WorldWideScience

Sample records for parent rock shale

  1. Geomechanical Anisotropy and Rock Fabric in Shales

    Science.gov (United States)

    Huffman, K. A.; Connolly, P.; Thornton, D. A.

    2017-12-01

    Digital rock physics (DRP) is an emerging area of qualitative and quantitative scientific analysis that has been employed on a variety of rock types at various scales to characterize petrophysical, mechanical, and hydraulic rock properties. This contribution presents a generic geomechanically focused DRP workflow involving image segmentation by geomechanical constituents, generation of finite element (FE) meshes, and application of various boundary conditions (i.e. at the edge of the domain and at boundaries of various components such as edges of individual grains). The generic workflow enables use of constituent geological objects and relationships in a computational based approach to address specific questions in a variety of rock types at various scales. Two examples are 1) modeling stress dependent permeability, where it occurs and why it occurs at the grain scale; 2) simulating the path and complexity of primary fractures and matrix damage in materials with minerals or intervals of different mechanical behavior. Geomechanical properties and fabric characterization obtained from 100 micron shale SEM images using the generic DRP workflow are presented. Image segmentation and development of FE simulation composed of relatively simple components (elastic materials, frictional contacts) and boundary conditions enable the determination of bulk static elastic properties. The procedure is repeated for co-located images at pertinent orientations to determine mechanical anisotropy. The static moduli obtained are benchmarked against lab derived measurements since material properties (esp. frictional ones) are poorly constrained at the scale of investigation. Once confidence in the input material parameters is gained, the procedure can be used to characterize more samples (i.e. images) than is possible from rock samples alone. Integration of static elastic properties with grain statistics and geologic (facies) conceptual models derived from core and geophysical logs

  2. Using Neutrons to Study Fluid-Rock Interactions in Shales

    Science.gov (United States)

    DiStefano, V. H.; McFarlane, J.; Anovitz, L. M.; Gordon, A.; Hale, R. E.; Hunt, R. D.; Lewis, S. A., Sr.; Littrell, K. C.; Stack, A. G.; Chipera, S.; Perfect, E.; Bilheux, H.; Kolbus, L. M.; Bingham, P. R.

    2015-12-01

    Recovery of hydrocarbons by hydraulic fracturing depends on complex fluid-rock interactions that we are beginning to understand using neutron imaging and scattering techniques. Organic matter is often thought to comprise the majority of porosity in a shale. In this study, correlations between the type of organic matter embedded in a shale and porosity were investigated experimentally. Selected shale cores from the Eagle Ford and Marcellus formations were subjected to pyrolysis-gas chromatography, Differential Thermal Analysis/Thermogravimetric analysis, and organic solvent extraction with the resulting affluent analyzed by gas chromatography-mass spectrometry. The pore size distribution of the microporosity (~1 nm to 2 µm) in the Eagle Ford shales was measured before and after solvent extraction using small angle neutron scattering. Organics representing mass fractions of between 0.1 to 1 wt.% were removed from the shales and porosity generally increased across the examined microporosity range, particularly at larger pore sizes, approximately 50 nm to 2 μm. This range reflects extraction of accessible organic material, including remaining gas molecules, bitumen, and kerogen derivatives, indicating where the larger amount of organic matter in shale is stored. An increase in porosity at smaller pore sizes, ~1-3 nm, was also present and could be indicative of extraction of organic material stored in the inter-particle spaces of clays. Additionally, a decrease in porosity after extraction for a sample was attributed to swelling of pores with solvent uptake. This occurred in a shale with high clay content and low thermal maturity. The extracted hydrocarbons were primarily paraffinic, although some breakdown of larger aromatic compounds was observed in toluene extractions. The amount of hydrocarbon extracted and an overall increase in porosity appeared to be primarily correlated with the clay percentage in the shale. This study complements fluid transport neutron

  3. Hydrologic properties of shale and related argillaceous rocks

    International Nuclear Information System (INIS)

    Moiseyev, A.N.

    1979-01-01

    This report is the result of a bibliographic study designed primarily to collect hydrologic data on American clay-rich rocks. The following information was also sought: stratigraphy, environment of deposition, mineralogic composition, and diagenetic changes. The collected numerical data are presented in tables which contain densities, porosities, and/or hydraulic conductivities of approximately 360 samples. Additional data include hydraulic diffusivities, resistivities, flow rates, and rock strengths. Geologic information suggests that large deposits of shale which may be suited for waste repository belong to all ages and were formed in both marine and continental environments. Of the studied units, the most promising are Paleozoic in the eastern half of the country, Mesozoic in the central part, and Cenozoic in the Gulf Coast area and the West. Less widespread units locally present some additional possibilities. Mineralogic investigations suggest that the smectite content in rocks shows a decrease in time (70% in Recent rocks; 35% in pre-Mesozoic rocks). Because of this predominance of smectite in younger rocks, the modeling of repositories in post-Paleozoic formations might require knowledge of additional and poorly known parameters. Results of investigations into the mathematical relationships between porosity and permeability (or hydralic conductivity) suggest that in situ permeabilities could be estimated from sonic logs and fluid pressure changes at depth. 16 figures, 8 tables

  4. Do scaly clays control seismicity on faulted shale rocks?

    Science.gov (United States)

    Orellana, Luis Felipe; Scuderi, Marco M.; Collettini, Cristiano; Violay, Marie

    2018-04-01

    One of the major challenges regarding the disposal of radioactive waste in geological formations is to ensure isolation of radioactive contamination from the environment and the population. Shales are suitable candidates as geological barriers. However, the presence of tectonic faults within clay formations put the long-term safety of geological repositories into question. In this study, we carry out frictional experiments on intact samples of Opalinus Clay, i.e. the host rock for nuclear waste storage in Switzerland. We report experimental evidence suggesting that scaly clays form at low normal stress (≤20 MPa), at sub-seismic velocities (≤300 μm/s) and is related to pre-existing bedding planes with an ongoing process where frictional sliding is the controlling deformation mechanism. We have found that scaly clays show a velocity-weakening and -strengthening behaviour, low frictional strength, and poor re-strengthening over time, conditions required to allow the potential nucleation and propagation of earthquakes within the scaly clays portion of the formation. The strong similarities between the microstructures of natural and experimental scaly clays suggest important implications for the slip behaviour of shallow faults in shales. If natural and anthropogenic perturbations modify the stress conditions of the fault zone, earthquakes might have the potential to nucleate within zones of scaly clays controlling the seismicity of the clay-rich tectonic system, thus, potentially compromising the long-term safeness of geological repositories situated in shales.

  5. Spherocylindrical microplane constitutive model for shale and other anisotropic rocks

    Science.gov (United States)

    Li, Cunbao; Caner, Ferhun C.; Chau, Viet T.; Bažant, Zdeněk P.

    2017-06-01

    Constitutive equations for inelastic behavior of anisotropic materials have been a challenge for decades. Presented is a new spherocylindrical microplane constitutive model that meets this challenge for the inelastic fracturing behavior of orthotropic materials, and particularly the shale, which is transversely isotropic and is important for hydraulic fracturing (aka fracking) as well as many geotechnical structures. The basic idea is to couple a cylindrical microplane system to the classical spherical microplane system. Each system is subjected to the same strain tensor while their stress tensors are superposed. The spherical phase is similar to the previous microplane models for concrete and isotropic rock. The integration of stresses over spherical microplanes of all spatial orientations relies on the previously developed optimal Gaussian integration over a spherical surface. The cylindrical phase, which is what creates the transverse isotropy, involves only microplanes that are normal to plane of isotropy, or the bedding layers, and enhance the stiffness and strength in that plane. Unlike all the microplane models except the spectral one, the present one can reproduce all the five independent elastic constants of transversely isotropic shales. Vice versa, from these constants, one can easily calculate all the microplane elastic moduli, which are all positive if the elastic in-to-out-of plane moduli ratio is not too big (usually less than 3.75, which applies to all shales). Oriented micro-crack openings, frictional micro-slips and bedding plane behavior can be modeled more intuitively than with the spectral approach. Data fitting shows that the microplane resistance depends on the angle with the bedding layers non-monotonically, and compressive resistance reaches a minimum at 60°. A robust algorithm for explicit step-by-step structural analysis is formulated. Like all microplane models, there are many material parameters, but they can be identified sequentially

  6. Prospect of shale gas recovery enhancement by oxidation-induced rock burst

    Directory of Open Access Journals (Sweden)

    Lijun You

    2017-11-01

    Full Text Available By horizontal well multi-staged fracturing technology, shale rocks can be broken to form fracture networks via hydraulic force and increase the production rate of shale gas wells. Nonetheless, the fracturing stimulation effect may be offset by the water phase trapping damage caused by water retention. In this paper, a technique in transferring the negative factor of fracturing fluid retention into a positive factor of changing the gas existence state and facilitating shale cracking was discussed using the easy oxidation characteristics of organic matter, pyrite and other minerals in shale rocks. Furthermore, the prospect of this technique in tackling the challenges of large retention volume of hydraulic fracturing fluid in shale gas reservoirs, high reservoir damage risks, sharp production decline rate of gas wells and low gas recovery, was analyzed. The organic matter and pyrite in shale rocks can produce a large number of dissolved pores and seams to improve the gas deliverability of the matrix pore throats to the fracture systems. Meanwhile, in the oxidation process, released heat and increased pore pressure will make shale rock burst, inducing expansion and extension of shale micro-fractures, increasing the drainage area and shortening the gas flowing path in matrix, and ultimately, removing reservoir damage and improving gas recovery. To sum up, the technique discussed in the paper can be used to “break” shale rocks via hydraulic force and to “burst” shale rocks via chemical oxidation by adding oxidizing fluid to the hydraulic fracturing fluid. It can thus be concluded that this method can be a favorable supplementation for the conventional hydraulic fracturing of shale gas reservoirs. It has a broad application future in terms of reducing costs and increasing profits, maintaining plateau shale gas production and improving shale gas recovery.

  7. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    OpenAIRE

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-01-01

    The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/supe...

  8. Experimental study on influence of carbon dioxide on porous structure and mechanical properties of shale rock

    Directory of Open Access Journals (Sweden)

    Danuta Miedzińska

    2017-12-01

    Full Text Available Shale rocks are geological formations which can be unconventional gas reservoirs. During their interaction with carbon dioxide, which can be used as a fracturing fluid in shale gas recovery process, many phenomena take place that can influence rock structure and mechanical properties. The research on changes in rock structure under super critical carbon dioxide interaction and their influence of shale properties were presented in the paper. The structural tests were carried out with the use of microscopic techniques with different resolutions of visualization. The uniaxial compression test was applied as a mechanical properties’ assessment experiment. As a result of research, some dependence was observed. The bigger decrease was in porosity after infiltration in lower zooms, the bigger increase in porosity in high zooms and mechanical properties was noticed. Keywords: geomechanics, shale rock, carbon dioxide

  9. Experimental Study and Numerical Modeling of Fracture Propagation in Shale Rocks During Brazilian Disk Test

    Science.gov (United States)

    Mousavi Nezhad, Mohaddeseh; Fisher, Quentin J.; Gironacci, Elia; Rezania, Mohammad

    2018-06-01

    Reliable prediction of fracture process in shale-gas rocks remains one of the most significant challenges for establishing sustained economic oil and gas production. This paper presents a modeling framework for simulation of crack propagation in heterogeneous shale rocks. The framework is on the basis of a variational approach, consistent with Griffith's theory. The modeling framework is used to reproduce the fracture propagation process in shale rock samples under standard Brazilian disk test conditions. Data collected from the experiments are employed to determine the testing specimens' tensile strength and fracture toughness. To incorporate the effects of shale formation heterogeneity in the simulation of crack paths, fracture properties of the specimens are defined as spatially random fields. A computational strategy on the basis of stochastic finite element theory is developed that allows to incorporate the effects of heterogeneity of shale rocks on the fracture evolution. A parametric study has been carried out to better understand how anisotropy and heterogeneity of the mechanical properties affect both direction of cracks and rock strength.

  10. Process of extraction in liquid way, of the bitumen from asphaltic and bituminous rocks, shale, etc

    Energy Technology Data Exchange (ETDEWEB)

    Freda, L

    1936-06-04

    A process is described for liquid extraction of the bitumen in asphaltic and bituminous rocks, shales, and the like. The substances impregnated with bitumen are suitably treated for the extraction of pitch with any given solvent derived from ethylene, in a series of apparatuses fixed and rotary at atmospheric pressure or in vacuum with vapor and hot air.

  11. Fracture Initiation of an Inhomogeneous Shale Rock under a Pressurized Supercritical CO2 Jet

    Directory of Open Access Journals (Sweden)

    Yi Hu

    2017-10-01

    Full Text Available Due to the advantages of good fracture performance and the application of carbon capture and storage (CCS, supercritical carbon dioxide (SC-CO2 is considered a promising alternative for hydraulic fracturing. However, the fracture initiation mechanism and its propagation under pressurized SC-CO2 jet are still unknown. To address these problems, a fluid–structure interaction (FSI-based numerical simulation model along with a user-defined code was used to investigate the fracture initiation in an inhomogeneous shale rock. The mechanism of fracturing under the effect of SC-CO2 jet was explored, and the effects of various influencing factors were analyzed and discussed. The results indicated that higher velocity jets of SC-CO2 not only caused hydraulic-fracturing ring, but also resulted in the increase of stress in the shale rock. It was found that, with the increase of perforation pressure, more cracks initiated at the tip. In contrast, the length of cracks at the root decreased. The length-to-diameter ratio and the aperture ratio distinctly affected the pressurization of SC-CO2 jet, and contributed to the non-linear distribution and various maximum values of the stress in shale rock. The results proved that Weibull probability distribution was appropriate for analysis of the fracture initiation. The studied parameters explain the distribution of weak elements, and they affect the stress field in shale rock.

  12. Rock-physics and seismic-inversion based reservoir characterization of the Haynesville Shale

    International Nuclear Information System (INIS)

    Jiang, Meijuan; Spikes, Kyle T

    2016-01-01

    Seismic reservoir characterization of unconventional gas shales is challenging due to their heterogeneity and anisotropy. Rock properties of unconventional gas shales such as porosity, pore-shape distribution, and composition are important for interpreting seismic data amplitude variations in order to locate optimal drilling locations. The presented seismic reservoir characterization procedure applied a grid-search algorithm to estimate the composition, pore-shape distribution, and porosity at the seismic scale from the seismically inverted impedances and a rock-physics model, using the Haynesville Shale as a case study. All the proposed rock properties affected the seismic velocities, and the combined effects of these rock properties on the seismic amplitude were investigated simultaneously. The P- and S-impedances correlated negatively with porosity, and the V _P/V _S correlated positively with clay fraction and negatively with the pore-shape distribution and quartz fraction. The reliability of these estimated rock properties at the seismic scale was verified through comparisons between two sets of elastic properties: one coming from inverted impedances, which were obtained from simultaneous inversion of prestack seismic data, and one derived from these estimated rock properties. The differences between the two sets of elastic properties were less than a few percent, verifying the feasibility of the presented seismic reservoir characterization. (paper)

  13. Mechanical Behavior of Shale Rock under Uniaxial Cyclic Loading and Unloading Condition

    Directory of Open Access Journals (Sweden)

    Baoyun Zhao

    2018-01-01

    Full Text Available In order to investigate the mechanical behavior of shale rock under cyclic loading and unloading condition, two kinds of incremental cyclic loading tests were conducted. Based on the result of the short-term uniaxial incremental cyclic loading test, the permanent residual strain, modulus, and damage evolution were analyzed firstly. Results showed that the relationship between the residual strains and the cycle number can be expressed by an exponential function. The deformation modulus E50 and elastic modulus ES first increased and then decreased with the peak stress under the loading condition, and both of them increased approximately linearly with the peak stress under the unloading condition. On the basis of the energy dissipation, the damage variables showed an exponential increasing with the strain at peak stress. The creep behavior of the shale rock was also analyzed. Results showed that there are obvious instantaneous strain, decay creep, and steady creep under each stress level and the specimen appears the accelerated creep stage under the 4th stress of 51.16 MPa. Based on the characteristics of the Burgers creep model, a viscoelastic-plastic creep model was proposed through viscoplastic mechanics, which agrees very well with the experimental results and can better describe the creep behavior of shale rock better than the Burgers creep model. Results can provide some mechanics reference evidence for shale gas development.

  14. Shale characterization in mass transport complex as a potential source rock: An example from onshore West Java Basin, Indonesia

    Science.gov (United States)

    Nugraha, A. M. S.; Widiarti, R.; Kusumah, E. P.

    2017-12-01

    This study describes a deep-water slump facies shale of the Early Miocene Jatiluhur/Cibulakan Formation to understand its potential as a source rock in an active tectonic region, the onshore West Java. The formation is equivalent with the Gumai Formation, which has been well-known as another prolific source rock besides the Oligocene Talang Akar Formation in North West Java Basin, Indonesia. The equivalent shale formation is expected to have same potential source rock towards the onshore of Central Java. The shale samples were taken onshore, 150 km away from the basin. The shale must be rich of organic matter, have good quality of kerogen, and thermally matured to be categorized as a potential source rock. Investigations from petrography, X-Ray diffractions (XRD), and backscattered electron show heterogeneous mineralogy in the shales. The mineralogy consists of clay minerals, minor quartz, muscovite, calcite, chlorite, clinopyroxene, and other weathered minerals. This composition makes the shale more brittle. Scanning Electron Microscope (SEM) analysis indicate secondary porosities and microstructures. Total Organic Carbon (TOC) shows 0.8-1.1 wt%, compared to the basinal shale 1.5-8 wt%. The shale properties from this outcropped formation indicate a good potential source rock that can be found in the subsurface area with better quality and maturity.

  15. The Role of the Rock on Hydraulic Fracturing of Tight Shales

    Science.gov (United States)

    Suarez-Rivera, R.; Green, S.; Stanchits, S.; Yang, Y.

    2011-12-01

    Successful economic production of oil and gas from nano-darcy-range permeability, tight shale reservoirs, is achieved via massive hydraulic fracturing. This is so despite their limited hydrocarbon in place, on per unit rock volume basis. As a reference, consider a typical average porosity of 6% and an average hydrocarbon saturation of 50% to 75%. The importance of tight shales results from their large areal extent and vertical thickness. For example, the areal extent of the Anwar field in Saudi Arabia of 3230 square miles (and 300 ft thick), while the Marcellus shale alone is over 100,000 square miles (and 70 to 150 ft thick). The low permeability of the rock matrix, the predominantly mineralized rock fabric, and the high capillary forces to both brines and hydrocarbons, restrict the mobility of pore fluids in these reservoirs. Thus, one anticipates that fluids do not move very far within tight shales. Successful production, therefore results from maximizing the surface area of contact with the reservoir by massive hydraulic fracturing from horizontal bore holes. This was the conceptual breakthrough of the previous decade and the one that triggered the emergence of gas shales, and recently oily shales, as important economic sources of energy. It is now understood that the process can be made substantially more efficient, more sustainable, and more cost effective by understanding the rock. This will be the breakthrough of this decade. Microseismic monitoring, mass balance calculations, and laboratory experiments of hydraulic fracturing on tight shales indicate the development of fracture complexity and fracture propagation that can not be explained in detail in this layered heterogeneous media. It is now clear that in tight shales the large-scale formation fabric is responsible for fracture complexity. For example, the presence and pervasiveness of mineralized fractures, bed interfaces, lithologic contacts, and other types of discontinuities, and their orientation

  16. Estimation of anisotropy parameters in organic-rich shale: Rock physics forward modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Herawati, Ida, E-mail: ida.herawati@students.itb.ac.id; Winardhi, Sonny; Priyono, Awali [Mining and Petroleum Engineering Faculty, Institut Teknologi Bandung, Bandung, 40132 (Indonesia)

    2015-09-30

    Anisotropy analysis becomes an important step in processing and interpretation of seismic data. One of the most important things in anisotropy analysis is anisotropy parameter estimation which can be estimated using well data, core data or seismic data. In seismic data, anisotropy parameter calculation is generally based on velocity moveout analysis. However, the accuracy depends on data quality, available offset, and velocity moveout picking. Anisotropy estimation using seismic data is needed to obtain wide coverage of particular layer anisotropy. In anisotropic reservoir, analysis of anisotropy parameters also helps us to better understand the reservoir characteristics. Anisotropy parameters, especially ε, are related to rock property and lithology determination. Current research aims to estimate anisotropy parameter from seismic data and integrate well data with case study in potential shale gas reservoir. Due to complexity in organic-rich shale reservoir, extensive study from different disciplines is needed to understand the reservoir. Shale itself has intrinsic anisotropy caused by lamination of their formed minerals. In order to link rock physic with seismic response, it is necessary to build forward modeling in organic-rich shale. This paper focuses on studying relationship between reservoir properties such as clay content, porosity and total organic content with anisotropy. Organic content which defines prospectivity of shale gas can be considered as solid background or solid inclusion or both. From the forward modeling result, it is shown that organic matter presence increases anisotropy in shale. The relationships between total organic content and other seismic properties such as acoustic impedance and Vp/Vs are also presented.

  17. Estimation of anisotropy parameters in organic-rich shale: Rock physics forward modeling approach

    International Nuclear Information System (INIS)

    Herawati, Ida; Winardhi, Sonny; Priyono, Awali

    2015-01-01

    Anisotropy analysis becomes an important step in processing and interpretation of seismic data. One of the most important things in anisotropy analysis is anisotropy parameter estimation which can be estimated using well data, core data or seismic data. In seismic data, anisotropy parameter calculation is generally based on velocity moveout analysis. However, the accuracy depends on data quality, available offset, and velocity moveout picking. Anisotropy estimation using seismic data is needed to obtain wide coverage of particular layer anisotropy. In anisotropic reservoir, analysis of anisotropy parameters also helps us to better understand the reservoir characteristics. Anisotropy parameters, especially ε, are related to rock property and lithology determination. Current research aims to estimate anisotropy parameter from seismic data and integrate well data with case study in potential shale gas reservoir. Due to complexity in organic-rich shale reservoir, extensive study from different disciplines is needed to understand the reservoir. Shale itself has intrinsic anisotropy caused by lamination of their formed minerals. In order to link rock physic with seismic response, it is necessary to build forward modeling in organic-rich shale. This paper focuses on studying relationship between reservoir properties such as clay content, porosity and total organic content with anisotropy. Organic content which defines prospectivity of shale gas can be considered as solid background or solid inclusion or both. From the forward modeling result, it is shown that organic matter presence increases anisotropy in shale. The relationships between total organic content and other seismic properties such as acoustic impedance and Vp/Vs are also presented

  18. Experimental Investigation of Mechanical Properties of Black Shales after CO₂-Water-Rock Interaction.

    Science.gov (United States)

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-08-06

    The effects of CO₂-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO₂ in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/super-critical CO₂. According to the experimental results, the values of UCS, Young's modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO₂. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young's modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young's modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO₂, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO₂). SC-CO₂ causes a greater reduction of shale's mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO₂. The EDS results show that CO₂-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation.

  19. Preliminary assessment of shales and other argillaceous rocks in the United States

    International Nuclear Information System (INIS)

    Gonzales, S.; Johnson, K.S.

    1981-01-01

    Shales and related clay-rich rock types throughout the conterminous United States are geologically characterized and evaluated on a regional basis relative to their promise as possible candidate rock sequences for the repository disposal of high-level radioactive wastes. Only stratigraphic intervals or parts of them that are laterally persistent, consist of 75 m or more of shale, mudstone, or argillite, and lie at depths of 305 to 915 m below the land surface are included. The general properties of clay-rich rocks, as well as the several desirable characteristics that make them potentially attractive as disposal host candidates, are reviewed. Also discussed are the geologic factors that dictate the potential acceptability of any shale sequence relative to the regional subsurface distribution of units that meet the basic criteria of extent, thickness, and depth. Included in this context are the tectonic setting, geologic structure, seismicity, groundwater hydrology, mineralogy and content of organic matter, mineral resource potential of both the shales and the enclosing geologic basins, and any construction experience on underground openings, such as hydrocarbon-storage facilities. The clay-rich strata that appear to be promising on the basis of this evaluation are inventoried according to their occurrence and distribution within nine geologic-geomorphic regions throughout the country. Also considered are several, more localized occurrences of Precambrian argillites whose mineralogies make them a related yet separate group in comparison with the sedimentary strata already summarized. Topics for which data are insufficient or on which inadequate study has been conducted to date are also identified

  20. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    Directory of Open Access Journals (Sweden)

    Qiao Lyu

    2016-08-01

    Full Text Available The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS tests together with an acoustic emission (AE system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days in water dissoluted with gaseous/super-critical CO2. According to the experimental results, the values of UCS, Young’s modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO2. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young’s modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young’s modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO2, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO2. SC-CO2 causes a greater reduction of shale’s mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO2. The EDS results show that CO2-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation.

  1. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    Science.gov (United States)

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-01-01

    The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/super-critical CO2. According to the experimental results, the values of UCS, Young’s modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO2. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young’s modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young’s modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO2, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO2). SC-CO2 causes a greater reduction of shale’s mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO2. The EDS results show that CO2-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation. PMID:28773784

  2. A Study of Nonlinear Elasticity Effects on Permeability of Stress Sensitive Shale Rocks Using an Improved Coupled Flow and Geomechanics Model: A Case Study of the Longmaxi Shale in China

    Directory of Open Access Journals (Sweden)

    Chenji Wei

    2018-02-01

    Full Text Available Gas transport in shale gas reservoirs is largely affected by rock properties such as permeability. These properties are often sensitive to the in-situ stress state changes. Accurate modeling of shale gas transport in shale reservoir rocks considering the stress sensitive effects on rock petrophysical properties is important for successful shale gas extraction. Nonlinear elasticity in stress sensitive reservoir rocks depicts the nonlinear stress-strain relationship, yet it is not thoroughly studied in previous reservoir modeling works. In this study, an improved coupled flow and geomechanics model that considers nonlinear elasticity is proposed. The model is based on finite element methods, and the nonlinear elasticity in the model is validated with experimental data on shale samples selected from the Longmaxi Formation in Sichuan Basin China. Numerical results indicate that, in stress sensitive shale rocks, nonlinear elasticity affects shale permeability, shale porosity, and distributions of effective stress and pore pressure. Elastic modulus change is dependent on not only in-situ stress state but also stress history path. Without considering nonlinear elasticity, the modeling of shale rock permeability in Longmaxi Formation can overestimate permeability values by 1.6 to 53 times.

  3. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 6. Baseline rock properties-shale

    International Nuclear Information System (INIS)

    1978-04-01

    This volume, Y/OWI/TM36/6 Baseline Rock Properties--Shale, is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-36'' which supplements a ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-44.'' The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. The report is a result of a literature survey of the rock properties of shales occurring in the United States. Firstly, data were collected from a wide variety of sources in order to obtain a feel for the range of properties encountered. Secondly, some typical shales were selected for detailed review and these are written up as separate chapters in this report. Owing to the wide variability in lithology and properties of shales occurring in the United States, it became necessary to focus the study on consolidated illite shales. Using the specific information already generated, a consistent set of intact properties for a typical, consolidated illite shale was obtained. Correction factors, largely based on geological considerations, were then applied to the intact data in order to yield typical rock mass properties for this type of shale. Lastly, excavation problems in shale formations were reviewed and three tunnel jobs were written up as case histories

  4. Environmental consequences of shale gas exploitation and the crucial role of rock microfracturing

    Science.gov (United States)

    Renard, Francois

    2015-04-01

    The growing exploitation of unconventional gas and oil resources has dramatically changed the international market of hydrocarbons in the past ten years. However, several environmental concerns have also been identified such as the increased microseismicity, the leakage of gas into freshwater aquifers, and the enhanced water-rock interactions inducing the release of heavy metals and other toxic elements in the produced water. In all these processes, fluids are transported into a network of fracture, ranging from nanoscale microcracks at the interface between minerals and the kerogen of the source rock, to well-developed fractures at the meter scale. Characterizing the fracture network and the mechanisms of its formation remains a crucial goal. A major difficulty when analyzing fractures from core samples drilled at depth is that some of them are produced by the coring process, while some other are produced naturally at depth by the coupling between geochemical and mechanical forces. Here, I present new results of high resolution synchrotron 3D X-ray microtomography imaging of shale samples, at different resolutions, to characterize their microfractures and their mechanisms of formation. The heterogeneities of rock microstructure are also imaged, as they create local stress concentrations where cracks may nucleate or along which they propagate. The main results are that microcracks form preferentially along kerogen-mineral interfaces and propagate along initial heterogeneities according to the local stress direction, connecting to increase the total volume of fractured rock. Their lifetime is also an important parameter because they may seal by fluid circulation, fluid-rock interactions, and precipitation of a cement. Understanding the multi-scale processes of fracture network development in shales and the coupling with fluid circulation represents a key challenge for future research directions.

  5. Constructibility Challenges for Perimeter Control Blasting and Slope Development in Shale and Other "Weak" Rocks

    Science.gov (United States)

    Scarpato, D. J.

    2016-02-01

    Slope construction in shale can present some interesting challenges for geotechnical design engineers and contractors alike. There are challenges that can be expected and designed for; however, all too frequently, such challenges manifest themselves as "surprises" in the field. Common constructibility challenges can include drill hole deviation during drilling for controlled blasting; and, excavation slope instability arising from inconsistent perimeter control drilling. Drill hole deviation results from the cumulative effects from both drilling mechanics and rock mass conditions. Once a hole has initiated the deviation trajectory, it is difficult to rectify drill steel position. Although such challenges are not necessarily unique to shale, they are often exacerbated by weak, weathered and transversely isotropic nature of bedrock conditions. All too often, the working assumption is that shale is "soft" and easily excavatable; however, this blanket assumption can prove to be costly. This paper is intended to provide design professionals and contractors with the practical considerations needed to avoid the "surprises" associated with drill hole deviation, and minimize the potential for costly claims.

  6. A non-Linear transport model for determining shale rock characteristics

    Science.gov (United States)

    Ali, Iftikhar; Malik, Nadeem

    2016-04-01

    Unconventional hydrocarbon reservoirs consist of tight porous rocks which are characterised by nano-scale size porous networks with ultra-low permeability [1,2]. Transport of gas through them is not well understood at the present time, and realistic transport models are needed in order to determine rock properties and for estimating future gas pressure distribution in the reservoirs. Here, we consider a recently developed non-linear gas transport equation [3], ∂p-+ U ∂p- = D ∂2p-, t > 0, (1) ∂t ∂x ∂x2 complimented with suitable initial and boundary conditions, in order to determine shale rock properties such as the permeability K, the porosity φ and the tortuosity, τ. In our new model, the apparent convection velocity, U = U(p,px), and the apparent diffusivity D = D(p), are both highly non-linear functions of the pressure. The model incorporate various flow regimes (slip, surface diffusion, transition, continuum) based upon the Knudsen number Kn, and also includes Forchchiemers turbulence correction terms. In application, the model parameters and associated compressibility factors are fully pressure dependent, giving the model more realism than previous models. See [4]. Rock properties are determined by solving an inverse problem, with model parameters adjustment to minimise the error between the model simulation and available data. It is has been found that the proposed model performs better than previous models. Results and details of the model will be presented at the conference. Corresponding author: namalik@kfupm.edu.sa and nadeem_malik@cantab.net References [1] Cui, X., Bustin, A.M. and Bustin, R., "Measurements of gas permeability and diffusivity of tight reservoir rocks: different approaches and their applications", Geofluids 9, 208-223 (2009). [2] Chiba R., Fomin S., Chugunov V., Niibori Y. and Hashida T., "Numerical Simulation of Non Fickian Diffusion and Advection in a Fractured Porous Aquifer", AIP Conference Proceedings 898, 75 (2007

  7. Universal Stochastic Multiscale Image Fusion: An Example Application for Shale Rock.

    Science.gov (United States)

    Gerke, Kirill M; Karsanina, Marina V; Mallants, Dirk

    2015-11-02

    Spatial data captured with sensors of different resolution would provide a maximum degree of information if the data were to be merged into a single image representing all scales. We develop a general solution for merging multiscale categorical spatial data into a single dataset using stochastic reconstructions with rescaled correlation functions. The versatility of the method is demonstrated by merging three images of shale rock representing macro, micro and nanoscale spatial information on mineral, organic matter and porosity distribution. Merging multiscale images of shale rock is pivotal to quantify more reliably petrophysical properties needed for production optimization and environmental impacts minimization. Images obtained by X-ray microtomography and scanning electron microscopy were fused into a single image with predefined resolution. The methodology is sufficiently generic for implementation of other stochastic reconstruction techniques, any number of scales, any number of material phases, and any number of images for a given scale. The methodology can be further used to assess effective properties of fused porous media images or to compress voluminous spatial datasets for efficient data storage. Practical applications are not limited to petroleum engineering or more broadly geosciences, but will also find their way in material sciences, climatology, and remote sensing.

  8. Eo-Oligocene Oil Shales of the Talawi, Lubuktaruk, and Kiliranjao Areas, West Sumatra: Are they potential source rocks?

    Directory of Open Access Journals (Sweden)

    M. Iqbal

    2014-12-01

    Full Text Available DOI:10.17014/ijog.v1i3.198To anticipate the increasing energy demand, additional data and information covering unconventional fossil fuels such as oil shale must be acquired to promote the usage of alternative energy sources to crude oil. The Talawi and Lubuktaruk regions situated within intra-montane Ombilin Basin, and the Kiliranjao assumed to be a small intra montane basin are occupied by Eo-Oligocene sediments of Sangkarewang and Kiliran Formations, respectively. Field activity, geochemical screening techniques, and organic petrographic analysis, supported by SEM mode, are methods used. Most of the oil shale sequence is typically of an organically rich-succession comprising predominantly well-bedded, laminated and fissile, brownish to dark grey organic-rich shale and mudstone rocks. The exinite macerals within oil shale comprise mainly Pediastrum-lamalginite with minor cutinite, resinite, liptodetrinite, sporinite, bituminite, and rare Botryococcus-telalginite. Therefore; the oil shale deposits can be described as “lamosites”. Minor vitrinite maceral is also recognized. TOC analysis on selected shale samples corresponds to a fair up to excellent category of source rock characterization. The hydrogen index (HI for all samples shows a range of values from 207 - 864, and pyrolysis yield (PY ranges from 2.67 to 79.72 mg HC/g rock. The kerogen is suggested to be of mixed Type II and Type I autochthonous materials such as alginite, with minor allochthonous substances. Oil samples collected appear to be positioned within more oil prone rather than gas prone. Thermal maturity of the oil shales gained from Tmax value and production index (PI tends to show immature to marginally/early mature stage. A consistency in the thermal maturity level results by using both Tmax and vitrinite reflectance value is recognized. On the basis of  SEM analysis, the oil shale has undergone a late eodiagenetic process. Thereby, overall, vitrinite reflectance

  9. Factors controlling Li concentration and isotopic composition in formation waters and host rocks of Marcellus Shale, Appalachian Basin

    Science.gov (United States)

    Phan, Thai T.; Capo, Rosemary C; Stewart, Brian W.; Macpherson, Gwen; Rowan, Elisabeth L.; Hammack, Richard W.

    2015-01-01

    In this study, water and whole rock samples from hydraulically fractured wells in the Marcellus Shale (Middle Devonian), and water from conventional wells producing from Upper Devonian sandstones were analyzed for lithium concentrations and isotope ratios (δ7Li). The distribution of lithium concentrations in different mineral groups was determined using sequential extraction. Structurally bound Li, predominantly in clays, accounted for 75-91 wt. % of total Li, whereas exchangeable sites and carbonate cement contain negligible Li (< 3%). Up to 20% of the Li is present in the oxidizable fraction (organic matter and sulfides). The δ7Li values for whole rock shale in Greene Co., Pennsylvania, and Tioga Co., New York, ranged from -2.3 to + 4.3‰, similar to values reported for other shales in the literature. The δ7Li values in shale rocks with stratigraphic depth record progressive weathering of the source region; the most weathered and clay-rich strata with isotopically light Li are found closest to the top of the stratigraphic section. Diagenetic illite-smectite transition could also have partially affected the bulk Li content and isotope ratios of the Marcellus Shale.

  10. Pore Characterization of Shale Rock and Shale Interaction with Fluids at Reservoir Pressure-Temperature Conditions Using Small-Angle Neutron Scattering

    Science.gov (United States)

    Ding, M.; Hjelm, R.; Watkins, E.; Xu, H.; Pawar, R.

    2015-12-01

    Oil/gas produced from unconventional reservoirs has become strategically important for the US domestic energy independence. In unconventional realm, hydrocarbons are generated and stored in nanopores media ranging from a few to hundreds of nanometers. Fundamental knowledge of coupled thermo-hydro-mechanical-chemical (THMC) processes that control fluid flow and propagation within nano-pore confinement is critical for maximizing unconventional oil/gas production. The size and confinement of the nanometer pores creates many complex rock-fluid interface interactions. It is imperative to promote innovative experimental studies to decipher physical and chemical processes at the nanopore scale that govern hydrocarbon generation and mass transport of hydrocarbon mixtures in tight shale and other low permeability formations at reservoir pressure-temperature conditions. We have carried out laboratory investigations exploring quantitative relationship between pore characteristics of the Wolfcamp shale from Western Texas and the shale interaction with fluids at reservoir P-T conditions using small-angle neutron scattering (SANS). We have performed SANS measurements of the shale rock in single fluid (e.g., H2O and D2O) and multifluid (CH4/(30% H2O+70% D2O)) systems at various pressures up to 20000 psi and temperature up to 150 oF. Figure 1 shows our SANS data at different pressures with H2O as the pressure medium. Our data analysis using IRENA software suggests that the principal changes of pore volume in the shale occurred on smaller than 50 nm pores and pressure at 5000 psi (Figure 2). Our results also suggest that with increasing P, more water flows into pores; with decreasing P, water is retained in the pores.

  11. Comprehensive Interpretation of the Laboratory Experiments Results to Construct Model of the Polish Shale Gas Rocks

    Science.gov (United States)

    Jarzyna, Jadwiga A.; Krakowska, Paulina I.; Puskarczyk, Edyta; Wawrzyniak-Guz, Kamila; Zych, Marcin

    2018-03-01

    More than 70 rock samples from so-called sweet spots, i.e. the Ordovician Sa Formation and Silurian Ja Member of Pa Formation from the Baltic Basin (North Poland) were examined in the laboratory to determine bulk and grain density, total and effective/dynamic porosity, absolute permeability, pore diameters size, total surface area, and natural radioactivity. Results of the pyrolysis, i.e., TOC (Total Organic Carbon) together with S1 and S2 - parameters used to determine the hydrocarbon generation potential of rocks, were also considered. Elemental composition from chemical analyses and mineral composition from XRD measurements were also included. SCAL analysis, NMR experiments, Pressure Decay Permeability measurements together with water immersion porosimetry and adsorption/ desorption of nitrogen vapors method were carried out along with the comprehensive interpretation of the outcomes. Simple and multiple linear statistical regressions were used to recognize mutual relationships between parameters. Observed correlations and in some cases big dispersion of data and discrepancies in the property values obtained from different methods were the basis for building shale gas rock model for well logging interpretation. The model was verified by the result of the Monte Carlo modelling of spectral neutron-gamma log response in comparison with GEM log results.

  12. Factors controlling Li concentration and isotopic composition in formation waters and host rocks of Marcellus Shale, Appalachian Basin

    Science.gov (United States)

    Phan, Thai T.; Capo, Rosemary C; Stewart, Brian W.; Macpherson, Gwen; Rowan, Elisabeth L.; Hammack, Richard W.

    2015-01-01

    In this study, water and whole rock samples from hydraulically fractured wells in the Marcellus Shale (Middle Devonian), and water from conventional wells producing from Upper Devonian sandstones were analyzed for lithium concentrations and isotope ratios (δ7Li). The distribution of lithium concentrations in different mineral groups was determined using sequential extraction. Structurally bound Li, predominantly in clays, accounted for 75-91 wt. % of total Li, whereas exchangeable sites and carbonate cement contain negligible Li (shale in Greene Co., Pennsylvania, and Tioga Co., New York, ranged from -2.3 to + 4.3‰, similar to values reported for other shales in the literature. The δ7Li values in shale rocks with stratigraphic depth record progressive weathering of the source region; the most weathered and clay-rich strata with isotopically light Li are found closest to the top of the stratigraphic section. Diagenetic illite-smectite transition could also have partially affected the bulk Li content and isotope ratios of the Marcellus Shale.

  13. A microfluidic approach to water-rock interactions using thin rock sections: Pb and U sorption onto thin shale and granite sections

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Youn Soo [Institute of Mine Reclamation Technology, Mine Reclamation Corp., 2 Segye-ro, Wonju-si, Gangwon-do, 26464 (Korea, Republic of); Jo, Ho Young, E-mail: hyjo@korea.ac.kr [Department of Earth and Environmental Sciences, Korea University, Anam-dong, Seongbuk-gu, Seoul, 02841 (Korea, Republic of); Ryu, Ji-Hun; Kim, Geon-Young [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon, 34057 (Korea, Republic of)

    2017-02-15

    Highlights: • Microfluidic tests was used to investigate water-rock (mineral) interactions. • Pb and U sorption onto thin shale and granite sections was evaluated. • Pb removal by thin shale section is related primarily to Fe-containing minerals. • A slightly larger amount of U was removed onto the thin granite section with Fe-containing minerals. - Abstract: The feasibility of using microfluidic tests to investigate water-rock (mineral) interactions in fractures regarding sorption onto thin rock sections (i.e., shale and granite) of lead (Pb) and uranium (U) was evaluated using a synthetic PbCl{sub 2} solution and uranium-containing natural groundwater as fluids. Effluent composition and element distribution on the thin rock sections before and after microfluidic testing were analyzed. Most Pb removal (9.8 mg/cm{sup 2}) occurred within 3.5 h (140 PVF), which was 74% of the total Pb removal (13.2 mg/cm{sup 2}) at the end of testing (14.5 h, 560 PVF). Element composition on the thin shale sections determined by μ-XRF analysis indicated that Pb removal was related primarily to Fe-containing minerals (e.g., pyrite). Two thin granite sections (biotite rich, Bt-R and biotite poor, Bt-P) exhibited no marked difference in uranium removal capacity, but a slightly higher amount of uranium was removed onto the thin Bt-R section (266 μg/cm{sup 2}) than the thin Bt-P section (240 μg/cm{sup 2}) within 120 h (4800 PVF). However, uranium could not be detected by micro X-ray fluorescence (μ-XRF) analysis, likely due to the detection limit. These results suggest that microfluidic testing on thin rock sections enables quantitative evaluation of rock (mineral)-water interactions at the micro-fracture or pore scale.

  14. Clay shale as host rock. A geomechanical contribution about Opalinus clay

    International Nuclear Information System (INIS)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon

    2016-01-01

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  15. Full waveform seismic AVAZ signatures of anisotropic shales by integrated rock physics and the reflectivity method

    Science.gov (United States)

    Liu, Xiwu; Guo, Zhiqi; Han, Xu

    2018-06-01

    A set of parallel vertical fractures embedded in a vertically transverse isotropy (VTI) background leads to orthorhombic anisotropy and corresponding azimuthal seismic responses. We conducted seismic modeling of full waveform amplitude variations versus azimuth (AVAZ) responses of anisotropic shale by integrating a rock physics model and a reflectivity method. The results indicate that the azimuthal variation of P-wave velocity tends to be more complicated for orthorhombic medium compared to the horizontally transverse isotropy (HTI) case, especially at high polar angles. Correspondingly, for the HTI layer in the theoretical model, the short axis of the azimuthal PP amplitudes at the top interface is parallel to the fracture strike, while the long axis at the bottom reflection directs the fracture strike. In contrast, the orthorhombic layer in the theoretical model shows distinct AVAZ responses in terms of PP reflections. Nevertheless, the azimuthal signatures of the R- and T-components of the mode-converted PS reflections show similar AVAZ features for the HTI and orthorhombic layers, which may imply that the PS responses are dominated by fractures. For the application to real data, a seismic-well tie based on upscaled data and a reflectivity method illustrate good agreement between the reference layers and the corresponding reflected events. Finally, the full waveform seismic AVAZ responses of the Longmaxi shale formation are computed for the cases of HTI and orthorhombic anisotropy for comparison. For the two cases, the azimuthal features represent differences mainly in amplitudes, while slightly in the phases of the reflected waveforms. Azimuth variations in the PP reflections from the reference layers show distinct behaviors for the HTI and orthorhombic cases, while the mode-converted PS reflections in terms of the R- and T-components show little differences in azimuthal features. It may suggest that the behaviors of the PS waves are dominated by vertically

  16. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    International Nuclear Information System (INIS)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-01-01

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  17. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-06-20

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  18. Migration and Enrichment of Arsenic in the Rock-Soil-Crop Plant System in Areas Covered with Black Shale, Korea

    Directory of Open Access Journals (Sweden)

    Ji-Min Yi

    2003-01-01

    Full Text Available The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4 were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg-1 is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg-1 and the Chubu areas (32.6 mg kg-1. As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg-1 and the Chubu areas (1.35 mg kg-1. The biological absorption coefficient (BAC of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  19. Hydrocarbon Potential in Sandstone Reservoir Isolated inside Low Permeability Shale Rock (Case Study: Beruk Field, Central Sumatra Basin)

    Science.gov (United States)

    Diria, Shidqi A.; Musu, Junita T.; Hasan, Meutia F.; Permono, Widyo; Anwari, Jakson; Purba, Humbang; Rahmi, Shafa; Sadjati, Ory; Sopandi, Iyep; Ruzi, Fadli

    2018-03-01

    Upper Red Bed, Menggala Formation, Bangko Formation, Bekasap Formation and Duri Formationare considered as the major reservoirs in Central Sumatra Basin (CSB). However, Telisa Formation which is well-known as seal within CSB also has potential as reservoir rock. Field study discovered that lenses and layers which has low to high permeability sandstone enclosed inside low permeability shale of Telisa Formation. This matter is very distinctive and giving a new perspective and information related to the invention of hydrocarbon potential in reservoir sandstone that isolated inside low permeability shale. This study has been conducted by integrating seismic data, well logs, and petrophysical data throughly. Facies and static model are constructed to estimate hydrocarbon potential resource. Facies model shows that Telisa Formation was deposited in deltaic system while the potential reservoir was deposited in distributary mouth bar sandstone but would be discontinued bedding among shale mud-flat. Besides, well log data shows crossover between RHOB and NPHI, indicated that distributary mouth bar sandstone is potentially saturated by hydrocarbon. Target area has permeability ranging from 0.01-1000 mD, whereas porosity varies from 1-30% and water saturation varies from 30-70%. The hydrocarbon resource calculation approximates 36.723 MSTB.

