run, Kerbel) and carbonates layers (Knox Dolomite) as well as on the Silurian-Devonian carbonates (Bass Island, Salina) and sandstones (Clinton, Oriskany, Berea). Factors controlling the development of porosity and permeability, such as the depositional setting have been explored. In northern Michigan the Bass Islands Dolomite appears to have favorable reservoir development. In west central Michigan the St. Peter sandstone exhibits excellent porosity in the Hart and Feuring well and looks promising. In Southeastern Kentucky in the Appalachian Basin, the Batten and Baird well provided valuable data on sequestration potential in organic shales through adsorption. In central and eastern Ohio and western West Virginia, the majority of the wells provided an insight to the complex geologic framework of the relatively little known Precambrian through Silurian potential injection targets. Although valuable data was acquired and a number of critical data gaps were filled through this effort, there are still many challenges ahead and questions that need answered. The lateral extent to which favorable potential injection conditions exist in most reservoirs is still generally uncertain. The prolongation of the characterization of regional geologic framework through partnership would continue to build confidence and greatly benefit the overall CO{sub 2} sequestration effort.

  11. Impact experiments onto heterogeneous targets and their interpretation in relation with formation of the asteroid families

    NASA Astrophysics Data System (ADS)

    Leliwa-Kopystynski, J.; Arakawa, M.

    2014-07-01

    Results of laboratory impact experiments, when extrapolated to the planetary scale of events, are aimed for better understanding of cratering and/or disruption of asteroids, satellites, and cometary nuclei. There is absolutely no reason to assume that these bodies are uniform rocky or icy monoliths. So, we studied reactions of the heterogeneous targets on the impacts. A series of impact experiments onto solid decimeter-sized cylinders made of porous gypsum mixed with approximately one-centimeter-sized pebbles have been performed. The mean density of the material of the targets was 1867 kg m^{-3}, the mean mass ratio (pebbles / gypsum) = 0.856 / 0.144, and the mean volume ratio (pebbles / gypsum / pores) = 0.585 / 0.116 / 0.299. The target densities and their heterogeneous structures could be representative of those of the asteroids Ida, Eros, and many others, because asteroid sub-surface volumes could be composed of consolidated boulders formed by self-compaction and/or by impact compaction. Impact velocities in the experiments ranged from 2.0 km/s to 6.7 km/s (collision velocity in the asteroid main belt is approximately 5 km/s). By means of weighting and counting the post-impact fragments, their distribution function was found. Let Q [J/kg] be the specific energy of impact per unit of the target mass. Of particular interest is the value of impact strength, that is, the specific energy of disruption Q^*, corresponding to the ratio (mass of the largest fragment) / (mass of the target) = m_l/M = 0.5, which is, by convention, the value separating the cratering events from the catastrophic disruption impacts. Mass or size distribution of the post-impact fragments is expressed by the power law N ∝ m^{-p} ∝ r^{-3p}, p=p(Q/Q^{*}) A parameter that can be measured in the laboratory is the exponent p. For the case of a swarm of asteroids forming an asteroid family, the observationally estimated value is not the exponent p but rather the exponent q = 3p, since the sizes

  12. Geologic map of the Peach Orchard Flat quadrangle, Carbon County, Wyoming, and descriptions of new stratigraphic units in the Upper Cretaceous Lance Formation and Paleocene Fort Union Formation, eastern Greater Green River Basin, Wyoming-Colorado

    USGS Publications Warehouse

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

    2004-01-01

    This report provides a geologic map of the Peach Orchard Flat 7.5-minute quadrangle, located along the eastern flank of the Washakie Basin, Wyo. Geologic formations and individual coal beds were mapped at a scale of 1:24,000; surface stratigraphic sections were measured and described; and well logs were examined to determine coal correlations and thicknesses in the subsurface. In addition, four lithostratigraphic units were named: the Red Rim Member of the Upper Cretaceous Lance Formation, and the China Butte, Blue Gap, and Overland Members of the Paleocene Fort Union Formation.

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

    SciTech Connect

    Ernest A. Mancini

    2002-09-25

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

  14. Geology of the Hanna Formation, Hanna Underground Coal Gasification Site, Hanna, Wyoming

    SciTech Connect

    Oliver, R.L.; Youngberg, A.D.