  20. Subaqueous early eruptive phase of the late Aptian Rajmahal volcanism, India: Evidence from volcaniclastic rocks, bentonite, black shales, and oolite

    Directory of Open Access Journals (Sweden)

    Naresh C. Ghose

    2017-07-01

    Full Text Available The late Aptian (118–115 Ma continental flood basalts of the Rajmahal Volcanic Province (RVP are part of the Kerguelen Large Igneous Province, and constitute the uppermost part of the Gondwana Supergroup on the eastern Indian shield margin. The lower one-third of the Rajmahal volcanic succession contains thin layers of plant fossil-rich inter-trappean sedimentary rocks with pyroclasts, bentonite, grey and black shale/mudstone and oolite, whereas the upper two-thirds consist of sub-aerial fine-grained aphyric basalts with no inter-trappean material. At the eastern margin and the north-central sector of the RVP, the volcanics in the lower part include rhyolites and dacites overlain by enstatite-bearing basalts and enstatite-andesites. The pyroclastic rocks are largely felsic in composition, and comprise ignimbrite as well as coarse-grained tuff with lithic clasts, and tuff breccia with bombs, lapilli and ash that indicate explosive eruption of viscous rhyolitic magma. The rhyolites/dacites (>68 wt.% are separated from the andesites (<60 wt.% by a gap in silica content indicating their formation through upper crustal anatexis with only heat supplied by the basaltic magma. On the other hand, partially melted siltstone xenoliths in enstatite-bearing basalts suggest that the enstatite-andesites originated through mixing of the upper crust with basaltic magma, crystallizing orthopyroxene at a pressure-temperature of ∼3 kb/1150 °C. In contrast, the northwestern sector of the RVP is devoid of felsic-intermediate rocks, and the volcaniclastic rocks are predominantly mafic (basaltic in composition. Here, the presence of fine-grained tuffs, tuff breccia containing sideromelane shards and quenched texture, welded tuff breccia, peperite, shale/mudstone and oolite substantiates a subaqueous environment. Based on these observations, we conclude that the early phase of Rajmahal volcanism occurred under predominantly subaqueous conditions. The presence

  1. Laboratory investigation of shale rock to identify fracture propagation in vertical direction to bedding

    Science.gov (United States)

    Peng, Tan; Yan, Jin; Bing, Hou; Yingcao, Zhou; Ruxin, Zhang; Zhi, Chang; Meng, Fan

    2018-06-01

    Affected by beddings and natural fractures, fracture geometry in the vertical plane is complex in shale formation, which differs from a simple fracture in homogeneous sandstone reservoirs. However, the propagation mechanism of a hydraulic fracture in the vertical plane has not been well understood. In this paper, a true tri-axial pressure machine was deployed for shale horizontal well fracturing simulation experiments of shale outcrops. The effects of multiple factors on hydraulic fracture vertical propagation were studied. The results revealed that hydraulic fracture initiation and propagation displayed four basic patterns in the vertical plane of laminated shale formation. A hydraulic fracture would cross the beddings under the high vertical stress difference between a vertical stress and horizontal minimum stress of 12 MPa, while a hydraulic fracture propagates along the beddings under a low vertical stress difference of 3 MPa. Four kinds of fracture geometry, including a single main fracture, a nonplanar fracture, a complex fracture, and a complex fracture network, were observed due to the combined effects of flow rate and viscosity. Due to the influence of binding strength (or cementing strength) on the fracture communication effects between a hydraulic fracture and the beddings, the opening region of the beddings takes the shape of an ellipse.

  2. Rock Springs Site 12 hydraulic/explosive true in situ oil shale fracturing experiment

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, R.L.; Boade, R.R.; Stevens, A.L.; Long, A. Jr.; Turner, T.F.

    1980-06-01

    The experiment plan involved the creation and characterization of three horizontal hydraulic fractures, followed by the insertion and simultaneous detonation of slurry explosive in the two lower fractures. Core analyses, wellbore logging, and airflow and /sup 85/Kr tracer tests were used for site characterization and assessment of the hydraulic and explosive fracturing. Tiltmeters, wellhead pressure and flow gages, and in-formation pressure, flow and crack-opening sensors were used to monitor hydrofracture creation and explosive insertion. Explosive detonation diagnostic data were taken with stress and time-of-arrival gages and surface and in-formation accelerometers. The post-fracturing assessments indicated that: (1) hydrofracture creation and explosive insertion and detonation were accomplished essentially as planned; (2) induced fractures were randomly distributed through the shale with no extensively fractured regions or dislocation of shale; and (3) enhancement of permeability was limited to enlargement of the explosive-filled fractures.

  3. The Influence of Shale Rock Fracturing Equipment Operation on Atmospheric Air Quality

    Science.gov (United States)

    Bogacki, Marek; Macuda, Jan

    2014-12-01

    The hydraulic fracturing jobs performed on shale rocks are connected with atmospheric emissions of dusts and exhaust gases from high-power motors supplying pump aggregates used for fracturing operations and from other technological devices. The total power of motors driving technological systems depends on the specific character of deposit and well and may range between a dozen to tens of thousands kW. An exemplary set of technological systems used for frac jobs is presented in figure 1. The following substances are emitted to the atmosphere during engine operation, e.g. nitrogen oxides (NOx), sulfur dioxide (SO2), carbon oxide (CO), dust PM10, ammonia, benzo(a)pyrene (B(a)P), benzene, toluene, xylene, formaldehyde, acetaldehyde, acrolein. As a consequence admissible concentrations of these substances in air can be exceeded. The influence of dust and gaseous emissions accompanying shale rock fracturing jobs is addressed in this paper. Model analyses were performed. An exemplary model of a process used for simulating propagation of atmospheric emissions in a specified calculation area (1,150 m × 1,150 m) were based on the analysis of hydraulic fracturing jobs performed in wells in Poland and abroad. For making calculations more actual, the model was located in the Gdańsk area and was ascribed its typical meteorological and orographic parameters. In the center of this area a rig site 150 m x 150 m was distinguished. The emission field was generated by 12 high-power engines supplying pump aggregates, 1680 kW each. The time of work of particular engines was established for 52 hrs (13 frac jobs, each lasting 4 hrs). It was assumed that all engines will operate simultaneously and using 100% of their power. Attention was paid to the correct modelling of the real emission field. Technical parameters of motors and the applied fuels were characterized. Emission indices were worked out by, e.g. U.S. Environmental Protection Agency or European Environment Agency. The

  4. Clay shale as host rock. A geomechanical contribution about Opalinus clay; Tonstein als Wirtsgestein. Ein geomechanischer Beitrag ueber Opalinuston

    Energy Technology Data Exchange (ETDEWEB)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon [Halle-Wittenberg Univ., Halle (Saale) (Germany). Inst. fuer Geowissenschaften und Geographie

    2016-12-15

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  5. Characterising the vertical separation of shale-gas source rocks and aquifers across England and Wales (UK)

    Science.gov (United States)

    Loveless, Sian E.; Bloomfield, John P.; Ward, Robert S.; Hart, Alwyn J.; Davey, Ian R.; Lewis, Melinda A.

    2018-03-01

    Shale gas is considered by many to have the potential to provide the UK with greater energy security, economic growth and jobs. However, development of a shale gas industry is highly contentious due to environmental concerns including the risk of groundwater pollution. Evidence suggests that the vertical separation between exploited shale units and aquifers is an important factor in the risk to groundwater from shale gas exploitation. A methodology is presented to assess the vertical separation between different pairs of aquifers and shales that are present across England and Wales. The application of the method is then demonstrated for two of these pairs—the Cretaceous Chalk Group aquifer and the Upper Jurassic Kimmeridge Clay Formation, and the Triassic sandstone aquifer and the Carboniferous Bowland Shale Formation. Challenges in defining what might be considered criteria for `safe separation' between a shale gas formation and an overlying aquifer are discussed, in particular with respect to uncertainties in geological properties, aquifer extents and determination of socially acceptable risk levels. Modelled vertical separations suggest that the risk of aquifer contamination from shale exploration will vary greatly between shale-aquifer pairs and between regions and this will need to be considered carefully as part of the risk assessment and management for any shale gas development.

  6. Mineralogical, chemical and K-Ar isotopic changes in Kreyenhagen Shale whole rocks and <2 µm clay fractions during natural burial and hydrous-pyrolysis experimental maturation

    Science.gov (United States)

    Clauer, Norbert; Lewan, Michael D.; Dolan, Michael P.; Chaudhuri, Sambhudas; Curtis, John B.

    2014-01-01

    Progressive maturation of the Eocene Kreyenhagen Shale from the San Joaquin Basin of California was studied by combining mineralogical and chemical analyses with K–Ar dating of whole rocks and sequence, indicating that there is no detectable variation in the crystallo-chemical organization of the K-bearing alumino-silicates with depth. No supply of K from outside of the rock volumes occurred, which indicates a closed-system behavior for it. Conversely, the content of the total organic carbon (TOC) content decreases significantly with burial, based on the progressive increasing Al/TOC ratio of the whole rocks. The initial varied mineralogy and chemistry of the rocks and their <2 μm fractions resulting from differences in detrital sources and depositional settings give scattered results that homogenize progressively during burial due to increased authigenesis, and concomitant increased alteration of the detrital material.

  7. Tectono-thermal Evolution of the Lower Paleozoic Petroleum Source Rocks in the Southern Lublin Trough: Implications for Shale Gas Exploration from Maturity Modelling

    Science.gov (United States)

    Botor, Dariusz

    2018-03-01

    The Lower Paleozoic basins of eastern Poland have recently been the focus of intensive exploration for shale gas. In the Lublin Basin potential unconventional play is related to Lower Silurian source rocks. In order to assess petroleum charge history of these shale gas reservoirs, 1-D maturity modeling has been performed. In the Łopiennik IG-1 well, which is the only well that penetrated Lower Paleozoic strata in the study area, the uniform vitrinite reflectance values within the Paleozoic section are interpreted as being mainly the result of higher heat flow in the Late Carboniferous to Early Permian times and 3500 m thick overburden eroded due to the Variscan inversion. Moreover, our model has been supported by zircon helium and apatite fission track dating. The Lower Paleozoic strata in the study area reached maximum temperature in the Late Carboniferous time. Accomplished tectono-thermal model allowed establishing that petroleum generation in the Lower Silurian source rocks developed mainly in the Devonian - Carboniferous period. Whereas, during Mesozoic burial, hydrocarbon generation processes did not develop again. This has negative influence on potential durability of shale gas reservoirs.

  8. The Devonian Marcellus Shale and Millboro Shale

    Science.gov (United States)

    Soeder, Daniel J.; Enomoto, Catherine B.; Chermak, John A.

    2014-01-01

    The recent development of unconventional oil and natural gas resources in the United States builds upon many decades of research, which included resource assessment and the development of well completion and extraction technology. The Eastern Gas Shales Project, funded by the U.S. Department of Energy in the 1980s, investigated the gas potential of organic-rich, Devonian black shales in the Appalachian, Michigan, and Illinois basins. One of these eastern shales is the Middle Devonian Marcellus Shale, which has been extensively developed for natural gas and natural gas liquids since 2007. The Marcellus is one of the basal units in a thick Devonian shale sedimentary sequence in the Appalachian basin. The Marcellus rests on the Onondaga Limestone throughout most of the basin, or on the time-equivalent Needmore Shale in the southeastern parts of the basin. Another basal unit, the Huntersville Chert, underlies the Marcellus in the southern part of the basin. The Devonian section is compressed to the south, and the Marcellus Shale, along with several overlying units, grades into the age-equivalent Millboro Shale in Virginia. The Marcellus-Millboro interval is far from a uniform slab of black rock. This field trip will examine a number of natural and engineered exposures in the vicinity of the West Virginia–Virginia state line, where participants will have the opportunity to view a variety of sedimentary facies within the shale itself, sedimentary structures, tectonic structures, fossils, overlying and underlying formations, volcaniclastic ash beds, and to view a basaltic intrusion.

  9. Geologic report of the Maquoketa Shale, New Albany Shale, and Borden Group rocks in the Illinois Basin as potential solid waste repository sites

    International Nuclear Information System (INIS)

    Droste, J.B.; Vitaliano, C.J.

    1976-06-01

    We have evaluated the Illinois Basin in order to select a ''target site'' for a possible solid nuclear waste repository. In the process we have been mindful of geology (particularly stratigraphy and lithology and structure), terrane, population density, land use, land ownership and accessibility. After taking these restrictions into account, we have singled out a strip of land in south central Indiana in which we have selected four potential sites worthy of further exploration. In three of the sites the geology, lithology, and depth below the surface are more than adequate for crypt purposes in two separate formations--the Maquoketa Shale of the Ordovician System and the New Albany Shale-Borden Group of the Upper Devonian-Mississippian Systems. The interval between the two is several hundred feet. The geology and associated features in the fourth site are undoubtedly similar to those in the first three. In all four selections a sizeable proportion of the land is in public ownership and the population density in the nonpublicly owned land is low. The geology, lithology, and position of the target formations have been projected into the sites in question from data provided by drill core records of the Indiana Geological Survey. Precise details would, of course, require exploratory drilling on the selected site

  10. Chemical and isotopic characterization of water-rock interactions in shales induced by the intrusion of a basaltic dike: A natural analogue for radioactive waste disposal

    International Nuclear Information System (INIS)

    Techer, Isabelle; Rousset, Davy; Clauer, Norbert; Lancelot, Joel; Boisson, Jean-Yves

    2006-01-01

    Disposal of nuclear waste in deep geological formations is expected to induce thermal fluxes for hundreds of years with maximum temperature reaching about 100-150 deg. C in the nearfield argillaceous environment. The long-term behavior of clays subjected to such thermal gradients needs to be perfectly understood in safety assessment considerations. In this respect, a Toarcian argillaceous unit thermally disturbed by the intrusion of a 1.1-m wide basaltic dike at the Perthus pass (Herault, France), was studied in detail as a natural analogue. The thermal imprint induced by the dike was evaluated by a mineralogical, chemical and K-Ar study of the <2 μm clay fraction of shale samples collected at increasing distance from the basalt. The data suggest that the mineral composition of the shales was not significantly disturbed when the temperature was below 100-150 deg. C. Closer to the dike at 150-300 deg. C, changes such as progressive dissolution of chlorite and kaolinite, increased content of the mixed layers illite-smectite with more illite layers, complete decalcification and subsequent increased content of quartz, were found. At the eastern contact with the dike, the mineral and chemical compositions of both the shales and the basalt suggest water-rock interactions subsequent to the intrusion with precipitation of palagonite and renewed but discrete deposition of carbonate. A pencil cleavage developed in the shales during the dike emplacement probably favored water circulation along the contact. Strontium isotopic data suggest that the fluids of probable meteoric origin, reacted with Bathonian and Bajocian limestones before entering the underlying Toarcian shales. By analogy with deep geological radioactive waste repositories, the results report discrete mineralogical variations of the clays when subjected to temperatures of 100-150 deg. C that are expected in deep storage conditions. Beyond 150 deg. C, significant mineralogical changes may alter the physical and

  11. Process of recovering shale oil

    Energy Technology Data Exchange (ETDEWEB)

    1949-01-17

    A process is disclosed for recovering oil from shale rock by means of channels cut in the shale deposit, to which heat is carried for warming the shale mass and which are separated from the fume channels formed in the shale by parts of the shale rock, characterized in that heating elements are put down in the heating channels, which occupy less cross section than these channels, and in the so-formed space between the channel wall and the heating element a filling is placed, which facilitates heat transfer between the heating element and the shale and simultaneously prevents a streaming of the oily product gasified out of the shale from working into the heating element and stopping it.

  12. Some clastic rocks as parent rocks in beech forests of Brezovica - Južni Kučaj

    Directory of Open Access Journals (Sweden)

    Joksimović Vesna

    2003-01-01

    Full Text Available On the large forest areas, where the measures of soil quality improvement are absent or rarely undertaken, the rocks are the sources of a great number of elements in plant nutrition and one of the factors affecting the contents of some elements in plants. The aim of the study is to determine the differences in the contents of Cu, Zn, Mn, Ni, Fe, Cd, Co, Pb and Cr in the beech leaves developed in the same climate conditions, on morphologically similar terrains, composed of different types of sedimentary rocks. This paper presents the study results of the contents of the above elements in argillites, sandstones (grauwackes and microconglomerates occurring as the parent rocks in high beech forests in the region of GJ Bogovina (Brezovica Južni Kučaj and in the leaves of beech developed on these rocks.

  13. Basal Ottawa Limestone, Chattanooga Shale, Floyd Shale, Porters Creek Clay, and Yazoo Clay in parts of Alabama, Mississippi and Tennessee as potential host rocks for underground emplacement of waste

    International Nuclear Information System (INIS)

    Mellen, F.F.

    1976-01-01

    Impermeable rock units, preferably at least 500 feet thick and lying 1000 to 3000 feet below land surface, were sought in the region consisting roughly of the western 3 / 5 ths of Tennessee and the northern 3 / 5 ths of Alabama and Mississippi. All rock sequences, Cambrian through Eocene, were examined in varying detail, except the Cretaceous Selma Chalk and except the diapiric salt. These rocks were studied for their relative impermeable homogeneity, their continuity, their background of structural and seismic stability and their hydrologic associations. The Central Mississippi Ridge of north-central Mississippi is overlain by a long-stable mass of Porters Creek Clay 500-700 feet thick, in an area roughly 50-60 miles wide and about 150 miles long. The Yazoo Clay, where best developed in the west-central and southwest part of Mississippi, is in the 400-500 foot thickness range, but locally exceeds 500 feet. The entire area mapped is underlain by the Louann Salt which has produced many deep-seated salt domes and numerous piercement salt domes. Salt flow has complicated shallow structural geology throughout that area. The Chattanooga Shale rarely exceeds 60 feet in thickness in the region studied and is generally much thinner and is absent in many places. In the lower part of the Middle Ordovician (Ottawa Megagroup), the Murphreesboro and associated dense limestones appear to offer a potential disposal unit 250-400 feet thick, having the advantages of rock competency and freedom from association with prolific aquifers in the overburden or beneath. Other less conspicuous stratigraphic units are reviewed

  14. Shale gas. Shale gas formation and extraction

    International Nuclear Information System (INIS)

    Renard, Francois; Artru, Philippe

    2015-10-01

    A first article recalls the origin of shale gases and technological breakthroughs which allowed their exploitation, describes the development of shale gas exploitation in the USA during the 2000's and the consequences for the gas and electricity markets, and discusses the various environmental impacts (risks of pollution of aquifers, risks of induced seismicity, use and processing of drilling and production waters). The second article describes the formation of shale gas: presence of organic matter in sediments, early evolution with the biogenic gas, burrowing, diagenesis and oil formation, thermal generation of gas (condensates and methane). The author indicates the location of gas within the rock, and the main sites of shale oils and shale gases in the World. In the next part, the author describes the various phases of shale gas extraction: exploration, oriented drillings, well preparation for hydraulic fracturing, fracturing, processing of fracturing fluids, flow-back, gas production and transport, aquifer protection. He finally gives a brief overview of technical evolution and of shale gas economy

  15. Shale distillation

    Energy Technology Data Exchange (ETDEWEB)

    Blanding, F H

    1946-08-29

    A continuous method of distilling shale to produce valuable hydrocarbon oils is described which comprises providing a fluidized mass of the shale in a distillation zone, withdrawing hydrocarbon vapors from the zone, mixing fresh cold shale with the hydrocarbon vapors to quench the same, whereby the fresh shale is preheated, recovering hydrocarbon vapors and product vapors from the mixture and withdrawing preheated shale from the mixture and charging it to a shale distillation zone.

  16. Improvements in shale retorts

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, A C

    1915-05-01

    This invention has reference to shale retorts and particularly related to the discharge of the spent material from the bottom of retorts or gas producers for the destructive distillation of shale, coal or other bituminous substances. It consists in the combination of a blade and means for rocking the same, a bottom piece or table, holes or slots in the same, a passage in the front brick-work of the retort, and a hopper with discharge doors.

  17. Organic-rich shales from internal Betic basins (SE Spain): potential source rocks analogs for the pre-Messinian Salt play in the western Mediterranean

    Energy Technology Data Exchange (ETDEWEB)

    Permanyer, A.; Jorge, R.; Baudino, R.; Gilbert, L.

    2016-07-01

    Southeastern Spain has a large number of Late Neogene basins with substantial evaporitic deposits that developed under an overall NNW-SSE compressional regime related to the African-European tectonic plates collision. Located in the Betic Cordillera, they can be considered as marginal Mediterranean basins that became gradually isolated during the Tortonian and Early Messinian due to tectonic uplift. Different evaporitic units accumulated in these basins during isolation and, in several cases, evaporitic conditions were associated to episodes of important organic matter accumulation. Results obtained from Late Tortonian to Early Messinian shales collected from boreholes, mines and outcrops in the internal Betic basins of Las Minas de Hellín, Cenajo and Socovos are presented. The organic matter was studied under fluorescence and scanning electron microscopy (SEM), and the main geochemical characteristics defined. They show a relation between organic-rich intervals with high potential of hydrocarbon generation, native sulfur, bio-induced dolomite and evaporitic deposits. These organicrich shales can be found before, during and after the evaporitic episodes. Results from the present study are compared with those previously obtained in the pre-evaporitic deposits of the Lorca Basin that showed high oil generation potential, a restricted-marine origin of the organic matter and a low degree of maturity. The occurrence of such potential source rocks in several basins points to a broad regional distribution. At a larger scale, in the Mediterranean Basin, organic-rich sediments were deposited before and during the Messinian Salinity Crisis. The studied examples could represent analogs for potential source rocks of the pre-Messinian salt play in the Western Mediterranean. (Author)

  18. Origin of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham-Craig, E H

    1915-01-01

    Kerogen was believed to be formed by the inspissation of petroleum. During this process nitrogen and sulfur compounds were concentrated in the most inspissated or weathered products. At a certain stage, reached gradually, the organic matter became insoluble in carbon-disulfide and ceased to be a bitumen. Oil shale was formed by the power of certain clays or shales to absorb inspissated petroleum, particularly unsaturated hydrocarbons. This adsorption apparently depended on the colloid content of the argillaceous rock. This rock retained these impregnated petroleum residues long after porous sandstones in the vicinity had lost all traces of petroleum by weathering and leaching.

  19. Adsorption of hydraulic fracturing fluid components 2-butoxyethanol and furfural onto granular activated carbon and shale rock.

    Science.gov (United States)

    Manz, Katherine E; Haerr, Gregory; Lucchesi, Jessica; Carter, Kimberly E

    2016-12-01

    The objective of this study was to understand the adsorption ability of a surfactant and a non-surfactant chemical additive used in hydraulic fracturing onto shale and GAC. Experiments were performed at varying temperatures and sodium chloride concentrations to establish these impacts on the adsorption of the furfural (a non-surfactant) and 2-Butoxyethanol (2-BE) (a surfactant). Experiments were carried out in continuously mixed batch experiments with Langmuir and Freundlich isotherm modeling. The results of the experiments showed that adsorption of these compounds onto shale does not occur, which may allow these compounds to return to the surface in flowback and produced waters. The adsorption potential for these chemicals onto GAC follows the assumptions of the Langmuir model more strongly than those of the Freundlich model. The results show uptake of furfural and 2-BE occurs within 23 h in the presence of DI water, 0.1 mol L -1 sodium chloride, and in lab synthesized hydraulic fracturing brine. Based on the data, 83% of the furfural and 62% of the 2-BE was adsorbed using GAC. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Rock fragment distributions and regolith evolution in the Ouachita Mountains, Arkansas, USA

    Science.gov (United States)

    Jonathan D. Phillips; Ken Luckow; Daniel A. Marion; Kristin R. Adams

    2005-01-01

    Rock fragments in the regolith are a persistent property that reflects the combined influences of geologic controls, erosion, deposition, bioturbation, and weathering. The distribution of rock fragments in regoliths of the Ouachita Mountains, Arkansas, shows that sandstone fragments are common in all layers, even if sandstone is absent in parent material. Shale and...

  1. Shale distillation

    Energy Technology Data Exchange (ETDEWEB)

    Blanding, F H

    1948-08-03

    A continuous method of distilling shale to produce valuable hydrocarbon oils is described, which comprises providing a fluidized mass of the shale in a distillation zone, withdrawing hydrocarbon vapors containing shale fines from the zone, mixing sufficient fresh cold shale with the hydrocarbon vapors to quench the same and to cause condensation of the higher boiling constituents thereof, charging the mixture of vapors, condensate, and cold shale to a separation zone where the shale is maintained in a fluidized condition by the upward movement of the hydrocarbon vapors, withdrawing condensate from the separation zone and recycling a portion of the condensate to the top of the separation zone where it flows countercurrent to the vapors passing therethrough and causes shale fines to be removed from the vapors by the scrubbing action of the condensate, recovering hydrocarbon vapors and product vapors from the separation zone, withdrawing preheated shale from the separation zone and charging it to a shale distillation zone.

  2. Implicit fracture modelling in FLAC3D: Assessing the behaviour of fractured shales, carbonates and other fractured rock types

    NARCIS (Netherlands)

    Osinga, S.; Pizzocolo, F.; Veer, E.F. van der; Heege, J.H. ter

    2016-01-01

    Fractured rocks play an important role in many types of petroleum and geo-energy operations. From fractured limestone reservoirs to unconventionals, understanding the geomechanical behaviour and the dynamically coupled (dual) permeability system is paramount for optimal development of these systems.

  3. shales: a review of their classifications, properties and importance to ...

    African Journals Online (AJOL)

    DJFLEX

    In the Niger Delta petroleum province, the source rocks and seal rocks are the marine/deltaic, plastic and over-pressured shales of Akata and Agbada Formations. KEY WORDS: Shales, Classification, Strength, Composition, Petroleum Industry, Niger Delta. INTRODUCTION. Shales are fine-grained laminated or fissile.

  4. Laboratory characterization of shale pores

    Science.gov (United States)

    Nur Listiyowati, Lina

    2018-02-01

    To estimate the potential of shale gas reservoir, one needs to understand the characteristics of pore structures. Characterization of shale gas reservoir microstructure is still a challenge due to ultra-fine grained micro-fabric and micro level heterogeneity of these sedimentary rocks. The sample used in the analysis is a small portion of any reservoir. Thus, each measurement technique has a different result. It raises the question which methods are suitable for characterizing pore shale. The goal of this paper is to summarize some of the microstructure analysis tools of shale rock to get near-real results. The two analyzing pore structure methods are indirect measurement (MIP, He, NMR, LTNA) and direct observation (SEM, TEM, Xray CT). Shale rocks have a high heterogeneity; thus, it needs multiscale quantification techniques to understand their pore structures. To describe the complex pore system of shale, several measurement techniques are needed to characterize the surface area and pore size distribution (LTNA, MIP), shapes, size and distribution of pore (FIB-SEM, TEM, Xray CT), and total porosity (He pycnometer, NMR). The choice of techniques and methods should take into account the purpose of the analysis and also the time and budget.

  5. Contrasting environmental memories by ancient soils on different parent rocks in the South-western Italian Alps

    Science.gov (United States)

    D'Amico, Michele; Catoni, Marcella; Bonifacio, Eleonora; Zanini, Ermanno

    2014-05-01

    Ancient soils (pre-Holocenic paleosols and vetusols) are uncommon on the Alps, because of the extensive Pleistocenic glaciations which erased most of the previously existing soils, the slope steepness and climatic conditions favoring soil erosion. However, in few sites, particularly in the outermost sections of the Alpine range, Pleistocene glaciers covered only small and scattered surfaces because of the low altitude reached in the basins, and ancient soils could be preserved for long periods of time on particularly stable surfaces. We described and sampled soils on 11 stable surfaces in the Upper Tanaro valley, Ligurian Alps (Southwestern Piemonte, Italy). The sampling sites were characterized by low steepness and elevation between 600 to 1600 m, under present day lower montane Castanea sativa/Ostrya carpinifolia forests, montane Fagus sylvatica and Pinus uncinata forests or montane heath/grazed grassland, on different substrata. In particular, we sampled soils developed on dolomite, limestone, quartzite, gneiss and shales. The soils were always well representative of the pedogenic trends active on the respective parent materials, i.e. the skeletal fraction in each soil was always composed of just one rock type, despite the proximity of lithological boundaries and the small dimensions of the different outcrops, often coexisting on the same stable surface. All the considered profiles showed signs of extremely long pedogenesis and/or different phases of intense pedogenesis interrupted by the deposition of periglacial cover beds in the steepest sites. Up to four phases of intense pedogenesis were recognized where cover beds were developed, presumably during cold Pleistocene phases, as present-day climate is not cold enough to create such periglacial morphologies. In such cases, each cover bed underwent similar pedogenesis, strongly dependent on the parent material: on quartzite, podzols with thick E horizons and well developed placic ones were formed in all phases

  6. A Study of Parental Attitudes and Values Towards Education on the Navajo and Hopi Reservations. Part II, Parental Attitudes [Window Rock].

    Science.gov (United States)

    Biglin, J. E.; And Others

    Objectives of this study were (1) to determine the parental attitudes of those parents who reside in the Chinle, Keams Canyon, Kayenta, Ganado, Window Rock, or Tuba City school district toward public education on the Navajo and Hopi reservations in the areas of teachers, curriculum, social behaviors of children, school services, school policies,…

  7. Investigation of the dielectric properties of shale

    International Nuclear Information System (INIS)

    Martemyanov, Sergey M.

    2011-01-01

    The article is dedicated to investigation of the dielectric properties of oil shale. Investigations for samples prepared from shale mined at the deposit in Jilin Province in China were done. The temperature and frequency dependences of rock characteristics needed to calculate the processes of their thermal processing are investigated. Frequency dependences for the relative dielectric constant and dissipation factor of rock in the frequency range from 0,1 Hz to 1 MHz are investigated. The temperature dependences for rock resistance, dielectric capacitance and dissipation factor in the temperature range from 20 to 600°C are studied. Key words: shale, dielectric properties, relative dielectric constant, dissipation factor, temperature dependence, frequency dependence

  8. Fluid flow from matrix to fractures in Early Jurassic shales

    NARCIS (Netherlands)

    Houben, M.E.; Hardebol, N.J.; Barnhoorn, A.; Boersma, Quinten; Carone, A.; Liu, Y.; de Winter, D.A.M.; Peach, C.J.; Drury, M.R.

    2017-01-01

    The potential of shale reservoirs for gas extraction is largely determined by the permeability of the rock. Typical pore diameters in shales range from the μm down to the nm scale. The permeability of shale reservoirs is a function of the interconnectivity between the pore space and the natural

  9. Fluid flow from matrix to fractures in Early Jurassic shales

    NARCIS (Netherlands)

    Houben, M. E.; Hardebol, N.J.; Barnhoorn, A.; Boersma, Q.D.; Carone, A.; Liu, Y.; de Winter, D. A.M.; Peach, C. J.; Drury, M. R.

    2017-01-01

    The potential of shale reservoirs for gas extraction is largely determined by the permeability of the rock. Typical pore diameters in shales range from the μm down to the nm scale. The permeability of shale reservoirs is a function of the interconnectivity between the pore space and the natural

  10. Fourier Transform Infrared Spectroscopic Determination of Shale ...

    African Journals Online (AJOL)

    acer

    minerals in the mixtures. Samples from a suite of shale reservoir rocks were analysed using standard .... qualitatative and quantitative analysis of soil properties. For example a .... using Cobalt Ka radiation range. Samples were analysed in ...

  11. Distilling shale

    Energy Technology Data Exchange (ETDEWEB)

    Heyl, G E

    1917-02-06

    The yield of oil obtained by distilling shale is increased by first soaking the shale with about 10 percent of its volume of a liquid hydrocarbon for a period of 24 hours or longer. Distillation is carried on up to a temperature of about 220/sup 0/C., and a further 10 percent of hydrocarbon is then added and the distillation continued up to a temperature of about 400/sup 0/C.

  12. Weathering of the New Albany Shale, Kentucky, USA: I. Weathering zones defined by mineralogy and major-element composition

    Science.gov (United States)

    Tuttle, M.L.W.; Breit, G.N.

    2009-01-01

    Comprehensive understanding of chemical and mineralogical changes induced by weathering is valuable information when considering the supply of nutrients and toxic elements from rocks. Here minerals that release and fix major elements during progressive weathering of a bed of Devonian New Albany Shale in eastern Kentucky are documented. Samples were collected from unweathered core (parent shale) and across an outcrop excavated into a hillside 40 year prior to sampling. Quantitative X-ray diffraction mineralogical data record progressive shale alteration across the outcrop. Mineral compositional changes reflect subtle alteration processes such as incongruent dissolution and cation exchange. Altered primary minerals include K-feldspars, plagioclase, calcite, pyrite, and chlorite. Secondary minerals include jarosite, gypsum, goethite, amorphous Fe(III) oxides and Fe(II)-Al sulfate salt (efflorescence). The mineralogy in weathered shale defines four weathered intervals on the outcrop-Zones A-C and soil. Alteration of the weakly weathered shale (Zone A) is attributed to the 40-a exposure of the shale. In this zone, pyrite oxidization produces acid that dissolves calcite and attacks chlorite, forming gypsum, jarosite, and minor efflorescent salt. The pre-excavation, active weathering front (Zone B) is where complete pyrite oxidation and alteration of feldspar and organic matter result in increased permeability. Acidic weathering solutions seep through the permeable shale and evaporate on the surface forming abundant efflorescent salt, jarosite and minor goethite. Intensely weathered shale (Zone C) is depleted in feldspars, chlorite, gypsum, jarosite and efflorescent salts, but has retained much of its primary quartz, illite and illite-smectite. Goethite and amorphous FE(III) oxides increase due to hydrolysis of jarosite. Enhanced permeability in this zone is due to a 14% loss of the original mass in parent shale. Denudation rates suggest that characteristics of Zone C

  13. A Damage Constitutive Model for the Effects of CO2-Brine-Rock Interactions on the Brittleness of a Low-Clay Shale

    Directory of Open Access Journals (Sweden)

    Qiao Lyu

    2018-01-01

    Full Text Available CO2 is a very promising fluid for drilling and nonaqueous fracturing, especially for CO2-enhanced shale gas recovery. Brittleness is a very important characteristic to evaluate the drillability and fracability. However, there is not much relevant research works on the influence of CO2 and CO2-based fluids on shale’s brittleness been carried out. Therefore, a series of strength tests were conducted to obtain the stress-strain characteristics of shale soaked in different phases of CO2 including subcritical or supercritical CO2 with formation of water for different time intervals (10 days, 20 days, and 30 days. Two damage constitutive equations based on the power function distribution and Weibull distribution were established to predict the threshold stress for both intact and soaked shale samples. Based on the results, physical and chemical reactions during the imbibition cause reductions of shales’ peak axial strength (20.79%~61.52% and Young’s modulus (13.14%~62.44%. Weibull distribution-based constitutive model with a damage threshold value of 0.8 has better agreement with the experiments than that of the power function distribution-based constitutive model. The energy balance method together with the Weibull distribution-based constitutive model is applied to calculate the brittleness values of samples with or without soaking. The intact shale sample has the highest BI value of 0.9961, which is in accordance with the high percentage of brittleness minerals of the shale samples. The CO2-NaCl-shale interactions during the imbibition decrease the brittleness values. Among the three soaking durations, the minimum brittleness values occur on samples with 20 days’ imbibition in subcritical and supercritical CO2 + NaCl solutions and the reductions of which are 2.08% and 2.49%, respectively. Subcritical/supercritical CO2 + NaCl imbibition has higher effect on shale’s strength and Young’s modulus than on the brittleness. The

  14. Implementation of an anisotropic mechanical model for shale in Geodyn

    Energy Technology Data Exchange (ETDEWEB)

    Attia, A; Vorobiev, O; Walsh, S

    2015-05-15

    The purpose of this report is to present the implementation of a shale model in the Geodyn code, based on published rock material models and properties that can help a petroleum engineer in his design of various strategies for oil/gas recovery from shale rock formation.

  15. Distilling shale

    Energy Technology Data Exchange (ETDEWEB)

    Kern, L

    1922-07-21

    In the distillation of shale and similar materials the shale is ground and briquetted and the briquettes are placed in a retort so that air passages are left between them, after which they are uniformly and slowly heated to at least 700/sup 0/C, the air passages facilitating the escape of the oil vapors, and the slow heating preventing fusion of the flux forming constituents. After the bitumen has been driven off, air is passed into the retort and heating continued to about 1050/sup 0/C, the result being a porous product suitable for insulating purposes or as a substitute for kieselguhr. The ground shale may be mixed prior to distillation with peat, sawdust, or the like, and with substances which yield acids, such as chlorides, more particularly magnesium chloride, the acids acting on the bitumen.

  16. Correlation between parent and daughter element concentrations as a means of valuing isochrons of igneous rocks

    International Nuclear Information System (INIS)

    Wetzel, K.

    1989-01-01

    The question whether a series of samples from an igneous rock can be attributed to an isochron for radiogeochronological dating or for determining the initial isotope ratio of the daughter element of the radioactive decay can be valued by investigating the correlation between the concentrations 1 c and 2 c of mother ( 1 c) and daughter element ( 2 c). The slope of the regression line in a lg 1 c to lg 2 c diagram is given by 1 D - 1/ 2 D - 1 or 1 D - 1/ 2 D - 1 · 2 D/ 1 D, where 1 D and 2 D are the solid-liquid distribution coefficients of parent and daughter element, if the concentration patterns are ruled by fractional crystallization or by partial melting, respectively. The agreement between experimentally found slopes and those calculated from distribution coefficients thus gives additional evidence whether or not the isochron reflects a magma solidification or magma generation age, respectively. The method is discussed for the Rb-Sr-, Sm-Nd-, La-Ce-, La-Ba- and K-Ca-geochronometers, using distribution coefficients calculated on the basis of a global model of the generation of the most abundant continental igneous rocks. The application on Rb-Sr-isochrons of a series of various granites of the Erzgebirge and the Saxonian Granulite Massif in the Southern Part of the GDR reveals new evidence of postmagmatic autosomatosis having altered the chemical composition of the Younger granites of the Western Ore Mountains (Erzgebirge). (author)

  17. Shale distillation

    Energy Technology Data Exchange (ETDEWEB)

    Jacomini, V V

    1938-06-07

    To produce valuable oils from shale by continuous distillation it is preheated by a heated fluid and introduced into a distilling retort from which the oil vapours and spent material are separately removed and the vapours condensed to recover the oil. The shale is preheated to 400 to 500/sup 0/F in the hopper by combustion gases from a flue and is fed in measured quantities to a surge drum, a loading chamber and surge drum, the latter two being connected to a steam pipe which equalises the pressure thereon. The material passes by two screw conveyors to a retort with deflector bars to scatter the material so that lean hot cycling gas flowing through a pipe is spread out as it makes its way upwardly through the shale and heats the oil so that it is driven off as vapour, collected in the lean gas and carried off through an outlet pipe. A measuring valve is provided at the bottom of a retort and cutter knives cut the spent shale and distribute cooling water thereto. The gases travel through heat exchangers and a condenser to an accumulator where the cycling gas is separated from the vapours, passed to compression, and preheated in a gas exchanger and spiral coils before it is returned to the retort. The oil passes to a storage tank by way of a unit tank in which oil vapours are recovered. Water is collected by a pipe in the tank bottom and returned by shaft to a retort.

  18. Shale processing

    Energy Technology Data Exchange (ETDEWEB)

    Hampton, W H

    1928-05-29

    The process of treating bituminiferous solid materials such as shale or the like to obtain valuable products therefrom, which comprises digesting a mixture of such material in comminuted condition with a suitable digestion liquid, such as an oil, recovering products vaporized in the digestion, and separating residual solid matter from the digestion liquid by centrifuging.

  19. [Effect of Different Purple Parent Rock on Removal Rates of Nitrogen, Phosphorus and Organics in Landscape Water].

    Science.gov (United States)

    Huang, Xue-jiao; Liu, Xiao-chen; Li, Zhen-lun; Shi, Wen-hao; Yang, Shan

    2015-05-01

    In order to understand the impacts of physicochemical properties of purple parent rock on the removal rates of nitrogen, phosphorus and organics in landscape water systems, four types of purple parent rocks including Peng-lai-zhen Formation (S1) , Sha-xi-miao Formation (S2) , Fei-xian-guan Formation (S3) and Sui-ning Formation (S4) , which distribute widely in Chongqing, were selected and autoclaved, and added to unsterile landscape water collected from Chong-de Lake in Southwest University, and the landscape water only was used as control. And several indicators such as total nitrogen and phosphorus and so on of every disposal were investigated periodically. The results indicated that: (1) The highest removal rates of total nitrogen, total phosphorus and Ammonia nitrogen were observed in Sl, which were 45.1%, 62.3% and 90%, respectively; the highest removal rate of COD was 94.5% in S4; the ammonia nitrogen content in the purple parent rocks was not obviously changed before and after the experiments, which indicated that the adsorption of ammonia nitrogen on purple parent rock surface was not the main reason for the decrease of ammonia nitrogen in water. (2) Arsenate had inhibitory effect on the sulfate-reducing bacteria, while copper and magnesium had promoting effect on gram-negative bacteria. (3) The microbial diversity was positively correlated to total nitrogen in water. (4) Based on the PCA analyses of microbial community structure and environmental factors, the mineral elements released from parent rock affected the structure and composition of microbial community in the test water, and then influenced the removal rates of nitrogen, phosphorus and organics in water systems.

  20. Distillation of shale

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J

    1877-01-05

    The retort consists of a trough fitted with a hood, the edges of which hood dip into a channel of water formed round the sides of the trough, and thereby seal the retort. The shale is introduced at one end of the hood through a double-valved inlet hopper, and is moved along the retort by transverse scrapers or paddles. At the other end it falls through a double-valved outlet upon a set of firebars which carry it along under the retort, where either alone or in admixture with other fuel it is used for heating the vessel. The vapors from the shale pass off through pipes in the hood, or an inverted channel may be formed along the center of the hood for collecting the vapors from different parts of the vessel. The scrapers are worked by rocking shafts supported on bearings in the edges of the trough, and are made to feather when moving in a direction from the discharged end. Levers from the rocking shafts project down into the water channel, where they are connected with horizontal bars made to reciprocate longitudinally by suitable means, thus working the scrapers without using stuffing-boxes. Rotating scrapers may be substituted for the reciprocating ones.

  1. Gas pressure from a nuclear explosion in oil shale

    International Nuclear Information System (INIS)

    Taylor, R.W.

    1975-01-01

    The quantity of gas and the gas pressure resulting from a nuclear explosion in oil shale is estimated. These estimates are based on the thermal history of the rock during and after the explosion and the amount of gas that oil shale releases when heated. It is estimated that for oil shale containing less than a few percent of kerogen the gas pressure will be lower than the hydrostatic pressure. A field program to determine the effects of nuclear explosions in rocks that simulate the unique features of oil shale is recommended. (U.S.)

  2. Diffusive transport and reaction in clay rocks: A storage (nuclear waste, CO2, H2), energy (shale gas) and water quality issue

    Science.gov (United States)

    Charlet, Laurent; Alt-Epping, Peter; Wersin, Paul; Gilbert, Benjamin

    2017-08-01

    Clay rocks are low permeability sedimentary formations that provide records of Earth history, influence the quality of water resources, and that are increasingly used for the extraction or storage of energy resources and the sequestration of waste materials. Informed use of clay rock formations to achieve low-carbon or carbon-free energy goals requires the ability to predict the rates of diffusive transport processes for chemically diverse dissolved and gaseous species over periods up to thousands of years. We survey the composition, properties and uses of clay rock and summarize fundamental science challenges in developing confident conceptual and quantitative gas and solute transport models.

  3. Shale treatment

    Energy Technology Data Exchange (ETDEWEB)

    1941-03-03

    The charge of shale, coal, or the like, is placed in a cartridge which is inserted in a metal cylinder gas and/or steam heated to a temperature of between 300 to 500/sup 0/C is admitted through pipe and passes through two perforations through the charge which is held at a pressure of about .1 to 2 pounds per square inch and an out pipe together with evolved gases and vapours. A lid is clamped in position over the cartridge by means of an eye bolt and a nut.

  4. Geology, sequence stratigraphy, and oil and gas assessment of the Lewis Shale Total Petroleum System, San Juan Basin, New Mexico and Colorado: Chapter 5 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado

    Science.gov (United States)

    Dubiel, R.F.

    2013-01-01

    The Lewis Shale Total Petroleum System (TPS) in the San Juan Basin Province contains a continuous gas accumulation in three distinct stratigraphic units deposited in genetically related depositional environments: offshore-marine shales, mudstones, siltstones, and sandstones of the Lewis Shale, and marginal-marine shoreface sandstones and siltstones of both the La Ventana Tongue and the Chacra Tongue of the Cliff House Sandstone. The Lewis Shale was not a completion target in the San Juan Basin (SJB) in early drilling from about the 1950s through 1990. During that time, only 16 wells were completed in the Lewis from natural fracture systems encountered while drilling for deeper reservoir objectives. In 1991, existing wells that penetrated the Lewis Shale were re-entered by petroleum industry operators in order to fracture-stimulate the Lewis and to add Lewis gas production onto preexisting, and presumably often declining, Mesaverde Group production stratigraphically lower in the section. By 1997, approximately 101 Lewis completions had been made, both as re-entries into existing wells and as add-ons to Mesaverde production in new wells. Based on recent industry drilling and completion practices leading to successful gas production from the Lewis and because new geologic models indicate that the Lewis Shale contains both source rocks and reservoir rocks, the Lewis Shale TPS was defined and evaluated as part of this U.S. Geological Survey oil and gas assessment of the San Juan Basin. Gas in the Lewis Shale Total Petroleum System is produced from shoreface sandstones and siltstones in the La Ventana and Chacra Tongues and from distal facies of these prograding clastic units that extend into marine rocks of the Lewis Shale in the central part of the San Juan Basin. Reservoirs are in shoreface sandstone parasequences of the La Ventana and Chacra and their correlative distal parasequences in the Lewis Shale where both natural and artificially enhanced fractures produce

  5. Geology of the Devonian black shales of the Appalachian Basin

    Science.gov (United States)

    Roen, J.B.

    1984-01-01

    Black shales of Devonian age in the Appalachian Basin are a unique rock sequence. The high content of organic matter, which imparts the characteristic lithology, has for years attracted considerable interest in the shales as a possible source of energy. The recent energy shortage prompted the U.S. Department of Energy through the Eastern Gas Shales Project of the Morgantown Energy Technology Center to underwrite a research program to determine the geologic, geochemical, and structural characteristics of the Devonian black shales in order to enhance the recovery of gas from the shales. Geologic studies by Federal and State agencies and academic institutions produced a regional stratigraphic network that correlates the 15 ft black shale sequence in Tennessee with 3000 ft of interbedded black and gray shales in central New York. These studies correlate the classic Devonian black shale sequence in New York with the Ohio Shale of Ohio and Kentucky and the Chattanooga Shale of Tennessee and southwestern Virginia. Biostratigraphic and lithostratigraphic markers in conjunction with gamma-ray logs facilitated long-range correlations within the Appalachian Basin. Basinwide correlations, including the subsurface rocks, provided a basis for determining the areal distribution and thickness of the important black shale units. The organic carbon content of the dark shales generally increases from east to west across the basin and is sufficient to qualify as a hydrocarbon source rock. Significant structural features that involve the black shale and their hydrocarbon potential are the Rome trough, Kentucky River and Irvine-Paint Creek fault zone, and regional decollements and ramp zones. ?? 1984.

  6. Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale

    Science.gov (United States)

    Shao, Deyong; Ellis, Geoffrey S.; Li, Yanfang; Zhang, Tongwei

    2018-01-01

    Gold-tube pyrolysis experiments were conducted on miniature core plugs and powdered rock from a bitumen-rich sample of Eagle Ford Shale to investigate the role of rock fabric in gas generation and expulsion during thermal maturation. The samples were isothermally heated at 130, 300, 310, 333, 367, 400, and 425 °C for 72 h under a confining pressure of 68.0 MPa, corresponding to six levels of induced thermal maturity: pre-oil generation (130 °C/72 h), incipient oil/bitumen generation (300 and 310 °C/72 h), early oil generation (333 °C/72 h), peak oil generation (367 °C/72 h), early oil cracking (400 °C/72 h), and late oil cracking (425 °C/72 h). Experimental results show that gas retention coupled with compositional fractionation occurs in the core plug experiments and varies as a function of thermal maturity. During the incipient oil/bitumen generation stage, yields of methane through pentane (C1–C5) from core plugs are significantly lower than those from rock powder, and gases from core plugs are enriched in methane. However, the differences in C1–C5 gas yield and composition decrease throughout the oil generation stage, and by the oil cracking stage no obvious compositional difference in C1–C5 gases exists. The decrease in the effect of rock fabric on gas yield and composition with increasing maturity is the result of an increase in gas expulsion efficiency. Pyrolysis of rock powder yields 4–16 times more CO2 compared to miniature core plugs, with δ13CCO2 values ranging from −2.9‰ to −0.6‰, likely due to carbonate decomposition accelerated by reactions with organic acids. Furthermore, lower yields of gaseous alkenes and H2 from core plug experiments sugge

  7. Distilling shale

    Energy Technology Data Exchange (ETDEWEB)

    Justice, P M

    1917-09-19

    Light paraffin oils and other oils for motors are obtained from shale, and benzene, toluene, and solvent naphtha are obtained from coal by a process in which the coal or shale is preferably powered to pass through a mesh of 64 to the inch and is heated with a mixture of finely ground carbonate or the like which under the action of heat gives off carbonic acid, and with small iron scrap or its equivalent which is adapted to increase the volume of hydrocarbons evolved. The temperature of the retort is maintained between 175 and 800/sup 0/C., and after all the vapors are given off at the higher temperature a fine jet of water may be injected into the retort and the temperature increased. The produced oil is condensed and purified by fractional distillation, and the gas formed is stored after passing it through a tower packed with coke saturated with a non-volatile oil with recovery of an oil of light specific gravity which is condensed in the tower. The residuum from the still in which the produced oil is fractionated may be treated with carbonate and iron, as in the first stage of the process, and the distillate therefrom passed to a second retort containing manganese dioxide and iron scrap preferably in the proportion of one part or two. The mixture, e.g., one containing shale or oil with six to thirteen percent of oxygen, to which is added three to eight per cent of carbonate, and from one and a half to four per cent of scrap iron, is conveyed by belts and an overhead skip to a hopper of a retort in a furnace heated by burners supplied with producer gas. The retort is fitted with a detachable lid and the vapors formed are led by a pipe to a vertical water-cooled condenser with a drain-cock which leads the condensed oils to a tank, from which a pipe leads to a packed tower for removing light oils and from which the gas passes to a holder.

  8. Shale retort

    Energy Technology Data Exchange (ETDEWEB)

    Overton, P C

    1936-07-22

    A vertical distillation retort with an enclosed annular heating chamber has enclosed therein tiered compartments spaced apart by chambers into which burners deliver heating gases which pass via ports to the chamber and thence to the atmosphere. Shale is delivered by means of an air tight chute to the uppermost compartment and is spread therein and passed downwardly from compartment to compartment through ports, finally passing from the retort through an airtight chute, by means of scrapers rotatably mounted on a hollow shaft through which noncondensible gases are delivered to the distilling material via jets. The gaseous products of distillation are educted through ports and a manifold, which is also in communication with the head of the retort through the delivery pipe.

  9. Distilling shale

    Energy Technology Data Exchange (ETDEWEB)

    Armour, J; Armour, H

    1889-05-07

    The invention relates to retorts and accessory apparatus for distilling shale or other oil-yielding minerals. A series of long vertical retorts, composed of fire-brick or similar refractory material, are arranged in two rows in a bench, being divided into groups of four by transverse vertical partitions. The retorts are surmounted by metal casings or hoppers into which the fresh mineral is charged, and from which the distillate passes off through lateral pipes. Any uncondensed gases from the retorts may be passed into the flues surrounding them by the pipe and burned. The products of combustion from a furnace pass through a series of horizontal flues, being compelled to pass completely round each retort before entering the flue above. The products from two or more sets pass from the upper flues into flues running along the top of the bench, and return through a central flue to the chimney.

  10. A review of the organic geochemistry of shales and possible interactions between the organic matter of shales and radionuclides

    International Nuclear Information System (INIS)

    Ho, P.C.

    1990-01-01

    Shale formations have been suggested as potential host rocks for high level nuclear waste repositories. Several studies have demonstrated the interactions of nuclides with organic compounds found in shales. In order to understand the possibility of interaction between organic components of shales and trace elements, literature on the identification of organic compounds from various shales of the continental United States and evidences of interactions have been reviewed first. The Green River Formation of the Cenozoic era is the most studied shale followed by the Pierre Shale of the Mesozoic era and the Devonian Black Shale of the Paleozoic era. Organic compounds that have been identified from these shales are mainly hydrocarbons and carboxylates along with small amounts of other compounds. These organic compounds, however, constitute only a small fraction of the organic matter in shales; the majority of the organic compounds in shales are still unidentified. Interaction between organics and trace elements are found mostly due to the formation of complexes between carboxylates of shales and the elements. (orig.)

  11. Geothermal alteration of clay minerals and shales: diagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.E.

    1979-07-01

    The objective of this report is to perform a critical review of the data on the mineral and chemical alterations that occur during diagenesis and low-grade metamorphism of shale and other clay-rich rocks - conditions similar to those expected from emplacement of heat-producing radioactive waste in a geologic repository. The conclusions drawn in this document are that the following type of alterations could occur: smectite alteration, ion mobilization, illitic shales, kaolinite reactions, chlorite reactions, organic reactions, paleotemperatures, low temperature shales, high temperature shales, and phase equilibrium changes.

  12. Geothermal alteration of clay minerals and shales: diagenesis

    International Nuclear Information System (INIS)

    Weaver, C.E.

    1979-07-01

    The objective of this report is to perform a critical review of the data on the mineral and chemical alterations that occur during diagenesis and low-grade metamorphism of shale and other clay-rich rocks - conditions similar to those expected from emplacement of heat-producing radioactive waste in a geologic repository. The conclusions drawn in this document are that the following type of alterations could occur: smectite alteration, ion mobilization, illitic shales, kaolinite reactions, chlorite reactions, organic reactions, paleotemperatures, low temperature shales, high temperature shales, and phase equilibrium changes

  13. Shale: an overlooked option for US nuclear waste disposal

    Science.gov (United States)

    Neuzil, Christopher E.

    2014-01-01

    Toss a dart at a map of the United States and, more often than not, it will land where shale can be found underground. A drab, relatively featureless sedimentary rock that historically attracted little interest, shale (as used here, the term includes clay and a range of clay-rich rocks) is entering Americans’ consciousness as a new source of gas and oil. But shale may also offer something entirely different—the ability to safely and permanently house high-level nuclear waste.

  14. Fourier Transform Infrared Spectroscopic Determination of Shale ...

    African Journals Online (AJOL)

    A Classical Least Square (CLS) model was developed from the attenuated spectra of mixtures of five mineral standards chosen to represent the most frequently encountered minerals in shale-type reservoir rocks namely: quartz, illite/smectite (30:70), kaolinite, calcite and dolomite. The CLS model developed was able to ...

  15. Shale engineering application: the MAL-145 project in West Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Vassilellis, George D.; Li, Charles; Bust, Vivian K. [Gaffney, Cline and Associates (United States); Moos, Daniel; Cade, Randal [Baker Hughes Inc (United States)

    2011-07-01

    With the depletion of conventional fossil fuels and the rising energy demand, oil shale and shale gas are becoming an important component of the oil and gas markets in North America. The aim of this paper is to present a novel methodology for predicting production in shale and tight formations. This method, known as the shale engineering approach and modeling, provides reservoir simulations based on modeling the propagation of the simulated rock volume. This technique was applied to an Upper Devonian shale formation in West Virginia, United States, and was compared to available data such as production logs and downhole microseismic data. Results showed a good match between the shale engineering approach data and early well performance. This paper presented a new reservoir simulation methodology which is successful in forecasting production and which can also be used for field development design and optimization.

  16. The shale gas potential of the Opalinus Clay and Posidonia Shale in Switzerland - A first assessment

    Energy Technology Data Exchange (ETDEWEB)

    Leu, W. [Geoform Ltd, Villeneuve (Switzerland); Gautschi, A. [NAGRA, Wettingen (Switzerland)

    2014-07-01

    There has been recent interest in the shale gas potential of the Opalinus Clay and Posidonia Shale (Middle and Lower Jurassic) below the Swiss Molasse Basin in the light of the future role of domestic gas production within the expected future energy shift of Switzerland and possible conflicts in underground use. The Opalinus Clay of northern Switzerland is a potential host rock for repositories of both high-level and low-to-intermediate level radioactive waste and the exploitation of shale gas resources within or below this formation would represent a serious conflict of use. Well data from northern Switzerland shows that these two formations are unsuitable for future shale gas recovery. They never reached the gas window during their burial history (maturity values are ≤ 0.6% R{sub o}) and as a consequence never generated significant quantities of thermogenic gas. Geochemical data further shows that the average TOC values are in the range of 0.7%, i.e. clearly below accepted values of more than 1.5% for prospective shales. A review of available exploration data for the Opalinus Clay and Posidonia Shale in the deeper and western part of the Swiss Molasse Basin indicate that their shale gas potential may be substantial. The gross Posidonia Shale thickness increases from central Switzerland from less than 10 m to over 100 m in the Yverdon-Geneva area and is characterised by numerous bituminous intervals. A simplified shale gas resource calculation results for a geologically likely scenario in a technically recoverable gas volume of ∼120 billions m{sup 3}. The current database for such estimates is small and as a consequence, the uncertainties are large. However, these first encouraging results support a more detailed exploration phase with specific geochemical and petrophysical analysis of existing rock and well log data. (authors)

  17. The shale gas potential of the Opalinus Clay and Posidonia Shale in Switzerland - A first assessment

    International Nuclear Information System (INIS)

    Leu, W.; Gautschi, A.

    2014-01-01

    There has been recent interest in the shale gas potential of the Opalinus Clay and Posidonia Shale (Middle and Lower Jurassic) below the Swiss Molasse Basin in the light of the future role of domestic gas production within the expected future energy shift of Switzerland and possible conflicts in underground use. The Opalinus Clay of northern Switzerland is a potential host rock for repositories of both high-level and low-to-intermediate level radioactive waste and the exploitation of shale gas resources within or below this formation would represent a serious conflict of use. Well data from northern Switzerland shows that these two formations are unsuitable for future shale gas recovery. They never reached the gas window during their burial history (maturity values are ≤ 0.6% R o ) and as a consequence never generated significant quantities of thermogenic gas. Geochemical data further shows that the average TOC values are in the range of 0.7%, i.e. clearly below accepted values of more than 1.5% for prospective shales. A review of available exploration data for the Opalinus Clay and Posidonia Shale in the deeper and western part of the Swiss Molasse Basin indicate that their shale gas potential may be substantial. The gross Posidonia Shale thickness increases from central Switzerland from less than 10 m to over 100 m in the Yverdon-Geneva area and is characterised by numerous bituminous intervals. A simplified shale gas resource calculation results for a geologically likely scenario in a technically recoverable gas volume of ∼120 billions m 3 . The current database for such estimates is small and as a consequence, the uncertainties are large. However, these first encouraging results support a more detailed exploration phase with specific geochemical and petrophysical analysis of existing rock and well log data. (authors)

  18. Rocking the Cradle: Ensuring the Rights of Parents with Disabilities and Their Children

    Science.gov (United States)

    National Council on Disability, 2012

    2012-01-01

    Despite a dark history marked by the eugenics movement, increasing numbers of people with disabilities are choosing to become parents. Recent research reveals that more than 4 million parents--6 percent of American mothers and fathers--are disabled. This number will unquestionably increase as more people with disabilities exercise a broader range…

  19. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 3. Stratigraphies of salt, granite, shale, and basalt

    International Nuclear Information System (INIS)

    1978-04-01

    This study presents the methodology and basic literature used to develop generic stratigraphic sections for the various geologic repository host rocks under considerations: salt, granite, shale and basalt

  20. Process for retorting shale

    Energy Technology Data Exchange (ETDEWEB)

    1952-03-19

    The method of retorting oil shale to recover valuable liquid and gaseous hydrocarbons consists of heating the oil shale in a retorting zone to a temperature sufficient to convert its kerogenic constituents to normally liquid and normally gaseous hydrocarbons by contact with hot gas previously recovered from shale, cooling the gases and vapors effluent from the retorting zone by direct countercurrent contact with fresh shale to condense the normally liquid constituents of the gases and vapors, separating the fixed gas from the liquid product, heating the fixed gas, and returning it to the retorting zone to contact further quantities of shale.

  1. Male rock sparrows adjust their breeding strategy according to female ornamentation: parental or mating investment?

    DEFF Research Database (Denmark)

    Pilastro, Andrea; Griggio, Matteo; Matessi, Giuliano

    2003-01-01

    We investigated the relations between female quality and ornamentation and between male breeding investment and female ornamentation in the rock sparrow, Petronia petronia, a passerine in which both sexes have a yellow breast patch. Breast patch size in females was positively correlated with body...

  2. Black shales and naftogenesis. A review

    International Nuclear Information System (INIS)

    Yudovich, Yu.E.; Ketris, M.P.

    1993-01-01

    A genetic relation between petroleum plus hydrocarbon gases and bio organic authigenic matter has been well established. As black shales are enriched in organic matter they may serve as potential petroleum beds on the depths suitable for petroleum generation (2-5 km). The calculations made by petroleum geologists showed that hydrocarbon amounts generated by black shales made up to one fifth of the initial organic matter at the end of MK-2 stage of catagenesis. Consequently, black shales may serve as the main oil producers in many sedimentary basins. Petroleum generation in black shales has some peculiarities. Abundant masses of organic matter generate huge amounts of hydrocarbon gases which in turn produce anomalous high bed pressures followed by pulse cavitation effect. Bed pressures 1.5 times higher than normal lithostatic pressure have been detected in oil-bearing black shales of the Cis-Caucasus on the depth of 2.0-2.5 km, along with very high (6 degrees per 100 m) geothermal gradient. According to Stavropol oil geologists, there occurs an effect of rock-by-fluid-destruction after fluid pressure has greatly exceeded the lithostatic pressure. Stress tensions discharge by impulses and cracks may appear with a rate of 0.3-0.7 of the sound speed. Cavitation of gaseous bubbles is produced by sharp crack extension. Such cavitation accounts for impact waves and increased local pressure and temperature. Such an increase, in turn, fastens petroleum generation and new rock cracking. The effect of over-pressed rocks associated with black shales may serve as a process indicator. That is why the geophysical methods detect enhanced specific gravity and decreased porosity zones in such black shales. Cracks and petroleum accumulation occur on the flanks of such zones of rock-by-fluid-destruction. Some black shales may be petroleum-productive due to enhanced uranium content. There exist ideas about uranium-derived heat or radiolytic effects on the petroleum generation. Such

  3. Oil shale commercialization study

    Energy Technology Data Exchange (ETDEWEB)

    Warner, M.M.

    1981-09-01

    Ninety four possible oil shale sections in southern Idaho were located and chemically analyzed. Sixty-two of these shales show good promise of possible oil and probable gas potential. Sixty of the potential oil and gas shales represent the Succor Creek Formation of Miocene age in southwestern Idaho. Two of the shales represent Cretaceous formations in eastern Idaho, which should be further investigated to determine their realistic value and areal extent. Samples of the older Mesozonic and paleozoic sections show promise but have not been chemically analyzed and will need greater attention to determine their potential. Geothermal resources are of high potential in Idaho and are important to oil shale prospects. Geothermal conditions raise the geothermal gradient and act as maturing agents to oil shale. They also might be used in the retorting and refining processes. Oil shales at the surface, which appear to have good oil or gas potential should have much higher potential at depth where the geothermal gradient is high. Samples from deep petroleum exploration wells indicate that the succor Creek shales have undergone considerable maturation with depth of burial and should produce gas and possibly oil. Most of Idaho's shales that have been analyzed have a greater potential for gas than for oil but some oil potential is indicated. The Miocene shales of the Succor Creek Formation should be considered as gas and possibly oil source material for the future when technology has been perfectes. 11 refs.

  4. Oil shale, shale oil, shale gas and non-conventional hydrocarbons

    Directory of Open Access Journals (Sweden)

    Clerici A.

    2015-01-01

    Full Text Available In recent years there has been a world “revolution” in the field of unconventional hydrocarbon reserves, which goes by the name of “shale gas”, gas contained inside clay sediments micropores. Shale gas finds particular development in the United States, which are now independent of imports and see a price reduction to less than one third of that in Europe. With the high oil prices, in addition to the non-conventional gas also “oil shales” (fine-grained sedimentary rocks that contain a large amount of organic material to be used both to be directly burned or to extract liquid fuels which go under the name of shale oil, extra heavy oils and bitumen are becoming an industrial reality. Both unconventional gas and oil reserves far exceed in the world the conventional oil and gas reserves, subverting the theory of fossil fuels scarcity. Values and location of these new fossil reserves in different countries and their production by comparison with conventional resources are presented. In view of the clear advantages of unconventional fossil resources, the potential environmental risks associated with their extraction and processing are also highlighted.

  5. Preliminary creep and pillar closure data for shales

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Russell, J.E.

    1987-10-01

    The results of fourteen laboratory creep tests on model pillars of four different shales are reported. Initial pillar stresses range from 6.9 MPa (1000 psi) to 69 MPa (10,000 psi) and temperatures range from ambient to 100 0 C. Laboratory response data are used to evaluate the parameters in the transient power-law pillar closure equation similar to that previously used for model pillars of rock salt. The response of the model pillars of shale shows many of the same characteristics as for rock salt. Deformation is enhanced by higher stresses and temperatures, although the shale pillars are not as sensitive to either stress or temperature as are pillars of rock salt. These test results must be considered very preliminary since they represent the initial, or scoping, phase of a comprehensive model pillar test program that will lead to the development and validation of creep laws for clay-rich rocks. 11 refs., 9 figs., 7 tabs

  6. Improving horizontal completions on heterogeneous tight shales

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Rivera, Roberto; Deenadayalu, Chaitanya; Chertov, Maxim; Novalo Hartanto, Ricardo; Gathogo, Patrick [Schlumberger (United States); Kunjir, Rahul [University of Utah (United States)

    2011-07-01

    Evaluation of the two formation characteristics conducive to economic well production is important when tight shale formation characterization and completion design are being considered. This paper presents the basic understanding required to improve the efficiency of horizontal completions in oil and gas producing shales. Guidelines are defined for effective perforation and fracturing to improve the efficiency and sustainability of horizontal completions using extensive laboratory characterization of mechanical properties on core, core/log integration and continuous mapping of these properties by logging-while-drilling (LWD) methods. The objective is to improve completion design efficiency. This is accomplished by suitable selection of perforation intervals based on an understanding of the relevant physical processes and rock characterization. Conditions at two reservoir regions, the near-wellbore and the far-wellbore, are outlined and are essential to completion design. From the study, it can be concluded that tight shales are strongly anisotropic and cannot be approximated using isotropic models.

  7. Cracking mechanism of shale cracks during fracturing

    Science.gov (United States)

    Zhao, X. J.; Zhan, Q.; Fan, H.; Zhao, H. B.; An, F. J.

    2018-06-01

    In this paper, we set up a model for calculating the shale fracture pressure on the basis of Huang’s model by the theory of elastic-plastic mechanics, rock mechanics and the application of the maximum tensile stress criterion, which takes into account such factors as the crustal stress field, chemical field, temperature field, tectonic stress field, the porosity of shale and seepage of drilling fluid and so on. Combined with the experimental data of field fracturing and the experimental results of three axis compression of shale core with different water contents, the results show that the error between the present study and the measured value is 3.85%, so the present study can provide technical support for drilling engineering.

  8. Multiphysical Testing of Soils and Shales

    CERN Document Server

    Ferrari, Alessio

    2013-01-01

    Significant advancements in the experimental analysis of soils and shales have been achieved during the last few decades. Outstanding progress in the field has led to the theoretical development of geomechanical theories and important engineering applications. This book provides the reader with an overview of recent advances in a variety of advanced experimental techniques and results for the analysis of the behaviour of geomaterials under multiphysical testing conditions. Modern trends in experimental geomechanics for soils and shales are discussed, including testing materials in variably saturated conditions, non-isothermal experiments, micro-scale investigations and image analysis techniques. Six theme papers from leading researchers in experimental geomechanics are also included. This book is intended for postgraduate students, researchers and practitioners in fields where multiphysical testing of soils and shales plays a fundamental role, such as unsaturated soil and rock mechanics, petroleum engineering...

  9. Distillation of bituminous shale

    Energy Technology Data Exchange (ETDEWEB)

    Seguin, M

    1875-02-16

    The retort with its accessories constitutes a distillation apparatus for shale composed of a cylindrical, vertical, fixed, tubular, and of ring form metal retort. Also it is comprised of a special hearth of large dimensions in the form of a circular pocket receiving from the retort as heating agent the distilled shale and emitting by radiation the heat that makes the distillation apparatus for the shale act.

  10. Barnett shale completions

    Energy Technology Data Exchange (ETDEWEB)

    Schein, G. [BJ Services, Dallas, TX (United States)

    2006-07-01

    Fractured shales yield oil and gas in various basins across the United States. A map indicating these fractured shale source-reservoir systems in the United States was presented along with the numerous similarities and differences that exist among these systems. Hydrocarbons in the organic rich black shale come from the bacterial decomposition of organic matter, primary thermogenic decomposition of organic matter or secondary thermogenic cracking of oil. The shale may be the reservoir or other horizons may be the primary or secondary reservoir. The reservoir has induced micro fractures or tectonic fractures. This paper described the well completions in the Barnett Shale in north Texas with reference to major players, reservoir properties, mineralogy, fluid sensitivity, previous treatments, design criteria and production examples. The Barnett Shale is an organic, black shale with thickness ranging from 100 to 1000 feet. The total organic carbon (TOC) averages 4.5 per cent. The unit has undergone high rate frac treatments. A review of the vertical wells in the Barnett Shale was presented along with the fracture treatment schedule and technology changes. A discussion of refracturing opportunities and proppant settling and transport revealed that additional proppant increases fluid recovery and enhances production. Compatible scale inhibitors and biocides can be beneficial. Horizontal completions in the Barnett Shale have shown better results than vertical wells, as demonstrated in a production comparison of 3 major horizontal wells in the basin. tabs., figs.

  11. Geothermometry methods for determining the thermal history of shales

    International Nuclear Information System (INIS)

    Weaver, C.E.

    1977-01-01

    When clays and muds are deposited, the clay mineral suite is usually not an equilibrium assemblage. With time and increased depth of burial and temperature, the clay mineral suite undergoes continuous chemical and mineral changes as it adjusts to increasingly higher temperatures. Significant changes are observed at temperatures as low as 50 0 C and continue to 400 0 C (beginning of metamorphism) and above. Once these clay-rich rocks are exposed to elevated temperatures and then later uplifted to areas of lower temperature, no significant changes occur unless the rock is exposed to weathering or to temperatures higher than that to which they have been exposed previously. An initial objective is to develop the ability to determine the mineral, chemical, and textural changes which are produced in shales by increased temperature. This will allow prediction of the diagenetic changes that occur in shales when they are exposed to the heat generated by radioactive waste. A second objective is to develop the ability to determine the maximum temperature to which a shale has been exposed. Once a shale has been exposed to temperatures of 200 to 400 0 C for thousands of years, an equilibrium assemblage is obtained which persists after the shale is elevated to near surface conditions and is only altered if the shale is exposed to temperatures higher than those of the maximum to which the shale was originally exposed. A proposal is made to select for initial study a thick Paleozoic shale, probably of Cambro-Ordovician or Devonian age, in the Appalachian region. A shale sequence will be selected which has rocks ranging from deeply buried geosynclinal environments (approx.300 to 400 0 C) to shallow shelf environments

  12. Petrology of the Devonian gas-bearing shale along Lake Erie helps explain gas shows

    Energy Technology Data Exchange (ETDEWEB)

    Broadhead, R.F.; Potter, P.E.

    1980-11-01

    Comprehensive petrologic study of 136 thin sections of the Ohio Shale along Lake Erie, when combined with detailed stratigraphic study, helps explain the occurrence of its gas shows, most of which occur in the silty, greenish-gray, organic poor Chagrin Shale and Three Lick Bed. Both have thicker siltstone laminae and more siltstone beds than other members of the Ohio Shale and both units also contain more clayshales. The source of the gas in the Chagrin Shale and Three Lick Bed of the Ohio Shale is believed to be the bituminous-rich shales of the middle and lower parts of the underlying Huron Member of the Ohio Shale. Eleven petrographic types were recognized and extended descriptions are provided of the major ones - claystones, clayshales, mudshales, and bituminous shales plus laminated and unlaminated siltstones and very minor marlstones and sandstones. In addition three major types of lamination were identified and studied. Thirty-two shale samples were analyzed for organic carbon, whole rock hydrogen and whole rock nitrogen with a Perkin-Elmer 240 Elemental Analyzer and provided the data base for source rock evaluation of the Ohio Shale.

  13. Characterization of nanoporous shales with gas sorption

    Science.gov (United States)

    Joewondo, N.; Prasad, M.

    2017-12-01

    The understanding of the fluid flow in porous media requires the knowledge of the pore system involved. Fluid flow in fine grained shales falls under different regime than transport regime in conventional reservoir due to the different average pore sizes in the two materials; the average pore diameter of conventional sandstones is on the micrometer scale, while of shales can be as small as several nanometers. Mercury intrusion porosimetry is normally used to characterize the pores of conventional reservoir, however with increasingly small pores, the injection pressure required to imbibe the pores becomes infinitely large due to surface tension. Characterization of pores can be expressed by a pore size distribution (PSD) plot, which reflects distribution of pore volume or surface area with respect to pore size. For the case of nanoporous materials, the surface area, which serves as the interface between the rock matrix and fluid, becomes increasingly large and important. Physisorption of gas has been extensively studied as a method of nanoporous solid characterization (particularly for the application of catalysis, metal organic frameworks, etc). The PSD is obtained by matching the experimental result to the calculated theoretical result (using Density Functional Theory (DFT), a quantum mechanics based modelling method for molecular scale interactions). We present the challenges and experimental result of Nitrogen and CO2 gas sorption on shales with various mineralogy and the interpreted PSD obtained by DFT method. Our result shows significant surface area contributed by the nanopores of shales, hence the importance of surface area measurements for the characterization of shales.

  14. Modified Standard Penetration Test–based Drilled Shaft Design Method for Weak Rocks (Phase 2 Study)

    Science.gov (United States)

    2017-12-15

    In this project, Illinois-specific design procedures were developed for drilled shafts founded in weak shale or rock. In particular, a modified standard penetration test was developed and verified to characterize the in situ condition of weak shales ...

  15. Oil shale technology

    International Nuclear Information System (INIS)

    Lee, S.

    1991-01-01

    Oil shale is undoubtedly an excellent energy source that has great abundance and world-wide distribution. Oil shale industries have seen ups and downs over more than 100 years, depending on the availability and price of conventional petroleum crudes. Market forces as well as environmental factors will greatly affect the interest in development of oil shale. Besides competing with conventional crude oil and natural gas, shale oil will have to compete favorably with coal-derived fuels for similar markets. Crude shale oil is obtained from oil shale by a relatively simple process called retorting. However, the process economics are greatly affected by the thermal efficiencies, the richness of shale, the mass transfer effectiveness, the conversion efficiency, the design of retort, the environmental post-treatment, etc. A great many process ideas and patents related to the oil shale pyrolysis have been developed; however, relatively few field and engineering data have been published. Due to the vast heterogeneity of oil shale and to the complexities of physicochemical process mechanisms, scientific or technological generalization of oil shale retorting is difficult to achieve. Dwindling supplied of worldwide petroleum reserves, as well as the unprecedented appetite of mankind for clean liquid fuel, has made the public concern for future energy market grow rapidly. the clean coal technology and the alternate fuel technology are currently of great significance not only to policy makers, but also to process and chemical researchers. In this book, efforts have been made to make a comprehensive text for the science and technology of oil shale utilization. Therefore, subjects dealing with the terminological definitions, geology and petrology, chemistry, characterization, process engineering, mathematical modeling, chemical reaction engineering, experimental methods, and statistical experimental design, etc. are covered in detail

  16. Experimental Characterization of Dielectric Properties in Fluid Saturated Artificial Shales

    OpenAIRE

    Beloborodov, Roman; Pervukhina, Marina; Han, Tongcheng; Josh, Matthew

    2017-01-01

    High dielectric contrast between water and hydrocarbons provides a useful method for distinguishing between producible layers of reservoir rocks and surrounding media. Dielectric response at high frequencies is related to the moisture content of rocks. Correlations between the dielectric permittivity and specific surface area can be used for the estimation of elastic and geomechanical properties of rocks. Knowledge of dielectric loss-factor and relaxation frequency in shales is critical for t...

  17. Shale oil. II. Gases from oil shale

    Energy Technology Data Exchange (ETDEWEB)

    McKee, R H; Manning, P D.V.

    1927-01-01

    Oil shale (from Colorado) was pyrolyzed, and the gaseous products obtained were studied. The organic material present in oil shale contains carboxyl groups that lose carbon dioxide during pyrolysis before the formation of soluble bitumen. Nitrogen was evolved as ammonia in two stages and was not continuous. The first evolution was from loosely combined nitrogen structures, whereas the second was from more stable forms. No hydrocarbons were present as such in the kerogen. The gaseous products from oil-shale pyrolysis were similar to those obtained by distillation of colophony, amber, coal, and wood. This places the kerogen of the oil shale in the same series of carbonaceous substances as those from which coals are formed. Kerogen appeared to be decomposed in three steps; namely, to insoluble bitumen, to soluble bitumen, and to oil (gas evolution accompanied each step). Its low solubility and the character of its pyrolytic gas indicated that kerogen is largely a resinous residue from vegetation of the past era and may have been formed by the tranportation of coal-forming organic debris to inland salty lakes or carried to the sea by clay-laden waters. The salt water and the natural settling action precipitated the clay and organic matter in an almost homogeneous deposit. Oil shales have existed to the present time because they have not been subjected to high pressures or elevated temperatures that would have changed them to petroleum.

  18. Parenting

    Science.gov (United States)

    ... parents, people are always ready to offer advice. Parenting tips, parents' survival guides, dos, don'ts, shoulds ... right" way to be a good parent. Good parenting includes Keeping your child safe Showing affection and ...

  19. Phase Equilibrium Modeling for Shale Production Simulation

    DEFF Research Database (Denmark)

    Sandoval Lemus, Diego Rolando

    is obtained for hydrocarbon mixtures. Such behavior is mainly caused by compositional changes in the bulk phase due to selective adsorption of the heavier components onto the rock, while the change in bubble point pressure is mainly due to capillary pressure. This study has developed several robust......Production of oil and gas from shale reservoirs has gained more attention in the past few decades due to its increasing economic feasibility and the size of potential sources around the world. Shale reservoirs are characterized by a more tight nature in comparison with conventional reservoirs......, having pore size distributions ranging in the nanometer scale. Such a confined nature introduces new challenges in the fluid phase behavior. High capillary forces can be experienced between the liquid and vapor, and selective adsorption of components onto the rock becomes relevant. The impact...

  20. Origin of oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, W G

    1923-01-01

    The theory by Jones was questioned. Oil shales do not contain partly decomposed vegetable matter, and, where particles of vegetation are identified, they do not prove that kerogen was formed in its place. Some shales do contain free oil that can be extracted with solvents.

  1. The validity of generic trends on multiple scales in rock-physical and rock-mechanical properties of the Whitby Mudstone, United Kingdom

    NARCIS (Netherlands)

    Douma, L.A.N.R.; Primarini, M.I.W.; Houben, M.E.; Barnhoorn, A.

    Finding generic trends in mechanical and physical rock properties will help to make predictions of the rock-mechanical behaviour of shales. Understanding the rock-mechanical behaviour of shales is important for the successful development of unconventional hydrocarbon reservoirs. This paper presents

  2. Study on geochemical occurrences of REE in Wangqing oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Jing-ru; Wang, Qing; Liu, Tong; Wei, Yan-zhen; Bai, Zhang [Northeast Dianli Univ., Jilin (China). Engineering Research Centre

    2013-07-01

    Sequential chemical extraction experiment (SCEE) and Float- sink experiment (FSE) have been employed on oil shale research from Wangqing, Jilin province China, in order to determine the binding forms of rare earth elements (REE) in oil shale. The REE contents were determined by the inductively coupled plasma-mass spectrometry (ICP-MS). Wangqing oil shale was screened into specific gravity density level: <1.5g/cm{sup 3}, 1.5-1.6g/cm{sup 3}, 1.6-2.0g/cm{sup 3}, 2.0-2.4g/cm{sup 3}, >2.4g/cm{sup 3}. The mode of occurrences of rare earth elements in Wangqing oil shale was studied by six-step SCEE. FSE results show that REEs in Wangqing oil shale exist mainly in inorganic minerals and more in excluded mineral, while SCEE results show that REEs of Wangqing oil shale is primarily occurred in minerals, including carbonate, Fe-Mn oxide, sulfide, and Si-minerals. FSE and SCEE results fully illustrate excluded mineral is mainly mode of occurrence of REEs in Wangqing oil shale, whereas inorganic minerals and organic matter is not that. The REE distribution pattern curves of FSE density and SCEE fraction products are similar with that of raw oil shale. The REE in different densities products has a close connection with terrigenous clastic rock, and the supply of terrestrial material is stable.

  3. Updated methodology for nuclear magnetic resonance characterization of shales

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.

    2013-08-01

    Unconventional petroleum resources, particularly in shales, are expected to play an increasingly important role in the world's energy portfolio in the coming years. Nuclear magnetic resonance (NMR), particularly at low-field, provides important information in the evaluation of shale resources. Most of the low-field NMR analyses performed on shale samples rely heavily on standard T1 and T2 measurements. We present a new approach using solid echoes in the measurement of T1 and T1-T2 correlations that addresses some of the challenges encountered when making NMR measurements on shale samples compared to conventional reservoir rocks. Combining these techniques with standard T1 and T2 measurements provides a more complete assessment of the hydrogen-bearing constituents (e.g., bitumen, kerogen, clay-bound water) in shale samples. These methods are applied to immature and pyrolyzed oil shale samples to examine the solid and highly viscous organic phases present during the petroleum generation process. The solid echo measurements produce additional signal in the oil shale samples compared to the standard methodologies, indicating the presence of components undergoing homonuclear dipolar coupling. The results presented here include the first low-field NMR measurements performed on kerogen as well as detailed NMR analysis of highly viscous thermally generated bitumen present in pyrolyzed oil shale.

  4. Chemical aspects of shale and shale oils

    Energy Technology Data Exchange (ETDEWEB)

    Hackford, J E

    1922-01-01

    To prove that the kerogen in oil shale is a form of bitumen, several experiments were made with oil shale and a heavy asphaltic oil mixed with fuller's earth. When distilled, both the oil shale and asphalt-impregnated fuller's earth yielded paraffin oil, wax, and hydrogen sulfide (if sulfur was present). Both yielded ammonia if nitrogen was present. The organic material in each was partly isolated by extraction with pyridine and appeared to be the same. Oil shale is a marl that was saturated with oil or through which oil has passed or filtered. The insolubilities of its organic compounds are due to a slightly elevated temperature for a prolonged period and to the retaining effect exerted by the finely divided marl. The marl exerted a selective action on the oil and absorbed the asphaltum, sulfur, and nitrogen compounds from the oil. The class of oil evolved from a shale depended on the nature of the original compounds absorbed. Asphaltenes obtained from crude oil by precipitation with ethyl ether produced distillation products of water, hydrogen sulfide, ammonia, oil, wax, and a carbonaceous residue. Water was formed by decomposition of oxyasphaltenes and hydrogen sulfide by decomposition of thioasphaltenes. Ammonia was evolved during decomposition if lime was present, but if there was not sufficient free lime present, pyridine and pyrrole derivatives were redistilled as such. The oil and wax that resulted from the dry distillation were true decomposition products and equaled about 60 weight-percent of the asphaltenes. The oil and wax content of the mixture varied between 8 and 10 percent. The carbonaceous residue, which represented approximately 40 percent of the original asphaltene, was a decomposition product of the asphaltenes. Geologic comparisons of oil-shale deposits and oil-well fields were also made.

  5. Source rock

    Directory of Open Access Journals (Sweden)

    Abubakr F. Makky

    2014-03-01

    Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

  6. Oil shale activities in China

    International Nuclear Information System (INIS)

    Peng, D.; Jialin, Q.

    1991-01-01

    China has abundant oil shale resources, of the Early Silurian to Neogene age, the most important being the Tertiary period. The proved oil shale reserves in Fushun amount to 3.6 billion t, in Maoming 4.1 billion t. In Fushun, oil shale is produced by open-pit mining as a byproduct of coal, in Maoming it is also mined in open pits, but without coal. In China, scale oil has been produced from oil shale for 60 years. Annual production of crude shale oil amounts to about 200 000 t. The production costs of shale oil are lower than the price of crude petroleum on the world market. China has accumulated the experience and technologies of oil shale retorting. The Fushun type retort has been elaborated, in which the latent and sensible heat of shale coke is well utilized. But the capacity of such retort is relatively small, therefore it is suitable for use in small or medium oil plants. China has a policy of steadily developing shale oil industry. China is conducting oil shale research and developing oil shale processing technology. Much attention is being pay ed to the comprehensive utilization of oil shale, shale oil, and to environmental problems. In China, oil shale is mostly used for producing shale by retorting, attention will also be paid to direct combustion for power generation. Great achievements in oil shale research have been made in the eighties, and there will be a further development in the nineties. (author), 12 refs., 3 tabs

  7. Characterization of clay minerals and organic matter in shales: Application to high-level nuclear waste isolation

    International Nuclear Information System (INIS)

    Gueven, N.; Landis, C.R.; Jacobs, G.K.

    1988-10-01

    The objective of the Sedimentary Rock Program at the Oak Ridge National Laboratory is to conduct investigations to assess the potential for shale to serve as a host medium for the isolation of high-level nuclear wastes. The emphasis on shale is a result of screening major sedimentary rock types (shale, sandstone, carbonate , anhydrite, and chalk) for a variety of attributes that affect the performance of repositories. The retardation of radionuclides was recognized as one of the potentially favorable features of shale. Because shale contains both clay minerals and organic matter, phases that may provide significant sorption of radioelement, the characterization of these phases is essential. In addition, the organic matter in shale has been identified as a critical area for study because of its potential to play either a favorable (reductant) or deleterious (organic ligands) role in the performance of a repository sited in shale. 36 refs., 36 figs., 10 tabs

  8. Common clay and shale

    Science.gov (United States)

    Virta, R.L.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. The clay and shale market in 1999 is reviewed. In the U.S., sales or use of clay and shale increased from 26.4 million st in 1998 to 27.3 million st in 1999, with an estimated 1999 value of production of $143 million. These materials were used to produce structural clay products, lightweight aggregates, cement, and ceramics and refractories. Production statistics for clays and shales and for their uses in 1999 are presented.

  9. Attenuation of Chemical Reactivity of Shale Matrixes following Scale Precipitation

    Science.gov (United States)

    Li, Q.; Jew, A. D.; Kohli, A. H.; Alalli, G.; Kiss, A. M.; Kovscek, A. R.; Zoback, M. D.; Brown, G. E.; Maher, K.; Bargar, J.

    2017-12-01

    Introduction of fracture fluids into shales initiates a myriad of fluid-rock reactions that can strongly influence migration of fluid and hydrocarbon through shale/fracture interfaces. Due to the extremely low permeability of shale matrixes, studies on chemical reactivity of shales have mostly focused on shale surfaces. Shale-fluid interactions inside within shale matrixes have not been examined, yet the matrix is the primary conduit through which hydrocarbons and potential contaminants are transmitted. To characterize changes in matrix mineralogy, porosity, diffusivity, and permeability during hydraulic stimulation, we reacted Marcellus (high clay and low carbonate) and Eagle Ford (low clay and high carbonate) shale cores with fracture fluids for 3 weeks at elevated pressure and temperature (80 oC, and 77 bars). In the carbonate-poor Marcellus system, fluid pH increased from 2 to 4, and secondary Fe(OH)3 precipitates were observed in the fluid. Sulfur X-ray fluorescence maps show that fluids had saturated and reacted with the entire 1-cm-diameter core. In the carbonate-rich Eagle Ford system, pH increased from 2 to 6 due to calcite dissolution. When additional Ba2+ and SO42- were present (log10(Q/K)=1.3), extensive barite precipitation was observed in the matrix of the Eagle Ford core (and on the surface). Barite precipitation was also observed on the surface of the Marcellus core, although to a lesser extent. In the Marcellus system, the presence of barite scale attenuated diffusivity in the matrix, as demonstrated by sharply reduced Fe leaching and much less sulfide oxidation. Systematic studies in homogeneous solution show that barite scale precipitation rates are highly sensitive to pH, salinity, and the presence of organic compounds. These findings imply that chemical reactions are not confined to shale/fluid interfaces but can penetrate into shale matrices, and that barite scale formation can clog diffusion pathways for both fluid and hydrocarbon.

  10. Bayesian inversion of synthetic AVO data to assess fluid and shale ...

    Indian Academy of Sciences (India)

    Hafiz Mubbasher Anwer

    Rock-physics models are often used to link ... AVO data, i.e., reflection coefficients from top ... sion method for estimation of reservoir parameters ..... the probability of finding the elliptic shale inclusion or spatial ..... Science & Business Media.

  11. [Chemical hazards arising from shale gas extraction].

    Science.gov (United States)

    Pakulska, Daria

    2015-01-01

    The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extreiely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest, concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction.

  12. Chemical hazards arising from shale gas extraction

    Directory of Open Access Journals (Sweden)

    Daria Pakulska

    2015-02-01

    Full Text Available The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extremely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction. Med Pr 2015;66(1:99–117

  13. Geochemical controls on groundwater chemistry in shales

    International Nuclear Information System (INIS)

    Von Damm, K.L.

    1989-01-01

    The chemistry of groundwaters is one of the most important parameters in determining the mobility of species within a rock formation. A three pronged approach was used to determine the composition of, and geochemical controls, on groundwaters specifically within shale formations: (1) available data were collected from the literature, the US Geological Survey WATSTORE data base, and field sampling, (2) the geochemical modeling code EQ3/6 was used to simulate interaction of various shales and groundwaters, and (3) several types of shale were reacted with synthetic groundwaters in the laboratory. The comparison of model results to field and laboratory data provide a means of validating the models, as well as a means of deconvoluting complex field interactions. Results suggest that groundwaters in shales have a wide range in composition and are primarily of the Na-Cl-HCO 3 - type. The constancy of the Na:Cl (molar) ratio at 1:1 and the Ca:Mg ratio from 3:1 to 1:1 suggests the importance of halite and carbonates in controlling groundwater compositions. In agreement with the reaction path modeling, most of the groundwaters are neutral to slightly alkaline at low temperatures. Model and experimental results suggest that reaction (1) at elevated temperatures, or (2) in the presence of oxygen will lead to more acidic conditions. Some acetate was found to be produced in the experiments; depending on the constraints applied, large amounts of acetate were produced in the model results. 13 refs., 1 tab

  14. Shale gases, a windfall for France?

    International Nuclear Information System (INIS)

    Tonnac, Alain de; Perves, Jean-Pierre

    2013-11-01

    After having recalled the definition and origin of shale gases, the different non conventional gases and their exploitation techniques (hydraulic fracturing and horizontal drilling) this report examines whether these gases are an opportunity for France. Some characteristics and data of the fossil and gas markets are presented and commented: world primary energy consumption, proved reserves of non conventional gases and their locations, European regions which may possess reserves of shale gases and coal-bed methane, origins of gas imports in France. The second part addresses shale gas deposits and their exploitation: discussion of the influence of the various rock parameters, evolution of production. The third part discusses the exploitation techniques and specific drilling tools. The issue of exploitation safety and security is addressed as well as the associated controversies: about the pollution of underground waters, about the fact that deep drillings result in pollution, about the risks associated with hydraulic fracturing and injections of chemical products, about the hold on ground and site degradation, about water consumption, about pollution due to gas pipeline leakage, about seismic risk, about noise drawbacks, about risks for health, about exploration and production authorization and license, and about air pollution and climate. The last part addresses the French situation and its future: status of the energy bill, recommendations made by a previous government, cancellation of authorizations, etc. Other information are provided in appendix about non conventional hydrocarbons, about shale gas exploitation in the USA, and about the Lacq gas

  15. Wet separation processes as method to separate limestone and oil shale

    Science.gov (United States)

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

  16. Subsidence prediction in Estonia's oil shale mines

    International Nuclear Information System (INIS)

    Pastarus, J.R.; Toomik, A.

    2000-01-01

    This paper analysis the stability of the mining blocks in Estonian oil shale mines, where the room-and-pillar mining system is used. The pillars are arranged in a singular grid. The oil shale bed is embedded at the depth of 40-75 m. The processes in overburden rocks and pillars have caused the subsidence of the ground surface. The conditional thickness and sliding rectangle methods performed calculations. The results are presented by conditional thickness contours. Error does not exceed 4%. Model allows determining the parameters of spontaneous collapse of the pillars and surface subsidence. The surface subsidence parameters will be determined by conventional calculation scheme. Proposed method suits for stability analysis, failure prognosis and monitoring. 8 refs

  17. Organic geochemistry: Effects of organic components of shales on adsorption: Progress report

    International Nuclear Information System (INIS)

    Ho, P.C.

    1988-11-01

    The Sedimentary Rock Program at the Oak Ridge National Laboratory is investigating shale to determine its potential suitability as a host rock for the disposal of high-level radioactive wastes (HLW). The selected shales are Upper Dowelltown, Pierre, Green River Formation, and two Conasauga (Nolichucky and Pumpkin Valley) Shales, which represent mineralogical and compositional extremes of shales in the United States. According to mineralogical studies, the first three shales contain 5 to 13 wt % of organic matter, and the two Conasauga Shales only contain trace amounts (2 wt %) of organic matter. Soxhlet extraction with chloroform and a mixture of chloroform and methanol can remove 0.07 to 5.9 wt % of the total organic matter from these shales. Preliminary analysis if these organic extracts reveals the existence of organic carboxylic acids and hydrocarbons in these samples. Adsorption of elements such as Cs(I), Sr(II) and Tc(VII) on the organic-extracted Upper Dowelltown, Pierre, green River Formation and Pumpkin Valley Shales in synthetic groundwaters (simulating groundwaters in the Conasauga Shales) and in 0.03-M NaHCO 3 solution indicates interaction between each of the three elements and the organic-extractable bitumen. 28 refs., 8 figs., 10 tabs

  18. Experimental analysis and application of the effect of stress on continental shale reservoir brittleness

    Science.gov (United States)

    Yin, Shuai; Lv, Dawei; Jin, Lin; Ding, Wenlong

    2018-04-01

    Hydraulic fracturing is an effective measure of reservoir modification for the development of shale gas. The evaluation of rock brittleness can provide a basis for the optimization of fracturing. In this paper, the effect of stress on the brittleness of shale is systematically analyzed by designing triaxial mechanics tests. The strain analysis method was used to evaluate the shale brittleness. The research indicates that, with the increase of effective confining pressure, the value of the brittleness index (B 1) decreases. There is a linear and positive correlation between the average reduction ratio of B 1 and the buried depth. The stress has a significant effect on the shale brittleness. Therefore, the rock brittleness can be overestimated without considering the influence of the buried depth or the stress of formation when using the mineral composition method. Being affected by the stress, when the brittle mineral content of the shale reservoir is 70%, 65%, 60%, and 55%, the lower limit depth of the shale gas development is 5000 m, 4400 m, 3000 m, and 1800 m, respectively. However, when the brittle mineral content of the shale is less than 50%, the brittleness index is less than 50% in all of the buried depths. In this case, the shale will not have any commercial development potential. The logging interpretation results of the brittleness index conducted with stress correction are more consistent with the real situation, and thus, this method can be better used to help the optimization of the fracturing intervals of shale gas.