    1984-01-01

    The Hanna Underground Coal Gasification (UCG) study area consists of the SW1/4 of Section 29 and the E1/2SE1/4 of Section 30 in Township 22 North, Range 81 West, Wyoming. Regionally, this is located in the coal-bearing Hanna Syncline of the Hanna Basin in southeast Wyoming. The structure of the site is characterized by beds dipping gently to the northeast. An east-west fault graben complex interrupts this basic trend in the center of the area. The target coal bed of the UCG experiments was the Hanna No. 1 coal in the Hanna Formation. Sedimentary rocks comprising the Hanna Formation consist of a sequence of nonmarine shales, sandstones, coals and conglomerates. The overburden of the Hanna No. 1 coal bed at the Hanna UCG site was divided into four broad local stratigraphic units. Analytical studies were made on overburden and coal samples taken from cores to determine their mineralogical composition. Textural and mineralogical characteristics of sandstones from local stratigraphic units A, B, and C were analyzed and compared. Petrographic analyses were done on the coal including oxides, forms of sulfur, pyrite types, maceral composition, and coal rank. Semi-quantitative spectrographic and analytic geochemical analyses were done on the overburden and coal and relative element concentrations were compared. Trends within each stratigraphic unit were also presented and related to depositional environments. The spectrographic analysis was also done by lithotype. 34 references, 60 figures, 18 tables.

  15. Pore-scale study of capillary trapping mechanism during CO2 injection in geological formations

    SciTech Connect

    Bandara, Uditha C.; Tartakovsky, Alexandre M.; Palmer, Bruce J.

    2011-11-01

    Geological sequestration of CO{sub 2} gas emerged as a promising solution for reducing amount of green house gases in atmosphere. A number of continuum scale models are available to describe the transport phenomena of CO{sub 2} sequestration. These models rely heavily on a phenomenological description of subsurface transport phenomena and the predictions can be highly uncertain. Pore-scale models provide a better understanding of fluid displacement processes, nonetheless such models are rare. In this work we use a Smoothed Particle Hydrodynamics (SPH) model to study pore-scale displacement and capillary trapping mechanisms of super-critical CO{sub 2} in the subsurface. Simulations are carried out to investigate the effects of gravitational, viscous, and capillary forces in terms of Gravity, Capillary, and Bond numbers. Contrary to the other published continuum scale investigations, we found that not only Gravity number but also Capillary number plays an important role on the fate of injected CO{sub 2}. For large Gravity numbers (on the order of 10), most of the injected CO{sub 2} reaches the cap-rock due to gravity segregation. A significant portion of CO{sub 2} gets trapped by capillary forces when Gravity number is small (on the order of 0.1). When Gravity number is moderately high (on the order of 1), trapping patterns are heavily dependent on Capillary number. If Capillary number is very small (less than 0.001), then capillary forces dominate the buoyancy forces and a significant fraction of injected CO{sub 2} is trapped by the capillary forces. Conversely, if Capillary number is high (higher than 0.001), capillary trapping is relatively small since buoyancy dominates the capillary forces. In addition, our simulations reveal different types of capillary trapping and flow displacement mechanisms during and after injection. In gravity dominated cases leave behind was the widespread trapping mechanism. Division was the primary trapping mechanism in viscous

  16. The Fokker-Planck law of diffusion and pattern formation in heterogeneous environments.

    PubMed

    Bengfort, Michael; Malchow, Horst; Hilker, Frank M

    2016-09-01

    We analyze the influence of spatially inhomogeneous diffusion on several common ecological problems. Diffusion is modeled with Fick's law and the Fokker-Planck law of diffusion. We discuss the differences between the two formalisms and when to use either the one or the other. In doing so, we start with a pure diffusion equation, then turn to a reaction-diffusion system with one logistically growing component which invades the spatial domain. We also look at systems of two reacting components, namely a trimolecular oscillating chemical model system and an excitable predator-prey model. Contrary to Fickian diffusion, spatial inhomogeneities promote spatial and spatiotemporal pattern formation in case of Fokker-Planck diffusion. PMID:26803768

  17. The upper Bow Island (Blackleaf) Formation of southwestern Alberta: Geological aspects and exploration approaches

    SciTech Connect

    Putnam, P.E.; Christensen, S.L. )

    1991-06-01

    The upper parts of the Bow Island Formation (Albian) of southwestern Alberta are significant gas reservoirs. The main westernmost reservoir zone is part of a complex package of interbedded lenticular sandstones, mudstones, and localized chert pebble conglomerates. The depositional setting for these sediments comprised a wave-dominated shoreline with conglomerates found proximal to drowned river mouths. The coarse nature of the upper Bow Island is related to tectonic movements associated with Crowsnest (Vaughn) volcanism. Conglomerates form the most impressive Bow Island reservoirs because of their thickness (up to 25 m) and petrophysical properties (17% porosity, 24 d permeability). Diagenesis dominantly comprises compaction features within grain-supported conglomerates. Increasing quartz content is related to decreasing grain size and is associated with porosity occlusion by quartz overgrowths. Bow Island reservoirs in southwestern Alberta are cool (under 50C) and significantly underpressured (0.2 psi). The high permeabilities and low pressures at depths of 1,000 to 1,500 m suggest the potential for formation damage is high, and many wells in the region were targeted for deeper, high-pressure zones. In spite of the low pressures, however, many Bow Island wells are capable of excellent gas deliveries with individual well recoveries of up to 10 bcf. All significant Bow Island porosity in the deepest, undisturbed parts of southwestern Alberta is gas saturated with updip aquifers flanking the gas. Seismic definition of the thickest Bow Island targets is feasible but has been hampered, in part, by difficult surface conditions and a prior emphasis on deeper targets.

  18. Geologic controls on the formation of lakes in north-central Florida

    USGS Publications Warehouse

    Kindinger, Jack G.; Davis, Jeffrey B.; Flocks, James G.

    1998-01-01

    Fluid exchange between surficial waters and groundwater, as well as the processes that control this exchange, are of critical concern to water management districts and planners. Digital high-resolution seismic systems were used to collect geophysical data from 30 lakes of north-central Florida. Although using seismic profile data in the past has been less than successful, the use of digital technology has increased the potential for success. Seismic profiles collected from the lakes of north-central Florida have shown the potential application of these techniques in understanding the formation of individual lakes. In each case study, lake structure and geomorphology were controlled by solution and/or mechanical processes. Processes that control lake development are twofold: 1) karstification or dissolution of the underlying limestone, and 2) me collapse, subsidence, or slumping of overburden to form sinkholes. Initial lake formation is directly related to the karst topography of the underlying host limestone. Lake size and shape are a factor of the thickness of overburden and size of the collapse or subsidence and/or clustering of depressions allowing for lake development. Lake development is through progressive sequence stages to maturity that can be delineated into geomorphic types. Case studies have shown that lakes can be divided by geomorphic types into progressive developmental phases: (1) active subsidence or collapse phase (young) - the open to partially filled collapse structures typically associated with sink holes; (2) transitional phase (middle age) - the sinkhole is plugged as the voids within the collapse are filled with sediment, periodic reactivation may occur; (3) baselevel phase (mature) - active sinkholes are progressively plugged by the continual erosion of material into the basin, and eventually sediment fills the basins; and (4) polje (drowned prairie) - broad flat-bottom basins located within the epiphreatic zone that are inundated at high

  19. Formation of flower structures in a geological layer at a strike-slip displacement in the basement

    NASA Astrophysics Data System (ADS)

    Stefanov, Yu. P.; Bakeev, R. A.

    2015-07-01

    Formation of dislocations in a geological layer at a strike-slip displacement in its basement is studied by three-dimensional (3D) numerical modeling. It is shown that the pattern of strain localization is determined by the initial stress state or thickness of the deformed layer as well as by the Poisson ratio and strength of the medium. Three types of fracture zones are observed. Shear bands of the first type are dominated by the propeller-like surfaces of Riedel R-shears, which merge into a single main fault with feathering structures. In the second type of dislocation zones, the primary role is played by the surfaces oriented at an angle of ˜40° to the shear axis in the horizontal projections. After reaching the free surface, these discontinuities are cut by a V-shaped fault. In this case, the pattern of dislocations most closely corresponds to the flower structures. The third type is a trough, which may accommodate the formation of yet another strain localization zone along its axial part—a vertical fault.

  20. Geological and geochemical characterization of the Lower Cretaceous Pearsall Formation, Maverick Basin, south Texas: A future shale gas resource?

    USGS Publications Warehouse

    Hackley, Paul C.