  19. Mineralogical, geochemical and hydrocarbon potential of subsurface Cretaceous shales, Northern Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    D.A. Mousa

    2014-03-01

    Full Text Available Twenty four Cretaceous shale core samples of Gibb Afia-1, Betty-1, Salam-1X and Mersa Matruh-1 wells were mineralogically and geochemically studied using XRD, XRF and Rock Eval Pyrolysis. Kaolinite, smectite and illite are the main clay minerals in addition to rare chlorite, while the non-clay minerals include quartz, calcite, dolomite and rare siderite. The shales were derived through intensive chemical weathering of mafic basement and older sedimentary rocks. These sediments were deposited in a near-shore shallow marine environment with some terrestrial material input. The shales have poor to fair organic content. It is marginally to rarely mature.

  20. The Lower Jurassic Posidonia Shale in southern Germany: results of a shale gas analogue study

    Science.gov (United States)

    Biermann, Steffen; Schulz, Hans-Martin; Horsfield, Brian

    2013-04-01

    The shale gas potential of Germany was recently assessed by the Federal Institute for Geosciences and Natural Resources (2012 NiKo-Project) and is - in respect of the general natural gas occurrence in Germany - regarded as a good alternative hydrocarbon source. The Posidonia Shale in northern and southern Germany is one of the evaluated rock formation and easily accessible in outcrops in the Swabian Alps (southern Germany). The area of interest in this work is located in such an outcrop that is actively used for open pit mining next to the town of Dotternhausen, 70 km southwest of Stuttgart. 31 samples from the quarry of Dotternhausen were analyzed in order to characterize the immature Posidonia Shale (Lower Toarcian, Lias ɛ) of southern Germany as a gas shale precursor. Methods included are Rock Eval, Open Pyrolysis GC, SEM, Mercury Intrusion Porosimetry, XRD, and other. The samples of Dotternhausen contain exclusively type II kerogen. The majority of the organic matter is structureless and occurs in the argillaceous-calcareous matrix. Structured organic matter appears predominantly as alginite, in particular the algae "tasmanite" is noticeable. The TOC content ranges up to 16 wt% with a high bitumen content. The mineral content characterizes the Posidonia Shale as a marlstone or mudstone with varying clay-calcite ratios. The quartz and pyrite content reaches up to 20 wt% and 9 wt%, respectively. The rock fabric is characterized by a fine grained and laminated matrix. The mean porosity lies between 4 and 12 %. Fractures other than those introduced by sample preparation were not observed. The Posidonia Shale is predicted to have an excellent source rock potential and will generate intermediate, P-N-A low wax oil when exposed to higher P-T-conditions ("oil kitchen"). Contact surfaces between the kerogen and matrix will be vulnerable to pressure induced fracturing caused by hydrocarbon formation. Additional porosity will be formed during maturation due to the

  1. Intergrated study of the Devonian-age black shales in eastern Ohio. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.D.; Struble, R.A.; Carlton, R.W.; Hodges, D.A.; Honeycutt, F.M.; Kingsbury, R.H.; Knapp, N.F.; Majchszak, F.L.; Stith, D.A.

    1982-09-01

    This integrated study of the Devonian-age shales in eastern Ohio by the Ohio Department of Natural Resources, Division of Geological Survey is part of the Eastern Gas Shales Project sponsored by the US Department of Energy. The six areas of research included in the study are: (1) detailed stratigraphic mapping, (2) detailed structure mapping, (3) mineralogic and petrographic characterization, (4) geochemical characterization, (5) fracture trace and lineament analysis, and (6) a gas-show monitoring program. The data generated by the study provide a basis for assessing the most promising stratigraphic horizons for occurrences of natural gas within the Devonian shale sequence and the most favorable geographic areas of the state for natural gas exploration and should be useful in the planning and design of production-stimulation techniques. Four major radioactive units in the Devonian shale sequence are believed to be important source rocks and reservoir beds for natural gas. In order of potential for development as an unconventional gas resource, they are (1) lower and upper radioactive facies of the Huron Shale Member of the Ohio Shale, (2) upper Olentangy Shale (Rhinestreet facies equivalent), (3) Cleveland Shale Member of the Ohio Shale, and (4) lower Olentangy Shale (Marcellus facies equivalent). These primary exploration targets are recommended on the basis of areal distribution, net thickness of radioactive shale, shows of natural gas, and drilling depth to the radioactive unit. Fracture trends indicate prospective areas for Devonian shale reservoirs. Good geological prospects in the Devonian shales should be located where the fracture trends coincide with thick sequences of organic-rich highly radioactive shale.

  2. ) Geochemistry and Hydrocarbon Potential of Cretaceous Shales in the Chad Basin

    International Nuclear Information System (INIS)

    Alalade, B.; Ogunyemi, A. T.; Abimbola, A.F.; Olugbemiro, R. O.

    2003-01-01

    The Chad Basin is the largest intracratonic basin in Africa and is filled with more than 400m of Cretaceous to Recent sediments. Geochemical and petrographic studies of Cretaceous shales form the Bima, Gongola and Fika Formations were carried out to establish their hydrocarbon potential and thermal maturity. Ditch cuttings of the shales were collected from the Wa di and Karen's exploration wells located in the Nigerian sector of the Chad Basin.The geochemical analysis of the shales indicate that, except for Si02 and K20, all other oxides (Mg O, Fe2O3, AL2O3, CaO) are more abundant in the Fika shale than the Gongola shale. This suggests a more marine condition for the Fika shale compared to the Gongola shale. The Fika and Gongola shales were further classified into Iron shale and shale respectively. Organic carbon contents of the Bima, Gongola and exceed the minimum (0.5wt%) usually required for siliciclastic petroleum source rock. However, the soluble organic matter (SOM) and saturated hydrocarbon (SHC) contents of the shales, which ranges from 108pm to 743ppm and 23ppm to 100ppm respectively, are generally low and are therefore, organically lean. The organic matter of the shales is predominantly terrestrially derived, vitrinite rich, Type III kerogen and are therefore, gas prone. Thermal maturity assessed from SOM/TOC, SHC/TOC ratios and spore color index (SCI) indicate that the Fika shale is immature while the Gongola and Bima shales are within the oil window

  3. Microstructural and mineralogical characterization of selected shales in support of nuclear waste repository studies

    International Nuclear Information System (INIS)

    Lee, S.Y.; Hyder, L.K.; Alley, P.D.

    1988-01-01

    Five shales were examined as part of the Sedimentary Rock Program evaluation of this medium as a potential host for a US civilian nuclear waste repository. The units selected for characterization were the Chattanooga Shale from Fentress County, Tennessee; the Pierre Shale from Gregory County, South Dakota; the Green River Formation from Garfield County, Colorado; and the Nolichucky Shale and Pumpkin Valley Shale from Roane County, Tennessee. The micromorphology and structure of the shales were examined by petrographic, scanning electron, and high-resolution transmission electron microscopy. Chemical and mineralogical compositions were studied through the use of energy-dispersive x-ray, neutron activation, atomic absorption, thermal, and x-ray diffraction analysis techniques. 18 refs., 12 figs., 2 tabs

  4. Process for oil shale retorting

    Science.gov (United States)

    Jones, John B.; Kunchal, S. Kumar

    1981-10-27

    Particulate oil shale is subjected to a pyrolysis with a hot, non-oxygenous gas in a pyrolysis vessel, with the products of the pyrolysis of the shale contained kerogen being withdrawn as an entrained mist of shale oil droplets in a gas for a separation of the liquid from the gas. Hot retorted shale withdrawn from the pyrolysis vessel is treated in a separate container with an oxygenous gas so as to provide combustion of residual carbon retained on the shale, producing a high temperature gas for the production of some steam and for heating the non-oxygenous gas used in the oil shale retorting process in the first vessel. The net energy recovery includes essentially complete recovery of the organic hydrocarbon material in the oil shale as a liquid shale oil, a high BTU gas, and high temperature steam.

  5. Process for extracting oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1920-08-22

    A process is described for recovering bituminous material from oil shale, characterized in that the oil shale is extracted with wood spirits oil (byproduct of woodspirit rectification), if necessary in admixture with other solvents in the cold or the hot.

  6. A molecular organic geochemical study of black shales associated with diatomites from the Oligocene Meinilite Shale (Flysch Carpathians, SE Poland)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Koster, J.; Rospondek, M.; Zubrzycki, A.; Kolouba, M.; Leeuw, J.W. de

    1995-01-01

    Black shales of the Menilite Formation, the source rock for oils in the Carpathian overthrust belt, display a large variability in their bulk and molecular geochemical parameters. Biomarker and stable carbon isotope analyses indicate a variable contribution from different algae (particularly

  7. Apparatus for treating bituminous shale

    Energy Technology Data Exchange (ETDEWEB)

    1942-11-24

    A method is given of transforming finely crushed bituminous shale, for instance of maximum particle size of about 5 mm, into balls, nodules, or similar shapes, in which the shale to be treated is passed in the form of lumps through a rotary drum. The finely crushed shale with a higher content of moisture is brought into contact with finely crushed shale of a lower content of moisture, and thereby serves as kernel material during the formation of the nodules or similar shapes.

  8. Shale oil combustion

    International Nuclear Information System (INIS)

    Al-dabbas, M.A.

    1992-05-01

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

  9. Oil shale highlights

    International Nuclear Information System (INIS)

    1994-01-01

    The low prices of crude oil have continued to retard the commercial development of oil shale and other syn fuels. Although research funds are more difficult to find, some R and D work by industry, academia, and governmental agencies continues in the United States and in other parts of the world. Improvements in retorting technology, upgrading oil-shale feedstock, and developing high-value niche-market products from shale oil are three notable areas of research that have been prominent for the past several years. Although the future prices of conventional crude cannot be predicted, it seems evident that diminishing supplies and a burgeoning world population will force us to turn to alternate fossil fuels as well as to cleaner sources of non-fossil energy. (author)

  10. Shale oil combustion

    Energy Technology Data Exchange (ETDEWEB)

    Al-dabbas, M A

    1992-05-01

    A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

  11. Shale gas - Risks and stakes

    International Nuclear Information System (INIS)

    Parks, Olivier

    2014-01-01

    This book aims at exploring all aspects of the shale gas issue: geological data, environmental impacts, financial aspects and economical impacts of shale gas exploitation. It compares the available information with the field reality and defeats the dogmatic mirages. The research and compilation work carried out by the author make this book a reference in the domain of shale gas exploitation

  12. Process of briquetting fine shale

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, J

    1943-05-05

    A process is described for the preparation of briquetts of fine bituminous shale, so-called Mansfield copper shale, without addition of binding material, characterized in that the fine shale is warmed to about 100/sup 0/C and concurrently briquetted in a high-pressure rolling press or piece press under a pressure of 300 to 800 kg/cm/sup 2/.

  13. Marcellus shale gas potential in the southern tier of New York

    Energy Technology Data Exchange (ETDEWEB)

    Faraj, B. [Talisman Energy Inc., Calgary, AB (Canada); Duggan, J. [Hunt Oil Canada, Calgary, AB (Canada)

    2008-07-01

    Marcellus shale is a significant, underexplored, shale gas target in the Appalachian Basin. Gas-in-place estimates in the Marcellus shale range from 200 to 100 billion cubic feet (bcf). The Devonian shales have favorable attributes such as high total organic content (TOC), high gas content, favorable mineralogy and over-pressured. Land owned by Fortuna Energy in the northern Appalachian Basin may contain significant shale gas with unrisked gas-in-place in excess of 10 trillion cubic feet. Unlocking the true shale gas potential requires innovative drilling and completion techniques. This presentation discussed Marcellus shale gas potential in the southern tier and a test program being conducted by Fortuna to test the potential. Several photographs were shown, including Taughannock Falls, Finger Lakes and the Ithaca Shale, Sherburne Sandstone, and Geneseo Shale; two orthogonal fracture sets in the Upper Devonian Geneseo Shale; and two orthogonal fracture sets in the Upper Devonian Rocks, near Corning, New York. Figures that were presented included the supercontinent Pangaea in the early Triassic; undiscovered gas resources in the Appalachian Basin; stratigraphy; and total gas production in New York since 1998. Fortuna's work is ongoing in the northern Appalachian Basin. tabs., figs.

  14. Duvernay shale lithofacies distribution analysis in the West Canadian Sedimentary Basin

    Science.gov (United States)

    Zhu, Houqin; Kong, Xiangwen; Long, Huashan; Huai, Yinchao

    2018-02-01

    In the West Canadian Sedimentary Basin (WCSB), Duvernay shale is considered to contribute most of the Canadian shale gas reserve and production. According to global shale gas exploration and development practice, reservoir property and well completion quality are the two key factors determining the shale gas economics. The two key factors are strongly depending on shale lithofacies. On the basis of inorganic mineralogy theory, all available thin section, X-ray diffraction, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) data were used to assist lithofacies analysis. Gamma ray (GR), acoustic (AC), bulk density (RHOB), neutron porosity (NPHI) and photoelectric absorption cross-section index (PE) were selected for log response analysis of various minerals. Reservoir representative equation was created constrained by quantitative core analysis results, and matrix mineral percentage of quartz, carbonate, feldspar and pyrite were calculated to classify shale lithofacies. Considering the horizontal continuity of seismic data, rock physics model was built, and acoustic impedance integrated with core data and log data was used to predict the horizontal distribution of different lithofacies. The results indicate that: (1) nine lithofacies can be categorized in Duvernay shale, (2) the horizontal distribution of different lithofacies is quite diversified, siliceous shale mainly occurs in Simonette area, calcareous shale is prone to develop in the vicinity of reef, while calcareous-siliceous shale dominates in Willesdon Green area.

  15. The geochemistry of claystone-shale deposits from the Maastritchian Patti formation, Southern Bida basin, Nigeria

    Directory of Open Access Journals (Sweden)

    O Okunlola

    2012-07-01

    Full Text Available An inorganic geochemical study of a claystone and shale sequence from the Patti Formation around Ahoko in the Southern Bida basin, Nigeria, was carried out to determine the basin's depositional conditions,provenance and tectonics. Representative samples underwent mineralogical and geochemical analysis involving major, trace and rare earth element analysis.Mineralogical studies using X-ray diffraction analysis revealed prominent kaolinite, dickite and illite peaks; accessory minerals included quartz and microcline. Major element abundance showed thatthe shale samples had SiO2 (61.26%, Al2O3 (16.88% and Fe2O3 (3.75% constituting more than 79% of bulk chemical composition whilst claystone samples contained SiO2 (67.79%, Al2O3 (17.81% andFe2O3 (1.67%. Higher SiO2, Ba, Sr, V, and Nb concentrations were observed in claystone samples rather than shale whereas the shale samples were observed to be more Zr-, Ni- and Zn-enriched than theclaystone ones. The shale and claystone samples showed slightly light rare earth enrichment and slightly flat heavy rare earth depleted patterns having a negative Eu and Tm anomaly. High TiO2 and Rb/K2Ovalues also indicated that the shale and claystone samples were matured. Geochemical parameters such as U, U/Th, Ni/Co and Cu/Zn ratios indicated that these shales were deposited in oxic conditions; theAl2O3/TiO2 ratio suggested that intermediate igneous rocks were probable source rocks for the shales, while mafic rocks were suggested as being source rocks for the claystone. However, the La/Sc, Th/Sc, Th/Co ratios and shales and claystone plots revealed that they came within the range given for felsic rocks as provenance, thereby suggesting mixed provenace for the sediments. A passive-margin tectonic settingwas adduced for the sedimentary sequences.

  16. Treating oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Dolbear, S H

    1921-01-04

    Oil shale is treated for the separation of the valuable organic compounds, with a view to economy in subsequent destructive distillation, by grinding to powder, mixing with water to form a pulp, adding a small quantity of an oil liquid and aerating the mixture to form a froth containing the organic compounds. If the powdered shale contains sufficient free oil, the addition of oil to the pulp may be dispensed with. In some cases an electrolyte such as sulfuric acid may be added to the pulp.

  17. Treating bituminous shale

    Energy Technology Data Exchange (ETDEWEB)

    Ginet, J H

    1921-03-09

    Apparatus for the treatment of bituminous shales is described wherein a number of separate compartments are arranged in alignment and communicate with each other near the bottom thereof, each of the compartments being provided with outlets for the gases evolved therein, while agitators are arranged in each of the compartments, each agitator being composed of a number of shovels which sweep up the comminuted shale at their forward end and discharge it at their rearward end into the path of the next adjacent agitator.

  18. Almahata Sitta MS-MU-011 and MS-MU-012: Formation Conditions of Two Unusual Rocks From the Ureilite Parent Body

    Science.gov (United States)

    Mikouchi, T.; Takenouchi, A.; Zolensky, M. E.; Hoffmann, V. H.

    2018-01-01

    Almahata Sitta meteorites are unique polymict breccia, comprising of many different meteorite groups as individual fragments dominated by ureilite lithologies and are considered to be recovered fragments of the asteroid 2008TC3. Recently, two unusual Almahata Sitta samples (MS-MU-011 and MS-MU-012) have been reported that show close petrogenetic relationships to ureilites. MS-MU-011 is a trachyandesite mainly composed of feldspar (plagioclase and anorthoclase) and pyroxene (pigeonite and augite) having ureilitic oxygen isotopic ratios. MS-MU-012 is the first ureilite example (unbrecciated) containing primary plagioclase crystals. The findings of these two rock types are important to better understand formation conditions of ureilites and the evolution of their parent body(s). In this abstract we discuss formation conditions of these ureilite-related rocks using redox state estimate by Fe valence states of plagioclase and olivine cooling rate calculations.

  19. Wellbore stability in shales considering chemo-poroelastic effects

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Ewerton M.P.; Pastor, Jorge A.S.C.; Fontoura, Sergio A.B.; Rabe, Claudio [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil. Grupo de Tecnologia e Engenharia de Petroleo

    2004-07-01

    Under compaction and low geothermal gradients are deep water characteristics. Both under compaction and low geothermal gradients generate considerable thickness of smectite-rich shales. These rocks are the major source of wellbore stability problems, because they are susceptible to adverse physico-chemical reactions when in contact with inadequate drilling fluids. Due shales are low permeability rocks diffusion processes dominate the changes of pore pressure around wellbore. Diffusion of fluids, ions and temperature occurs in shales during drilling and demand a fully coupled modelling taking account these factors. Despite temperature importance, in this paper wellbore stability in shales is analyzed through a model that considers only the coupling between poroelastic and physico-chemical effects. The coupled equations are solved analytically and have been implemented in a computational simulator with user-friendly interface. Time-dependent simulations of wellbore stability in shales are presented for a typical deep water scenario. The results show that physico-chemical effects change pore pressure around wellbore and have high impact on the wellbore stability. (author)

  20. Evaluation of excavation experience: Pierre shale. Final report

    International Nuclear Information System (INIS)

    Abel, J.F. Jr.; Gentry, D.W.

    1975-01-01

    Pierre shale and its stratigraphic equivalents represent a potentially favorable geologic environment for underground storage of hazardous waste products. These rock formations cover great areal and vertical extents, and represent some of the least permeable rock formations within the continental United States. There are, however, several engineering problems associated with constructing underground openings in Pierre shale. This formation is relatively weak and tends to deteriorate rather rapidly if not protected from the mine environment. It will be necessary to place all underground openings below the surficially weathered upper 50 to 70 feet of Pierre shale which contains groundwater moving on fracture permeability. The optimum site for disposal of hazardous waste in Pierre shale, or its stratigraphic equivalents, would be a seismically stable platform bounded on all sides by faults. The optimum size of individual openings would be the minimum necessary for access, storage, and retrieval of waste components. Underground excavations in Pierre shale must be made with care, must be of limited dimensions, must be widely spaced, must be protected from prolonged contact with the mine environment, must be supported immediately after excavation, and must be sited to avoid areas of faulting and(or) intense jointing. Underground openings constructed with boring machines and supported with wet shotcrete are recommended

  1. Release of Particulate Iron Sulfide during Shale-Fluid Interaction.

    Science.gov (United States)

    Kreisserman, Yevgeny; Emmanuel, Simon

    2018-01-16

    During hydraulic fracturing, a technique often used to extract hydrocarbons from shales, large volumes of water are injected into the subsurface. Although the injected fluid typically contains various reagents, it can become further contaminated by interaction with minerals present in the rocks. Pyrite, which is common in organic-rich shales, is a potential source of toxic elements, including arsenic and lead, and it is generally thought that for these elements to become mobilized, pyrite must first dissolve. Here, we use atomic force microscopy and environmental scanning electron microscopy to show that during fluid-rock interaction, the dissolution of carbonate minerals in Eagle Ford shale leads to the physical detachment, and mobilization, of embedded pyrite grains. In experiments carried out over a range of pH, salinity, and temperature we found that in all cases pyrite particles became detached from the shale surfaces. On average, the amount of pyrite detached was equivalent to 6.5 × 10 -11 mol m -2 s -1 , which is over an order of magnitude greater than the rate of pyrite oxidation expected under similar conditions. This result suggests that mechanical detachment of pyrite grains could be an important pathway for the mobilization of arsenic in hydraulic fracturing operations and in groundwater systems containing shales.

  2. Shale Gas and Oil in Germany - Resources and Environmental Impacts

    Science.gov (United States)

    Ladage, Stefan; Blumenberg, Martin; Houben, Georg; Pfunt, Helena; Gestermann, Nicolai; Franke, Dieter; Erbacher, Jochen

    2017-04-01

    In light of the controversial debate on "unconventional" oil and gas resources and the environmental impacts of "fracking", the Federal Institute for Geosciences and Natural Resources (BGR) conducted a comprehensive resource assessment of shale gas and light tight oil in Germany and studied the potential environmental impacts of shale gas development and hydraulic fracturing from a geoscientific perspective. Here, we present our final results (BGR 2016), incorporating the majority of potential shale source rock formations in Germany. Besides shale gas, light tight oil has been assessed. According to our set of criteria - i.e. thermal maturity 0.6-1.2 %vitrinite reflectance (VR; oil) and >1.2 % VR (gas) respectively, organic carbon content > 2%, depth between 500/1000 m and 5000 m as well as a net thickness >20 m - seven potentially generative shale formations were indentified, the most important of them being the Lower Jurassic (Toarcian) Posidonia shale with both shale gas and tight oil potential. The North German basin is by far the most prolific basin. The resource assessment was carried out using a volumetric in-place approach. Variability inherent in the input parameters was accounted for using Monte-Carlo simulations. Technically recoverable resources (TRR) were estimated using recent, production-based recovery factors of North American shale plays and also employing Monte-Carlo simulations. In total, shale gas TRR range between 320 and 2030 bcm and tight oil TRR between 13 and 164 Mio. t in Germany. Tight oil potential is therefore considered minor, whereas the shale gas potential exceeds that of conventional resources by far. Furthermore an overview of numerical transport modelling approaches concerning environmental impacts of the hydraulic fracturing is given. These simulations are based on a representative lithostratigraphy model of the North-German basin, where major shale plays can be expected. Numerical hydrogeological modelling of frac fluid

  3. A collapse pressure prediction model for horizontal shale gas wells with multiple weak planes

    Directory of Open Access Journals (Sweden)

    Ping Chen

    2015-01-01

    Full Text Available Since collapse of horizontal wellbore through long brittle shale interval is a major problem, the occurrence characteristics of weak planes were analyzed according to outcrop, core, and SEM and FMI data of shale rocks. A strength analysis method was developed for shale rocks with multiple weak planes based on weak-plane strength theory. An analysis was also conducted of the strength characteristics of shale rocks with uniform distribution of multiple weak planes. A collapse pressure prediction model for horizontal wells in shale formation with multiple weak planes was established, which takes into consideration the occurrence of each weak plane, wellbore stress condition, borehole azimuth, and in-situ stress azimuth. Finally, a case study of a horizontal shale gas well in southern Sichuan Basin was conducted. The results show that the intersection angle between the shale bedding plane and the structural fracture is generally large (nearly orthogonal; with the increase of weak plane number, the strength of rock mass declines sharply and is more heavily influenced by weak planes; when there are more than four weak planes, the rock strength tends to be isotropic and the whole strength of rock mass is greatly weakened, significantly increasing the risk of wellbore collapse. With the increase of weak plane number, the drilling fluid density (collapse pressure to keep borehole stability goes up gradually. For instance, the collapse pressure is 1.04 g/cm3 when there are no weak planes, and 1.55 g/cm3 when there is one weak plane, and 1.84 g/cm3 when there are two weak planes. The collapse pressure prediction model for horizontal wells proposed in this paper presented results in better agreement with those in actual situation. This model, more accurate and practical than traditional models, can effectively improve the accuracy of wellbore collapse pressure prediction of horizontal shale gas wells.

  4. Using presence of calcite cap rock in shales to predict occurrence of reservoirs composed of leached secondary porosity in the geopressured zone. Annual report, June 1, 1980-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, W.R.; Magara, K.; Milliken, K.L.; Richmann, D.L.

    1981-01-01

    The distribution of high-resistivity shale in the Frio Formation between hydropressured and geopressured strata has been mapped along the Texas Gulf Coast. Two high-resistivity intervals more than 1000 ft thick have been mapped, one in Brazoria and Galveston Counties and the other in Kenedy County. They coincide with Frio delta systems and may be related to extraordinary quantities of CO/sub 2/ produced by deltaic sediments rich in woody and herbaceous matter. Beyond being calcareous, the nature of the high-resistivity interval is enigmatic and its relationship to deep secondary porosity problematic. Most of the contained carbonate is microscopically and isotopically skeletal in origin, revealing no evidence of diagenetic modification. Minor rhombs of iron-bearing carbonate tens of microns in size were identified. Detrital feldspar compositions are being established to test subsequent changes in feldspar composition resulting from progressive burial and albitization. Hydrolysis reactions for authigenic minerals and reactions between key pairs of minerals have been written. Thermodynamic functions for complex phyllosilicates at temperatures up to 200/sup 0/C have been calculated. From thermodynamic calculations it was predicted that ferroan calcite would be the favored authigenic carbonate in shales.

  5. Apparatus for decomposing shale

    Energy Technology Data Exchange (ETDEWEB)

    Gislain, M

    1865-06-20

    The apparatus is designed to fulfill the three following conditions: (1) complete extraction of the mineral oil, by avoiding partial decomposition; (2) purification of the said oil from products formed in the decomposition of the shale; (3) breaking down of the said oil into more products of different density. The separation of the heavy and bituminous products is claimed.

  6. Organic-rich shale lithofacies geophysical prediction: A case study in the fifth organic-matter-rich interval of Paleogene Hetaoyuan Formation, Biyang Depression

    Science.gov (United States)

    Fei, S.; Xinong, X.

    2017-12-01

    The fifth organic-matter-rich interval (ORI 5) in the He-third Member of the Paleogene Hetaoyuan Formation is believed to be the main exploration target for shale oil in Biyang Depression, eastern China. An important part of successful explorating and producing shale oil is to identify and predict organic-rich shale lithofacies with different reservoir capacities and rock geomechanical properties, which are related to organic matter content and mineral components. In this study, shale lithofacies are defined by core analysis data, well-logging and seismic data, and the spatial-temporal distribution of various lithologies are predicted qualitatively by seismic attribute technology and quantitatively by geostatistical inversion analysis, and the prediction results are confirmed by the logging data and geological background. ORI 5 is present in lacustrine expanding system tract and can be further divided into four parasequence sets based on the analysis of conventional logs, TOC content and wavelet transform. Calcareous shale, dolomitic shale, argillaceous shale, silty shale and muddy siltstone are defined within ORI 5, and can be separated and predicted in regional-scale by root mean square amplitude (RMS) analysis and wave impedance. The results indicate that in the early expansion system tract, dolomitic shale and calcareous shale widely developed in the study area, and argillaceous shale, silty shale, and muddy siltstone only developed in periphery of deep depression. With the lake level rising, argillaceous shale and calcareous shale are well developed, and argillaceous shale interbeded with silty shale or muddy siltstone developed in deep or semi-deep lake. In the late expansion system tract, argillaceous shale is widely deposited in the deepest depression, calcareous shale presented band distribution in the east of the depression. Actual test results indicate that these methods are feasible to predict the spatial distribution of shale lithofacies.

  7. Impact of ductility on hydraulic fracturing in shales

    Science.gov (United States)

    MacMinn, Chris; Auton, Lucy

    2016-04-01

    Hydraulic fracturing is a method for extracting natural gas and oil from low-permeability rocks such as shale via the high-pressure injection of fluid into the bulk of the rock. The goal is to initiate and propagate fractures that will provide hydraulic access deeper into the reservoir, enabling gas or oil to be collected from a larger region of the rock. Fracture is the tensile failure of a brittle material upon reaching a threshold tensile stress, but some shales have a high clay content and may yield plastically before fracturing. Plastic deformation is the shear failure of a ductile material, during which stress relaxes through irreversible rearrangements of the particles of the material. Here, we investigate the impact of the ductility of shales on hydraulic fracturing. We first consider a simple, axisymmetric model for radially outward fluid injection from a wellbore into a ductile porous rock. We use this model to show that plastic deformation greatly reduces the maximum tensile stress, and that this maximum stress does not always occur at the wellbore. We then complement these results with laboratory experiments in an analogue system, and with numerical simulations based on the discrete element method (DEM), both of which suggest that ductile failure can indeed dramatically change the resulting deformation pattern. These results imply that hydraulic fracturing may fail in ductile rocks, or that the required injection rate for fracking may be much larger than the rate predicted from models that assume purely elastic mechanical behavior.

  8. Shale-brine-CO2 interactions and the long-term stability of carbonate-rich shale caprock

    Science.gov (United States)

    Ilgen, A.; Aman, M.; Espinoza, D. N.; Rodriguez, M. A.; Griego, J.; Dewers, T. A.; Feldman, J.; Stewart, T.; Choens, R. C., II

    2017-12-01

    Geological carbon storage (GCS) requires an impermeable caprock (e.g., shale) that prevents the upward migration and escape of carbon dioxide (CO2) from the subsurface. Geochemical alteration can occur at the caprock-reservoir rock interface, which could lead to the altering of the rock's mechanical properties, compromising the seal. We performed laboratory experiments on Mancos shale to quantify the coupled chemical-mechanical response of carbonate-rich shale in CO2-brine mixtures at conditions typical to GCS. We constructed geochemical models, calibrated them using laboratory results, and extended to time scales required for GCS. We observed the dissolution of calcite and kaolinite and the precipitation of gypsum and amorphous aluminum (hydr)oxide following the introduction of CO2. To address whether this mineral alteration causes changes in micro-mechanical properties, we examined altered Mancos shale using micro-mechanical (scratch) testing, measuring the scratch toughness of mm-scale shale lithofacies. The quartz-rich regions of the Mancos shale did not show significant changes in scratch toughness following 1-week alteration in a CO2-brine mixture. However, the scratch toughness of the calcite-rich, originally softer regions decreased by about 50%. These observations illustrate a coupled and localized chemical-mechanical response of carbonate-rich shale to the injection of CO2. This suggests a localized weakening of the caprock may occur, potentially leading to the development of preferential flow paths. The identification of vulnerable lithofacies within caprock and a characterization of mineralogical heterogeneity is imperative at prospective GCS sites. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE

  9. Trace metal chemistry in the Marcellus shale

    Energy Technology Data Exchange (ETDEWEB)

    Bank, Tracy [University at Buffalo (United States)

    2010-07-01

    In recent years, due to the depletion of traditional fossil fuel resources and the rising price of energy, the production of unconventional gas has increased. Several black shales contain uranium both in insoluble species, U4+, and in soluble U6+ phase. Those two forms of uranium are weakly radioactive, however they are toxic and can lead to kidney and liver damage. The aim of this paper is to assess the oxidation state of uranium in the Marcellus shale formation. Samples were analyzed using several methods such as XRD, X-ray absorption near edge structure, and time of flight secondary ion mass spectrometry to determine the rock geochemistry and examine the interaction between the uranium and the hydrocarbons. It was found that uranium exists in both UO2 and U-C forms with a dominance of U6+. This study demonstrated that uranium is present in the Marcellus shale in both U4+ and U6+ states and that more research must therefore be undertaken to determine how to dispose of waste from drilling and fracking activities.

  10. Kinetics of selenium release in mine waste from the Meade Peak Phosphatic Shale, Phosphoria Formation, Wooley Valley, Idaho, USA

    Science.gov (United States)

    Lisa L. Stillings; Michael C. Amacher

    2010-01-01

    Phosphorite from the Meade Peak Phosphatic Shale member of the Permian Phosphoria Formation has been mined in southeastern Idaho since 1906. Dumps of waste rock from mining operations contain high concentrations of Se which readily leach into nearby streams and wetlands. While the most common mineralogical residence of Se in the phosphatic shale is elemental Se, Se(0...

  11. Effects of strain rate and confining pressure on the deformation and failure of shale

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.M. (Schlumberger Cambridge Research (GB)); Sheppard, M.C. (Anadrill/Schlumberger (US)); Houwen, O.H. (Sedco Forex (FR))

    1991-06-01

    Previous work on shale mechanical properties has focused on the slow deformation rates appropriate to wellbore deformation. Deformation of shale under a drill bit occurs at a very high rate, and the failure properties of the rock under these conditions are crucial in determining bit performance and in extracting lithology and pore-pressure information from drilling parameters. Triaxial tests were performed on two nonswelling shales under a wide range of strain rates and confining and pore pressures. At low strain rates, when fluid is relatively free to move within the shale, shale deformation and failure are governed by effective stress or pressure (i.e., total confining pressure minus pore pressure), as is the case for ordinary rock. If the pore pressure in the shale is high, increasing the strain rate beyond about 0.1%/sec causes large increases in the strength and ductility of the shale. Total pressure begins to influence the strength. At high stain rates, the influence of effective pressure decreases, except when it is very low (i.e., when pore pressure is very high); ductility then rises rapidly. This behavior is opposite that expected in ordinary rocks. This paper briefly discusses the reasons for these phenomena and their impact on wellbore and drilling problems.

  12. Distribution and evolution of Zn, Cd, and Pb in Apollo 16 regolith samples and the average U-Pb ages of the parent rocks

    Science.gov (United States)

    Cirlin, E. H.; Housley, R. M.

    1982-01-01

    The concentration of surface (low temperature site) and interior (high temperature site) Cd, Zn, and Pb in 13 Apollo 16 highland fines samples, pristine rock 65325, and mare fines sample 75081 were analyzed directly from the thermal release profiles obtained by flameless atomic absorption technique (FLAA). Cd and Zn in pristine ferroan anothosite 65325, anorthositic grains of the most mature fines 65701, and basaltic rock fragments of mare fines 75081 were almost all surface Cd and Zn indicating that most volatiles were deposited on the surfaces of vugs, vesicles and microcracks during the initial cooling process. A considerable amount of interior Cd and Zn was observed in agglutinates. This result suggests that high temperature site interior volatiles originate from entrapment during the lunar maturation processes. Interior Cd found in the most mature fines sample 65701 was only about 15% of the total Cd in the sample. Interior Pb present in Apollo 16 fines samples went up to 60%. From our Cd studies we can assume that this interior Pb in highland fines samples is largely due to the radiogenic decay which occurred after the redistribution of the volatiles took place. We obtained an average age of 4.0 b.y. for the parent rocks of Apollo 16 highland regolith from our interior Pb analyses.

  13. Nature of parent rocks, mineralization styles and ore genesis of regolith-hosted REE deposits in South China: An integrated genetic model

    Science.gov (United States)

    Li, Yan Hei Martin; Zhao, Wen Winston; Zhou, Mei-Fu

    2017-10-01

    Regolith-hosted rare earth element (REE) deposits, also called ion-adsorption or weathered crust elution-deposited REE deposits are distributed over Jiangxi, Guangdong, Fujian, Hunan, Guangxi and Yunnan provinces in South China. In general, these deposits can be categorized into the HREE-dominated type, for example the famous Zudong deposit in southern Jiangxi province and the LREE-dominated type, such as the Heling and Dingnan deposits in southern Jiangxi province. Most of these deposits form from weathering of biotite and muscovite granites, syenites, monzogranites, granodiorites, granite porphyries, and rhyolitic tuffs. The parent rocks are generally peraluminous, siliceous, alkaline and contain a variety of REE-bearing minerals. Mostly, REE patterns of regolith are inherited from the parent rocks, and therefore, characteristics of the parent rocks impose a significant control on the ore formation. Data compilation shows that autometasomatism during the latest stage of granite crystallization is likely essential in forming the HREE-enriched granites, whereas LREE-enriched granites could form through magmatic differentiation. These deposits are normally two- to three-fold, but could be up to ten-fold enrichment in REE compared to the parent granites, where the maximum enrichment usually occurs from the lower B to the upper C horizon. Ce shows different behavior with the other REEs. Strongly positive Ce anomalies commonly occur at the upper part of weathering profiles, likely due to oxidation of Ce3+ to Ce4+ and removal of Ce from soil solutions through precipitation of cerianite. Vertical pH and redox gradients in weathering crusts facilitate dissolution of REE-bearing minerals at shallow level and fixation of REE at depth through either adsorption on clay minerals or precipitation of secondary minerals. At the same time, mass removal of major elements plays an important role in concentrating REE in regolith. Combination of mass removal and eluviation

  14. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    Heuze, F.E.

    1981-09-01

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  15. Shale gas - uncertain destiny?

    International Nuclear Information System (INIS)

    Signoret, Stephane

    2013-01-01

    This article outlines that, even if it would be allowed, the exploitation of shale gas in France would need ten years to start, and no one can say what would be our needs then and what would be the situation of the gas market at that time. Even if the government decided to forbid hydraulic fracturing, there could be some opportunity for experimentation with a search for alternative technology. The article notices that risks associated with hydraulic fracturing and extraction of non conventional hydrocarbons, i.e. water pollution and consumption and land use, are variously perceived in different European countries (Germany, Romania, Poland) where important American actors are present (Chevron, Exxon) to exploit shale gases. In the USA, the economic profitability seems in fact to rapidly decrease

  16. Let us talk about shale gas in 30 questions

    International Nuclear Information System (INIS)

    Bauquis, Pierre-Rene

    2014-01-01

    The author addresses and gives an overview of the issue of shale gas extraction and production by answering 30 questions. These questions concern the origins of hydrocarbons, the definition of shale gas and oil, how gases and oils are produced from source rocks, the principle of hydraulic fracturing, where and how to perform this fracturing, the issue of water wastage, the risks of water pollution, seismic risks, nuisances for the neighbourhood, alternatives to hydraulic fracturing, production technical and economic characteristics, the issue of production profitability, economic benefits in the USA, impacts on the world refining industry, the possibility of creation of a new bubble, the role played by US authorities, the US shale oil and gas production, the technical potential outside the USA, the French resources, the stakes for the French economy, the macro-economic and geo-strategic impacts, the consequences for climate change, impacts on the world energy production

  17. Measurement of water activity from shales through thermo hygrometer

    Energy Technology Data Exchange (ETDEWEB)

    Rabe, Claudio [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Civil. Grupo de Tecnologia e Engenharia de Petroleo (GTEP)

    2004-07-01

    This paper presents a campaign of lab tests to obtain the water activity from shales and its pore fluid originated from offshore and onshore basin. The results of water activity from shales indicate that the values rang from 0.754 to 0.923 and for the pore fluid are between 0.987 and 0.940. The results show that the water activity of interstitial water can be obtained in 6 days and the rock in 10 days using the thermo hygrometer used. The degree of saturation, water content, kind and tenor of expansible and hydratable clay mineral, total and interconnected porosity, salinity of interstitial fluid and the capillary pressure of shale samples affected the results of water activity. (author)

  18. Effect of water on the mechanical behaviour of shales

    International Nuclear Information System (INIS)

    Wakim, J.; Hadj-Hassen, F.; Tijani, M.; Noirel, J.F.

    2005-01-01

    This paper aims to presenting the results of a research conducted in order to study the effect of water on the mechanical behaviour of the Lorraine Basin Colliery shale. The work performed can be divided into four main parts. The first part is dedicated to classical tests and it includes geological and mineralogical analysis as well as mechanical laboratory tests. The second part is devoted to the phenomenon of shale swelling under water effect. New procedures and equipment of testing were set up in order to characterise this swelling behaviour and to determine its model parameters. The tests performed in this second part are allowed to develop a phenomenological model which describes the elasto-visco-plastic behaviour of shales before and after saturation. The last phase of the work is dedicated to implement the new model in the finite element code VIPLEF in order to apply in tunnel excavated in swelling anisotropic rocks. (authors)

  19. Simultaneous caving and surface restoration system for oil shale mining

    Energy Technology Data Exchange (ETDEWEB)

    Allsman, P.T.

    1968-10-01

    A modified caving method is introduced for mining oil shale and simultaneous restoration of the land surface by return of spent shale onto the subsided area. Other methods have been designed to mine the relatively thin richer beds occurring near outcrops in the Piceance Creek Basin of NW. Colorado. Since the discovery of the much thicker beds in the N.-central part of the basin, some attention has focused on in situ and open-pit methods of recovery. Although caving has been recognized as a possible means of mining shale, most people have been skeptical of its success. This stems from the unknown and salient factors of cavability and size of broken rock with caving. Wisdom would seem to dictate that serious evaluation of the caving method be made along with the other methods.

  20. Chemical process for improved oil recovery from Bakken shale

    Energy Technology Data Exchange (ETDEWEB)

    Shuler, Patrick; Tang, Hongxin; Lu, Zayne [ChemEOR Inc (United States); Tang, Youngchun [Power Environmental Energy Research Institute (United States)

    2011-07-01

    This paper presents the new chemically-improved oil recovery process (IOR) process for Bakken formation reservoirs. A custom surfactant agent can be used in standard hydraulic fracturing treatments in the Bakken to increase oil recovery. The rock formation consists of three members: the lower shale, middle dolostone and the upper shale. The dolostone was deposited as a coastal carbonate during shallower water and the shales were deposited in a relatively deep marine condition. With the widespread advent of horizontal well drilling and large-volume hydraulic fracturing treatments, production from the Bakken has become very active. The experimental results exhibited that specialized surfactant formulations will interact with this mixed oil-wet low permeability middle member to produce more oil. It was also observed that oil recovery by spontaneous imbibition was fast and significant. The best surfactant found in this study is compatible with a common fracture fluid system.

  1. Liberation play : technology and prices help release shale gas from unconventional status

    International Nuclear Information System (INIS)

    Roche, P.

    2006-01-01

    Shale gas production is set to increase in Canada. The British Columbia (BC) Oil and Gas Commission has approved more than 20 blocks of potential shale lands as experimental scheme areas targeting Cretaceous-age and Devonian-age shales. The BC government is currently working on a royalty scheme to benefit shale gas producers by allowing them to defer the bulk of the royalty collection until projects have reached a certain economic payout point. Interest in unconventional gas has spawned activity in previously unexplored areas of BC. Coals and shales are currently being evaluated near the community of Hudson's Hope, which has an estimated 1.8 tcf of shale gas. Canadian Spirit Resources Inc., who have leased the land, are now focusing on optimizing production processes to improve the economics of shale gas recovery. In Saskatchewan, shale gas exploration is occurring in the central region of the province, far from existing oil and gas production. PanTerra Resources Corp. has recently drilled 16 wells on its Foam Lake project, and detailed core and log analyses are being conducted to improve the understanding of the lithology and rock fabric and allow the company to design completion and stimulation programs. Stealth Ventures Ltd. is concentrating on developing the tight, biogenic Colorado Shale, which extends from Manitoba to the foothills of Alberta. Because of the shallow depths, the initial drilling costs are lower for biogenic gas than for thermogenic gas. Success will depend on the right drilling and completion methods. Junior explorers are also exploring for shale gas in an area straddling the St. Lawrence River between Quebec City and Montreal. Several large companies are examining the economic potential of shale gas production throughout North America. It was concluded that oil and gas operators are becoming more confident that domestic shale gas resources will be cheaper in future than imported liquefied natural gas (LNG), which requires special ships

  2. Distillation of oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Bronder, G A

    1926-03-22

    To distill oil shales, cannel coals, and other carbonaceous materials for the extraction therefrom of hydrocarbons and volatile nitrogenous compounds, hard non-condensable gases from the condensers and scrubbers are withdrawn by blowers and admixed with burnt gases, obtained through conduits from the flues of heaters, and forced downwardly through horizontal chambers, connected by vertical conduits, of the heaters and delivered into the retort beneath the grate. Passing upwardly through the charge they vaporize the volatile substances in the shale, and a suction pump removes the vapors from the top of the retort. Immediately they are produced and at substantially the same temperature as that at which they emanate, thus preventing cracking of the oil vapors and condensation of the oil at the top of the retort. The amount of burnt flue gas admixed with the hard gases is regulated by two valves until a required uniform temperature is obtained. A generator supplies producer gas to a heater at the commencement of the retorting operation for circulation through the shale charge to initially produce oil vapors. The generator is connected by a pipe to the gas conduit leading to blowers.

  3. Evaluating the oxidation of shale during hydraulic fracturing using SEM-EDS and spectrocolorimetry

    Science.gov (United States)

    Tan, X. Y.; Nakashima, S.

    2017-12-01

    During hydraulic fracturing (fracking) for shale gas/oil extraction, oxygen is introduced into deep oxygen-poor environments, and Fe2+-bearing minerals in rocks can be oxidized thus leading to the degradation of rock quality. Akita diatomaceous shale is considered to be one of the source rocks for oil and gas fields in northwestern Japan. Outcrops of Akita shale often show presence of jarosite (Fe sulfate: yellow) and/or goethite (Fe hydroxide: brown to orange) as oxidation products of pyrite (FeS2). Several series of oxidation experiments of Akita shale under dry, humid, and wet conditions were conducted at temperatures of around 30 oC and 50oC for 30-40 days. Portable color spectro-colorimeters were used to monitor color changes of the rock surfaces every hour. SEM-EDS, UV-Vis, and Raman spectroscopic analyses were performed on the rock sample surface to examine the chemical and mineralogical compositions of Akita shale before and after the dry, humid, and wet experiments. In SEM-EDS analyses before the humid experiment, Fe and S containing phases show their atomic ratio close to 1:2 indicating that this is pyrite (FeS2). After the experiment, the ratio changed to around 1:1 suggesting a conversion from pyrite (FeS2) to mackinawite-like mineral (FeS). In addition, the formation of Ca sulfate (possibly gypsum: CaSO4.2H2O) and goethite-like Fe hydroxide were identified which were not present initially. Therefore, oxidation pathways of iron sulfide (pyrite: FeS2) via FeS to sulfate is confirmed by our humid experiments around 30oC on Akita shale. These oxidation processes might occur during the fracking of shale within relatively short time periods associated with precipitation of sulfates and hydroxides. Therefore, further studies are needed for their effects on rock properties and gas/oil production.