    2012-01-01

    As part of an assessment of undiscovered hydrocarbon resources in the northern Gulf of Mexico onshore Mesozoic section, the U.S. Geological Survey (USGS) evaluated the Lower Cretaceous Pearsall Formation of the Maverick Basin, south Texas, as a potential shale gas resource. Wireline logs were used to determine the stratigraphic distribution of the Pearsall Formation and to select available core and cuttings samples for analytical investigation. Samples used for this study spanned updip to downdip environments in the Maverick Basin, including several from the current shale gas-producing area of the Pearsall Formation.The term shale does not adequately describe any of the Pearsall samples evaluated for this study, which included argillaceous lime wackestones from more proximal marine depositional environments in Maverick County and argillaceous lime mudstones from the distal Lower Cretaceous shelf edge in western Bee County. Most facies in the Pearsall Formation were deposited in oxygenated environments as evidenced by the presence of biota preserved as shell fragments and the near absence of sediment laminae, which is probably caused by bioturbation. Organic material is poorly preserved and primarily consists of type III kerogen (terrestrial) and type IV kerogen (inert solid bitumen), with a minor contribution from type II kerogen (marine) based on petrographic analysis and pyrolysis. Carbonate dominates the mineralogy followed by clays and quartz. The low abundance and broad size distribution of pyrite are consistent with the presence of oxic conditions during sediment deposition. The Pearsall Formation is in the dry gas window of hydrocarbon generation (mean random vitrinite reflectance values, Ro = 1.2–2.2%) and contains moderate levels of total organic carbon (average 0.86 wt. %), which primarily resides in the inert solid bitumen. Solid bitumen is interpreted to result from in-situ thermal cracking of liquid hydrocarbon generated from original type II kerogen

  1. Evaluation of the geological relationships to gas hydrate formation and stability

    SciTech Connect

    Not Available

    1985-01-01

    During the reported year we have enhanced our knowledge on and gained considerable experience in assessment of the gas hydrate resources in the offshore environments. Specifically, we have learned and gained experience in the following: Efficiently locating data sources, including published literature and unpublished information. We have established personal communication extremely critical in data accessability and acquisition. We have updated information pertinent to gas hydrate knowledge, also based on thorough study and evaluation of most Russian literature and additional publications in languages other than English. Besides critical evaluation of widely spread literature, in many cases our reports include previously unpublished information (e.g. BSRs from the Gulf of Mexico). The assessment of the gas resources potential associated with the gas hydrates, although in most cases at a low level of confidence, appears also very encouraging for further, more detailed, study. We are also confident that, because of the present reports' format, new data and a concept-oriented approach, the result of our study will be of strong interest to various industries, research institutions and numerous governmental agencies.

  2. Geochemical Characteristics and its Geological Significance of Oil Shale from the Youganwo Formation, Maoming Basin, China

    NASA Astrophysics Data System (ADS)

    Zhou, Yuanyuan; Qiu, Nansheng

    2016-04-01

    Geochemical elements of oil shale in the Maoming Basin were analyzed to discuss provenance attribute and depositional environment of the Youganwo formation. Experimental date of the major elements, trace elements and rare earth elements of 24 samples from the Maoye 1 well were examined.The analyzed oil shale samples were characterized by enrichment of Th, U, Pb and LREE, depleted of Zr, Cr and Hf,negative Eu and Ce anomalies, indicating that these samples were originated from continental crust. The chemical index of alteration (CIA) values and the Zr/Sc-Th/Sc diagrams indicate that source rocks had undergone intense chemical weathering and deposition recirculation. Based on the La/Th-Hf and La/Yb-∑REE diagrams and the negative anomaly of Eu element, the oil shale in the Maoming Basin has diverse sources, which mainly came from felsic source region of the upper crust or the mixture of felsic volcanic rocks, granite and sedimentary rocks. Ratios of the Sr/Cu, MgO/CaO suggest that oil shale was formed in fresh water under warm and humid climate, shallow water column became deeper during the middle and late sedimentary period. The depositional environment is interpreted to be limnetic with weak reduction at the early stage and gradually turned into semi-deep to deep lacustrine.

  3. Thermal Decomposition of Gaseous Ammonium Nitrate at Low Pressure: Kinetic Modeling of Product Formation and Heterogeneous Decomposition of Nitric Acid

    NASA Astrophysics Data System (ADS)

    Park, J.; Lin, M. C.

    2009-10-01

    The thermal decomposition of ammonium nitrate, NH4NO3 (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH4NO3 at 423 K was proposed to produce equal amounts of NH3 and HNO3, followed by the decomposition reaction of HNO3, HNO3 + M → OH + NO2 + M (where M = third-body and reactor surface). The absolute yields of N2, N2O, H2O, and NH3, which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH3-NO2 (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO3 itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO3 in our kinetic modeling. The heterogeneous decomposition rate of HNO3, HNO3 + (B2O3/SiO2) → OH + NO2 + (B2O3/SiO2), was determined by varying its rate to match the modeled result to the measured concentrations of NH3 and H2O; the rate could be represented by k2b = 7.91 × 107 exp(-12 600/T) s-1, which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO3 decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

  4. Relationship between Mineralogy and Porosity in Subsurface Formations Relevant to Geologic CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Cole, D. R.; Swift, A.; Sheets, J.; Welch, S.; Anovitz, L. M.; Rother, G.; Vlcek, L.