  4. Proceedings of the first thermomechanical workshop for shale

    International Nuclear Information System (INIS)

    1986-03-01

    Chapter 2 provides a description of the three federal regulations that pertain to the development of a high-level nuclear waste repository regardless of the rock type. Chapter 3 summarizes the reference shale repository conditions selected for this workshop. A room-and-pillar configuration was considered at an extraction ratio of about 0.25. The depth was assumed to be 700 m. Chapter 4 gives a summary of several case histories that were considered to be valuable in gaining an understanding of some of the design and construction features that might be unique in creating underground openings in shale. Chapter 5 assesses the data and information needs, availability, technology for acquisition, and the research and development necessary for analytical/numerical modeling in heat transfer, fluid flow, and thermomechanics. Chapter 6 assesses data and information needs in the laboratory and considerations associated with shale rock characterization. Chapter 7 assesses the data and information needs, availability, technology for acquisition, and the research and development necessary for field/in situ testing. Chapter 8 presents the consensus of the workshop participants that there is a definite need to advance the state of knowledge concerning the thermomechanical behavior of shales and to gain experience in applying this knowledge to the design of room-and-pillar excavations. Finally, Chapter 9 provides a summary of the research and development needs in the various interacting activities of repository development, including analytical/numerical modeling, laboratory testing, and field/in situ testing. The main conclusion of the workshop was that a need exists for an aggressive program in laboratory, field, numerical modeling, and design studies to provide a thermomechanical, technological base for comparison of shale types and shale regions/areas/sites

  5. Fracture lines: will Canada's water be protected in the rush to develop shale gas?

    Energy Technology Data Exchange (ETDEWEB)

    Parfitt, Ben [Munk School of Global Affairs at the University of Toronto (Canada)

    2010-10-15

    By combining hydraulic fracking with horizontal drilling, the gas industry has been able to unlock significant amounts of natural gas trapped inside deep and densely packed shale rock. The exploitation of shale gas has been a remarkable revolution in the last decade, going from hardly any production in 2000 to 20% of the United States' gas production in 2010. This cheap and abundant resource has been referred to as a game changer by North American industries and governments. However concerns about water usage and groundwater contamination have been raised. Indeed, the shale gas industry is responsible for the contamination of about 1,000 water wells and has been criticized for its important water withdrawals. This report intends to present the effects of shale gas production on the water supplies in Canada. It reviews the state of groundwater mapping in shale rich regions and reviews regulatory frameworks to determine if they are sufficient to protect water resources.

  6. Parents.

    Science.gov (United States)

    Hurst, Hunter, Ed.; And Others

    1986-01-01

    This document contains the fifth volume of "Today's Delinquent," an annual publication of the National Center for Juvenile Justice. This volume deals with the issue of the family and delinquency, examining the impact of parental behavior on the production of delinquent behavior. "Parents: Neglectful and Neglected" (Laurence D. Steinberg) posits…

  7. The Shale Gas potential of Lower Carboniferous Sediments in Germany

    Science.gov (United States)

    Kerschke, D.; Mihailovic, A.; Schulz, H., -M.; Horsfield, B.

    2012-04-01

    Organic-rich Carboniferous sediments are proven source rocks for conventional gas systems in NW Europe and are likely gas shale candidates. Within the framework of GeoEnergie, an initiative to strengthen scientific excellence, funded by the German Ministry of Education and Research (BMBF), the influence of palaeogeography and basin dynamics on sedimentology and diagenesis is being investigated. Our aim is to unravel the evolution of shale gas-relevant properties which control gas prospectivity and production parameters like porosity, brittleness, etc. for the Lower Carboniferous in Germany. Northern Germany is underlain by thick, mudstone-bearing Carboniferous successions with a wide range of thermal maturities. Some of these mudstone horizons are rich in organic carbon which is either of marine and/or terrigenous origin. During the Carboniferous deposition of fine-grained, TOC-rich basinal sediments changed into shallow marine to paralic siliciclastic sediments (carbonates during the Lower Carboniferous) in the north, and grade into coarse-grained sediments close to the uprising Variscan mountains in the south. As a result different architectural elements including TOC-rich fine-grained sediments like basinal shales, fine-grained parts of turbidites, and shallow marine mudstones occur in both the Lower and the Upper Carboniferous section. A high shale gas potential occurs in basinal shales of Namurian age with marine organic material and TOC contents of up to 8 % (Rhenish Alum Shales). Such sediments with thermal maturities between 1.3 to 3.0 % vitrinite reflectance and sufficient quartz contents occur in wide areas of present-day Central European Basins System (CEBS), and are at favourable depth for shale gas exploration predominantly along the southern CEBS margin.

  8. Ozone impacts of natural gas development in the Haynesville Shale.

    Science.gov (United States)

    Kemball-Cook, Susan; Bar-Ilan, Amnon; Grant, John; Parker, Lynsey; Jung, Jaegun; Santamaria, Wilson; Mathews, Jim; Yarwood, Greg

    2010-12-15

    The Haynesville Shale is a subsurface rock formation located beneath the Northeast Texas/Northwest Louisiana border near Shreveport. This formation is estimated to contain very large recoverable reserves of natural gas, and during the two years since the drilling of the first highly productive wells in 2008, has been the focus of intensive leasing and exploration activity. The development of natural gas resources within the Haynesville Shale is likely to be economically important but may also generate significant emissions of ozone precursors. Using well production data from state regulatory agencies and a review of the available literature, projections of future year Haynesville Shale natural gas production were derived for 2009-2020 for three scenarios corresponding to limited, moderate, and aggressive development. These production estimates were then used to develop an emission inventory for each of the three scenarios. Photochemical modeling of the year 2012 showed increases in 2012 8-h ozone design values of up to 5 ppb within Northeast Texas and Northwest Louisiana resulting from development in the Haynesville Shale. Ozone increases due to Haynesville Shale emissions can affect regions outside Northeast Texas and Northwest Louisiana due to ozone transport. This study evaluates only near-term ozone impacts, but the emission inventory projections indicate that Haynesville emissions may be expected to increase through 2020.

  9. Stress dependence of permeability of intact and fractured shale cores.

    Science.gov (United States)

    van Noort, Reinier; Yarushina, Viktoriya

    2016-04-01

    Whether a shale acts as a caprock, source rock, or reservoir, understanding fluid flow through shale is of major importance for understanding fluid flow in geological systems. Because of the low permeability of shale, flow is thought to be largely confined to fractures and similar features. In fracking operations, fractures are induced specifically to allow for hydrocarbon exploration. We have constructed an experimental setup to measure core permeabilities, using constant flow or a transient pulse. In this setup, we have measured the permeability of intact and fractured shale core samples, using either water or supercritical CO2 as the transporting fluid. Our measurements show decreasing permeability with increasing confining pressure, mainly due to time-dependent creep. Furthermore, our measurements show that for a simple splitting fracture, time-dependent creep will also eliminate any significant effect of this fracture on permeability. This effect of confinement on fracture permeability can have important implications regarding the effects of fracturing on shale permeability, and hence for operations depending on that.

  10. Geochemistry of shale groundwaters: Results of preliminary laboratory leaching experiments

    International Nuclear Information System (INIS)

    Von Damm, K.L.; Johnson, K.O.

    1987-09-01

    Twelve shales were reacted with distilled water at 20 0 C and 100 0 C; the composition of the waters and the mineralogy were determined before and after reaction. The experiments were conducted in a batch mode over a period of approximately 40 days. Major changes occurred in the solution chemistry; in most cases sulfate became the dominant anion while either sodium or calcium was the major cation. The high sulfate is most likely a result of the oxidation of pyrite in the samples. In the 100 0 C experiments some of the solutions became quite acidic. Examination of the observed mineralogy and comparison to the mineral assemblage calculated to be in equilibrium with the experimentally determined waters, suggests that the acidic waters are generated when no carbonate minerals remain to buffer the groundwaters to a more neutral pH. The pH of shale waters will be determined by the balance between the oxidation of pyrite and organic matter and the dissolution of carbonate minerals. The experimental data are helping to elucidate the chemical reactions that control the pH of shale groundwaters, a critical parameter in determining other water-rock and waste-water-rock interactions and ultimate solute mobility. An experimental approach also provides a means of obtaining data for shales for which no groundwater data are available as well as data on chemical species which are not usually determined or reported

  11. Geochemistry of shale groundwaters: Results of preliminary laboratory leaching experiments

    Energy Technology Data Exchange (ETDEWEB)

    Von Damm, K.L.; Johnson, K.O.

    1987-09-01

    Twelve shales were reacted with distilled water at 20/sup 0/C and 100/sup 0/C; the composition of the waters and the mineralogy were determined before and after reaction. The experiments were conducted in a batch mode over a period of approximately 40 days. Major changes occurred in the solution chemistry; in most cases sulfate became the dominant anion while either sodium or calcium was the major cation. The high sulfate is most likely a result of the oxidation of pyrite in the samples. In the 100/sup 0/C experiments some of the solutions became quite acidic. Examination of the observed mineralogy and comparison to the mineral assemblage calculated to be in equilibrium with the experimentally determined waters, suggests that the acidic waters are generated when no carbonate minerals remain to buffer the groundwaters to a more neutral pH. The pH of shale waters will be determined by the balance between the oxidation of pyrite and organic matter and the dissolution of carbonate minerals. The experimental data are helping to elucidate the chemical reactions that control the pH of shale groundwaters, a critical parameter in determining other water-rock and waste-water-rock interactions and ultimate solute mobility. An experimental approach also provides a means of obtaining data for shales for which no groundwater data are available as well as data on chemical species which are not usually determined or reported.

  12. The role of technology in unlocking the possibilities of shale gas

    CSIR Research Space (South Africa)

    Heydenrich, PR

    2017-10-01

    Full Text Available expelled from the Shale during burial and maturation and so it can be targeted without regard to structural closure. In some cases, a topseal (tight rock) is required Conventional System: Requires trap, or closure Unconventional System: Does... 2. Production of Shale Gas requires: ● Drilling technology capable of horizontal/geosteered well targeting (up to 3000m horizontal length is common) ● Completions technology to optimise the extraction of gas from the formation: ● Temporary...

  13. ) Organic Facies Variations in the Middle Cretaceous Black Shales of the Abakaliki Fold Belt, South-East, Nigeria

    International Nuclear Information System (INIS)

    Ehinola, O. A.; Badejoko, T.A.; Ekweozor, C.M.; Adebowale, K. O.

    2003-01-01

    An assessment, based on organic facies characteristics, have been carried out on the middle Cretaceous black shales, in order to determine their hydrocarbon source potential, thermal maturity, and depositional environments. The methods employed include evaluation of organic carbon content, rockeval pyrolysis, extractable organic matter, maceral composition and biomarker distributions.Organic facies criteria such as TOC, HI, Tmax, liptinite content, SOMIFOC and SHC/AHC indicate that Albian to middle Cenomanian shales are could only generate gas. The late Cenomanian to early Turonian shales are characterized by Type I/II kerogen, mature and could generate both oil and characterized by Type III kerogen, immature and could generate gas with little oil. The biomarker distributions indicate immature to mature source rock, moderately biodegraded and with reduced marine environment prevailing during the deposition of the lack shales. The late Cenomanian to early Turonian black shales show the highest source-rock potential

  14. Molecular characterization and geological microenvironment of a microbial community inhabiting weathered receding shale cliffs.

    Science.gov (United States)

    Cockell, Charles S; Pybus, David; Olsson-Francis, Karen; Kelly, Laura; Petley, David; Rosser, Nick; Howard, Kieren; Mosselmans, Fred

    2011-01-01

    Shales play an important role in many earth system processes including coastal erosion, and they form the foundations of many engineering structures. The geobiology of the interior of pyrite-containing receding shale cliffs on the coast of northeast England was examined. The surface of the weathered shales was characterised by a thin layer of disordered authigenic iron oxyhydroxides and localised acicular, platy and aggregated gypsum, which was characterised by Raman spectroscopy, XAS and SEM. These chemical changes are likely to play an important role in causing rock weakening along fractures at the micron scale, which ultimately lead to coastal retreat at the larger scale. The surface of the shale hosts a novel, low-diversity microbial community. The bacterial community was dominated by Proteobacteria, with phylotypes closely associating with Methylocella and other members of the γ-subdivision. The second largest phylogenetic group corresponded to Nitrospira. The archaeal 16S rRNA phylotypes were dominated by a single group of sequences that matched phylotypes reported from South African gold mines and possessed ammonia monooxygenase (amoA) genes. Both the phylogenetic and the mineral data show that acidic microenvironments play an important role in shale weathering, but the shale has a higher microbial diversity than previously described pyritic acid mine drainage sites. The presence of a potentially biogeochemically active microbial population on the rock surface suggests that microorganisms may contribute to early events of shale degradation and coastal erosion.

  15. The atmospheric inventory of Xenon and noble cases in shales The plastic bag experiment

    Science.gov (United States)

    Bernatowicz, T. J.; Podosek, F. A.; Honda, M.; Kramer, F. E.

    1984-01-01

    A novel trapped gas analysis protocol is applied to five shales in which the samples are sealed in air to eliminate the possibility of gas loss in the preanalysis laboratory vacuum exposure of a conventional protocol. The test is aimed at a determination concerning the hypothesis that atmospheric noble gases occur in the same proportion as planetary gases in meteorites, and that the factor-of-23 deficiency of air Xe relative to planetary Xe is made up by Xe stored in shales or other sedimentary rocks. The results obtained do not support the shale hypothesis.

  16. Variations in petrophysical properties of shales along a stratigraphic section in the Whitby mudstone (UK)

    Science.gov (United States)

    Barnhoorn, Auke; Houben, Maartje; Lie-A-Fat, Joella; Ravestein, Thomas; Drury, Martyn

    2015-04-01

    In unconventional tough gas reservoirs (e.g. tight sandstones or shales) the presence of fractures, either naturally formed or hydraulically induced, is almost always a prerequisite for hydrocarbon productivity to be economically viable. One of the formations classified so far as a potential interesting formation for shale gas exploration in the Netherlands is the Lower Jurassic Posidonia Shale Formation (PSF). However data of the Posidonia Shale Formation is scarce so far and samples are hard to come by, especially on the variability and heterogeneity of the petrophysical parameters of this shale little is known. Therefore research and sample collection is conducted on a time and depositional analogue of the PSF: the Whitby Mudstone Formation (WMF) in the United Kingdom. A large number of samples along a ~7m stratigraphic section of the Whitby Mudstone Formation have been collected and analysed. Standard petrophysical properties such as porosity and matrix densities are quantified for a number of samples throughout the section, as well as mineral composition analysis based on XRD/XRF and SEM analyses. Seismic velocity measurements are also conducted at multiple heights in the section and in multiple directions to elaborate on anisotropy of the material. Attenuation anisotropy is incorporated as well as Thomsen's parameters combined with elastic parameters, e.g. Young's modulus and Poisson's ratio, to quantify the elastic anisotropy. Furthermore rock mechanical experiments are conducted to determine the elastic constants, rock strength, fracture characteristics, brittleness index, fraccability and rock mechanical anisotropy across the stratigraphic section of the Whitby mudstone formation. Results show that the WMF is highly anisotropic and it exhibits an anisotropy on the large limit of anisotropy reported for US gas shales. The high anisotropy of the Whitby shales has an even larger control on the formation of the fracture network. Furthermore, most petrophysical

  17. Yield and characteristics of shale oil from the retorting of oil shale and fine oil-shale ash mixtures

    International Nuclear Information System (INIS)

    Niu, Mengting; Wang, Sha; Han, Xiangxin; Jiang, Xiumin

    2013-01-01

    Highlights: • The whole formation process of shale oil might be divided into four stages. • Higher ash/shale mass ratio intensified the cracking and coking of shale oil. • Ash/shale ratio of 1:2 was recommended for oil shale fluidized bed retort with fine oil-shale ash as solid heat carrier. - Abstract: For exploring and optimizing the oil shale fluidized bed retort with fine oil-shale ash as a solid heat carrier, retorting experiments of oil shale and fine oil-shale ash mixtures were conducted in a lab-scale retorting reactor to investigate the effects of fine oil-shale ash on shale oil. Oil shale samples were obtained from Dachengzi Mine, China, and mixed with fine oil-shale ash in the ash/shale mass ratios of 0:1, 1:4, 1:2, 1:1, 2:1 and 4:1. The experimental retorting temperature was enhanced from room temperature to 520 °C and the average heating rate was 12 °C min −1 . It was found that, with the increase of the oil-shale ash fraction, the shale oil yield first increased and then decreased obviously, whereas the gas yield appeared conversely. Shale oil was analyzed for the elemental analysis, presenting its atomic H/C ratio of 1.78–1.87. Further, extraction and simulated distillation of shale oil were also conducted to explore the quality of shale oil. As a result, the ash/shale mixing mass ratio of 1:2 was recommended only for the consideration of increasing the yield and quality of shale oil

  18. Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

    Science.gov (United States)

    Langenbruch, C.; Shapiro, S. A.

    2014-12-01

    seismicity in unconventional reservoirs is the role of anisotropy of rocks. We evaluate an elastic VTI rock model corresponding to a shale gas reservoir in the Horn River Basin to understand the relation between stress, event occurrence and elastic heterogeneity in anisotropic rocks.

  19. Oil shale (in memoriam)

    International Nuclear Information System (INIS)

    Strandberg, Marek

    2000-01-01

    Plans for the continued use of oil shale may lead the development of this country into an impasse. To this day no plans have been made for transition from the use of energy based on fossil fuels to that based on renewable resources. Without having any clear strategic plan politicians have been comforting both themselves and the population with promises to tackle the problem when the right time comes. Today the only enterprise whose cash flows and capital would really make it possible to reform the power industry is the firm Eesti Energia (Estonian Energy). However, its sole present shareholder - the state - prefers the sale of the firm's shares to carrying out a radical reform. At the same time, local consumers are likely to rather be willing to pay for the expensive electric energy produced from renewable resources than for that produced from fossil fuels, the price of which will also remain high due to the pollution tax. Practically it is impossible to buy a globally balanced environment for money - pollution taxes are but punitive mechanisms. The investments made into the oil-shale industry will also reinforce the cultural distance of North-East Estonia from the rest of Estonia - the uniform and prevalently Russian-speaking industrial area will be preserved as long as capital will continue to flow into the oil shale industry concentrated there. The way out would be for industries to make wider use of ecological and ecosystemic technologies and for the state to enforce ecologically balanced economic and social policies. (author)

  20. Process for refining shale bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Plauson, H

    1920-09-19

    A process is disclosed for refining shale bitumen for use as heavy mineral oil, characterized by mixtures of blown hard shale pitch and heavy mineral oil being blown with hot air at temperatures of 120 to 150/sup 0/ with 1 to 3 percent sulfur, and if necessary with 0.5 to 3 percent of an aldehyde.

  1. Distilling shale and the like

    Energy Technology Data Exchange (ETDEWEB)

    Gee, H T.P.

    1922-02-23

    In distilling shale or like bituminous fuels by internal heating with hot gas obtained by the gasifying of the shale residues with air or steam or a mixture of these, the amount and temperature of the gaseous distilling medium is regulated between the gasifying and the distilling chambers, by the introduction of cold gas or air.

  2. Shale Gas Technology. White Paper

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    Shale gas is extracted using horizontal drilling and hydraulic fracturing or 'fracking'. None of which are particularly new technologies or shale gas specific. In this white paper attention is paid to Horizontal drilling; Hydraulic fracturing or 'frackin'; Other 'unconventionals'; and Costs.

  3. Shale Gas Technology. White Paper

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    Shale gas is extracted using horizontal drilling and hydraulic fracturing or 'fracking'. None of which are particularly new technologies or shale gas specific. In this white paper attention is paid to Horizontal drilling; Hydraulic fracturing or 'frackin'; Other 'unconventionals'; and Costs.

  4. Recovering valuable shale oils, etc

    Energy Technology Data Exchange (ETDEWEB)

    Engler, C

    1922-09-26

    A process is described for the recovery of valuable shale oils or tars, characterized in that the oil shale is heated to about 300/sup 0/C or a temperature not exceeding this essentially and then is treated with a solvent with utilization of this heat.

  5. Analysis of oil shale and oil shale products for certain minor elements

    International Nuclear Information System (INIS)

    Dickman, P.T.; Purdy, M.; Doerges, J.E.; Ryan, V.A.; Poulson, R.E.

    1977-01-01

    The University of Wyoming was contracted by the Department of Energy's Laramie Energy Research Center (LERC) to develop rapid, inexpensive, and simple methods of quantitative and qualitative elemental analysis for products used and generated in the simulated in-situ retorting of oil shale. Alpha particle spectrometry was used to determine the radioisotope content of the aqueous retort products. Alpha particles are mono-energetic and the spectrometry method employed had very low background levels (1 count per 2000 seconds). These factors allow for both the quantitative and qualitative analysis of natural radioisotopes at the 1 ppm level. Sample preparation does not require any chemical treatment. Energy dispersive x-ray fluorescence (XRF) was used for the multi-element analysis of the retort products. The XRF, integrated with a mini-computer, allows rapid analysis of several elements in multiple samples. XRF samples require minimal amounts of preparation and analytical results are highly reproducible. This paper presents the methods developed and preliminary analytical results from oil shale by-products. Results from the analysis of oil shale rocks are not yet ready for presentation

  6. Strength curves for shales and sandstones under hydrostatic confining pressures

    International Nuclear Information System (INIS)

    Gupta, S.C.; Sikka, S.K.

    1978-01-01

    The experimental data for the effect of confining pressures on the fracture stress have been analysed for shales and sandstones. The normalized compressive strengths are found to lie in a narrow region so that Ohnaka's equation for crystalline rocks, can be fitted to the data. The fitted parameters are physically reasonable and indicate that the functional dependence of strength on porosity, strain rate and temperature is independent of the confining pressures. (author)

  7. Organic substances of bituminous shales

    Energy Technology Data Exchange (ETDEWEB)

    Lanin, V A; Pronina, M V

    1944-01-01

    Samples of Gdov (Estonia) and Volga (Russia) oil shales were oxidized by alkaline permanganate to study the distribution of carbon and the composition of the resulting oxidation products. Gdov shale was rather stable to oxidation and, after 42 hours 61.2 percent of the organic material remained unoxidized. Five hundred hours were required for complete oxidation, and the oxidation products consisted of CO/sub 2/, acetic, oxalic, and succinic acids. The oxidation products from Volga shale consisted of CO/sub 2/, acetic, oxalic, succinic, adipic, phthalic, benzenetricarboxylic, benzenetetracarboxylic, and benzenepentacarboxylic acids. The results indicated that Gdov shale is free of humic substances and is of sapropelic origin, while Volga shale is of sapropelic-humic origin.

  8. Numerical Simulation of Natural Gas Flow in Anisotropic Shale Reservoirs

    KAUST Repository

    Negara, Ardiansyah

    2015-11-09

    Shale gas resources have received great attention in the last decade due to the decline of the conventional gas resources. Unlike conventional gas reservoirs, the gas flow in shale formations involves complex processes with many mechanisms such as Knudsen diffusion, slip flow (Klinkenberg effect), gas adsorption and desorption, strong rock-fluid interaction, etc. Shale formations are characterized by the tiny porosity and extremely low-permeability such that the Darcy equation may no longer be valid. Therefore, the Darcy equation needs to be revised through the permeability factor by introducing the apparent permeability. With respect to the rock formations, several studies have shown the existence of anisotropy in shale reservoirs, which is an essential feature that has been established as a consequence of the different geological processes over long period of time. Anisotropy of hydraulic properties of subsurface rock formations plays a significant role in dictating the direction of fluid flow. The direction of fluid flow is not only dependent on the direction of pressure gradient, but it also depends on the principal directions of anisotropy. Therefore, it is very important to take into consideration anisotropy when modeling gas flow in shale reservoirs. In this work, the gas flow mechanisms as mentioned earlier together with anisotropy are incorporated into the dual-porosity dual-permeability model through the full-tensor apparent permeability. We employ the multipoint flux approximation (MPFA) method to handle the full-tensor apparent permeability. We combine MPFA method with the experimenting pressure field approach, i.e., a newly developed technique that enables us to solve the global problem by breaking it into a multitude of local problems. This approach generates a set of predefined pressure fields in the solution domain in such a way that the undetermined coefficients are calculated from these pressure fields. In other words, the matrix of coefficients

  9. Numerical Simulation of Natural Gas Flow in Anisotropic Shale Reservoirs

    KAUST Repository

    Negara, Ardiansyah; Salama, Amgad; Sun, Shuyu; Elgassier, Mokhtar; Wu, Yu-Shu

    2015-01-01

    Shale gas resources have received great attention in the last decade due to the decline of the conventional gas resources. Unlike conventional gas reservoirs, the gas flow in shale formations involves complex processes with many mechanisms such as Knudsen diffusion, slip flow (Klinkenberg effect), gas adsorption and desorption, strong rock-fluid interaction, etc. Shale formations are characterized by the tiny porosity and extremely low-permeability such that the Darcy equation may no longer be valid. Therefore, the Darcy equation needs to be revised through the permeability factor by introducing the apparent permeability. With respect to the rock formations, several studies have shown the existence of anisotropy in shale reservoirs, which is an essential feature that has been established as a consequence of the different geological processes over long period of time. Anisotropy of hydraulic properties of subsurface rock formations plays a significant role in dictating the direction of fluid flow. The direction of fluid flow is not only dependent on the direction of pressure gradient, but it also depends on the principal directions of anisotropy. Therefore, it is very important to take into consideration anisotropy when modeling gas flow in shale reservoirs. In this work, the gas flow mechanisms as mentioned earlier together with anisotropy are incorporated into the dual-porosity dual-permeability model through the full-tensor apparent permeability. We employ the multipoint flux approximation (MPFA) method to handle the full-tensor apparent permeability. We combine MPFA method with the experimenting pressure field approach, i.e., a newly developed technique that enables us to solve the global problem by breaking it into a multitude of local problems. This approach generates a set of predefined pressure fields in the solution domain in such a way that the undetermined coefficients are calculated from these pressure fields. In other words, the matrix of coefficients

  10. Results of chemical analyses of soil, shale, and soil/shale extract from the Mancos Shale formation in the Gunnison Gorge National Conservation Area, southwestern Colorado, and at Hanksville, Utah

    Science.gov (United States)

    Tuttle, Michele L.W.; Fahy, Juli; Grauch, Richard I.; Ball, Bridget A.; Chong, Geneva W.; Elliott, John G.; Kosovich, John J.; Livo, Keith E.; Stillings, Lisa L.

    2007-01-01

    Results of chemical and some isotopic analyses of soil, shale, and water extracts collected from the surface, trenches, and pits in the Mancos Shale are presented in this report. Most data are for sites on the Gunnison Gorge National Conservation Area (GGNCA) in southwestern Colorado. For comparison, data from a few sites from the Mancos landscape near Hanksville, Utah, are included. Twelve trenches were dug on the GGNCA from which 258 samples for whole-rock (total) analyses and 187 samples for saturation paste extracts were collected. Sixteen of the extract samples were duplicated and subjected to a 1:5 water extraction for comparison. A regional soil survey across the Mancos landscape on the GGNCA generated 253 samples for whole-rock analyses and saturation paste extractions. Seventeen gypsum samples were collected on the GGNCA for sulfur and oxygen isotopic analysis. Sixteen samples were collected from shallow pits in the Mancos Shale near Hanksville, Utah.

  11. Clay mineralogy and geochemistry of the soils derived from metamorphic and mafic igneous parent rocks in Lahijan area

    International Nuclear Information System (INIS)

    Ramezanpour, H.; Hesami, R.; Zanjanchi, M. A.

    2007-01-01

    The mineralogical and geochemical composition of the soils of three representative pedons formed on basaltic andesite, andesitic basalt and phyllite were investigated. Results by x-ray diffraction showed that progressive weathering of rocks have been marked by gradual accumulation of Al, Fe, Ti, Mg, H 3 O + and depletion of Na, K, Ca and Si in the soil; although, predominant clay, loss and gain trend of elements was different on the various rocks. Based on x-ray diffraction analysis, minerals in basaltic andesite and andesitic basalt were similar but, the intensity of mica to smectite or vermiculite transformation for latter was relatively higher than the former. This process revealed the degradation mineral because of two reasons: (i) - smectite and vermiculite increased whereas mica decreased in surface horizons. (i i)-Irregular mixed layer of mica-smectite or vermiculite was present in deeper part (170 cm) of the soils from andesitic basalt but shallower depth (75 em) of the soils from basaltic andesite. Clay minerals in phyllite were mica and chlorite that stratified with vermiculite. However, the absence of smectite in phyllite might be attributed to more acidic condition or position of the Fe ion in the mineral lattice of chlorite (higher Fe in the interlayer hydroxide sheet)

  12. Treatment of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Brown, H L

    1922-07-04

    To distill oil shale in lump form, it is fed as a continuous charge through an axially rotating externally heated retorting chamber, where the exposed surfaces of the lumps are gradually decomposed by destructive distillation, and light physical shocks are continuously administered to them, due to their tumbling-over motion and their contact with the ribs, to knock off the decomposing surfaces and present fresh surfaces for distillation. The vapors are withdrawn through a conduit, and the partially distilled lumps are fed through a shoot into a plurality of rotating externally heated retorts, similar in character to the first retort, from whence the vapors pass through a conduit to condensing apparatus, from which the permanent gases are withdrawn, and used for fuel in the distillation zone, while the residue is discharged into a water well. An auxiliary heating conduit, having a burner discharging into it, may be employed, while in some cases steam may be used if required. In two modifications, different arrangements of the retorts are shown, as well as means within the retorts for breaking up the lumps of shale.

  13. Detailed description of oil shale organic and mineralogical heterogeneity via fourier transform infrared mircoscopy

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.; Foster, Michael; Gutierrez, Fernando

    2015-01-01

    Mineralogical and geochemical information on reservoir and source rocks is necessary to assess and produce from petroleum systems. The standard methods in the petroleum industry for obtaining these properties are bulk measurements on homogenized, generally crushed, and pulverized rock samples and can take from hours to days to perform. New methods using Fourier transform infrared (FTIR) spectroscopy have been developed to more rapidly obtain information on mineralogy and geochemistry. However, these methods are also typically performed on bulk, homogenized samples. We present a new approach to rock sample characterization incorporating multivariate analysis and FTIR microscopy to provide non-destructive, spatially resolved mineralogy and geochemistry on whole rock samples. We are able to predict bulk mineralogy and organic carbon content within the same margin of error as standard characterization techniques, including X-ray diffraction (XRD) and total organic carbon (TOC) analysis. Validation of the method was performed using two oil shale samples from the Green River Formation in the Piceance Basin with differing sedimentary structures. One sample represents laminated Green River oil shales, and the other is representative of oil shale breccia. The FTIR microscopy results on the oil shales agree with XRD and LECO TOC data from the homogenized samples but also give additional detail regarding sample heterogeneity by providing information on the distribution of mineral phases and organic content. While measurements for this study were performed on oil shales, the method could also be applied to other geological samples, such as other mudrocks, complex carbonates, and soils.

  14. Electric property evidences of carbonification of organic matters in marine shales and its geologic significance: A case study of the Lower Cambrian Qiongzhusi shale in the southern Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yuman Wang

    2014-12-01

    Full Text Available Searching for some reliable evidences that can verify the carbonification of organic matters in marine shales is a major scientific issue in selecting shale gas fairways in old strata. To this end, based on core, logging and testing data, the electric property of two organic-rich shale layers in the Lower Cambrian Qiongzhusi Fm. and the Lower Silurian Longmaxi Fm. in the southern Sichuan Basin was compared to examine the carbonification signs of organic matters in the Qiongzhusi shale and its influence on gas occurrence in the shales. The following conclusions were reached: (1 the electric property experiment shows that the Qiongzhusi shale in the study area has had carbonification of organic matters. The low resistivity of dry samples from this highly mature organic-rich shale and ultra-low resistivity on downhole logs can be used to directly judge the degree of organic matter carbonification and the quality of source rocks; (2 in the Changning area, the Qiongzhusi shale shows low resistivity of dry samples and low to ultra-low resistivity on logs, indicating that organic matters are seriously carbonized, while in the Weiyuan area, the Qiongzhusi shale shows a basically normal resistivity on log curves, indicating its degree of graphitization between the Longmaxi Fm. and Qiongzhusi Fm. in the Changning area; (3 shale with medium-to-high resistivity is remarkably better than that with ultra-low resistivity in terms of gas generation potential, matrix porosity and gas adsorption capacity; (4 industrial gas flow has been tested in the organic shales with medium-to-high resistivity in the Jianwei–Weiyuan–Tongnan area in the north, where the Qiongzhusi shale is a favorable shale gas exploration target.

  15. Utica Shale Energy and Environment Laboratory (USEEL)

    Science.gov (United States)

    Cole, D. R.

    2017-12-01

    Despite the rapid growth of the UOG industry in the Appalachian Basin of Pennsylvania and neighboring states, there are still fundamental concerns regarding the environmentally sound and cost efficient extraction of this unique asset. To address these concerns, Ohio State University has established the Department of Energy-funded Utica Shale Energy and Environment Laboratory, a dedicated research program where scientists from the university will work with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL), academia, industry, and regulatory partners, to measure and monitor reservoir response to UOG development and any associated environmental concerns. The USEEL site will be located in Greene County, Pennsylvania, in the heart of the deep Utica-Pt. Pleasant Shale play of the Appalachian Basin. The USEEL project team will characterize and quantify the gas-producing attributes of one of the deepest portions of the Utica-Pt. Pleasant formations in the Appalachian Basin via a multi-disciplinary collaboration that leverages state-of-the-art capabilities in geochemistry, core assessment, well design and logging, 3-D and micro-seismic, DTS and DAS fiber optics, and reservoir modelling. Fracture and rock strength analyses will be complemented by a comprehensive suite of geophysical and geochemical logs, water and chip samples, and cores (pressure sidewall and whole core) to evaluate fluids, mineral alteration, microbes, pore structure, and hydrocarbon formation and alteration in the shale pore space. Located on an existing Marcellus drill pads in southwestern Pennsylvania, USEEL will provide an unprecedented opportunity to evaluate the economic and environmental effects of Marcellus pad expansion on the integrity of near-by existing production wells, ground disruption and slope stability, and ultimate efforts to conduct site reclamation. Combined with the overall goal of an improved understanding of the Utica-Pt. Pleasant system, USEEL

  16. Experimental Characterization of Dielectric Properties in Fluid Saturated Artificial Shales

    Directory of Open Access Journals (Sweden)

    Roman Beloborodov

    2017-01-01

    Full Text Available High dielectric contrast between water and hydrocarbons provides a useful method for distinguishing between producible layers of reservoir rocks and surrounding media. Dielectric response at high frequencies is related to the moisture content of rocks. Correlations between the dielectric permittivity and specific surface area can be used for the estimation of elastic and geomechanical properties of rocks. Knowledge of dielectric loss-factor and relaxation frequency in shales is critical for the design of techniques for effective hydrocarbon extraction and production from unconventional reservoirs. Although applicability of dielectric measurements is intriguing, the data interpretation is very challenging due to many factors influencing the dielectric response. For instance, dielectric permittivity is determined by mineralogical composition of solid fraction, volumetric content and composition of saturating fluid, rock microstructure and geometrical features of its solid components and pore space, temperature, and pressure. In this experimental study, we investigate the frequency dependent dielectric properties of artificial shale rocks prepared from silt-clay mixtures via mechanical compaction. Samples are prepared with various clay contents and pore fluids of different salinity and cation compositions. Measurements of dielectric properties are conducted in two orientations to investigate the dielectric anisotropy as the samples acquire strongly oriented microstructures during the compaction process.

  17. The Architecture and Frictional Properties of Faults in Shale

    Science.gov (United States)

    De Paola, N.; Imber, J.; Murray, R.; Holdsworth, R.

    2015-12-01

    The geometry of brittle fault zones in shale rocks, as well as their frictional properties at reservoir conditions, are still poorly understood. Nevertheless, these factors may control the very low recovery factors (25% for gas and 5% for oil) obtained during fracking operations. Extensional brittle fault zones (maximum displacement hydraulic breccias; and a slip zone up to 20 mm thick, composed of a fine-grained black gouge. Hydraulic breccias are located within dilational jogs with aperture of up to 20 cm. Brittle fracturing and cataclastic flow are the dominant deformation mechanisms in the fault core of shale faults. Velocity-step and slide-hold-slide experiments at sub-seismic slip rates (microns/s) were performed in a rotary shear apparatus under dry, water and brine-saturated conditions, for displacements of up to 46 cm. Both the protolith shale and the slip zone black gouge display shear localization, velocity strengthening behaviour and negative healing rates, suggesting that slow, stable sliding faulting should occur within the protolith rocks and slip zone gouges. Experiments at seismic speed (1.3 m/s), performed on the same materials under dry conditions, show that after initial friction values of 0.5-0.55, friction decreases to steady-state values of 0.1-0.15 within the first 10 mm of slip. Contrastingly, water/brine saturated gouge mixtures, exhibit almost instantaneous attainment of very low steady-state sliding friction (0.1), suggesting that seismic ruptures may efficiently propagate in the slip zone of fluid-saturated shale faults. Stable sliding in faults in shale can cause slow fault/fracture propagation, affecting the rate at which new fracture areas are created and, hence, limiting oil and gas production during reservoir stimulation. However, fluid saturated conditions can favour seismic slip propagation, with fast and efficient creation of new fracture areas. These processes are very effective at dilational jogs, where fluid circulation may

  18. Preliminary view of geotechnical properties of soft rocks of Semanggol formation at Pokok Sena, Kedah

    Science.gov (United States)

    Ahmad, N. R.; Jamin, N. H.

    2018-04-01

    The research was inspired by series of geological studies on Semanggol formation found exposed at North Perak, South Kedah and North Kedah. The chert unit comprised interbedded chert-shale rocks are the main lithologies sampled in a small-scale outcrop of Pokok Sena area. Black shale materials were also observed associated with these sedimentary rocks. The well-known characteristics of shale that may swell when absorb water and leave shrinkage when dried make the formation weaker when load is applied on it. The presence of organic materials may worsen the condition apart from the other factors such as the history of geological processes and depositional environment. Thus, this research is important to find the preliminary relations of the geotechnical properties of soft rocks and the geological reasoning behind it. Series of basic soil tests and 1-D compression tests were carried out to obtain the soil parameters. The results obtained gave some preliminary insight to mechanical behaviour of these two samples. The black shale and weathered interbedded chert-shale were classified as sandy-clayey-SILT and clayey-silty-SAND respectively. The range of specific gravity of black shale and interbedded chert/shale 2.3 – 2.6 and fall in the common range of shale and chert specific gravity value. In terms of degree of plasticity, the interbedded chert/shale samples exhibit higher plastic degree compared to the black shale samples. Results from oedometer tests showed that black shale samples had higher overburden pressure (Pc) throughout its lifetime compare to weathered interbedded chert-shale, however the compression index (Cc) of black shale were 0.15 – 0.185 which was higher than that found in interbedded chert-shale. The geotechnical properties of these two samples were explained in correlation with their provenance and their history of geological processes involved which predominantly dictated the mechanical behaviour of these two samples.

  19. Volume fracturing of deep shale gas horizontal wells

    Directory of Open Access Journals (Sweden)

    Tingxue Jiang

    2017-03-01

    Full Text Available Deep shale gas reservoirs buried underground with depth being more than 3500 m are characterized by high in-situ stress, large horizontal stress difference, complex distribution of bedding and natural cracks, and strong rock plasticity. Thus, during hydraulic fracturing, these reservoirs often reveal difficult fracture extension, low fracture complexity, low stimulated reservoir volume (SRV, low conductivity and fast decline, which hinder greatly the economic and effective development of deep shale gas. In this paper, a specific and feasible technique of volume fracturing of deep shale gas horizontal wells is presented. In addition to planar perforation, multi-scale fracturing, full-scale fracture filling, and control over extension of high-angle natural fractures, some supporting techniques are proposed, including multi-stage alternate injection (of acid fluid, slick water and gel and the mixed- and small-grained proppant to be injected with variable viscosity and displacement. These techniques help to increase the effective stimulated reservoir volume (ESRV for deep gas production. Some of the techniques have been successfully used in the fracturing of deep shale gas horizontal wells in Yongchuan, Weiyuan and southern Jiaoshiba blocks in the Sichuan Basin. As a result, Wells YY1HF and WY1HF yielded initially 14.1 × 104 m3/d and 17.5 × 104 m3/d after fracturing. The volume fracturing of deep shale gas horizontal well is meaningful in achieving the productivity of 50 × 108 m3 gas from the interval of 3500–4000 m in Phase II development of Fuling and also in commercial production of huge shale gas resources at a vertical depth of less than 6000 m.

  20. Carbon sequestration in depleted oil shale deposits

    Science.gov (United States)

    Burnham, Alan K; Carroll, Susan A

    2014-12-02

    A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

  1. Distilling oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Crozier, R H

    1923-04-18

    In the fractional distillation of oils from oil shale and similar materials the charge is passed continuously through a vertical retort heated externally by hot combustion gases in flues and internally by the passage of these gases through flues passing through the retort so that zones of increasing temperature are maintained. A vapor trap is provided in each zone having an exit pipe leading through a dust trap to a condenser. The bottoms of the conical vapor traps are provided with annular passages perforated to permit of steam being sprayed into the charge to form screens which prevent the vapors in different zones from mingling, and steam may also be introduced through perforations in an annular steam box. Dampers are provided to control the passage of the heating gases through the flues independently.

  2. Distilling shale and coal

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, H; Young, G

    1923-01-09

    In a process of recovering oil from shale or coal the material is ground and may be subjected to a cleaning or concentrating process of the kind described in Specification 153,663 after which it is distilled in a furnace as described in Specification 13,625/09 the sections of the furnace forming different temperature zones, and the rate of the passage of the material is regulated so that distillation is complete with respect to the temperature of each zone, the whole distillation being accomplished in successive stages. The vapors are taken off at each zone and superheated steam may be passed into the furnace at suitable points and the distillation terminated at any stage of the process.

  3. Distillation of shale

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, E L

    1923-09-04

    To retort shale, lignite, coal, or the like for the recovery of gas and oils or spirits, it is fed through a hopper and then passed in a thin film through the space between the casing and outer shell by means of louvres which with the shell and the outer shell are reciprocated vertically. The top of the shell connected by brackets and lifting joists are pivoted to an eccentric driven by a shaft. The spent material passes through openings in the fixed base casting and openings in a moving ring which is rotated by a pawl and ratchet gear actuated by the reciprocation of the shell. The openings are opposite one another at the commencement of the downward movement of the louvres and shell and closed when the louvres are right down and on their upward movement.

  4. Hydrogenation of shale

    Energy Technology Data Exchange (ETDEWEB)

    Bedwell, A J; Clark, E D; Miebach, F W

    1935-09-28

    A process for the distillation, cracking, and hydrogenation of shale or other carbonaceous material consists in first distilling the material to produce hydrocarbon oils. Steam is introduced and is passed downwardly with hydrocarbon vapors from the upper portion of the retort where the temperature is maintained between 400/sup 0/C and 450/sup 0/C over the spent carbonaceous materials. The material is drawn off at the bottom of the retort which is maintained at a temperature ranging from 600/sup 0/C to 800/sup 0/C whereby the hydrocarbon vapors are cracked in the pressure of nascent hydrogen obtained by the action of the introduced steam on the spent material. The cracked gases and undecomposed steam are passed through a catalyst tower containing iron-magnesium oxides resulting in the formation of light volatile oils.

  5. Distilling coal, shale, etc

    Energy Technology Data Exchange (ETDEWEB)

    Bussey, C C

    1916-07-17

    In the extraction of vovolatile ingredients from coal, shale, lignite, and other hydrocarbonaceous materials by passing through the material a heating-agent produced by burning at the base of the charge a portion of the material from which the volatile ingredients have been extracted, the temperature of the heating agent is maintained constant by continuously removing the residue from the bottom of the apparatus. The temperature employed is 800/sup 0/F or slightly less, so as to avoid any breaking-down action. As shown the retort is flared downwardly, and is provided at the base with a fireplace, which is in communication with the interior of the retort through flues fitted with screens and dampers. Beneath the bottom of the retort is mounted a movable grate carried on endless sprocket chains, which are preferably set so that the grate inclines downwardly towards the coke, etc.

  6. Recovering oil from shale

    Energy Technology Data Exchange (ETDEWEB)

    Leahey, T; Wilson, H

    1920-11-13

    To recover oil free from inorganic impurities and water, and utilize the oil vapor and tarry matter for the production of heat, shale is heated in a retort at a temperature of not less than 120/sup 0/C. The vapors pass by a pipe into a water jacketed condenser from which the condensate and gas pass through a pipe into a chamber and then by a pipe to a setting chamber from where the light oils are decanted through a pipe into a tank. The heavy oil is siphoned through a pipe into a tank, while the gas passes through a pipe into a scrubber and then into a drier, exhauster and pipe to the flue and ports, above the fire-bars, into the retort. Air is introduced through a pipe, flue, and ports.

  7. Neutron activation determination of rhenium in shales shales and molybdenites

    International Nuclear Information System (INIS)

    Zajtsev, E.I.; Radinovich, B.S.

    1977-01-01

    Described is the technique for neutron activation determination of rhenium in shales and molybdenites with its radiochemical extraction separation by methyl-ethyl ketone. The sensitivity of the analysis is 5x10 -7 %. Experimental checking of the developed technique in reference to the analysis of shales and molybdenites was carried out. Estimated is the possibility of application of X-ray gamma-spectrometer to instrumental determination of rhenium in molybdenites

  8. Oil shale utilization in Israel

    International Nuclear Information System (INIS)

    Kaiser, A.

    1993-01-01

    Geological surveys have confirmed the existence of substantial Israeli oil shale reserves. The proven reserves contain approximately 12 billion tons of available ores, and the potential is deemed to be much higher. Economic studies conducted by PAMA indicate promising potential for power generation via Israel oil shale combustion. Electric power from oil shale appears competitive with power generated from coal fired power plants located along the coast. PAMA's demonstration power plant has been in operation since the end of 1989. Based on the successful results of the first year of operation, PAMA and IEC are now engaged in the pre-project program for a 1000 MW commercial oil shale fired power plant, based on eight 120 MW units; the first unit is scheduled to begin operation in 1996

  9. Shale gas: the water myth

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, Kerry [Dillon Consulting Limited (Canada)

    2010-07-01

    In recent years, due to the depletion of traditional fossil fuel resources and the rising price of energy, production from unconventional gas activities has increased. Large shale gas plays are available in Quebec but environmental concerns, mainly in terms of water resources, have been raised. The aim of this paper is to provide information on the impact of shale gas exploitation on water resources. It is shown herein that shale gas water use is not significant, the water use of 250 wells represents only 0.3% of the Quebec pulp and paper industry's water use, or 0.0004% of the flow of the St Lawrence. It is also shown that the environmental risk associated with fracking and drilling activities is low. This paper demonstrated that as long as industry practices conform to a well-designed regulatory framework, shale gas development in Quebec will have a low impact on water resources and the environment.

  10. BLM Colorado Oil Shale Leases

    Data.gov (United States)

    Department of the Interior — KMZ file Format –This data set contains the Oil Shale Leases for the State of Colorado, derived from Legal Land Descriptions (LLD) contained in the US Bureau of Land...

  11. Understanding gas production mechanism and effectiveness of well stimulation in the Haynesville shale through reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.; Thompson, J.W.; Robinson, J.R. [Schlumberger, Houston, TX (United States)

    2010-07-01

    The Haynesville Shale Basin is one of the large and most active shale gas plays in the United States, with 185 horizontal rigs currently in place. The Haynesville Shale is a very tight source rock and resource play. The gas resources are being converted into gas reserves with horizontal wells and hydraulic fracture treatments. A complex fracture network created during well stimulation is the main factor in generating superior early well performance in the area. The key to making better wells in all the gas shale plays is to understand how to create more surface area during hydraulic stimulation jobs and preserve the surface area for as long as possible. This paper presented a unique workflow and methodology that has enabled analysis of production data using reservoir simulation to explain the shale gas production mechanism and the effectiveness of stimulation treatments along laterals. Since 2008, this methodology has been used to analyze production data from more than 30 horizontal wells in the Haynesville Shale. Factors and parameters relating to short and long term well performance were investigated, including pore pressure, rock matrix quality, natural fractures, hydraulic fractures, and complex fracture networks. Operators can use the simulation results to determine where and how to spend resources to produce better wells and to reduce the uncertainties of developing these properties. 19 refs., 1 tab., 17 figs.

  12. Stabilization of gasoline from shale

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, L

    1929-03-14

    A process is described of stabilizing gasoline from shale, consisting in treating by agitating the gasoline freshly distilled from shale oil with 1.5 percent of its weight of sulfuric acid diluted to more than 10 times its volume, after which separating the pyridine, then treating by agitating with sulfuric acid which treatment separates the unsaturated hydrocarbons and finally treating by agitating with 1.5 percent of its weight of saturated caustic soda solution and washing with water.

  13. Regional Geologic Evaluations for Disposal of HLW and SNF: The Pierre Shale of the Northern Great Plains

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Frank Vinton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kelley, Richard E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-14

    The DOE Spent Fuel and Waste Technology (SWFT) R&D Campaign is supporting research on crystalline rock, shale (argillite) and salt as potential host rocks for disposal of HLW and SNF in a mined geologic repository. The distribution of these three potential repository host rocks is limited to specific regions of the US and to different geologic and hydrologic environments (Perry et al., 2014), many of which may be technically suitable as a site for mined geologic disposal. This report documents a regional geologic evaluation of the Pierre Shale, as an example of evaluating a potentially suitable shale for siting a geologic HLW repository. This report follows a similar report competed in 2016 on a regional evaluation of crystalline rock that focused on the Superior Province of the north-central US (Perry et al., 2016).

  14. Pore Scale Analysis of Oil Shale/Sands Pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chen-Luh [Univ. of Utah, Salt Lake City, UT (United States); Miller, Jan [Univ. of Utah, Salt Lake City, UT (United States)

    2011-03-01

    There are important questions concerning the quality and volume of pore space that is created when oil shale is pyrolyzed for the purpose of producing shale oil. In this report, 1.9 cm diameter cores of Mahogany oil shale were pyrolyzed at different temperatures and heating rates. Detailed 3D imaging of core samples was done using multiscale X-ray computed tomography (CT) before and after pyrolysis to establish the pore structure. The pore structure of the unreacted material was not clear. Selected images of a core pyrolyzed at 400oC were obtained at voxel resolutions from 39 microns (Οm) to 60 nanometers (nm). Some of the pore space created during pyrolysis was clearly visible at these resolutions and it was possible to distinguish between the reaction products and the host shale rock. The pore structure deduced from the images was used in Lattice Boltzmann simulations to calculate the permeability in the pore space. The permeabilities of the pyrolyzed samples of the silicate-rich zone were on the order of millidarcies, while the permeabilities of the kerogen-rich zone after pyrolysis were very anisotropic and about four orders of magnitude higher.

  15. Energy (in)security in Poland the case of shale gas

    International Nuclear Information System (INIS)

    Johnson, Corey; Boersma, Tim

    2013-01-01

    The large scale extraction of natural gas from shale rock layers in North America using hydraulic fracturing, or “fracking”, has prompted geologists, economists and politicians in various parts of the world to ask whether there are new reserves of this precious resource to be found under their soils. It has also raised a host of questions about the potential environmental impacts of extracting it. Drawing on research on both sides of the Atlantic, this paper assesses the most pressing issues for research and policy makers related to shale gas extraction. The paper first provides a survey of environmental and economic issues related to shale gas. It then turns to a case study of Poland, whose policy makers have been among the most fervent proponents of shale gas development in the European Union. We examine the status of shale gas extraction in that country and what the barriers are to overcome before commercial extraction can in fact take place, if at all. - Highlights: ► We examine geologic, economic, environmental and political issues of shale gas. ► Poland is used to assess prospects for shale gas development in Europe. ► Debate in Poland has largely been framed as an energy security issue. ► A number of significant hurdles may prevent large scale development there.

  16. Removing heavy metals from wastewaters with use of shales accompanying the coal beds.

    Science.gov (United States)

    Jabłońska, Beata; Siedlecka, Ewa

    2015-05-15

    A possibility of using clay waste rocks (shales) from coal mines in the removal of heavy metals from industrial wastewaters is considered in this paper. Raw and calcined (600 °C) shales accompanying the coal beds in two Polish coal mines were examined with respect to their adsorptive capabilities for Pb, Ni and Cu ions. The mineralogical composition of the shales was determined and the TG/DTG analysis was carried out. The granulometric compositions of raw and calcined shales were compared. Tests of adsorption for various Pb(II), Ni(II) and Cu(II) concentrations were conducted and the pH before and after adsorption was analyzed. The results indicate that the shales from both coal mines differ in adsorptive capabilities for particular metal ions. The calcination improved the adsorptive capabilities for lead, but worsened them for nickel. The examined shales have good adsorptive capabilities, and could be used as inexpensive adsorbents of heavy metal ions, especially in the regions where resources of shale are easy accessible in the form of spoil tips. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Modelling of underground geomechanical characteristics for electrophysical conversion of oil shale

    International Nuclear Information System (INIS)

    Bukharkin, A A; Koryashov, I A; Martemyanov, S M; Ivanov, A A

    2015-01-01

    Oil shale energy extraction is an urgent issue for modern science and technique. With the help of electrical discharge phenomena it is possible to create a new efficient technology for underground conversion of oil shale to shale gas and oil. This method is based on Joule heat in the rock volume. During the laboratory experiments the problem has arisen, when the significant part of a shale fragment is being heated, but the further heating is impossible due to specimen cracking. It leads to disruption in current flow and heat exchange. Evidently, in the underground conditions these failure processes will not proceed. Cement, clay and glass fiber/epoxy resin armature have been used for modelling of geomechanical underground conditions. Experiments have shown that the use of a reinforcing jacket makes it possible to convert a full rock fragment. Also, a thermal field extends radially from the centre of a tree-type structure, and it has an elliptic cross section shape. It is explained by the oil shale anisotropy connected with a rock laminar structure. Therefore, heat propagation is faster along the layers than across ones. (paper)

  18. Geochemical controls on shale groundwaters: Results of reaction path modeling

    International Nuclear Information System (INIS)

    Von Damm, K.L.; VandenBrook, A.J.

    1989-03-01

    The EQ3NR/EQ6 geochemical modeling code was used to simulate the reaction of several shale mineralogies with different groundwater compositions in order to elucidate changes that may occur in both the groundwater compositions, and rock mineralogies and compositions under conditions which may be encountered in a high-level radioactive waste repository. Shales with primarily illitic or smectitic compositions were the focus of this study. The reactions were run at the ambient temperatures of the groundwaters and to temperatures as high as 250/degree/C, the approximate temperature maximum expected in a repository. All modeling assumed that equilibrium was achieved and treated the rock and water assemblage as a closed system. Graphite was used as a proxy mineral for organic matter in the shales. The results show that the presence of even a very small amount of reducing mineral has a large influence on the redox state of the groundwaters, and that either pyrite or graphite provides essentially the same results, with slight differences in dissolved C, Fe and S concentrations. The thermodynamic data base is inadequate at the present time to fully evaluate the speciation of dissolved carbon, due to the paucity of thermodynamic data for organic compounds. In the illitic cases the groundwaters resulting from interaction at elevated temperatures are acid, while the smectitic cases remain alkaline, although the final equilibrium mineral assemblages are quite similar. 10 refs., 8 figs., 15 tabs

  19. Detachment of particulate iron sulfide during shale-water interaction

    Science.gov (United States)

    Emmanuel, S.; Kreisserman, Y.

    2017-12-01

    Hydraulic fracturing, a commonly used technique to extract oil and gas from shales, is controversial in part because of the threat it poses to water resources. The technique involves the injection into the subsurface of large amounts of fluid, which can become contaminated by fluid-rock interaction. The dissolution of pyrite is thought to be a primary pathway for the contamination of fracturing fluids with toxic elements, such as arsenic and lead. In this study, we use direct observations with atomic force microscopy to show that the dissolution of carbonate minerals in Eagle Ford shale leads to the physical detachment of embedded pyrite grains. To simulate the way fluid interacts with a fractured shale surface, we also reacted rock samples in a flow-through cell, and used environmental scanning electron microscopy to compare the surfaces before and after interaction with water. Crucially, our results show that the flux of particulate iron sulfide into the fluid may be orders of magnitude higher than the flux of pyrite from chemical dissolution. This result suggests that mechanical detachment of pyrite grains could be the dominant mode by which arsenic and other inorganic elements are mobilized in the subsurface. Thus, during hydraulic fracturing operations and in groundwater systems containing pyrite, the transport of many toxic species may be controlled by the transport of colloidal iron sulfide particles.

  20. Fracture lines: will Canada's water be protected in the rush to develop shale gas?

    Energy Technology Data Exchange (ETDEWEB)

    Parfitt, Ben [Munk School of Global Affairs at the University of Toronto (Canada)

    2010-10-15

    By combining hydraulic fracking with horizontal drilling, the gas industry has been able to unlock significant amounts of natural gas trapped inside deep and densely packed shale rock. The exploitation of shale gas has been a remarkable revolution in the last decade, going from hardly any production in 2000 to 20% of the United States' gas production in 2010. This cheap and abundant resource has been referred to as a game changer by North American industries and governments. However concerns about water usage and groundwater contamination have been raised. Indeed, the shale gas industry is responsible for the contamination of about 1,000 water wells and has been criticized for its important water withdrawals. This report intends to present the effects of shale gas production on the water supplies in Canada. It reviews the state of groundwater mapping in shale rich regions and reviews regulatory frameworks to determine if they are sufficient to protect water resources.

  1. Arctic black shale formation during Cretaceous Oceanic Anoxic Event 2

    DEFF Research Database (Denmark)

    Lenniger, Marc; Nøhr-Hansen, Henrik; Hills, Len V.

    2014-01-01

    The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid-paleolatitudes are re......The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid...... caused massive organic-carbon burial on the Arctic shelf in general, with important implications for hydrocarbon source-rock distribution in the Arctic region....

  2. 4D synchrotron X-ray imaging to understand porosity development in shales during exposure to hydraulic fracturing fluid

    Science.gov (United States)

    Kiss, A. M.; Bargar, J.; Kohli, A. H.; Harrison, A. L.; Jew, A. D.; Lim, J. H.; Liu, Y.; Maher, K.; Zoback, M. D.; Brown, G. E.

    2016-12-01

    Unconventional (shale) reservoirs have emerged as the most important source of petroleum resources in the United States and represent a two-fold decrease in greenhouse gas emissions compared to coal. Despite recent progress, hydraulic fracturing operations present substantial technical, economic, and environmental challenges, including inefficient recovery, wastewater production and disposal, contaminant and greenhouse gas pollution, and induced seismicity. A relatively unexplored facet of hydraulic fracturing operations is the fluid-rock interface, where hydraulic fracturing fluid (HFF) contacts shale along faults and fractures. Widely used, water-based fracturing fluids contain oxidants and acid, which react strongly with shale minerals. Consequently, fluid injection and soaking induces a host of fluid-rock interactions, most notably the dissolution of carbonates and sulfides, producing enhanced or "secondary" porosity networks, as well as mineral precipitation. The competition between these mechanisms determines how HFF affects reactive surface area and permeability of the shale matrix. The resultant microstructural and chemical changes may also create capillary barriers that can trap hydrocarbons and water. A mechanistic understanding of the microstructure and chemistry of the shale-HFF interface is needed to design new methodologies and fracturing fluids. Shales were imaged using synchrotron micro-X-ray computed tomography before, during, and after exposure to HFF to characterize changes to the initial 3D structure. CT reconstructions reveal how the secondary porosity networks advance into the shale matrix. Shale samples span a range of lithologies from siliceous to calcareous to organic-rich. By testing shales of different lithologies, we have obtained insights into the mineralogic controls on secondary pore network development and the morphologies at the shale-HFF interface and the ultimate composition of produced water from different facies. These results

  3. Source rock potential of middle cretaceous rocks in Southwestern Montana

    Science.gov (United States)

    Dyman, T.S.; Palacas, J.G.; Tysdal, R.G.; Perry, W.J.; Pawlewicz, M.J.

    1996-01-01

    The middle Cretaceous in southwestern Montana is composed of a marine and nonmarine succession of predominantly clastic rocks that were deposited along the western margin of the Western Interior Seaway. In places, middle Cretaceous rocks contain appreciable total organic carbon (TOC), such as 5.59% for the Mowry Shale and 8.11% for the Frontier Formation in the Madison Range. Most samples, however, exhibit less than 1.0% TOC. The genetic or hydrocarbon potential (S1+S2) of all the samples analyzed, except one, yield less than 1 mg HC/g rock, strongly indicating poor potential for generating commercial amounts of hydrocarbons. Out of 51 samples analyzed, only one (a Thermopolis Shale sample from the Snowcrest Range) showed a moderate petroleum potential of 3.1 mg HC/g rock. Most of the middle Cretaceous samples are thermally immature to marginally mature, with vitrinite reflectance ranging from about 0.4 to 0.6% Ro. Maturity is high in the Pioneer Mountains, where vitrinite reflectance averages 3.4% Ro, and at Big Sky Montana, where vitrinite reflectance averages 2.5% Ro. At both localities, high Ro values are due to local heat sources, such as the Pioneer batholith in the Pioneer Mountains.

  4. Shales and other argillaceous strata in the United States

    International Nuclear Information System (INIS)

    Gonzales, S.; Johnson, K.S.

    1985-03-01

    This report presents detailed geologic and hydrologic data that describe shales and other argillaceous rocks; data are from the open literature. These data are intended to be used in the future to aid in assessment of various strata and their potential for repository siting. No observations, conclusions, or recommendations are made by the authors of this report relative to the suitability of various argillaceous rocks for waste disposal. There are, however, other published reports that contain technical data and evaluative statements regarding the suitability of various argillaceous rocks for repository siting. Where appropriate, the authors of this report have referenced this previously published literature and have summarized the technical data. 838 refs., 121 figs., 6 tabs

  5. Shales and other argillaceous strata in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, S.; Johnson, K.S.

    1985-03-01

    This report presents detailed geologic and hydrologic data that describe shales and other argillaceous rocks; data are from the open literature. These data are intended to be used in the future to aid in assessment of various strata and their potential for repository siting. No observations, conclusions, or recommendations are made by the authors of this report relative to the suitability of various argillaceous rocks for waste disposal. There are, however, other published reports that contain technical data and evaluative statements regarding the suitability of various argillaceous rocks for repository siting. Where appropriate, the authors of this report have referenced this previously published literature and have summarized the technical data. 838 refs., 121 figs., 6 tabs.

  6. Energy (in)security in Poland the case of shale gas

    NARCIS (Netherlands)

    Johnson, Corey; Boersma, Tim

    The large scale extraction of natural gas from shale rock layers in North America using hydraulic fracturing, or 'Tracking", has prompted geologists, economists and politicians in various parts of the world to ask whether there are new reserves of this precious resource to be found under their

  7. Heterogeneity of shale documented by micro-FTIR and image analysis.

    Science.gov (United States)

    Chen, Yanyan; Mastalerz, Maria; Schimmelmann, Arndt

    2014-12-01

    In this study, four New Albany Shale Devonian and Mississippian samples, with vitrinite reflectance [Ro ] values ranging from 0.55% to 1.41%, were analyzed by micro-FTIR mapping of chemical and mineralogical properties. One additional postmature shale sample from the Haynesville Shale (Kimmeridgian, Ro = 3.0%) was included to test the limitation of the method for more mature substrates. Relative abundances of organic matter and mineral groups (carbonates, quartz and clays) were mapped across selected microscale regions based on characteristic infrared peaks and demonstrated to be consistent with corresponding bulk compositional percentages. Mapped distributions of organic matter provide information on the organic matter abundance and the connectivity of organic matter within the overall shale matrix. The pervasive distribution of organic matter mapped in the New Albany Shale sample MM4 is in agreement with this shale's high total organic carbon abundance relative to other samples. Mapped interconnectivity of organic matter domains in New Albany Shale samples is excellent in two early mature shale samples having Ro values from 0.55% to 0.65%, then dramatically decreases in a late mature sample having an intermediate Ro of 1.15% and finally increases again in the postmature sample, which has a Ro of 1.41%. Swanson permeabilities, derived from independent mercury intrusion capillary pressure porosimetry measurements, follow the same trend among the four New Albany Shale samples, suggesting that micro-FTIR, in combination with complementary porosimetric techniques, strengthens our understanding of porosity networks. In addition, image processing and analysis software (e.g. ImageJ) have the capability to quantify organic matter and total organic carbon - valuable parameters for highly mature rocks, because they cannot be analyzed by micro-FTIR owing to the weakness of the aliphatic carbon-hydrogen signal. © 2014 The Authors Journal of Microscopy © 2014 Royal

  8. Creep of Posidonia Shale at Elevated Pressure and Temperature

    Science.gov (United States)

    Rybacki, E.; Herrmann, J.; Wirth, R.; Dresen, G.

    2017-12-01

    The economic production of gas and oil from shales requires repeated hydraulic fracturing operations to stimulate these tight reservoir rocks. Besides simple depletion, the often observed decay of production rate with time may arise from creep-induced fracture closure. We examined experimentally the creep behavior of an immature carbonate-rich Posidonia shale, subjected to constant stress conditions at temperatures between 50 and 200 °C and confining pressures of 50-200 MPa, simulating elevated in situ depth conditions. Samples showed transient creep in the semibrittle regime with high deformation rates at high differential stress, high temperature and low confinement. Strain was mainly accommodated by deformation of the weak organic matter and phyllosilicates and by pore space reduction. The primary decelerating creep phase observed at relatively low stress can be described by an empirical power law relation between strain and time, where the fitted parameters vary with temperature, pressure and stress. Our results suggest that healing of hydraulic fractures at low stresses by creep-induced proppant embedment is unlikely within a creep period of several years. At higher differential stress, as may be expected in situ at contact areas due to stress concentrations, the shale showed secondary creep, followed by tertiary creep until failure. In this regime, microcrack propagation and coalescence may be assisted by stress corrosion. Secondary creep rates were also described by a power law, predicting faster fracture closure rates than for primary creep, likely contributing to production rate decline. Comparison of our data with published primary creep data on other shales suggests that the long-term creep behavior of shales can be correlated with their brittleness estimated from composition. Low creep strain is supported by a high fraction of strong minerals that can build up a load-bearing framework.

  9. GRI's Devonian Shales Research Program

    International Nuclear Information System (INIS)

    Guidry, F.K.

    1991-01-01

    This paper presents a summary of the key observations and conclusions from the Gas Research Institute's (GRI's) Comprehensive Study Well (CSW) research program conducted in the Devonian Shales of the Appalachian Basin. Initiated in 1987, the CSW program was a series of highly instrumented study wells drilled in cooperation with industry partners. Seven wells were drilled as part of the program. Extensive data sets were collected and special experiments were run on the CSW's in addition to the operator's normal operations, with the objectives of identifying geologic production controls, refining formation evaluation tools, and improving reservoir description and stimulation practices in the Devonian Shales. This paper highlights the key results from the research conducted in the CSW program in the areas of geologic production controls, formation evaluation, stimulation and reservoir engineering, and field operations. The development of geologic, log analysis, and reservoir models for the Shales from the data gathered and analysis, and reservoir models for the Shales from the data gathered and analyzed during the research is discussed. In addition, on the basis of what was learned in the CSW program, GRI's plans for new research in the Devonian Shales are described

  10. Distillation of shale in situ

    Energy Technology Data Exchange (ETDEWEB)

    de Ganahl, C F

    1922-07-04

    To distill buried shale or other carbon containing compounds in situ, a portion of the shale bed is rendered permeable to gases, and the temperature is raised to the point of distillation. An area in a shale bed is shattered by explosives, so that it is in a relatively finely divided form, and the tunnel is then blocked by a wall, and fuel and air are admitted through pipes until the temperature of the shale is raised to such a point that a portion of the released hydrocarbons will burn. When distillation of the shattered area takes place and the lighter products pass upwardly through uptakes to condensers and scrubbers, liquid oil passes to a tank and gas to a gasometer while heavy unvaporized products in the distillation zone collect in a drain, flow into a sump, and are drawn off through a pipe to a storage tank. In two modifications, methods of working are set out in cases where the shale lies beneath a substantially level surface.

  11. Sedimentology, organic matter and diagenesis of fishscale shales in the molasse basin of upper Austria (Upper Eocene - Lower Oligocene); Sedimentologie, organisches Material und Diagenese des Fischschiefers im oberoesterreichischen Molasse-Becken (Obereozaen - Unteroligozaen)

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H.M. [Inst. fuer Geologie und Palaeontologie der TU Clausthal, Clausthal-Zellerfeld (Germany); Sachsenhofer, R.F.; Bechtel, A. [Inst. fuer Geowiss. der Montanuniversitaet Leoben, Wien (Austria); Wagner, L.; Polesny, H.

    2002-07-01

    Fishscale shales (Schoeneck Formation) is an important parent rock of petroleum in prealpine molasse. Two different formation models are discussed, i.e. deposition and accumulation of organic matter (a) in a stagnating basin and (b) in a buoyancy zone. Both models were derived from samples, but they provide no information on the lithological and geochemical characteristics of complete fishscale shale sequences. This investigation focused on the vertical and lateral sedimentary development and the diagenetic changes of organic matter in the fishscale shales of upper Austria. Additionally, organic-geochemical data were used for validating the two deposition models. [German] Der Fischschiefer (Schoeneck Formation) stellt ein wichtiges Erdoelmuttergestein der alpinen Vorlandmolasse der. Waehrend seiner Ablagerung im Obereozaen(?)-Unteroligozaen wurde infolge der alpinen Orogenese die Paratethys von der Tethys abgetrennt und der Wasseraustausch zur Tethys eingeschraenkt. Gleichzeitig stroemten kalte Wassermassen ueber die polnische Senke in die Paratethys. Die Ablagerung der organisch-reichen Sedimente wird auf diese veraenderte palaeo-ozeanographische Situation zurueckgefuehrt. Zwei unterschiedliche Modelle werden fuer deren Bildung diskutiert: Ablagerung und Akkumulation von organischem Material in (a) einem stagnierenden Becken oder (b) in einer Auftriebszone. Die bislang diskutierten Modelle beruhen auf Ergebnissen vereinzelter Proben. Jedoch liegen keine Informationen hinsichtlich der lithologischen und geochemischen Charakteristika vollstaendiger Fischschiefer-Abfolgen vor. Es ist das Ziel dieses Beitrages, die vertikale und laterale sedimentaere Entwicklung, sowie die diagenetischen Veraenderungen des organischen Materials im Fischschiefer in Oberoesterreich vorzustellen. Zusaetzlich werden organisch-geochemische Daten eingesetzt, um die beiden vorgestellten Ablagerungsmodelle zu ueberpruefen. (orig.)

  12. Shale Gas characteristics of Permian black shales (Ecca group, Eastern Cape, South Africa)

    Science.gov (United States)

    Geel, Claire; Booth, Peter; Schulz, Hans-Martin; Horsfield, Brian; de Wit, Maarten

    2013-04-01

    and the evolution of organic material to bitumen characterise these sediments as overmature. The HI and OI results reveal that the Collingham and Whitehill sediments are type II kerogen and the Prince Albert is type III kerogen sediment. XRD data shows major rock forming minerals of the black shales to be quartz, illite, muscovite and chlorite with some plagioclase and large amounts of accessory pyrite. Average meso-and macro-porosity of these black shales is 1.5% and SEM images confirm that these sediments are tightly packed. The samples are highly affected by the Cape Fold Belt due to its location so far south and is unlikely to hold gas at this position, however this ongoing investigation will give greater insight to the gas potential of these black shales which are found more north of the region. At the GFZ open system pyrolyses and thermovaporization analyses are still underway.

  13. Intelligent fracture creation for shale gas development

    KAUST Repository

    Douglas, Craig C.; Qin, Guan; Collier, Nathan; Gong, Bin

    2011-01-01

    Shale gas represents a major fraction of the proven reserves of natural gas in the United States and a collection of other countries. Higher gas prices and the need for cleaner fuels provides motivation for commercializing shale gas deposits even

  14. Shale Failure Mechanics and Intervention Measures in Underground Coal Mines: Results From 50 Years of Ground Control Safety Research

    Science.gov (United States)

    2015-01-01

    Ground control research in underground coal mines has been ongoing for over 50 years. One of the most problematic issues in underground coal mines is roof failures associated with weak shale. This paper will present a historical narrative on the research the National Institute for Occupational Safety and Health has conducted in relation to rock mechanics and shale. This paper begins by first discussing how shale is classified in relation to coal mining. Characterizing and planning for weak roof sequences is an important step in developing an engineering solution to prevent roof failures. Next, the failure mechanics associated with the weak characteristics of shale will be discussed. Understanding these failure mechanics also aids in applying the correct engineering solutions. The various solutions that have been implemented in the underground coal mining industry to control the different modes of failure will be summarized. Finally, a discussion on current and future research relating to rock mechanics and shale is presented. The overall goal of the paper is to share the collective ground control experience of controlling roof structures dominated by shale rock in underground coal mining. PMID:26549926

  15. Shale gas exploitation: Status, problems and prospect

    Directory of Open Access Journals (Sweden)

    Shiqian Wang

    2018-02-01

    Full Text Available Over the past five years, great progress has been made in shale gas exploitation, which has become the most driving force for global gas output growth. Hydrocarbon extraction from shale helps drive the USA on the road to energy independence. Besides, shale oil & gas production has been kept in a sustained growth by continuous improvement in drilling efficiency and well productivity in the case of tumbling oil prices and rig counts. Shale gas reserves and production have been in a rapid growth in China owing to the Lower Paleozoic Wufeng and Longmaxi shale gas exploitation in the Sichuan Basin, which has become an important sector for the future increment of gas reserves and output in China. However, substantial progress has been made neither in non-marine shale gas exploitation as previously expected nor in the broad complicated tectonic areas in South China for which a considerable investment was made. Analysis of the basic situation and issues in domestic shale gas development shows that shale gas exploitation prospects are constrained by many problems in terms of resources endowment, horizontal well fracturing technology, etc. especially in non-marine shale deposits and complicated tectonic areas in South China where hot shales are widely distributed but geological structures are found severely deformed and over matured. Discussion on the prospects shows that the sustained and steady growth in shale gas reserves and production capacity in the coming years lies in the discovery and supersession of new shale plays in addition to Wufeng and Longmaxi shale plays, and that a technological breakthrough in ultra-high-pressure and ultra-deep (over 3500 m buried in the Sichuan Basin marine shale gas exploitation is the key and hope. Keywords: Shale gas, Exploitation, Marine facies, Hot shale, Resource endowment, Sichuan Basin, South China, Complicated tectonic area, Gas play

  16. Oil. The revenge of shales

    International Nuclear Information System (INIS)

    Dupin, Ludovic

    2017-01-01

    This article comments the evolutions noticed during these past years as the USA started to exploit non conventional hydrocarbons (shale gas and oil), and thus reduced their supplies from the Middle East. In reaction, OPEC members provoked a massive oil price decrease. If shale oil exploitation in the USA has slowed down for a while, it starts again: the number of platforms and production are increasing. Moreover, the profitability threshold is strongly decreasing. Argentina and China are also developing this sector, and Great-Britain and South-Africa are about to start projects. The article outlines that, even though France decided not to exploit shale gas and oil, French industries are present on this market and technology. In an interview, a representative of the French sector of non conventional hydrocarbons comments these evolutions as well as the French decision and its possible evolutions

  17. Process for treating oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1920-08-22

    A process for treating oil shale is characterized in that the shale is first finely ground, then heated in the presence of steam in a high-pressure retort at 1 to 50 atmospheres pressure at a temperature of 200/sup 0/ to 450/sup 0/C and then with large amounts of water with or without materials forming emulsions with water or with oil. Solution medium suitable for bitumen or paraffin is beaten up in a rapid hammer mill until all or most all of the oil or bitumen is emulsified. The emulsion is separated by filter-pressing and centrifuging from the solid shale residue and the oil or bitumen is again separated from the emulsion medium by heating, acidulating, standing, or centrifuging, and then in known ways is further separated, refined, and worked up.

  18. Iron isotope biogeochemistry of Neoproterozoic marine shales

    Science.gov (United States)

    Kunzmann, Marcus; Gibson, Timothy M.; Halverson, Galen P.; Hodgskiss, Malcolm S. W.; Bui, Thi Hao; Carozza, David A.; Sperling, Erik A.; Poirier, André; Cox, Grant M.; Wing, Boswell A.

    2017-07-01

    Iron isotopes have been widely applied to investigate the redox evolution of Earth's surface environments. However, it is still unclear whether iron cycling in the water column or during diagenesis represents the major control on the iron isotope composition of sediments and sedimentary rocks. Interpretation of isotopic data in terms of oceanic redox conditions is only possible if water column processes dominate the isotopic composition, whereas redox interpretations are less straightforward if diagenetic iron cycling controls the isotopic composition. In the latter scenario, iron isotope data is more directly related to microbial processes such as dissimilatory iron reduction. Here we present bulk rock iron isotope data from late Proterozoic marine shales from Svalbard, northwestern Canada, and Siberia, to better understand the controls on iron isotope fractionation in late Proterozoic marine environments. Bulk shales span a δ 56Fe range from -0.45 ‰ to +1.04 ‰ . Although δ 56Fe values show significant variation within individual stratigraphic units, their mean value is closer to that of bulk crust and hydrothermal iron in samples post-dating the ca. 717-660 Ma Sturtian glaciation compared to older samples. After correcting for the highly reactive iron content in our samples based on iron speciation data, more than 90% of the calculated δ 56Fe compositions of highly reactive iron falls in the range from ca. -0.8 ‰ to +3 ‰ . An isotope mass-balance model indicates that diagenetic iron cycling can only change the isotopic composition of highly reactive iron by control the isotopic composition of highly reactive iron. Considering a long-term decrease in the isotopic composition of the iron source to the dissolved seawater Fe(II) reservoir to be unlikely, we offer two possible explanations for the Neoproterozoic δ 56Fe trend. First, a decreasing supply of Fe(II) to the ferrous seawater iron reservoir could have caused the reservoir to decrease in size

  19. Indicative energy technology assessment of UK shale gas extraction

    International Nuclear Information System (INIS)

    Hammond, Geoffrey P.; O’Grady, Áine

    2017-01-01

    Highlights: • UK shale gas ‘fracking’ is at a very early stage with an uncertain size of resource. • Shale gas extraction might benefit UK fuel security, as well as jobs and growth. • Potentially harmful environmental ‘side-effects’ must be monitored and regulated. • Gas bills for UK household and industrial consumers are unlikely to fall sharply. • Costs & benefits of shale gas fracking are unevenly distributed between communities. - Abstract: There is at present much interest in unconventional sources of natural gas, especially in shale gas which is obtained by hydraulic fracturing, or ‘fracking’. Boreholes are drilled and then lined with steel tubes so that a mixture of water and sand with small quantities of chemicals – the fracking fluid – can be pumped into them at very high pressure. The sand grains that wedge into the cracks induced in the shale rock by a ‘perforating gun’ then releases gas which returns up the tubes. In the United Kingdom (UK) exploratory drilling is at an early stage, with licences being issued to drill a limited number of test boreholes around the country. However, such activities are already meeting community resistance and controversy. Like all energy technologies it exhibits unwanted ‘side-effects’; these simply differ in their level of severity between the various options. Shale gas may make, for example, a contribution to attaining the UK’s statutory ‘greenhouse gas’ emissions targets, but only if appropriate and robust regulations are enforced. The benefits and disadvantages of shale gas fracking are therefore discussed in order to illustrate a ‘balance sheet’ approach. It is also argued that it is desirable to bring together experts from a range of disciplines in order to carry out energy technology assessments. That should draw on and interact with national and local stakeholders: ‘actors’ both large and small. Community engagement in a genuinely participative process – where the

  20. Porosity characterization for heterogeneous shales using integrated multiscale microscopy

    Science.gov (United States)

    Rassouli, F.; Andrew, M.; Zoback, M. D.

    2016-12-01

    Pore size distribution analysis plays a critical role in gas storage capacity and fluid transport characterization of shales. Study of the diverse distribution of pore size and structure in such low permeably rocks is withheld by the lack of tools to visualize the microstructural properties of shale rocks. In this paper we try to use multiple techniques to investigate the full pore size range in different sample scales. Modern imaging techniques are combined with routine analytical investigations (x-ray diffraction, thin section analysis and mercury porosimetry) to describe pore size distribution of shale samples from Haynesville formation in East Texas to generate a more holistic understanding of the porosity structure in shales, ranging from standard core plug down to nm scales. Standard 1" diameter core plug samples were first imaged using a Versa 3D x-ray microscope at lower resolutions. Then we pick several regions of interest (ROIs) with various micro-features (such as micro-cracks and high organic matters) in the rock samples to run higher resolution CT scans using a non-destructive interior tomography scans. After this step, we cut the samples and drill 5 mm diameter cores out of the selected ROIs. Then we rescan the samples to measure porosity distribution of the 5 mm cores. We repeat this step for samples with diameter of 1 mm being cut out of the 5 mm cores using a laser cutting machine. After comparing the pore structure and distribution of the samples measured form micro-CT analysis, we move to nano-scale imaging to capture the ultra-fine pores within the shale samples. At this stage, the diameter of the 1 mm samples will be milled down to 70 microns using the laser beam. We scan these samples in a nano-CT Ultra x-ray microscope and calculate the porosity of the samples by image segmentation methods. Finally, we use images collected from focused ion beam scanning electron microscopy (FIB-SEM) to be able to compare the results of porosity measurements

  1. Obtaining shale distillate free from sulphur

    Energy Technology Data Exchange (ETDEWEB)

    Heyl, G E

    1917-09-14

    A process whereby, from sulfur-containing shale, products free from sulfur may be obtained, consisting of mixing with the finely ground shale a portion of iron salts containing sufficient metal to unite with all the sulfur in the shale and form sulfide therewith, grinding the mixture to a fine state of subdivision and subsequently subjecting it to destructive distillation.

  2. Experimental study on hydration damage mechanism of shale from the Longmaxi Formation in southern Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Xiangjun Liu

    2016-03-01

    Full Text Available As a serious problem in drilling operation, wellbore instability restricts efficient development of shale gas. The interaction between the drilling fluid and shale with hydration swelling property would have impact on the generation and propagation mechanism of cracks in shale formation, leading to wellbore instability. In order to investigate the influence of the hydration swelling on the crack propagation, mineral components and physicochemical properties of shale from the Lower Silurian Longmaxi Formation (LF were investigated by using the XRD analysis, cation exchange capabilities (CEC analysis, and SEM observation, and we researched the hydration mechanism of LF shale. Results show that quartz and clay mineral are dominated in mineral composition, and illite content averaged 67% in clay mineral. Meanwhile, CEC of the LF shale are 94.4 mmol/kg. The process of water intruding inside shale along microcracks was able to be observed through high power microscope, meanwhile, the hydration swelling stress would concentrate at the crack tip. The microcracks would propagate, bifurcate and connect with each other, with increase of water immersing time, and it would ultimately develop into macro-fracture. Moreover, the macrocracks extend and coalesce along the bedding, resulting in the rock failure into blocks. Hydration swelling is one of the major causes that lead to wellbore instability of the LF shale, and therefore improving sealing capacity and inhibition of drilling fluid system is an effective measure to stabilize a borehole.

  3. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  4. Maquoketa Shale Caprock Integrity Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Leetaru, Hannes

    2014-09-30

    The Knox Project objective is to evaluate the potential of formations within the Cambrian-Ordovician strata above the Mt. Simon Sandstone (St. Peter Sandstone and Potosi Dolomite) as potential targets for carbon dioxide (CO2) sequestration in the Illinois and Michigan Basins. The suitability of the St. Peter Sandstone and Potosi Dolomite to serve as reservoirs for CO2 sequestration is discussed in separate reports. In this report the data gathered from the Knox project, the Illinois Basin – Decatur Project (IBDP) and Illinois Industrial Carbon Capture and Sequestration project (IL-ICCS) are used to make some conclusions about the suitability of the Maquoketa shale as a confining layer for CO2 sequestration. These conclusions are then upscaled to basin-wide inferences based on regional knowledge. Data and interpretations (stratigraphic, petrophysical, fractures, geochemical, risk, seismic) applicable to the Maquoketa Shale from the above mentioned projects was inventoried and summarized. Based on the analysis of these data and interpretations, the Maquoketa Shale is considered to be an effective caprock for a CO2 injection project in either the Potosi Dolomite or St. Peter Sandstone because it has a suitable thickness (~200ft. ~61m), advantageous petrophysical properties (low effective porosity and low permeability), favorable geomechanical properties, an absence of observable fractures and is regionally extensive. Because it is unlikely that CO2 would migrate upward through the Maquoketa Shale, CO2, impact to above lying fresh water aquifers is unlikely. Furthermore, the observations indicate that CO2 injected into the St. Peter Sandstone or Potosi Dolomite may never even migrate up into the Maquoketa Shale at a high enough concentrations or pressure to threaten the integrity of the caprock. Site specific conclusions were reached by unifying the data and conclusions from the IBDP, ICCS and the Knox projects. In the Illinois Basin, as one looks further away from

  5. Origin of Scottish oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Conacher, H R.J.

    1916-12-01

    Oil shales contain two distinct types of organic material, one is comparable to the woody material in coal and the other consists of yellow bodies. When distilled, the latter yields the liquid product typical of oil shale, whereas the woody material produces large amounts of ammonia. The yellow bodies have been described by various investigators as fossil algae, spores, or dried-up globules of petroleum. In this study it was concluded that the yellow bodies were fragments of resins set free by the decay and oxidation of the vegetable matter with which they were originally associated.

  6. Forecasting production in Liquid Rich Shale plays

    Science.gov (United States)

    Nikfarman, Hanieh

    Production from Liquid Rich Shale (LRS) reservoirs is taking center stage in the exploration and production of unconventional reservoirs. Production from the low and ultra-low permeability LRS plays is possible only through multi-fractured horizontal wells (MFHW's). There is no existing workflow that is applicable to forecasting multi-phase production from MFHW's in LRS plays. This project presents a practical and rigorous workflow for forecasting multiphase production from MFHW's in LRS reservoirs. There has been much effort in developing workflows and methodology for forecasting in tight/shale plays in recent years. The existing workflows, however, are applicable only to single phase flow, and are primarily used in shale gas plays. These methodologies do not apply to the multi-phase flow that is inevitable in LRS plays. To account for complexities of multiphase flow in MFHW's the only available technique is dynamic modeling in compositional numerical simulators. These are time consuming and not practical when it comes to forecasting production and estimating reserves for a large number of producers. A workflow was developed, and validated by compositional numerical simulation. The workflow honors physics of flow, and is sufficiently accurate while practical so that an analyst can readily apply it to forecast production and estimate reserves in a large number of producers in a short period of time. To simplify the complex multiphase flow in MFHW, the workflow divides production periods into an initial period where large production and pressure declines are expected, and the subsequent period where production decline may converge into a common trend for a number of producers across an area of interest in the field. Initial period assumes the production is dominated by single-phase flow of oil and uses the tri-linear flow model of Erdal Ozkan to estimate the production history. Commercial software readily available can simulate flow and forecast production in this

  7. Fine-grained sheet silicate rocks

    International Nuclear Information System (INIS)

    Weaver, C.E.

    1977-09-01

    Considerable interest has been shown in the possibility of using shales as repositories for radioactive waste and a variety of other waste products, and it appears that over the next few years much money and effort will be expended to investigate and test a wide variety of shales. If shales are to be studied in detail by a large number of investigators, it is important that all concerned have the same concept of what constitutes a shale. The term shale and other terms for fine-grained rocks have been used for many years and have been continually redefined. Most definitions predate the development of modern instrumentation and are based on field observations and intuition; however, the main problem is the diversity of definitions. An attempt is made here to develop a simple, rational classification of fine-grained sediments, and it is hoped that this classification will eliminate some of the present ambiguity. In order that the classification be pertinent, mineral composition and textural data were compiled and evaluated. The data on unconsolidated and consolidated sediments were contrasted and the effects of burial diagenesis assessed. It was found necessary to introduce a new term, physil, to describe all sheet silicate minerals. In contrast to the term clay mineral, the term physil has no size connotation. A simple classification is proposed that is based on the percentage of physils and grain size. In Part II the fine-grained physil rocks are classified on the basis of physil type, non-physil minerals, and texture. Formations are listed which have the mineral and textural characteristics of the most important rock types volumetrically. Selected rock types, and the formations in which they can be found, are recommended for laboratory study to determine their suitability for the storage of high-level radioactive waste

  8. Dynamic compressive properties obtained from a split Hopkinson pressure bar test of Boryeong shale

    Science.gov (United States)

    Kang, Minju; Cho, Jung-Woo; Kim, Yang Gon; Park, Jaeyeong; Jeong, Myeong-Sik; Lee, Sunghak

    2016-09-01

    Dynamic compressive properties of a Boryeong shale were evaluated by using a split Hopkinson pressure bar, and were compared with those of a Hwangdeung granite which is a typical hard rock. The results indicated that the dynamic compressive loading reduced the resistance to fracture. The dynamic compressive strength was lower in the shale than in the granite, and was raised with increasing strain rate by microcracking effect as well as strain rate strengthening effect. Since the number of microcracked fragments increased with increasing strain rate in the shale having laminated weakness planes, the shale showed the better fragmentation performance than the granite at high strain rates. The effect of transversely isotropic plane on compressive strength decreased with increasing strain rate, which was desirable for increasing the fragmentation performance. Thus, the shale can be more reliably applied to industrial areas requiring good fragmentation performance as the striking speed of drilling or hydraulic fracturing machines increased. The present dynamic compressive test effectively evaluated the fragmentation performance as well as compressive strength and strain energy density by controlling the air pressure, and provided an important idea on which rock was more readily fragmented under dynamically processing conditions such as high-speed drilling and blasting.

  9. Numerical simulation and fracture identification of dual laterolog in organic shale

    Science.gov (United States)

    Maojin, Tan; Peng, Wang; Qiong, Liu

    2012-09-01

    Fracture is one of important spaces in shale oil and shale gas reservoirs, and fractures identification and evaluation are an important part in organic shale interpretation. According to the fractured shale gas reservoir, a physical model is set up to study the dual laterolog logging responses. First, based on the principle of dual laterolog, three-dimensional finite element method (FEM) is used to simulate the dual laterolog responses in various formation models with different fractures widths, different fracture numbers, different fractures inclination angle. All the results are extremely important for the fracture identification and evaluation in shale reservoirs. Appointing to different base rock resistivity models, the fracture models are constructed respectively through a number of numerical simulation, and the fracture porosity can be calculated by solving the corresponding formulas. A case study about organic shale formation is analyst and discussed, and the fracture porosity is calculated from dual laterolog. The fracture evaluation results are also be validated right by Full borehole Micro-resistivity Imaging (FMI). So, in case of the absence of borehole resistivity imaging log, the dual laterolog resistivity can be used to estimate the fracture development.

  10. Anisotropic Failure Strength of Shale with Increasing Confinement: Behaviors, Factors and Mechanism.

    Science.gov (United States)

    Cheng, Cheng; Li, Xiao; Qian, Haitao

    2017-11-15

    Some studies reported that the anisotropic failure strength of shale will be weakened by increasing confinement. In this paper, it is found that there are various types of anisotropic strength behaviors. Four types of anisotropic strength ratio ( S A 1 ) behaviors and three types of anisotropic strength difference ( S A 2 ) behaviors have been classified based on laboratory experiments on nine groups of different shale samples. The cohesion c w and friction angle ϕ w of the weak planes are proven to be two dominant factors according to a series of bonded-particle discrete element modelling analyses. It is observed that shale is more prone to a slight increase of S A 1 and significant increase of S A 2 with increasing confinement for higher cohesion c w and lower to medium friction angle ϕ w . This study also investigated the mechanism of the anisotropic strength behaviors with increasing confinement. Owing to different contributions of c w and ϕ w under different confinements, different combinations of c w and ϕ w may have various types of influences on the minimum failure strength with the increasing confinement; therefore, different types of anisotropic behaviors occur for different shale specimens as the confinement increases. These findings are very important to understand the stability of wellbore and underground tunneling in the shale rock mass, and should be helpful for further studies on hydraulic fracture propagations in the shale reservoir.

  11. Perspective usage estimation of Volga region combustible shale as a power generating fuel alternative

    Science.gov (United States)

    Korolev, E.; Barieva, E.; Eskin, A.

    2018-05-01

    A comprehensive study of combustible shale, common within Tatarstan and Ulyanovsk region, is carried out. The rocks physicochemical parameters are found to meet the power generating fuels requirements. The predictive estimate of ash products properties of combustible shale burning is held. Minding furnace process technology it is necessary to know mineral and organic components behavior when combustible shale is burnt. Since the first will determine slagging properties of energy raw materials, the second – its calorific value. In consideration of this the main research methods were X-ray, thermal and X-ray fluorescence analyses. Summing up the obtained results, we can draw to the following conclusions: 1. The combustible shale in Tatarstan and the Ulyanovsk region has predominantly low calorific value (Qb d = 5-9 MJ/kg). In order to enhance its efficiency and to reduce cost it is possible to conduct rocks burning together with some other organic or organic mineral power generating fuels. 2. High ash content (Ad = 60-80%) that causes a high external ballast content in shale implies the appropriateness of using this fuel resource next to its exploitation site. The acceptable distance to a consumer will reduce unproductive transportation charges for large ash and moisture masses. 3. The performed fuel ash components characteristics, as well as the yield and volatiles composition allow us to specify the basic parameters for boiler units, designed for the Volga combustible shale burning. 4. The noncombustible residual components composition shows that shale ash can be used in manufacture of materials of construction.