    2013-12-01

    Porosity and permeability are the key variables that link the thermal, hydrological, geochemical and geomechanical processes that redistribute mass and energy in response to injection of CO2 into the subsurface. The size, shape, distribution and connectivity of rock pores dictate how fluids migrate into and through these micro- and nanoenvironments, wet and react with the solid. The link between pore size distribution and connectivity and pore-wall mineralogy is still poorly constrained for both reservoir and caprocks.. The objectives of this effort are to characterize the nano- to macropore features, quantify mineral-specific reactive surface areas in both pore and fracture networks, and determine how pores and fractures evolve in reacted systems at temperature-pressure-composition conditions relevant to CO2 injection. Representative caprocks and reservoir rocks associated with CO2 injection activities (e.g. shallow buried quartz arenites from the St. Peter Sandstone and the deeper Mt. Simon sandstone in Ohio as well as the Eau Claire Formation shale and mudrocks) are being interrogated with an array of complementary methods - e.g. SEM, TEM, neutron scattering, X-ray CT, neutron tomography as well as conventional petrophysics. (Ultra)small-angle neutron scattering and autocorrelations derived from BSE imaging provide a powerful method of quantifying pore structures in a statistically significant manner from the nanometer to the centimeter scale. Results will be described comparing shale and mudrocks that indicate there are significant variations not only in terms of total nano- to micro-porosity and pore interconnectivity, but also in terms of pore surface fractal (roughness) and mass fractal (pore distributions) dimensions as well as size distributions. For tight formations we have observed that: (a) total porosity exhibiting bimodality may be typical of shale and mudstones, (b) connected porosity exhibiting bimodal tendencies may not be uncommon in shale and

  5. Geologic uses of formation microscanner (FMS) in Antelope Shale Cymric field, San Joaquin Valley, California

    SciTech Connect

    White, R.E.

    1989-04-01

    A comparison between formation microscanner (FMS) log and core from the Cymric field was made to determine the effectiveness of the FMS in characterizing the Antelope Shale. Comparisons of the FMS log and core were based on a detailed core description, petrography, scanning electron microscopy (SEM), and mineralogical analysis. Results indicate that the FMS log in the Antelope Shale is useful for (1) distinguishing between certain rock types, (2) determining bed thickness and bedding-plane orientations, and (3) detecting some fractures and determining some fracture-plane orientations. However, the FMS log shows some ambiguous responses that can be interpreted only by comparison with the core or other wireline logs. Based on resistivity contrasts, three rock-type groups can be distinguished. From least to most resistive, they are (1) mudstone, (2) argillaceous diatomite/Porcelanite, and (3) sandstone, dolostone, clay-poor porcelanite, and chert. A bed thickness of 1 cm or greater can be resolved using the FMS. Bedding-plane orientations can also be determined and provide a means to orient the core. Detection of fractures in the Antelope Shale is generally limited to those fractures within rock type that display intermediate ranges of resistivity and to the large-scale fractures. Fracture-plane orientations of some fractures can be determined; however, because of poor fracture development in the majority of Antelope Shale rock types, fractures are commonly not visible on both FMS-pad images. This makes determination of fracture-plane orientation difficult, if not impossible, for many of these fractures.

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

    SciTech Connect

    Ernest A. Mancini

    2003-09-25

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

  7. Preliminary modeling of the long-term fate of CO2 following injection into deep geological formations

    SciTech Connect

    Strazisar, B.R.; Shu, C.; Hedges, S.W.

    2006-03-01

    The injection of CO2 into deep saline aquifers is a potential option for greenhouse gas mitigation. However, several key issues, such as underground storage time and the fate of the injected CO2, must be studied before this option becomes economically and socially acceptable. In the current study, a one-dimensional reactive mass-transport model was used to predict the long-term chemical behavior of a deep saline aquifer following CO2 injection, far away from the injection site and representative of basin-scale migration and long-term fate. The dissolution of the injected CO2 into brine causes a sharp drop in pH, and consequently, the acidic brine aggressively reacts with aquifer minerals. Our model also predicts the dissolution of aluminosilicate minerals with the formation of secondary minerals and the precipitation and dissolution of carbonate minerals and is consistent with laboratory-scale CO2 core-flooding experiments. However, the extent and development of reaction fronts depend on the reaction rates used. For example, our modeling results indicate that the transport of carbon can be significantly retarded with respect to the flow of the brine itself, and a significant amount of injected CO2 is immobilized because of mineral trapping. The precise locations and patterns of the carbon reactive transport are sensitive to the reaction rates used, illustrating the need for improved knowledge of reaction kinetics, particularly the in-situ rates of dissolution and precipitation of aluminosilicate minerals, in evaluating mineral trapping of CO2 in deep geological formations.