  12. The Multi-Porosity Multi-Permeability and Electrokinetic Natures of Shales and Their Effects in Hydraulic Fracturing of Unconventional Shale Reservoirs

    Science.gov (United States)

    Liu, C.; Hoang, S. K.; Tran, M. H.; Abousleiman, Y. N.

    2013-12-01

    Imaging studies of unconventional shale reservoir rocks have recently revealed the multi-porosity multi-permeability nature of these intricate formations. In particular, the porosity spectrum of shale reservoir rocks often comprises of the nano-porosity in the organic matters, the inter-particle micro-porosity, and the macroscopic porosity of the natural fracture network. Shale is also well-known for its chemically active behaviors, especially shrinking and swelling when exposed to aqueous solutions, as the results of pore fluid exchange with external environment due to the difference in electro-chemical potentials. In this work, the effects of natural fractures and electrokinetic nature of shale on the formation responses during hydraulic fracturing are examined using the dual-poro-chemo-electro-elasticity approach which is a generalization of the classical Biot's poroelastic formulation. The analyses show that the presence of natural fractures can substantially increase the leak-off rate of fracturing fluid into the formation and create a larger region of high pore pressure near the fracture face as shown in Fig.1a. Due to the additional fluid invasion, the naturally fractured shale swells up more and the fracture aperture closes faster compared to an intrinsically low permeability non-fractured shale formation as shown in Fig.1b. Since naturally fractured zones are commonly targeted as pay zones, it is important to account for the faster fracture closing rate in fractured shales in hydraulic fracturing design. Our results also show that the presence of negative fixed charges on the surface of clay minerals creates an osmotic pressure at the interface of the shale and the external fluid as shown in Fig.1c. This additional Donnan-induced pore pressure can result in significant tensile effective stresses and tensile damage in the shale as shown in Fig.1d. The induced tensile damage can exacerbate the problem of proppant embedment resulting in more fracture closure

  13. Mechanical Characterization of Mancos Shale

    Science.gov (United States)

    Broome, S.; Ingraham, M. D.; Dewers, T. A.

    2015-12-01

    A series of tests on Mancos shale have been undertaken to determine the failure surface and to characterize anisotropy. This work supports additional studies which are being performed on the same block of shale; fracture toughness, permeability, and chemical analysis. Mechanical tests are being conducted after specimens were conditioned for at least two weeks at 70% constant relative humidity conditions. Specimens are tested under drained conditions, with the constant relative humidity condition maintained on the downstream side of the specimen. The upstream is sealed. Anisotropy is determined through testing specimens that have been cored parallel and perpendicular to the bedding plane. Preliminary results show that when loaded parallel to bedding the shale is roughly 50% weaker. Test are run under constant mean stress conditions when possible (excepting indirect tension, unconfined compression, and hydrostatic). Tests are run in hydrostatic compaction to the desired mean stress, then differential stress is applied axially in displacement control to failure. The constant mean stress condition is maintained by decreasing the confining pressure by half of the increase in the axial stress. Results will be compared to typical failure criteria to investigate the effectiveness of capturing the behavior of the shale with traditional failure theory. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-6107 A.

  14. Generic Argillite/Shale Disposal Reference Case

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liange; Colon, Carlos Jové; Bianchi, Marco; Birkholzer, Jens

    2014-08-08

    Radioactive waste disposal in a deep subsurface repository hosted in clay/shale/argillite is a subject of widespread interest given the desirable isolation properties, geochemically reduced conditions, and widespread geologic occurrence of this rock type (Hansen 2010; Bianchi et al. 2013). Bianchi et al. (2013) provides a description of diffusion in a clay-hosted repository based on single-phase flow and full saturation using parametric data from documented studies in Europe (e.g., ANDRA 2005). The predominance of diffusive transport and sorption phenomena in this clay media are key attributes to impede radionuclide mobility making clay rock formations target sites for disposal of high-level radioactive waste. The reports by Hansen et al. (2010) and those from numerous studies in clay-hosted underground research laboratories (URLs) in Belgium, France and Switzerland outline the extensive scientific knowledge obtained to assess long-term clay/shale/argillite repository isolation performance of nuclear waste. In the past several years under the UFDC, various kinds of models have been developed for argillite repository to demonstrate the model capability, understand the spatial and temporal alteration of the repository, and evaluate different scenarios. These models include the coupled Thermal-Hydrological-Mechanical (THM) and Thermal-Hydrological-Mechanical-Chemical (THMC) models (e.g. Liu et al. 2013; Rutqvist et al. 2014a, Zheng et al. 2014a) that focus on THMC processes in the Engineered Barrier System (EBS) bentonite and argillite host hock, the large scale hydrogeologic model (Bianchi et al. 2014) that investigates the hydraulic connection between an emplacement drift and surrounding hydrogeological units, and Disposal Systems Evaluation Framework (DSEF) models (Greenberg et al. 2013) that evaluate thermal evolution in the host rock approximated as a thermal conduction process to facilitate the analysis of design options. However, the assumptions and the

  15. Improvements in the distillation of shale, etc

    Energy Technology Data Exchange (ETDEWEB)

    Noad, J

    1912-09-20

    A process for treating shale and other bituminous substances containing sulfur and obtaining desulfurized products of distillation consisting in the consecutive steps of crushing the shale, mixing a suitable liquid with the shale granules, mixing slaked lime with the liquid coated shale granules, and gradually feeding the lime coated shale granules into a retort presenting a series of ledges or the like and working the shale granules down from ledge to ledge so that they are continuously agitated while being heated, the volatile constituents escaping through the lime coating and being conducted away from the upper part of the retort to suitable condensing apparatus, and the sulfur being arrested by the lime coating and together with the exhausted shale and other impurities being discharged from the lower part of the retort.

  16. Fracking for shale gas production. A contribution to its assessment from the viewpoints of energy and environmental policy

    International Nuclear Information System (INIS)

    2013-01-01

    Shale gas is natural gas that is bound in unconventional reservoirs and can only be extracted by hydraulic fracturing, also referred to as fracking. This technology involves the high-pressure injection of water containing various additives into the gas-containing rock formation. This creates cracks in the rock, making it more permeable and allowing the gas to rise up to the surface. In its present opinion the German Advisory Council on the Environment sees the need for a differentiated view on the opportunities and risks of shale gas production by fracking. It advocates taking a bird's eye perspective that includes aspects of both energy and environmental policy.

  17. Desulfurization of Jordanian oil shale

    International Nuclear Information System (INIS)

    Abu-Jdayil, B. M.

    1990-01-01

    Oxy desulfurization process and caustic treatment were applied in this work to remove sulfur from Jordanian oil shale. The oxy desulfurization process has been studied in a batch process using a high pressure autoclave, with constant stirring speed, and oxygen and water were used as desulfurizing reagents. Temperature, oxygen pressure, batch time, and particle size were found to be important process variables, while solid/liquid ratio was found to have no significant effect on the desulfurization process. The response of different types of oil shale to this process varied, and the effect of the process variables on the removal of total sulfur, pyritic sulfur, organic sulfur, total carbon, and organic carbon were studied. An optimum condition for oxy desulfurization of El-Lajjun oil shale, which gave maximum sulfur removal with low loss of carbon, was determined from the results of this work. The continuous reaction model was found to be valid, and the rate of oxidation for El-Lajjun oil shale was of the first order with respect to total sulfur, organic sulfur, total carbon, and organic carbon. For pyritic sulfur oxidation, the shrinking core model was found to hold and the rate of reaction controlled by diffusion through product ash layer. An activation energy of total sulfur, organic sulfur, pyritic sulfur, total carbon, and organic carbon oxidation was calculated for the temperature range of 130 -190 degrees celsius. In caustic treatment process, aqueous sodium hydroxide at 160 degrees celsius was used to remove the sulfur from El-Lajjun oil shale. The variables tested (sodium hydroxide concentration and treatment time) were found to have a significant effect. The carbon losses in this process were less than in the oxy desulfurization process. 51 refs., 64 figs., 121 tabs. (A.M.H.)

  18. Experimental Study of Cement - Sandstone/Shale - Brine - CO2 Interactions.

    Science.gov (United States)

    Carroll, Susan A; McNab, Walt W; Torres, Sharon C

    2011-11-11

    Reactive-transport simulation is a tool that is being used to estimate long-term trapping of CO2, and wellbore and cap rock integrity for geologic CO2 storage. We reacted end member components of a heterolithic sandstone and shale unit that forms the upper section of the In Salah Gas Project carbon storage reservoir in Krechba, Algeria with supercritical CO2, brine, and with/without cement at reservoir conditions to develop experimentally constrained geochemical models for use in reactive transport simulations. We observe marked changes in solution composition when CO2 reacted with cement, sandstone, and shale components at reservoir conditions. The geochemical model for the reaction of sandstone and shale with CO2 and brine is a simple one in which albite, chlorite, illite and carbonate minerals partially dissolve and boehmite, smectite, and amorphous silica precipitate. The geochemical model for the wellbore environment is also fairly simple, in which alkaline cements and rock react with CO2-rich brines to form an Fe containing calcite, amorphous silica, smectite and boehmite or amorphous Al(OH)3. Our research shows that relatively simple geochemical models can describe the dominant reactions that are likely to occur when CO2 is stored in deep saline aquifers sealed with overlying shale cap rocks, as well as the dominant reactions for cement carbonation at the wellbore interface.

  19. Distribution of K, Na, Th and U in sandstones and shales from western Shikoku, Japan

    International Nuclear Information System (INIS)

    Ishihara, Shunso; Sakamaki, Yukio; Mochizuki, Tsunekazu; Terashima, Shigeru; Endo, Yuji

    1981-01-01

    The regional variation of K, Na, Th and U distributions was studied on 58 sandstones, 81 shales and 3 green schists from the sedimentary terrains across western Shikoku. The geological structure of the studied district is explained. The regional characteristics of the sedimentary rocks are best demonstrated in the composition of the sandstones. The sandstones, in the source areas of which granitic and rhyolitic rocks exist and which have been deposited rapidly, were rich in K, whereas those derived mainly from mafic volcanic areas showed high Na content. The sandstones of the Shimanto Supergroup had the intermediate values, and K and K + Na contents became low in the south where the younger Upper Shimanto Group is exposed. Th and U in both sandstones and shales were highest in the Izumi Group, and generally low in the Shimanto Supergroup. The black shales of the Shimanto Supergroup did not show U-anomaly. In each group, highly matured rocks gave slightly higher Th/U ratio. Highly matured polycyclic sediments contained the least amount of radioactive elements. The radioactive anomaly due to the anomalous K contained in sericite, and that due to U in black shale were found in Chichibu and Sambosan belts. Similar anomaly was discovered in the foot wall of Mn deposits in the same zone. The possibility of anomalous U may be the least in the Shimanto Supergroup. (Kako, I.)

  20. Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

    2003-11-15

    The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

  1. Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

    International Nuclear Information System (INIS)

    Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

    2003-01-01

    The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. How lithology and climate affect REE mobility and fractionation along a shale weathering transect of the Susquehanna Shale Hills Critical Zone Observatory

    Science.gov (United States)

    Ma, L.; Jin, L.; Dere, A. L.; White, T.; Mathur, R.; Brantley, S. L.

    2012-12-01

    Shale weathering is an important process in global elemental cycles. Accompanied by the transformation of bedrock into regolith, many elements including rare earth elements (REE) are mobilized primarily by chemical weathering in the Critical Zone. Then, REE are subsequently transported from the vadose zone to streams, with eventual deposition in the oceans. REE have been identified as crucial and strategic natural resources; and discovery of new REE deposits will be facilitated by understanding global REE cycles. At present, the mechanisms and environmental factors controlling release, transport, and deposition of REE - the sources and sinks - at Earth's surface remain unclear. Here, we present a systematic study of soils, stream sediments, stream waters, soil water and bedrock in six small watersheds that are developed on shale bedrock in the eastern USA to constrain the mobility and fractionation of REE during early stages of chemical weathering. The selected watersheds are part of the shale transect established by the Susquehanna Shale Hills Observatory (SSHO) and are well suited to investigate weathering on shales of different compositions or within different climate regimes but on the same shale unit. Our REE study from SSHO, a small gray shale watershed in central Pennsylvania, shows that up to 65% of the REE (relative to parent bedrock) is depleted in the acidic and organic-rich soils due to chemical leaching. Both weathering soil profiles and natural waters show a preferential removal of middle REE (MREE: Sm to Dy) relative to light REE (La to Nd) and heavy REE (Ho to Lu) during shale weathering, due to preferential release of MREE from a phosphate phase (rhabdophane). Strong positive Ce anomalies observed in the regolith and stream sediments point to the fractionation and preferential precipitation of Ce as compared to other REE, in the generally oxidizing conditions of the surface environments. One watershed developed on the Marcellus black shale in

  4. Towards the development of rapid screening techniques for shale gas core properties

    Science.gov (United States)

    Cave, Mark R.; Vane, Christopher; Kemp, Simon; Harrington, Jon; Cuss, Robert

    2013-04-01

    Shale gas has been produced for many years in the U.S.A. and forms around 8% of total their natural gas production. Recent testing for gas on the Fylde Coast in Lancashire UK suggests there are potentially large reserves which could be exploited. The increasing significance of shale gas has lead to the need for deeper understanding of shale behaviour. There are many factors which govern whether a particular shale will become a shale gas resource and these include: i) Organic matter abundance, type and thermal maturity; ii) Porosity-permeability relationships and pore size distribution; iii) Brittleness and its relationship to mineralogy and rock fabric. Measurements of these properties require sophisticated and time consuming laboratory techniques (Josh et al 2012), whereas rapid screening techniques could provide timely results which could improve the efficiency and cost effectiveness of exploration. In this study, techniques which are portable and provide rapid on-site measurements (X-ray Fluorescence (XRF) and Infra-red (IR) spectroscopy) have been calibrated against standard laboratory techniques (Rock-Eval 6 analyser-Vinci Technologies) and Powder whole-rock XRD analysis was carried out using a PANalytical X'Pert Pro series diffractometer equipped with a cobalt-target tube, X'Celerator detector and operated at 45kV and 40mA, to predict properties of potential shale gas material from core material from the Bowland shale Roosecote, south Cumbria. Preliminary work showed that, amongst various mineralogical and organic matter properties of the core, regression models could be used so that the total organic carbon content could be predicted from the IR spectra with a 95 percentile confidence prediction error of 0.6% organic carbon, the free hydrocarbons could be predicted with a 95 percentile confidence prediction error of 0.6 mgHC/g rock, the bound hydrocarbons could be predicted with a 95 percentile confidence prediction error of 2.4 mgHC/g rock, mica content

  5. Conversion characteristics of 10 selected oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Miknis, F.P.

    1989-08-01

    The conversion behavior of 10 oil shale from seven foreign and three domestic deposits has been studied by combining solid- and liquid-state nuclear magnetic resonance (NMR) measurements with material balance Fischer assay conversion data. The extent of aromatization of aliphatic carbons was determined. Between zero and 42% of the raw shale aliphatic carbon formed aromatic carbon during Fischer assay. For three of the shales, there was more aromatic carbon in the residue after Fisher assay than in the raw shale. Between 10 and 20% of the raw shale aliphatic carbons ended up as aliphatic carbons on the spent shale. Good correlations were found between the raw shale aliphatic carbon and carbon in the oil and between the raw shale aromatic carbon and aromatic carbon on the spent shale. Simulated distillations and molecular weight determinations were performed on the shale oils. Greater than 50% of the oil consisted of the atmospheric and vacuum gas oil boiling fractions. 14 refs., 15 figs., 1 tab.

  6. Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China

    Directory of Open Access Journals (Sweden)

    Taotao Cao

    2016-10-01

    Full Text Available The Permian shale, a set of transitional shale reservoir, is considered to be an important shale gas exploration target in the Lower Yangtze region. Due to little research conducted on the pore system characteristic and its controlling factors of the shale gas reservoir, SEM, FE-SEM, low-pressure N2 adsorption, and mercury intrusion tests were carried out on the Permian shales from the outcrop and HC well in the southern Anhui. The results show that the Permian shales mainly consist of organic matter, quartz, illite, calcite, and pyrite, of which pyrite occurs as framboids coexisting with organic matter and the organic matter is distributed in shales in stripped, interstitial, thin film and shell shapes. The basic pore types are inorganic mineral pore (intercrystalline pore, intergranular edge pore, intergranular pore, and interlayer pore in clay minerals and the organic pore and microfracture, of which organic pore and microfracture are the dominating pore types. In shale, organic pores are not developed at all in some organic grains but are well developed in others, which may be related to the types of and maceral compositions of kerogen. Under tectonic stress, shale rocks could develop mylonitization phenomenon exhibiting organic grains well blend with clay minerals, and produce a mass of microfractures and nanopores between organic matter grains and clay minerals. Mercury intrusion tests show that the shale is mainly composed of micropore and transition pore with high porosity, good pore connectivity and high efficiency of mercury withdraw, while the shale that mainly dominated by mesopore and macropore has a low porosity, poor pore connectivity, and low efficiency of the mercury withdraw. The volume percentage of mesopore and marcopore is increasing with the increase of quartz, and that of micropore and transition pore has a decreased tendency along with the increase of soluble organic matter (S1. Organic matter is the main contributor to

  7. The Eagle Ford Shale, Texas: an initial insight into Late Cretaceous organic-rich mudrock palaeoenvironments

    Science.gov (United States)

    Forshaw, Joline; Jarvis, Ian; Trabucho-Alexandre, João; Tocher, Bruce; Pearce, Martin

    2014-05-01

    The hypothesised reduction of oxygen within the oceans during the Cretaceous is believed to have led to extended intervals of regional anoxia in bottom waters, resulting in increased preservation of organic matter and the deposition of black shales. Episodes of more widespread anoxia, and even euxinia, in both bottom and surface waters are associated with widespread black shale deposition during Ocean Anoxic Events (OAEs). The most extensive Late Cretaceous OAE, which occurred ~ 94 Ma during Cenomanian-Turonian boundary times, and was particularly well developed in the proto-North Atlantic and Tethyan regions, lasted for around 500 kyr (OAE2). Although the causes of this and other events are still hotly debated, research is taking place internationally to produce a global picture of the causes and consequences of Cretaceous OAEs. Understanding OAEs will enable a better interpretation of the climate fluctuations that ensued, and their association with the widespread deposition of black shales, rising temperatures, increased pCO2, enhanced weathering, and increased nutrient fluxes. The Eagle Ford Formation, of Cenomanian - Turonian age, is a major shale gas play in SW and NE Texas, extending over an area of more than 45,000 km2. The formation, which consists predominantly of black shales (organic-rich calcareous mudstones), was deposited during an extended period of relative tectonic quiescence in the northern Gulf Coast of the Mexico Basin, bordered by reefs along the continental shelf. The area offers an opportunity to study the effects of OAE2 in an organic-rich shelf setting. The high degree of organic matter preservation in the formation has produced excellent oil and gas source rocks. Vast areas of petroleum-rich shales are now being exploited in the Southern States of the US for shale gas, and the Eagle Ford Shale is fast becoming one of the countries largest producers of gas, oil and condensate. The Eagle Ford Shale stratigraphy is complex and heterogeneous

  8. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  9. Hydrogenation of Estonian oil shale and shale oil

    Energy Technology Data Exchange (ETDEWEB)

    Kogerman, P N; Kopwillem, J

    1932-01-01

    Kukersite was heated in an atmosphere of hydrogen, nitrogen, or water in three series of experiments. Shale samples were heated at 370/sup 0/ to 410/sup 0/C for 2 to 3/sup 1///sub 2/ hours in the presence of 106 to 287 kg/sq cm pressure of water, nitrogen, or hydrogen. In some experiments 5 percent of iron oxide was added to the shale. The amount of kerogen liquefied by hydrogenation was not greater than the amount of liquid products obtained by ordinary distillation. On hydrogenation, kukersite absorbed 1.8 weight-percent of hydrogen. Almost no hydrogenation took place below the decomposition point of kerogen, and the lighter decomposition products were mainly hydrogenated. Hydrogenation of the shale prevented coke formation. Heating kukersite or its crude oil at temperatures of 400/sup 0/ to 410/sup 0/C under 250 kg/sq cm hydrogen pressure produced paraffinic and naphthenic oils of lower boiling points. At higher temperatures and after long-continued heating, the formation of aromatic hydrocarbons was observed.

  10. Pore-scale analysis of electrical properties in thinly bedded rock using digital rock physics

    International Nuclear Information System (INIS)

    Sun, Jianmeng; Zhao, Jianpeng; Liu, Xuefeng; Chen, Hui; Jiang, LiMing; Zhang, JinYan

    2014-01-01

    We investigated the electrical properties of laminated rock consist of macro-porous layers and micro-porous layers based on digital rock technology. Due to the bedding effect and anisotropy, traditional Archie equations cannot well describe the electrical behavior of laminated rock. The RI-Sw curve of laminated rock shows a nonlinear relationship. The RI-Sw curve can be divided into two linear segments with different saturation exponent. Laminated sand-shale sequences and laminated sands of different porosity or grain size will yield macroscopic electrical anisotropy. Numerical simulation and theoretical analysis lead to the conclusion that electrical anisotropy coefficient of laminated rock is a strong function of water saturation. The function curve can be divided into three segments by the turning point. Therefore, the electrical behavior of laminated rock should be considered in oil exploration and development. (paper)

  11. Silurian and Devonian source rocks and crude oils from the western part of Libya: Organic geochemistry, palynology and carbon stratigraphy

    NARCIS (Netherlands)

    Elkelani, Mohamed M.A.

    2015-01-01

    The Early Silurian “hot” shales and Late Devonian black shales are major regional oil and gas source rocks in North Africa. Their deposition probably played a major role in global carbon cycling in general because of the large areas of the ocean affected. Comparing the Libyan δ13C record with

  12. Mining and oil. Oil shale's contribution to future oil supply; Bergbau und Oel. Der Beitrag des Oelschiefers zur Oelversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Linden, Eike von der [Linden Advisory, Dreieich (Germany)

    2012-05-15

    Crude oil contributes in Germany and globally approximately one third to the consumption of primary energies and actually is and in the foreseeable future will be the most important energy source. Recently shale oil as an unconventional oil has gained attention in public discussions. Depending on temperatures oil shale contains either already matured fluid shale oil or immature waxy kerogen. For determination of kerogen containing oil shale and shale oil common definitions for fluid hydrocarbons will be presented. Fluid hydrocarbons (molecular chains > C{sub 5}H{sub 12}) originate from animal substance which had been settled millions of years in sediments on sea- or lakebeds under anaerobic conditions. High pressure and high temperatures effect conversion to hydrocarbons. With sufficient permeability the liquid hydrocarbons migrate from the sediment as the source rock and get assembled in porous rocks under the cover of an impermeable rock strata, in so called entrapment structures. In case there is no impermeable rock strate the hydrocarbons will diffuse into the atmosphere. The hydrocarbons in entrapment structures are called conventional oil and are extracted by drilling wells. The extractable oil as part of the oil in place depends on the viscosity of the oil, the permeability of the host rock and applied exploitation methods which can affect pressure, viscosity and permeability. The exploitation achieves 30 to 50% of the oil in place. When the source rock consisting of strata hundreds of meters thick is not sufficiently permeable the matured hydrocarbons remain at its place of origination. These hydrocarbons are called shale oil and belong to the unconventional oil resources. For exploitation of shale oil by wells the source rock must be treated by intensive energy input, amongst others, by fracking which creates artificial permeability and by pressure which affects migration of the hydrocarbons to the well. The exploitation methods for shale oil do not

  13. Depositional environments and oil potential of Jurassic/Cretaceous source rocks within the Seychelles microcontinent

    Energy Technology Data Exchange (ETDEWEB)

    Plummer, P.S.; Joseph, P.R.; Samson, P.J. [Seychelles National Oil Co., Mahe (Seychelles)

    1998-12-31

    The Seychelles microcontinent became isolated between the Somali, Mascarene and Arabian basins of the Indian Ocean as a result of the Mesozoic fragmentation of Gondwana. Major rifting events occurred during the Triassic-Middle Jurassic and Late Cretaceous (Cenomanian-Santonian and Maastrichtian) during which shaly source rock facies accumulated in principally marginal marine/deltaic environments. Between these times, post-rift passive margin deposition within restricted to open marine environments produced shaly source rocks during late Middle Jurasic-Early Cretaceous, Campanian-Maastrichtian and Paleocene times. Recent geochemical analysis of cuttings from the Seagull Shoals-1 well has identified an oil-prone liptinitic (Type II) coaly shale within early Middle Jurassic abandoned deltaic deposits. This coaly source rock is regionally developed, having also been identified in the Majunja and Morondava basins of Madagascar. Oil-prone Type II organic matter has also been identified in the Owen Bank A-1 well within restricted marine shales of late Middle Jurassic age. These shales are part of a thick post-rift source rock sequence that extends into the Early Cretaceous and is in part correlative with the proven Late Jurassic Uarandab Shale of Somalia. Analysis of Campanian marine shales from Reith Bank-1 well identified significant dilution of total organic carbon content in composite, compared to picked, well cuttings samples. This finding supports a published inference that these post-rift shales have source rock potential. (author)

  14. Shale Oil Value Enhancement Research

    Energy Technology Data Exchange (ETDEWEB)

    James W. Bunger

    2006-11-30

    Raw kerogen oil is rich in heteroatom-containing compounds. Heteroatoms, N, S & O, are undesirable as components of a refinery feedstock, but are the basis for product value in agrochemicals, pharmaceuticals, surfactants, solvents, polymers, and a host of industrial materials. An economically viable, technologically feasible process scheme was developed in this research that promises to enhance the economics of oil shale development, both in the US and elsewhere in the world, in particular Estonia. Products will compete in existing markets for products now manufactured by costly synthesis routes. A premium petroleum refinery feedstock is also produced. The technology is now ready for pilot plant engineering studies and is likely to play an important role in developing a US oil shale industry.

  15. Process of distilling bituminous shale

    Energy Technology Data Exchange (ETDEWEB)

    Mayet, M

    1859-05-19

    This new process consists of placing at the end of a tube or the end of one or more retorts, an aspirating pump and compressor or a blower with two valves doing the same work or, better yet, a fan for sucking the vapor from the shale as it is formed in order to prevent its accumulating in the retorts and being decomposed. A second tube, pierced with little holes, placed in series with the pump, blower, or fan, acts as a vessel or receiver for the water. The vapors from the shale are compressed by the aspirator in the receiver for the water and condensed completely, without loss of gas and disinfect themselves for the most part.

  16. Water Saturation Relations and Their Diffusion-Limited Equilibration in Gas Shale: Implications for Gas Flow in Unconventional Reservoirs

    Science.gov (United States)

    Tokunaga, Tetsu K.; Shen, Weijun; Wan, Jiamin; Kim, Yongman; Cihan, Abdullah; Zhang, Yingqi; Finsterle, Stefan

    2017-11-01

    Large volumes of water are used for hydraulic fracturing of low permeability shale reservoirs to stimulate gas production, with most of the water remaining unrecovered and distributed in a poorly understood manner within stimulated regions. Because water partitioning into shale pores controls gas release, we measured the water saturation dependence on relative humidity (rh) and capillary pressure (Pc) for imbibition (adsorption) as well as drainage (desorption) on samples of Woodford Shale. Experiments and modeling of water vapor adsorption into shale laminae at rh = 0.31 demonstrated that long times are needed to characterize equilibrium in larger (5 mm thick) pieces of shales, and yielded effective diffusion coefficients from 9 × 10-9 to 3 × 10-8 m2 s-1, similar in magnitude to the literature values for typical low porosity and low permeability rocks. Most of the experiments, conducted at 50°C on crushed shale grains in order to facilitate rapid equilibration, showed significant saturation hysteresis, and that very large Pc (˜1 MPa) are required to drain the shales. These results quantify the severity of the water blocking problem, and suggest that gas production from unconventional reservoirs is largely associated with stimulated regions that have had little or no exposure to injected water. Gravity drainage of water from fractures residing above horizontal wells reconciles gas production in the presence of largely unrecovered injected water, and is discussed in the broader context of unsaturated flow in fractures.

  17. Hydro mechanical behaviour of shales. Application to the Tournemire site

    International Nuclear Information System (INIS)

    Ramambasoa, N.

    2001-01-01

    In order to fulfill its mission of research and expertise about deep nuclear waste disposals, the French Institute for Nuclear Protection and Safety has selected the Tournemire site to study the confining properties of argillaceous media. This study is mainly motivated by the apparition of cracks that after the excavation of two galleries perpendicularly to an old tunnel. These cracks are not of mechanical or tectonic origin. They are regularly spaced and follow the rock sub-horizontal stratification. Their aperture is very sensitive to the hygrometry in the galleries. These cracks are supposed to result of the rock desaturation, which is in contact with an unsaturated atmosphere. In order to validate this hypothesis, an hydro-mechanical constitutive law for Tournemire shale is proposed. In order to take account of the shale desaturation and of microscopic interactions specific of argillaceous media, chemical potential is used as an hydric variable instead of interstitial pressure, which is classically used in poro-mechanics. This constitutive law differs from classical elastic law by the dependence of elastic parameters with the water chemical potential and by the adding of shrinkage strains and mechanical strains to get total strains. The numerical simulation of the Tournemire galleries desaturation shows the existence of high tractions around the excavation that certainly lead to material failure. The propagation of the cracks at the front faces is modeled by taking account of the interactions between the cracks in order to predict their depth and to explain their almost periodical distribution on the site. (author)

  18. Recovering bituminous matter from shale

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, H D

    1922-08-29

    A process is described for obtaining valuable hydro-carbons from bituminous solids such as shale and the like, which comprises digesting a mixture of such a bituminous solid with a hydro-carbon liquid, the digestion being conducted at temperature high enough to effectively liquefy heavy bituminous matter contained in the solid but insufficiently high to effect substantial distillation of heavy bituminous matter, separating a resultant liquid mixture of hydrocarbons from the residue of such bituminous solid and refining the liquid mixture.

  19. Fracking in Tight Shales: What Is It, What Does It Accomplish, and What Are Its Consequences?

    Science.gov (United States)

    Norris, J. Quinn; Turcotte, Donald L.; Moores, Eldridge M.; Brodsky, Emily E.; Rundle, John B.

    2016-06-01

    Fracking is a popular term referring to hydraulic fracturing when it is used to extract hydrocarbons. We distinguish between low-volume traditional fracking and the high-volume modern fracking used to recover large volumes of hydrocarbons from shales. Shales are fine-grained rocks with low granular permeabilities. During the formation of oil and gas, large fluid pressures are generated. These pressures result in natural fracking, and the resulting fracture permeability allows oil and gas to escape, reducing the fluid pressures. These fractures may subsequently be sealed by mineral deposition, resulting in tight shale formations. The objective of modern fracking is to reopen these fractures and/or create new fractures on a wide range of scales. Modern fracking has had a major impact on the availability of oil and gas globally; however, there are serious environmental objections to modern fracking, which should be weighed carefully against its benefits.

  20. Shale oil. I. Genesis of oil shales and its relation to petroleum and other fuels

    Energy Technology Data Exchange (ETDEWEB)

    McKee, R H; Manning, P D.V.

    1927-01-01

    Oil-shale kerogen originated from resinous vegetation residues of past eras, whereas well petroleum was formed from oil shales by pressure and mild heat. Petroleum migrated to its present reservoir from neighboring oil-shale deposits, leaving a residue of black bituminous shales. The high carbon dioxide content of gases present in petroleum wells originated from kerogen, as it gives off carbon dioxide gas before producing soluble oil or bitumen.

  1. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-01-01

    properties (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) using multivariate statistics. The application of these relations allows computing continuous borehole profiles for each rock thermal property. The uncertainties in the prediction...

  2. Quantifying porosity, compressibility and permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

    strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...... permeability estimate comparable to the measured one for shale rich in smectite. This is probably because Yang and Aplin model was calibrated in London clay which is rich in smectite....

  3. Method and arrangement of distillation of shales

    Energy Technology Data Exchange (ETDEWEB)

    Bergh, S V

    1920-03-29

    A method is given of distilling shale and other bituminous materials utilizing the heat from the combustion of the residue, possibly with additional heat from other fuels. It is characterized by the shale, which is arranged in layers, being first submitted to a process of distillation utilizing the heat mentioned, and at the same time recovering the products of distillation, and second the shale being burned without disturbing the layers to any appreciable extent. The patent has 16 more claims.

  4. Preparation of cement from oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1922-08-24

    A process for preparing cement from oil shale is described. The simultaneous recovery of shale oil by heating the oil shale formed into briquets with finely ground lime or limestone in a stream of hot gases is characterized by the fact that live steam or fine drops of water as preserving and carbonization means is introduced into the furnace, at the place, where the temperature of the briquet reaches about 500 to 600/sup 0/ C.

  5. Characteristics of stable carbon isotopic composition of shale gas

    Directory of Open Access Journals (Sweden)

    Zhenya Qu

    2016-04-01

    Full Text Available A type Ⅱ kerogen with low thermal maturity was adopted to perform hydrocarbon generation pyrolysis experiments in a vacuum (Micro-Scale Sealed Vessel system at the heating rates of 2 °C/h and 20 °C/h. The stable carbon isotopic compositions of gas hydrocarbons were measured to investigate their evolving characteristics and the possible reasons for isotope reversal. The δ13C values of methane became more negative with the increasing pyrolysis temperatures until it reached the lightest point, after which they became more positive. Meanwhile, the δ13C values of ethane and propane showed a positive trend with elevating pyrolysis temperatures. The carbon isotopic compositions of shale gasses were mainly determined by the type of parent organic matter, thermal evolutionary extent, and gas migration in shale systems. Our experiments and study proved that the isotope reversal shouldn't occur in a pure thermogenic gas reservoir, it must be involved with some other geochemical process/es; although mechanisms responsible for the reversal are still vague. Carbon isotopic composition of the Fayetteville and Barnett shale gas demonstrated that the isotope reversal was likely involved with water–gas reaction and Fischer-Tropsch synthesis during its generation.

  6. Dynamic mechanical properties and anisotropy of synthetic shales with different clay minerals under confining pressure

    Science.gov (United States)

    Gong, Fei; Di, Bangrang; Wei, Jianxin; Ding, Pinbo; Shuai, Da

    2018-03-01

    The presence of clay minerals can alter the elastic behaviour of reservoir rocks significantly as the type of clay minerals, their volume and distribution, and their orientation control the shale's intrinsic anisotropic behaviours. Clay minerals are the most abundant materials in shale, and it has been proven extremely difficult to measure the elastic properties of natural shale by means of a single variable (in this case, the type of clay minerals), due to the influences of multiple factors, including water, TOC content and complex mineral compositions. We used quartz, clay (kaolinite, illite and smectite), carbonate and kerogen extract as the primary materials to construct synthetic shale with different clay minerals. Ultrasonic experiments were conducted to investigate the anisotropy of velocity and mechanical properties in dry synthetic and natural shale as a function of confining pressure. Velocities in synthetic shale are sensitive to the type of clay minerals, possibly due to the different structures of the clay minerals. The velocities increase with confining pressure and show higher rate of velocity increase at low pressures, and P-wave velocity is usually more sensitive than S-wave velocity to confining pressure according to our results. Similarly, the dynamic Young's modulus and Poisson's ratio increase with applied pressure, and the results also reveal that E11 is always larger than E33 and ν31 is smaller than ν12. Velocity and mechanical anisotropy decrease with increasing stress, and are sensitive to stress and the type of clay minerals. However, the changes of mechanical anisotropy with applied stress are larger compared with the velocity anisotropy, indicating that mechanical properties are more sensitive to the change of rock properties.

  7. A lithology identification method for continental shale oil reservoir based on BP neural network

    Science.gov (United States)

    Han, Luo; Fuqiang, Lai; Zheng, Dong; Weixu, Xia

    2018-06-01

    The Dongying Depression and Jiyang Depression of the Bohai Bay Basin consist of continental sedimentary facies with a variable sedimentary environment and the shale layer system has a variety of lithologies and strong heterogeneity. It is difficult to accurately identify the lithologies with traditional lithology identification methods. The back propagation (BP) neural network was used to predict the lithology of continental shale oil reservoirs. Based on the rock slice identification, x-ray diffraction bulk rock mineral analysis, scanning electron microscope analysis, and the data of well logging and logging, the lithology was divided with carbonate, clay and felsic as end-member minerals. According to the core-electrical relationship, the frequency histogram was then used to calculate the logging response range of each lithology. The lithology-sensitive curves selected from 23 logging curves (GR, AC, CNL, DEN, etc) were chosen as the input variables. Finally, the BP neural network training model was established to predict the lithology. The lithology in the study area can be divided into four types: mudstone, lime mudstone, lime oil-mudstone, and lime argillaceous oil-shale. The logging responses of lithology were complicated and characterized by the low values of four indicators and medium values of two indicators. By comparing the number of hidden nodes and the number of training times, we found that the number of 15 hidden nodes and 1000 times of training yielded the best training results. The optimal neural network training model was established based on the above results. The lithology prediction results of BP neural network of well XX-1 showed that the accuracy rate was over 80%, indicating that the method was suitable for lithology identification of continental shale stratigraphy. The study provided the basis for the reservoir quality and oily evaluation of continental shale reservoirs and was of great significance to shale oil and gas exploration.

  8. Multi-scale Multi-dimensional Imaging and Characterization of Oil Shale Pyrolysis

    Science.gov (United States)

    Gao, Y.; Saif, T.; Lin, Q.; Al-Khulaifi, Y.; Blunt, M. J.; Bijeljic, B.

    2017-12-01

    The microstructural evaluation of fine grained rocks is challenging which demands the use of several complementary methods. Oil shale, a fine-grained organic-rich sedimentary rock, represents a large and mostly untapped unconventional hydrocarbon resource with global reserves estimated at 4.8 trillion barrels. The largest known deposit is the Eocene Green River Formation in Western Colorado, Eastern Utah, and Southern Wyoming. An improved insight into the mineralogy, organic matter distribution and pore network structure before, during and after oil shale pyrolysis is critical to understanding hydrocarbon flow behaviour and improving recovery. In this study, we image Mahogany zone oil shale samples in two dimensions (2-D) using scanning electron microscopy (SEM), and in three dimensions (3-D) using focused ion beam scanning electron microscopy (FIB-SEM), laboratory-based X-ray micro-tomography (µCT) and synchrotron X-ray µCT to reveal a complex and variable fine grained microstructure dominated by organic-rich parallel laminations which are tightly bound in a highly calcareous and heterogeneous mineral matrix. We report the results of a detailed µCT study of the Mahogany oil shale with increasing pyrolysis temperature. The physical transformation of the internal microstructure and evolution of pore space during the thermal conversion of kerogen in oil shale to produce hydrocarbon products was characterized. The 3-D volumes of pyrolyzed oil shale were reconstructed and image processed to visualize and quantify the volume and connectivity of the pore space. The results show a significant increase in anisotropic porosity associated with pyrolysis between 300-500°C with the formation of micron-scale connected pore channels developing principally along the kerogen-rich lamellar structures.

  9. Shale gas - the story of a deception

    International Nuclear Information System (INIS)

    Ambroise, Jacques

    2013-01-01

    This bibliographical sheet presents a book which aims at informing citizen about the irreversible consequences of shale gas exploitation on the environment, and about the economical and social aspects of an exploitation of this energy on a large scale. The author highlights the technical and environmental problems raised by hydraulic fracturing, outlines the complexity of the regulatory, legal and administrative framework, discusses the arguments which support shale gas exploitation, and outlines the importance of and energy transition without shale gas. The author notably outlines the conflicts of interest which pervert the debate on shale gas, notably within the French National Assembly

  10. A perspective on Canadian shale gas

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Mike; Davidson, Jim; Mortensen, Paul

    2010-09-15

    In a relatively new development over just the past few years, shale formations are being targeted for natural gas production. Based on initial results, there may be significant potential for shale gas in various regions of Canada, not only in traditional areas of conventional production but also non-traditional areas. However, there is much uncertainty because most Canadian shale gas production is currently in experimental or early developmental stages. Thus, its full potential will not be known for some time. If exploitation proves to be successful, Canadian shale gas may partially offset projected long-term declines in Canadian conventional natural gas production.

  11. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  12. Excess europium content in Precambrian sedimentary rocks and continental evolution

    Science.gov (United States)

    Jakes, P.; Taylor, S. R.

    1974-01-01

    It is proposed that the europium excess in Precambrian sedimentary rocks, relative to those of younger age, is derived from volcanic rocks of ancient island arcs, which were the source materials for the sediments. Precambrian sedimentary rocks and present-day volcanic rocks of island arcs have similar REE patterns, total REE abundances, and excess Eu, relative to the North American shale composite. The present upper crustal REE pattern, as exemplified by that of sediments, is depleted in Eu, relative to chondrites. This depletion is considered to be a consequence of development of a granodioritic upper crust by partial melting in the lower crust, which selectively retains europium.

  13. Correlation of resource plays and biodiversity patterns: accumulation of organic-rich shale tracks taxonomic turnover

    Science.gov (United States)

    Eoff, Jennifer D.

    2012-01-01

    Similar paleogeographic and paleotectonic settings characterize most self-sourced shale hydrocarbon plays. Their deposition occurred within similar orders of magnitude of eustatic events and during geologic periods characterized by “warm” (or transitional) climates and calcitic seas. In addition, the stratigraphic occurrence of shale plays parallels certain historical patterns of marine metazoan biodiversity. Such strong agreement among several correlation tools elucidates why these resources may be limited to discrete intervals of geological time. Correlation of self-sourced shale with biodiversity trends indicates that the factors controlling the deposition of marine organic matter may not be independent of those that induced taxonomic turnover. Paleoecological changes promoted accumulation and preservation of Type II kerogen. Deposition of self-sourced shale appears to correspond to reductions in absolute biodiversity and declining percentages of bioturbating taxa, with concomitant increases in proportions of pelagic taxa relative to infaunal and epifaunal organisms. Whereas upwelling and anoxia may have contributed to the deposition of kerogen in source rocks throughout much of the sedimentary record, diminished consumption of biomass by benthic metazoans likely augmented the preservation of organic carbon during deposition of this shale type. Rapid tectonic-plate reconfiguration induced coeval events, creating basins with sufficiently high rates of accommodation creation necessary to preserve additional organic material accumulating as the heterotrophic benthos suffered in response to rapidly changing environments. Combining sea-level curves, paleogeography, climate, and seawater chemistry provides a first-order approximation of the distribution of potential self-sourced shale in the geologic record. A model that predicts the stratigraphic distribution of self-sourced-shale deposition can aid in exploration of continuous hydrocarbon accumulations in self

  14. Experimental Characterization and Modeling of the Fracturing Behavior of Marcellus Shale

    Science.gov (United States)

    Jin, C.; Li, W.; Sageman, B. B.; Cusatis, G.

    2014-12-01

    Adequate knowledge and prediction of mechanical properties of shale are pivotal to the design of hydraulic fractures. The urgent technical challenge of such an endeavor is how to translate the highly heterogeneous nature of shale into a predictive model of the mechanical properties. Our group addressed this challenge by adopting a combined experimental and numerical approach to investigate fracture processes and failure mechanisms of shale.Lattice Discrete Particle Model (LDPM), having shown superior capabilities in predicting qualitative and quantitative behavior of concrete and concrete-like materials, as shown in Fig. 1, has been adopted to simulate mesoscale behavior of shale. The polyhedral cell system defining the geometric attributes of the rock microstructure is built via a 3D tessellation procedure based on X-ray microtomography results of microstructure and grain size distribution of shale specimens. The adopted tessellation procedure makes use of well-established packing algorithms for no-contact spherical particle placement and non-overlapping volume tessellation. The polyhedral particles interact through triangular facets where appropriate measure of stresses and strains are defined. Especially, LDPM is extended to simulate transversely isotropic materials by using orientation-dependent and strain-dependent strength limits coupled with orientation-dependent normal and shear stiffnesses on each facet. Appropriate interface constitutive equations are formulated to simulate all phenomena occurring at a scale that is smaller than the resolution of LDPM system, including microscopic fracture, frictional contact, particle breakage, pore collapse, and distributed damage. Bedding planes and natural joints are characterized by greatly decreased strength limits for facets within that region. To calibrate/validate the LDPM model, microscopic and mesoscopic experiments, including Brazilian tests, uniaxial compression tests, and three point-bending tests, are

  15. Hydraulic fracturing in shales: the spark that created an oil and gas boom

    Science.gov (United States)

    Olson, J. E.

    2017-12-01

    In the oil and gas business, one of the valued properties of a shale was its lack of flow capacity (its sealing integrity) and its propensity to provide mechanical barriers to hydraulic fracture height growth when exploiting oil and gas bearing sandstones. The other important property was the high organic content that made shale a potential source rock for oil and gas, commodities which migrated elsewhere to be produced. Technological advancements in horizontal drilling and hydraulic fracturing have turned this perspective on its head, making shale (or other ultra-low permeability rocks that are described with this catch-all term) the most prized reservoir rock in US onshore operations. Field and laboratory results have changed our view of how hydraulic fracturing works, suggesting heterogeneities like bedding planes and natural fractures can cause significant complexity in hydraulic fracture growth, resulting in induced networks of fractures whose details are controlled by factors including in situ stress contrasts, ductility contrasts in the stratigraphy, the orientation and strength of pre-existing natural fractures, injection fluid viscosity, perforation cluster spacing and effective mechanical layer thickness. The stress shadowing and stress relief concepts that structural geologists have long used to explain joint spacing and orthogonal fracture pattern development in stratified sequences are key to understanding optimal injection point spacing and promotion of more uniform length development in induced hydraulic fractures. Also, fracture interaction criterion to interpret abutting vs crossing natural fracture relationships in natural fracture systems are key to modeling hydraulic fracture propagation within natural fractured reservoirs such as shale. Scaled physical experiments provide constraints on models where the physics is uncertain. Numerous interesting technical questions remain to be answered, and the field is particularly appealing in that better

  16. Elements and gas enrichment laws of sweet spots in shale gas reservoir: A case study of the Longmaxi Fm in Changning block, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Renfang Pan

    2016-05-01

    Full Text Available Identification of sweet spot is of great significance in confirming shale gas prospects to realize large-scale economic shale gas development. In this paper, geological characteristics of shale gas reservoirs were compared and analyzed based on abundant data of domestic and foreign shale gas reservoirs. Key elements of sweet spots were illustrated, including net thickness of gas shale, total organic carbon (TOC content, types and maturity (Ro of organic matters, rock matrix and its physical properties (porosity and permeability, and development characteristics of natural fractures. After the data in Changning and Weiyuan blocks, the Sichuan Basin, were analyzed, the geologic laws of shale gas enrichment were summarized based on the economic exploitation characteristics of shale gas and the correlation between the elements. The elements of favorable “sweet spots” of marine shale gas reservoirs in the Changning block and their distribution characteristics were confirmed. Firstly, the quality of gas source rocks is ensured with the continuous thickness of effective gas shale larger than 30 m, TOC > 2.0% and Ro = 2.4–3.5%. Secondly, the quality of reservoir is ensured with the brittle minerals content being 30–69%, the clay mineral content lower than 30% and a single lamination thickness being 0.1–1.0 m. And thirdly, the porosity is higher than 2.0%, the permeability is larger than 50 nD, gas content is higher than 1.45 m3/t, and formation is under normal pressure–overpressure system, which ensures the production modes and capacities. Finally, the primary and secondary elements that control the “sweet spots” of shale gas reservoirs were further analyzed and their restrictive relationships with each other were also discussed.