  8. High-resolution photo geologic mapping of the Tuscan Formation cliffs in the BCCER and Upper Bidwell Park, Chico CA

    NASA Astrophysics Data System (ADS)

    gonzalez, M.; Greene, T.

    2013-12-01

    The Tuscan Formation rocks make up the uppermost cliffs of the Big Chico Creek Ecological Reserve (BCCER) and Upper Bidwell Park. These rocks are composed of 3.2 to 1.8 million year old tuffs, conglomerate and sandstone dominated by volcanic clasts, as well as siltstone and mudstone mostly derived from the ancient Mt. Yana volcanic complex near Lake Almanor. This study attempts to investigate stratal geometries of Tuscan deposits in the BCCER and Upper Bidwell Park by mapping stratigraphic sections and using high resolution aerial geologic photomosaics of the Tuscan rocks. In order to obtain the best perspective of the rocks, the photos have been taken directly perpendicular to the cliff face using a helicopter and high resolution photography. With these photos, detailed layering and features of the Tuscan, both in the breccia units and the interbedded fluvial units, can be detected. These 'head on' photos are the best way to see erosional surfaces, pinch-outs, and individual flow units. They can also be used to document how well these features correlate down-canyon. Additionally, aerial photos provide a foundation for recognizing larger scale features and trends which would otherwise go unnoticed (channel flow direction, cross-cutting flows). One example of these larger scale features are two larger debris flows at the top of the unit that are best seen by the aerial photos. By foot, these debris flows can be difficult to access because of steep terrain and vegetation cover. These photos will not only aid in the study of the Tuscan deposits, but will potentially benefit other research focused on the hydrology, ecology, or archeology of Upper Bidwell Park and the BCCER. The Tuscan Formation. Debris Flow layers can easily be mapped from high-resolution photos

  9. Effect of modeling factors on the dissolution-diffusion-convection process during CO2 geological storage in deep saline formations

    NASA Astrophysics Data System (ADS)

    Zhang, Wei

    2013-06-01

    It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells, consequently increasing permanence and security of storage. First, we investigated the effect of numerical perturbation caused by time and grid resolution and the convergence criteria on the dissolution-diffusion-convection (DDC) process. Then, using the model with appropriate spatial and temporal resolution, some uncertainty parameters investigated in our previous paper such as initial gas saturation and model boundaries, and other factors such as relative liquid permeability and porosity modification were used to examine their effects on the DDC process. Finally, we compared the effect of 2D and 3D models on the simulation of the DDC process. The above modeling results should contribute to clear understanding and accurate simulation of the DDC process, especially the onset of convective activity, and the CO2 dissolution rate during the convection-dominated stage.

  10. Site characterization of the highest-priority geologic formations for CO2 storage in Wyoming

    SciTech Connect

    Surdam, Ronald C.; Bentley, Ramsey; Campbell-Stone, Erin; Dahl, Shanna; Deiss, Allory; Ganshin, Yuri; Jiao, Zunsheng; Kaszuba, John; Mallick, Subhashis; McLaughlin, Fred; Myers, James; Quillinan, Scott

    2013-12-07

    This study, funded by U.S. Department of Energy National Energy Technology Laboratory award DE-FE0002142 along with the state of Wyoming, uses outcrop and core observations, a diverse electric log suite, a VSP survey, in-bore testing (DST, injection tests, and fluid sampling), a variety of rock/fluid analyses, and a wide range of seismic attributes derived from a 3-D seismic survey to thoroughly characterize the highest-potential storage reservoirs and confining layers at the premier CO2 geological storage site in Wyoming. An accurate site characterization was essential to assessing the following critical aspects of the storage site: (1) more accurately estimate the CO2 reservoir storage capacity (Madison Limestone and Weber Sandstone at the Rock Springs Uplift (RSU)), (2) evaluate the distribution, long-term integrity, and permanence of the confining layers, (3) manage CO2 injection pressures by removing formation fluids (brine production/treatment), and (4) evaluate potential utilization of the stored CO2