  17. An Effective Reservoir Parameter for Seismic Characterization of Organic Shale Reservoir

    Science.gov (United States)

    Zhao, Luanxiao; Qin, Xuan; Zhang, Jinqiang; Liu, Xiwu; Han, De-hua; Geng, Jianhua; Xiong, Yineng

    2017-12-01

    Sweet spots identification for unconventional shale reservoirs involves detection of organic-rich zones with abundant porosity. However, commonly used elastic attributes, such as P- and S-impedances, often show poor correlations with porosity and organic matter content separately and thus make the seismic characterization of sweet spots challenging. Based on an extensive analysis of worldwide laboratory database of core measurements, we find that P- and S-impedances exhibit much improved linear correlations with the sum of volume fraction of organic matter and porosity than the single parameter of organic matter volume fraction or porosity. Importantly, from the geological perspective, porosity in conjunction with organic matter content is also directly indicative of the total hydrocarbon content of shale resources plays. Consequently, we propose an effective reservoir parameter (ERP), the sum of volume fraction of organic matter and porosity, to bridge the gap between hydrocarbon accumulation and seismic measurements in organic shale reservoirs. ERP acts as the first-order factor in controlling the elastic properties as well as characterizing the hydrocarbon storage capacity of organic shale reservoirs. We also use rock physics modeling to demonstrate why there exists an improved linear correlation between elastic impedances and ERP. A case study in a shale gas reservoir illustrates that seismic-derived ERP can be effectively used to characterize the total gas content in place, which is also confirmed by the production well.

  18. Preferred Orientation and Anisotropy of Clay minerals and Pores in Posidonia Shales

    Science.gov (United States)

    Kanitpanyacharoen, W.; Chen, K.; Wenk, H.

    2010-12-01

    Shales compose a large part of sedimentary basins and form the seal and source rocks for hydrocarbon reservoirs. They are also of great interest in context of repositories for nuclear waste and carbon sequestration. A comprehensive study of shale properties is thus crucial for seismic prospecting, particularly due to high elastic anisotropy that is contributed by the alignment of constituent clay minerals during compaction and diagenesis. In this study, we quantitatively analyze composition, crystal preferred orientation (or texture), and the 3D porosity structure in four Posidonia shales from Germany using high energy synchrotron x-rays. We can infer texture information from x-ray diffraction images relying on the Rietveld method, as well as determine the 3D porosity structure from tomography images. We observed that quartz and calcite are dominating phases while illite-smectite, illite-mica and kaolinite are the major clay minerals. The texture strength of clays range from 4.22 to 6.12 m.r.d. A comparison of shallow Posidonia shales with deep shales from the North Sea, Saudi Arabia, and the Gulf of Mexico documents that P-wave anisotropy increases with increasing phyllosilicate content (mainly illite-smectite and kaolinite) and increasing burial. Low absorption features in microtomography images indicate porosity (including kerogen and fractures), which is estimated at 1 vol% and observed to be anisotropic, mainly organized parallel to bedding with little connectivity of flat pores in direction perpendicular to the bedding plane.

  19. Characterisation of Tertiary Catalan lacustrine oil shales: Discovery of extremely organic sulphur-rich type I kerogens

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Las Heras, F.X.C. de; Bergen, P.F. van; Leeuw, J.W. de

    1993-01-01

    The kerogens of three Tertiary Catalan lacustrine oil shales were analyzed by light microscopy, flash pyrolysis-gas chromatography-mass spectrometry, and bulk composition methods (elemental analysis, Rock Eval pyrolysis). Two of the three kerogens (Ribesalbes and Campins) are extremely rich in

  20. Effects of experimental parameters on the sorption of cesium, strontium, and uranium from saline groundwaters onto shales: Progress report

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.

    1988-11-01

    This report concerns an extension of the first series of experiments on the sorption properties of shales and their clay mineral components reported earlier. Studies on the sorption of cesium and strontium were carried out on samples of Chattanooga (Upper Dowelltown), Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales that had been heated to 120/degree/C in a 0.1-mol/L NaCl solution for periods up to several months and on samples of the same shales which had been heated to 250/degree/C in air for six months, to simulate limiting scenarios in a HLW repository. To investigate the kinetics of the sorption process in shale/groundwater systems, strontium sorption experiments were done on unheated Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales in a diluted, saline groundwater and in 0.03-mol/L NaHCO 3 , for periods of 0.25 to 28 days. Cesium sorption kinetics tests were performed on the same shales in a concentrated brine for the same time periods. The effect of the water/rock (W/R) ratio on sorption for the same combinations of unheated shales, nuclides, and groundwaters used in the kinetics experiments was investigated for a range of W/R ratios of 3 to 20 mL/g. Because of the complexity of the shale/groundwater interaction, a series of tests was conducted on the effects of contact time and W/R ratio on the pH of a 0.03-mol/L NaHCO 3 simulated groundwater in contact with shales. 8 refs., 12 figs., 15 tabs

  1. Geochemical behavior of Cs, Sr, Tc, Np, and U in saline groundwaters: Sorption experiments on shales and their clay mineral components: Progress report

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Ho, P.C.; Case, F.I.; O'Kelley, G.D.

    1987-11-01

    The Sedimentary Rock Program at the Oak Ridge National Laboratory is investigating shale to determine its potential suitability as a host rock for the disposal of high-level radioactive wastes (HLW). In support of this program, preliminary studies were carried out on sorption of cesium, strontium, technetium, neptunium, and uranium onto Chattanooga (Upper Dowelltown), Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales under oxic conditions (air present). Three simulated groundwaters were used. One of the groundwaters was a synthetic brine made up to simulate highly saline groundwaters in the Pumpkin Valley Shale. The second was a 100/1 dilution of this groundwater and the third was 0.03 M NaHCO 3 . Moderate to significant sorption was observed under most conditions for all of the tested radionuclides except technetium. Moderate technetium sorption occurred on Upper Dowelltown Shale, and although technetium sorption was low on the other shales, it was higher than expected for Tc(VII), present as the anion TcO 4 - . Little sorption of strontium onto the shales was observed from the concentrated saline groundwater. These data can be used in a generic fashion to help assess the sorption characteristics of shales in support of a national survey. 10 refs., 4 figs., 23 tabs

  2. Whole-rock U-Pb dating of the Shuijingtuo formation sedimentary rocks in the Yangtze Gorge

    International Nuclear Information System (INIS)

    Zheng, Y.F.; Huang, B.

    1990-01-01

    Black shale and enclosed limestone lenticule from Lower Cambrian Shuijingtuo Formation in the Yangtze Gorge is successfully dated by whole-rock U-Pb method. The results yield a concordant age of about 573±14 Ma, in excellent agreement with both stratigraphic and palaeontologic evidence. The whole-rock U-Pb method can provide a reliable approach for age determination of sedimentary stratum. (orig.) [de

  3. Chemical kinetics and oil shale process design

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A.K.

    1993-07-01

    Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.

  4. Oil shales and the nuclear process heat

    International Nuclear Information System (INIS)

    Scarpinella, C.A.

    1974-01-01

    Two of the primary energy sources most dited as alternatives to the traditional fossil fuels are oil shales and nuclear energy. Several proposed processes for the extraction and utilization of oil and gas from shale are given. Possible efficient ways in which nuclear heat may be used in these processes are discussed [pt

  5. Compaction Characteristics of Igumale Shale | Iorliam | Global ...

    African Journals Online (AJOL)

    This paper reports the outcome of an investigation into the effect of different compactive energies on the compaction characteristics of Igumale shale, to ascertain its suitability as fill material in highway ... The study showed that Igumale shale is not suitable for use as base, subbase and filling materials in road construction.

  6. Process for recovering oil from shale, etc

    Energy Technology Data Exchange (ETDEWEB)

    1920-08-20

    A process is described for recovering oil from oil-shale and the like, by the direct action of the hot gases obtained by burning the carbonized shale residue. It is immediately carried out in separate adjacent chambers, through which the feed goes from one to the other intermittently, from the upper to the lower.

  7. Method of distillation of sulfurous bituminous shales

    Energy Technology Data Exchange (ETDEWEB)

    Hallback, A J.S.; Bergh, S V

    1918-04-22

    A method of distillation of sulfur-containing bituminous shales is characterized by passing the hot sulfur-containing and oil-containing gases and vapors formed during the distillation through burned shale containing iron oxide, so that when these gases and vapors are thereafter cooled they will be, as far as possible, free from sulfur compounds. The patent contains six more claims.

  8. Nitrogen fixation by legumes in retorted shale

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, L E; Molitoris, E; Klein, D A

    1981-01-01

    A study was made to determine whether retorted shale additions would significantly affect symbiotic N/sub 2/ fixation. Results indicate that small additions of the shale may stimulate plant growth but with higher concentrations plants are stressed, resulting in a decreased biomass and a compensatory effect of an increased number of nodules and N/sub 2/ fixation potential. (JMT)

  9. Thermophysical properties of Conasauga shale

    International Nuclear Information System (INIS)

    Smith, D.D.

    1978-01-01

    Thermophysical-property characterizations of five Conasauga shale cores were determined at temperatures between 298 and 673 K. Methods of specimen fabrication for different tests were evaluated. Thermal-conductivity and thermal-expansion data were found to be dependent on the structure and orientation of the individual specimens. Thermal conductivities ranged between 2.8 and 1.0 W/m-K with a small negative temperature dependence. Thermal expansions were between 2 and 5 x 10 -3 over the temperature range for the group. Heat capacity varied with the composition. 17 figures, 3 tables

  10. Construction of Shale Gas Well

    Science.gov (United States)

    Sapińska-Śliwa, Aneta; Wiśniowski, Rafał; Skrzypaszek, Krzysztof

    2018-03-01

    The paper describes shale gas borehole axes trajectories (vertical, horizontal, multilateral). The methodology of trajectory design in a two-and three-dimensional space has been developed. The selection of the profile type of the trajectory axes of the directional borehole depends on the technical and technological possibilities of its implementation and the results of a comprehensive economic analysis of the availability and development of the field. The work assumes the possibility of a multivariate design of trajectories depending on the accepted (available or imposed) input data.

  11. Introduction to special section: China shale gas and shale oil plays

    Science.gov (United States)

    Jiang, Shu; Zeng, Hongliu; Zhang, Jinchuan; Fishman, Neil; Bai, Baojun; Xiao, Xianming; Zhang, Tongwei; Ellis, Geoffrey S.; Li, Xinjing; Richards-McClung, Bryony; Cai, Dongsheng; Ma, Yongsheng

    2015-01-01

    In the last 10 years, the success of shale gas and shale oil productions as a result of technological advances in horizontal drilling, hydraulic fracturing and nanoscale reservoir characterization have revolutionized the energy landscape in the United States. Resource assessment by the China Ministry of Land and Resources in 2010 and 2012 and by the U.S. Energy Information Administration in 2011 and 2013 indicates China’s shale gas resource is the largest in the world and shale oil resource in China is also potentially significant. Inspired by the success in the United States, China looks forward to replicating the U.S. experience to produce shale gas to power its economy and reduce greenhouse gas emissions. By 2014, China had drilled 400 wells targeting marine, lacustrine, and coastal swamp transitional shales spanning in age from the Precambrian to Cenozoic in the last five years. So far, China is the leading country outside of North America in the viable production of shale gas, with very promising prospects for shale gas and shale oil development, from the Lower Silurian Longmaxi marine shale in Fuling in the southeastern Sichuan Basin. Geological investigations by government and academic institutions as well as exploration and production activities from industry indicate that the tectonic framework, depositional settings, and geomechanical properties of most of the Chinese shales are more complex than many of the producing marine shales in the United States. These differences limit the applicability of geologic analogues from North America for use in Chinese shale oil and gas resource assessments, exploration strategies, reservoir characterization, and determination of optimal hydraulic fracturing techniques. Understanding the unique features of the geology, shale oil and gas resource potential, and reservoir characteristics is crucial for sweet spot identification, hydraulic fracturing optimization, and reservoir performance prediction.

  12. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid; van Oort, Eric; Patzek, Tadeusz

    2018-01-01

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  13. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid

    2018-05-17

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  14. Recreating Rocks

    DEFF Research Database (Denmark)

    Posth, Nicole R

    2008-01-01

    Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers.......Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers....

  15. Different Methods of Predicting Permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

    by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

  16. Intelligent fracture creation for shale gas development

    KAUST Repository

    Douglas, Craig C.

    2011-05-14

    Shale gas represents a major fraction of the proven reserves of natural gas in the United States and a collection of other countries. Higher gas prices and the need for cleaner fuels provides motivation for commercializing shale gas deposits even though the cost is substantially higher than traditional gas deposits. Recent advances in horizontal drilling and multistage hydraulic fracturing, which dramatically lower costs of developing shale gas fields, are key to renewed interest in shale gas deposits. Hydraulically induced fractures are quite complex in shale gas reservoirs. Massive, multistage, multiple cluster treatments lead to fractures that interact with existing fractures (whether natural or induced earlier). A dynamic approach to the fracturing process so that the resulting network of reservoirs is known during the drilling and fracturing process is economically enticing. The process needs to be automatic and done in faster than real-time in order to be useful to the drilling crews.

  17. Nitrogen fixation by legumes in retorted shale

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, L E; Molitoris, E; Klein, D A

    1981-01-01

    Although a soil-shale mixture was employed as the growth medium in this experiment, the results presentd are applicable to the proposed method of disposal mentioned earlier. Under field conditions, when covering the retorted shale with topsoil, some mixing of these materials might occur in the plant root region. In addition, it has been demonstrated that buried shale negatively affects enzyme activities in overburden surface soil. The occurrence of either of those events could affect symbiotic N/sub 2/ fixation in a manner similar to that reported in this paper. Researchers conclude that due to the varied effects of retorted shale on the legumes tested, further evaluation of other legumes may be necessary. Additional research would be required to determine which legumes have potential use for reclamation of retorted shale.

  18. Micro Mechanics and Microstructures of Major Subsurface Hydraulic Barriers: Shale Caprock vs Wellbore Cement

    Science.gov (United States)

    Radonjic, M.; Du, H.

    2015-12-01

    Shale caprocks and wellbore cements are two of the most common subsurface impermeable barriers in the oil and gas industry. More than 60% of effective seals for geologic hydrocarbon bearing formations as natural hydraulic barriers constitute of shale rocks. Wellbore cements provide zonal isolation as an engineered hydraulic barrier to ensure controlled fluid flow from the reservoir to the production facilities. Shale caprocks were deposited and formed by squeezing excess formation water and mineralogical transformations at different temperatures and pressures. In a similar process, wellbore cements are subjected to compression during expandable tubular operations, which lead to a rapid pore water propagation and secondary mineral precipitation within the cement. The focus of this research was to investigate the effect of wellbore cement compression on its microstructure and mechanical properties, as well as a preliminary comparison of shale caprocks and hydrated cement. The purpose of comparative evaluation of engineered vs natural hydraulic barrier materials is to further improve wellbore cement durability when in contact with geofluids. The micro-indentation was utilized to evaluate the change in cement mechanical properties caused by compression. Indentation experiments showed an overall increase in hardness and Young's modulus of compressed cement. Furthermore, SEM imaging and Electron Probe Microanalysis showed mineralogical alterations and decrease in porosity. These can be correlated with the cement rehydration caused by microstructure changes as a result of compression. The mechanical properties were also quantitatively compared to shale caprock samples in order to investigate the similarities of hydraulic barrier features that could help to improve the subsurface application of cement in zonal isolation. The comparison results showed that the poro-mechanical characteristics of wellbore cement appear to be improved when inherent pore sizes are shifted to

  19. Assimilation of carbonate country rock by the parent magma of the Panzhihua Fe-Ti-V deposit (SW China: Evidence from stable isotopes

    Directory of Open Access Journals (Sweden)

    Clément Ganino

    2013-09-01

    Full Text Available The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit. During emplacement of the main intrusion, multiple generations of mafic dykes invaded carbonate wall rocks, producing a large contact aureole. We measured the oxygen-isotope composition of the intrusions, their constituent minerals, and samples of the country rock. Magnetite and plagioclase from Panzhihua intrusion have δ18O values that are consistent with magmatic equilibrium, and formed from magmas with δ18O values that were 1–2‰ higher than expected in a mantle-derived magma. The unmetamorphosed country rock has high δ18O values, ranging from 13.2‰ (sandstone to 24.6–28.6‰ (dolomite. The skarns and marbles from the aureole have lower δ18O and δ13C values than their protolith suggesting interaction with fluids that were in exchange equilibrium with the adjacent mafic magmas and especially the numerous mafic dykes that intruded the aureole. This would explain the alteration of δ18O of the dykes which have significantly higher values than expected for a mantle-derived magma. Depending on the exact δ18O values assumed for the magma and contaminant, the amount of assimilation required to produce the elevated δ18O value of the Panzhihua intrusion was between 8 and 13.7 wt.%, assuming simple mixing. The exact mechanism of contamination is unclear but may involve a combination of assimilation of bulk country rock, mixing with a melt of the country rock and exchange with CO2-rich fluid derived from decarbonation of the marls and dolomites. These mechanisms, particularly the latter, were probably involved in the formation of the Fe-Ti-V ores.

  20. Relation of peat to oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Linker, S

    1924-01-01

    Samples of oil shale from the Green River formation and from Elko (Nev.), Brazil, Austria, and South Africa were examined, and several varieties of shale were found. Green River oil shale represents three of the more common types plus one less common type. These were: contorted shale with a velvety appearance, thin paper shale resembling the curled-up leaves of a book, massive black shale resembling a piece of rubber, and a less common type, which showed the bedding planes very clearly. The Elko (Nev.) shale was a light buff color; the shale from Brazil resembled a piece of petrified peat. When the shales were cut very thin, their colors ranged from yellow to reddish-brown. The composition, as seen under the microscope, was of well-preserved plant material such as spores, pollen grains, fragments of cell tissues, algae, fungi, bacteria, macerated organic residue, small pieces of resin, animal fossils, and translucent bodies. Oil shale was produced from organic material that accumulated in peat bogs, marshes, or swamps in fresh or salt waters. The organic matter was decomposed by bacterial action. Certain parts of the plants decayed more readily than others. Before lithification occurred, a chemical action took place that changed the softer tissues of the plant debris into a gel. This collodial matter penetrated and surrounded the more resistant fragments and preserved them from further decay. Certain bog waters contain a high percentage of humic acids in solution or collodial suspension and produce insoluble humates when neutralized. These humates are probably the so-called kerogen bodies.

  1. The variation of molybdenum isotopes within the weathering system of the black shales

    Science.gov (United States)

    Jianming, Z.

    2016-12-01

    Jian-Ming Zhu 1,2, De-Can Tan 2, Liang Liang 2, Wang Jing21 State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, China 2 State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China Molybdenum (Mo) stable isotopes have been developed as a tracer to indicate the evolution of the atmospheric and oceanic oxygenation related with continent weathering, and to reveal the extent of ancient oceanic euxinia. Molybdenum isotopic variation within the weathering system of basalts has been studied, and was presented the whole trend with heavier isotopes preferentially removed during weathering processes. However, there are few researches to study the variation of Mo isotopes during black shale weathering, especiall on the behavoir of Mo isotopes within the perfect shales' profiles. Here, the weathering profiles of Mo and selenium(Se)-rich carbonaceous rocks in Enshi southwest Hubei Province were selected. The Mo isotopes was measured on Nu Plasma II's MC-ICP-MS using 97Mo-100Mo double spike, and δ98/95Mo was reported relative to NIST 3134. A comprehensive set of Mo isotopic composition and concentration data from the unweathered, weakly and intensely weathered rocks were collected. The δ98/95Mo in fresh shales (220±248 mg/kg Mo, 1SD, n=41) from Shadi and Yutangba drill cores varies from 0.41‰ to 0.99‰ with an average of 0.67±0.16‰, while the strongly weathered shales (19.9±5.8 mg/kg Mo, 1SD, n=5) from Shadi profiles are isotopically heavier with average δ98/95Mo values of 1.03±0.10‰ (1SD, n=5). The Locally altered shales exposed in a quarry at Yutangba are highly enriched in Mo, varing from 31 to 2377 mg/kg with an average of 428 ±605mg/kg (1SD, n=24), approximately 2 times greater than that in fresh shales samples. These rocks are presented a significant variation in δ98/95Mo values varing from -0.24 ‰ to -3.99 ‰ with

  2. Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, Thomas; Pugmire, Ronald

    2015-01-01

    Three pristine Utah Green River oil shale samples were obtained and used for analysis by the combined research groups at the University of Utah and Brigham Young University. Oil shale samples were first demineralized and the separated kerogen and extracted bitumen samples were then studied by a host of techniques including high resolution liquid-state carbon-13 NMR, solid-state magic angle sample spinning 13C NMR, GC/MS, FTIR, and pyrolysis. Bitumen was extracted from the shale using methanol/dichloromethane and analyzed using high resolution 13C NMR liquid state spectroscopy, showing carbon aromaticities of 7 to 11%. The three parent shales and the demineralized kerogens were each analyzed with solid-state 13C NMR spectroscopy. Carbon aromaticity of the kerogen was 23-24%, with 10-12 aromatic carbons per cluster. Crushed samples of Green River oil shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000°C. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). The demineralized kerogen was pyrolyzed at 10 K/min in nitrogen at atmospheric pressure at temperatures up to 525°C, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, GC/MS, and FTIR. Details of the kerogen pyrolysis have been modeled by a modified version of the chemical percolation devolatilization (CPD) model that has been widely used to model coal combustion/pyrolysis. This refined CPD model has been successful in predicting the char, tar, and gas yields of the three shale samples during pyrolysis. This set of experiments and associated modeling represents the most sophisticated and complete analysis available for a given set of oil shale samples.

  3. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  4. Gas chromatograph study of bitumen from oil shale of Amman Formation (upper cretaceous), NW Jordan

    International Nuclear Information System (INIS)

    Darwish, H.; Mustafa, H.

    1997-01-01

    The extractable organic matter of seven outcrop samples of Amman Formation Oil Shale have been analysed by Gas Chromatography (GC). The bitumen is rich in heterocompounds contents (> 60 wt%). Gas chromatograms show a predominance of iosprenoids, specially phytane over n-alkanes, and low carbon preference index (CPI). This indicates that the organic matter is immature, and its origin is mainly of marine organisms. These rocks could be possible source rocks due to the high content of hydrocarbon. (authors). 22 refs., 4 figs. 3 tabs

  5. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  6. An Experimental Investigation of Hydraulic Fracturing in Shale Considering Anisotropy and Using Freshwater and Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Jianming He

    2018-03-01

    Full Text Available The process of hydraulic fracturing makes use of a liquid to fracture reservoir rocks for the exploitation of unconventional resources. Hence, it is vital to understand the processes that produce the fracture networks that occur during hydraulic fracturing. A shale reservoir is one of the largest unconventional resources and it displays obvious anisotropic characteristics due to its inherent sedimentary structures. The viscosity and flow ability of the fracturing fluid plays an important role in this process. We conducted a series of hydraulic fracturing tests on shale cores (from the southern Sichuan Basin using freshwater and supercritical CO2 (SCO2 as fracturing fluids to investigate the different modes of fracture propagation. The pump pressure curves that we obtained during the fracturing experiment show how the shale responded to each of the fracturing fluids. We examined the influence of the anisotropic characteristics on the propagation of hydraulic fractures by conducting a series of hydraulic fracturing experiments on the shale cores using different bedding orientations. The bedding orientation of the shale had a profound influence on the fracture propagation when using either freshwater or a SCO2 fluid. The breakdown pressure of the shale core was affected not only by the bedding orientation but also by the fracturing fluid. A macroscopic observation of the fractures revealed different fracture geometries and propagation patterns. The results demonstrated that the anisotropic structures and the fracturing fluids could influence the path of the hydraulic fracture.

  7. Revisions to the original extent of the Devonian Shale-Middle and Upper Paleozoic Total Petroleum System

    Science.gov (United States)

    Enomoto, Catherine B.; Rouse, William A.; Trippi, Michael H.; Higley, Debra K.

    2016-04-11

    Technically recoverable undiscovered hydrocarbon resources in continuous accumulations are present in Upper Devonian and Lower Mississippian strata in the Appalachian Basin Petroleum Province. The province includes parts of New York, Pennsylvania, Ohio, Maryland, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. The Upper Devonian and Lower Mississippian strata are part of the previously defined Devonian Shale-Middle and Upper Paleozoic Total Petroleum System (TPS) that extends from New York to Tennessee. This publication presents a revision to the extent of the Devonian Shale-Middle and Upper Paleozoic TPS. The most significant modification to the maximum extent of the Devonian Shale-Middle and Upper Paleozoic TPS is to the south and southwest, adding areas in Tennessee, Georgia, Alabama, and Mississippi where Devonian strata, including potential petroleum source rocks, are present in the subsurface up to the outcrop. The Middle to Upper Devonian Chattanooga Shale extends from southeastern Kentucky to Alabama and eastern Mississippi. Production from Devonian shale has been established in the Appalachian fold and thrust belt of northeastern Alabama. Exploratory drilling has encountered Middle to Upper Devonian strata containing organic-rich shale in west-central Alabama. The areas added to the TPS are located in the Valley and Ridge, Interior Low Plateaus, and Appalachian Plateaus physiographic provinces, including the portion of the Appalachian fold and thrust belt buried beneath Cretaceous and younger sediments that were deposited on the U.S. Gulf Coastal Plain.

  8. Determination of organic-matter content of Appalachian Devonian shales from gamma-ray logs

    International Nuclear Information System (INIS)

    Schmoker, J.W.

    1981-01-01

    The organic-matter content of the Devonian shale of the Appalachian basin is important for assessing the natural-gas resources of these rocks, and patterns of organic-matter distribution convey information on sedimentary processes and depositional environment. In most of the western part of the Appalachian basin the organic-matter content of the Devonian shale can be estimated from gamma-ray wire-line logs using the equation: phi 0 = (γ/sub B/ - γ)/1.378A, where phi 0 is the organic-matter content of the shale (fractional volume), γ the gamma-ray intensity (API units), γ/sub B/ the gamma-ray intensity if no organic matter is present (API units), and A the slope of the crossplot of gamma-ray intensity and formation density (API units/(g/cm 3 )). Organic-matter contents estimated using this equation are compared with organic-matter contents determined from direct laboratory analyses of organic carbon for 74 intervals of varying thickness from 12 widely separated wells. The organic-matter content of these intervals ranges from near zero to about 20% by volume. The gamma-ray intensity of the Cleveland Member of the Ohio Shale and the lower part of the Olentangy Shale is anomalously low compared to other Devonian shales of similar richness, so that organic-matter content computed for each of these units from gamma-ray logs is likely to be too low. Wire-line methods for estimating organic-matter content have the advantages of economy, readily available sources of data, and continuous sampling of the vertically heterogenous shale section. The gamma-ray log, in particular, is commonly run in the Devonian shale, its response characteristics are well known, and the cumulative pool of gamma-ray logs forms a large and geographically broad data base. The quantitative computation of organic-matter content from gamma-ray logs should be of practical value in studies of the Appalachian Devonian shale. 16 figures

  9. Performance Assessments of Generic Nuclear Waste Repositories in Shale

    Science.gov (United States)

    Stein, E. R.; Sevougian, S. D.; Mariner, P. E.; Hammond, G. E.; Frederick, J.

    2017-12-01

    Simulations of deep geologic disposal of nuclear waste in a generic shale formation showcase Geologic Disposal Safety Assessment (GDSA) Framework, a toolkit for repository performance assessment (PA) whose capabilities include domain discretization (Cubit), multiphysics simulations (PFLOTRAN), uncertainty and sensitivity analysis (Dakota), and visualization (Paraview). GDSA Framework is used to conduct PAs of two generic repositories in shale. The first considers the disposal of 22,000 metric tons heavy metal of commercial spent nuclear fuel. The second considers disposal of defense-related spent nuclear fuel and high level waste. Each PA accounts for the thermal load and radionuclide inventory of applicable waste types, components of the engineered barrier system, and components of the natural barrier system including the host rock shale and underlying and overlying stratigraphic units. Model domains are half-symmetry, gridded with Cubit, and contain between 7 and 22 million grid cells. Grid refinement captures the detail of individual waste packages, emplacement drifts, access drifts, and shafts. Simulations are run in a high performance computing environment on as many as 2048 processes. Equations describing coupled heat and fluid flow and reactive transport are solved with PFLOTRAN, an open-source, massively parallel multiphase flow and reactive transport code. Additional simulated processes include waste package degradation, waste form dissolution, radioactive decay and ingrowth, sorption, solubility, advection, dispersion, and diffusion. Simulations are run to 106 y, and radionuclide concentrations are observed within aquifers at a point approximately 5 km downgradient of the repository. Dakota is used to sample likely ranges of input parameters including waste form and waste package degradation rates and properties of engineered and natural materials to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia National

  10. Preparation of hydraulic cement from oil-shale

    Energy Technology Data Exchange (ETDEWEB)

    1921-08-28

    A process for the preparation of hydraulic cement from oil-shale or oil-shale residue is characterized in that, the oil-shale or shale-coke together with a slight amount of marl is burned under sintering conditions and the residue obtained is ground to a fine dust.

  11. Rock Physics

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2017-01-01

    Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

  12. Multiscale properties of unconventional reservoir rocks

    Science.gov (United States)

    Woodruff, W. F.

    A multidisciplinary study of unconventional reservoir rocks is presented, providing the theory, forward modeling and Bayesian inverse modeling approaches, and laboratory protocols to characterize clay-rich, low porosity and permeability shales and mudstones within an anisotropic framework. Several physical models characterizing oil and gas shales are developed across multiple length scales, ranging from microscale phenomena, e.g. the effect of the cation exchange capacity of reactive clay mineral surfaces on water adsorption isotherms, and the effects of infinitesimal porosity compaction on elastic and electrical properties, to meso-scale phenomena, e.g. the role of mineral foliations, tortuosity of conduction pathways and the effects of organic matter (kerogen and hydrocarbon fractions) on complex conductivity and their connections to intrinsic electrical anisotropy, as well as the macro-scale electrical and elastic properties including formulations for the complex conductivity tensor and undrained stiffness tensor within the context of effective stress and poroelasticity. Detailed laboratory protocols are described for sample preparation and measurement of these properties using spectral induced polarization (SIP) and ultrasonics for the anisotropic characterization of shales for both unjacketed samples under benchtop conditions and jacketed samples under differential loading. An ongoing study of the effects of kerogen maturation through hydrous pyrolysis on the complex conductivity is also provided in review. Experimental results are catalogued and presented for various unconventional formations in North America including the Haynesville, Bakken, and Woodford shales.

  13. A review of the organic geochemistry of shales

    International Nuclear Information System (INIS)

    Ho, P.C.; Meyer, R.E.

    1987-06-01

    Shale formations have been suggested as a potential site for a high level nuclear waste repository. As a first step in the study of the possible interaction of nuclides with the organic components of the shales, literature on the identification of organic compounds from various shales of the continent of the United States has been reviewed. The Green River shale of the Cenozoic era is the most studied shale followed by the Pierre shale of the Mesozoic era and the Devonian black shale of the Paleozoic era. Organic compounds that have been identified from these shales are hydrocarbons, fatty acids, fatty alcohols, steranes, terpanes, carotenes, carbohydrates, amino acids, and porphyrins. However, these organic compounds constitute only a small fraction of the organics in shales and the majority of the organic compounds in shales are still unidentified

  14. Fracking for shale gas production. A contribution to its assessment from the viewpoints of energy and environmental policy; Fracking zur Schiefergasgewinnung. Ein Beitrag zur energie- und umweltpolitischen Bewertung

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-05-15

    Shale gas is natural gas that is bound in unconventional reservoirs and can only be extracted by hydraulic fracturing, also referred to as fracking. This technology involves the high-pressure injection of water containing various additives into the gas-containing rock formation. This creates cracks in the rock, making it more permeable and allowing the gas to rise up to the surface. In its present opinion the German Advisory Council on the Environment sees the need for a differentiated view on the opportunities and risks of shale gas production by fracking. It advocates taking a bird's eye perspective that includes aspects of both energy and environmental policy.

  15. Technical considerations for Plowshare applications to oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Lombard, David B [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States); Bray, Bruce G [CER Geonuclear Corporation, Las Vegas, NV (United States); Sohns, Harold W [U. S. Bureau of Mines, Laramie, WY (United States)

    1970-05-15

    Nuclear explosions have been proposed for use in the recovery of oil from deep oil shale deposits. Before commercial feasibility can be established, a variety of technical problems must be examined. Some of these are related to nuclear explosion effects, others to the recovery of oil from the broken rock. Among the primary areas of interest are fracturing, chimney collapse, rubble size distribution, radioactivity, and retorting methods and variables. To test the concept, nuclear explosion experiments will be needed. One such experiment. Project Bronco, has been designed in detail, and is used here to illustrate a possible direction of development. The design is based on the following objectives: to evaluate the overall feasibility of nuclear breaking, followed by in situ retorting; to investigate the gross physical effects of a nuclear explosion in oil shale, and to assess the role of radioactivities in the production of oil by in situ retorting. The experimental plan provides for the accomplishment of these objectives by appropriate preshot studies, a postshot examination of explosion effects, and experimental retorting of the nuclear chimney. (author)

  16. Technical considerations for Plowshare applications to oil shale

    International Nuclear Information System (INIS)

    Lombard, David B.; Bray, Bruce G.; Sohns, Harold W.

    1970-01-01

    Nuclear explosions have been proposed for use in the recovery of oil from deep oil shale deposits. Before commercial feasibility can be established, a variety of technical problems must be examined. Some of these are related to nuclear explosion effects, others to the recovery of oil from the broken rock. Among the primary areas of interest are fracturing, chimney collapse, rubble size distribution, radioactivity, and retorting methods and variables. To test the concept, nuclear explosion experiments will be needed. One such experiment. Project Bronco, has been designed in detail, and is used here to illustrate a possible direction of development. The design is based on the following objectives: to evaluate the overall feasibility of nuclear breaking, followed by in situ retorting; to investigate the gross physical effects of a nuclear explosion in oil shale, and to assess the role of radioactivities in the production of oil by in situ retorting. The experimental plan provides for the accomplishment of these objectives by appropriate preshot studies, a postshot examination of explosion effects, and experimental retorting of the nuclear chimney. (author)

  17. Distribution and nature of fault architecture in a layered sandstone and shale sequence: An example from the Moab fault, Utah

    Science.gov (United States)

    Davatzes, N.C.; Aydin, A.

    2005-01-01

    We examined the distribution of fault rock and damage zone structures in sandstone and shale along the Moab fault, a basin-scale normal fault with nearly 1 km (0.62 mi) of throw, in southeast Utah. We find that fault rock and damage zone structures vary along strike and dip. Variations are related to changes in fault geometry, faulted slip, lithology, and the mechanism of faulting. In sandstone, we differentiated two structural assemblages: (1) deformation bands, zones of deformation bands, and polished slip surfaces and (2) joints, sheared joints, and breccia. These structural assemblages result from the deformation band-based mechanism and the joint-based mechanism, respectively. Along the Moab fault, where both types of structures are present, joint-based deformation is always younger. Where shale is juxtaposed against the fault, a third faulting mechanism, smearing of shale by ductile deformation and associated shale fault rocks, occurs. Based on the knowledge of these three mechanisms, we projected the distribution of their structural products in three dimensions along idealized fault surfaces and evaluated the potential effect on fluid and hydrocarbon flow. We contend that these mechanisms could be used to facilitate predictions of fault and damage zone structures and their permeability from limited data sets. Copyright ?? 2005 by The American Association of Petroleum Geologists.

  18. On the changing petroleum generation properties of Alum Shale over geological time caused by uranium irradiation

    Science.gov (United States)

    Yang, Shengyu; Schulz, Hans-Martin; Horsfield, Brian; Schovsbo, Niels H.; Noah, Mareike; Panova, Elena; Rothe, Heike; Hahne, Knut

    2018-05-01

    An interdisciplinary study was carried out to unravel organic-inorganic interactions caused by the radiogenic decay of uranium in the immature organic-rich Alum Shale (Middle Cambrian-Lower Ordovician). Based on pyrolysis experiments, uranium content is positively correlated with the gas-oil ratios and the aromaticities of both the free hydrocarbons residing in the rock and the pyrolysis products from its kerogen, indicating that irradiation has had a strong influence on organic matter composition overall and hence on petroleum potential. The Fourier Transform Ion Cyclotron Resonance mass spectrometry data reveal that macro-molecules in the uranium-rich Alum Shale samples are less alkylated than less irradiated counterparts, providing further evidence for structural alteration by α-particle bombardment. In addition, oxygen containing-compounds are enriched in the uranium-rich samples but are not easily degradable into low-molecular-weight products due to irradiation-induced crosslinking. Irradiation has induced changes in organic matter composition throughout the shale's entire ca. 500 Ma history, irrespective of thermal history. This factor has to be taken into account when reconstructing petroleum generation history. The Alum Shale's kerogen underwent catagenesis in the main petroleum kitchen area 420-340 Ma bp. Our calculations suggest the kerogen was much more aliphatic and oil-prone after deposition than that after extensive exposure to radiation. In addition, the gas sorption capacity of the organic matter in the Alum Shale can be assumed to have been less developed during Palaeozoic times, in contrast to results gained by sorption experiments performed at the present day, for the same reason. The kerogen reconstruction method developed here precludes overestimations of gas generation and gas retention in the Alum Shale by taking irradiation exposure into account and can thus significantly mitigate charge risk when applied in the explorations for both

  19. A Theoretical Investigation of Radial Lateral Wells with Shockwave Completion in Shale Gas Reservoirs

    Science.gov (United States)

    Shan, Jia

    As its role in satisfying the energy demand of the U.S. and as a clean fuel has become more significant than ever, the shale gas production in the U.S. has gained increasing momentum over recent years. Thus, effective and environmentally friendly methods to extract shale gas are critical. Hydraulic fracturing has been proven to be efficient in the production of shale gas. However, environmental issues such as underground water contamination and high usage of water make this technology controversial. A potential technology to eliminate the environmental issues concerning water usage and contamination is to use blast fracturing, which uses explosives to create fractures. It can be further aided by HEGF and multi-pulse pressure loading technology, which causes less crushing effect near the wellbore and induces longer fractures. Radial drilling is another relatively new technology that can bypass damage zones due to drilling and create a larger drainage area through drilling horizontal wellbores. Blast fracturing and radial drilling both have the advantage of cost saving. The successful combination of blast fracturing and radial drilling has a great potential for improving U.S. shale gas production. An analytical productivity model was built in this study, considering linear flow from the reservoir rock to the fracture face, to analyze factors affecting shale gas production from radial lateral wells with shockwave completion. Based on the model analyses, the number of fractures per lateral is concluded to be the most effective factor controlling the productivity index of blast-fractured radial lateral wells. This model can be used for feasibility studies of replacing hydraulic fracturing by blast fracturing in shale gas well completions. Prediction of fracture geometry is recommended for future studies.

  20. Preliminary organic geochemical investigation of the Kimmeridgian oil shales. [United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P F.V.; Douglas, A G

    1980-01-01

    The Kimmeridge oil shales have assumed renewed significance because of their role as the prime source-rock for North Sea oil, and because of the need to assess their potential as a possible future supply of shale oil. This paper presents the results of a preliminary investigation of selected Kimmeridge oil shales. The immature shales are rich in organic matter with a dominantly marine type II kerogen showing evidence of algal contributions and a general sparsity of land-derived, higher plant detritus. Column chromatographic and capillary column gas chromatographic examinations of bitumens, pyrolysates and pyrolysis gas chromatograms of kerogen isolates show a predominance of aromatics in the hydrocarbon fractions, with bitumen n-alkane gas chromatograms showing evidence of algal-derived organic matter with n-alkane maxima in the n-C/sub 17/ region. Possible contributions from lower land plants are indicated by a second n-alkane maximum at n-C/sub 23/, whilst higher land plant detritus makes only a limited contribution. Reflected light microscopic examination of the shales also shows a general sparsity of recognizable land-derived woody or herbaceous material. Shale oil compositions reflect their pyrolytic origin, with unsaturates forming a large part of the aliphatic hydrocarbon fraction, together with significant amounts of isoprenoid alkanes; organic sulphur compounds are also prominent in the hydrocarbon fractions. Finally, considerable amounts of sterane and pentacyclic triterpane hydrocarbons have been found in the bitumen aliphatic hydrocarbon fractions, their distributions allowing Blackstone samples to be differentiated from those of lower stratigraphic levels.

  1. Investigating the expected long-term production performance of shale reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Vassilellis, G.D.; Li, C.; Seager, R.J.H. [Gaffney, Cline and Associates, Houston, TX (United States); Moos, D. [Geomechanics International, Houston, TX (United States)

    2010-07-01

    Although there is global interest in developing shale plays, the traditional volumetric and material balance approaches that are used for petroleum asset evaluation do not address the special attributes of such formations. The performance of a particular deposit is currently determined by analyzing historical records statistically in developed areas and applying the derived type curves in new areas by assuming performance similarity. The assumption of similarity is challenged by the wealth of parameters influencing performance, which tend to differ, introducing considerable uncertainties into predictions. Historical records support only the early production history, while late performance is extrapolated without many reference points to match. This paper presented an investigation of the applicability of traditional and non-traditional empirical, analytical and numerical methods that are used to predict shale well performance. The purpose of the study was to rationalize the link between natural/stimulated rock description with oil and gas recovery mechanisms in a manner that is practical at different scales of resolution and covers early and late times. The paper discussed the use of special features such as flow through fracture networks, gas desorption and geomechanical effects that are incorporated in numerical simulation in a way that relates to the measurable petrophysical and geophysical input. The paper described the shale engineering concept and provided a description of the model. The Eagle Ford shale was presented as a case study. It was concluded that a reservoir simulation model with pseudo-lateral connections could describe the flow behaviour of a typical shale well, and could match shale gas well performance even if limited information was available. 20 refs., 9 figs.

  2. Rocking pneumonia

    OpenAIRE

    Rijkers, Ger T.; Rodriguez Gomez, Maria

    2017-01-01

    Ever since Chuck Berry coined the term “rocking pneumonia” in his 1956 song “Roll over Beethoven”, pneumonia has been mentioned frequently in modern blues and rock songs. We analyzed the lyrics of these songs to examine how various elements of pneumonia have been represented in popular music, specifically the cause of pneumonia, the risk groups, comorbidity (such as the boogie woogie flu), the clinical symptoms, and treatment and outcome. Up to this day, songwriters suggest that pneumonia is ...

  3. Production of oil from Israeli oil shale

    International Nuclear Information System (INIS)

    Givoni, D.

    1993-01-01

    Oil shale can be utilized in two-ways: direct combustion to generate steam and power or retorting to produce oil or gas. PAMA has been developing both direct combustion and retorting processes. Its main effort is in the combustion. An oil shale fired steam boiler was erected in the Rotem industrial complex for demonstration purposes. PAMA has also been looking into two alternative retorting concepts - slow heating of coarse particles and fast heating of fine particles. The present paper provides operating data of oil shale processing in the following scheme: (a) retorting in moving bed, pilot and bench scale units, and (b) retorting in a fluidized bed, bench scale units. (author)

  4. The real hazards of shale gas

    International Nuclear Information System (INIS)

    Favari, Daniele; Picot, Andre; Durand, Marc

    2013-01-01

    This bibliographical sheet presents a book which addresses the issue of shale gas. A first part describes the origin of this gaseous hydrocarbon, the composition of shale gas and its extraction, the technique of hydraulic fracturing, and the environmental risks. A second part addresses the economic, ecologic and political issues. The authors outline that all signs are there to prove the alarming hazards of shale gas. One of the authors outlines the necessity of an energy transition, far from fossil and nuclear energy, in order to guarantee a high level of protection of human health and of the environment

  5. Method of recovering hydrocarbons from oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Walton, D.K.; Slusser, M.S.

    1970-11-24

    A method is described for recovering hydrocarbons from an oil-shale formation by in situ retorting. A well penetrating the formation is heated and gas is injected until a pressure buildup within the well is reached, due to a decrease in the conductivity of naturally occurring fissures within the formation. The well is then vented, in order to produce spalling of the walls. This results in the formation of an enlarged cavity containing rubberized oil shale. A hot gas then is passed through the rubberized oil shale in order to retort hydrocarbons and these hydrocarbons are recovered from the well. (11 claims)

  6. Rock mechanics related to Jurassic underburden at Valdemar oil field

    DEFF Research Database (Denmark)

    Foged, Niels

    1999-01-01

    .It has been initiated as a feasibility study of the North Jens-1 core 12 taken in the top Jurassic clay shale as a test specimens for integrated petrological, mineralogical and rock mechanical studies. Following topics are studied:(1) Pore pressure generation due to conversion of organic matter...... and deformation properties of the clay shale using the actual core material or outcrop equivalents.(3) Flushing mechanisms for oil and gas from source rocks due to possibly very high pore water pressure creating unstable conditions in deeply burried sedimentsThere seems to be a need for integrating the knowledge...... in a number of geosciences to the benefit of common understanding of important reservoir mechanisms. Rock mechanics and geotechnical modelling might be key points for this understanding of reservoir geology and these may constitute a platform for future research in the maturing and migration from the Jurassic...

  7. Impact of Oxidative Dissolution on Black Shale Fracturing: Implication for Shale Fracturing Treatment Design

    Science.gov (United States)

    You, L.; Chen, Q.; Kang, Y.; Cheng, Q.; Sheng, J.

    2017-12-01

    Black shales contain a large amount of environment-sensitive compositions, e.g., clay minerals, carbonate, siderite, pyrite, and organic matter. There have been numerous studies on the black shales compositional and pore structure changes caused by oxic environments. However, most of the studies did not focus on their ability to facilitate shale fracturing. To test the redox-sensitive aspects of shale fracturing and its potentially favorable effects on hydraulic fracturing in shale gas reservoirs, the induced microfractures of Longmaxi black shales exposed to deionized water, hydrochloric acid, and hydrogen peroxide at room-temperature for 240 hours were imaged by scanning electron microscopy (SEM) and CT-scanning in this paper. Mineral composition, acoustic emission, swelling, and zeta potential of the untreated and oxidative treatment shale samples were also recorded to decipher the coupled physical and chemical effects of oxidizing environments on shale fracturing processes. Results show that pervasive microfractures (Fig.1) with apertures ranging from tens of nanometers to tens of microns formed in response to oxidative dissolution by hydrogen peroxide, whereas no new microfracture was observed after the exposure to deionized water and hydrochloric acid. The trajectory of these oxidation-induced microfractures was controlled by the distribution of phyllosilicate framework and flaky or stringy organic matter in shale. The experiments reported in this paper indicate that black shales present the least resistance to crack initiation and subcritical slow propagation in hydrogen peroxide, a process we refer to as oxidation-sensitive fracturing, which are closely related to the expansive stress of clay minerals, dissolution of redox-sensitive compositions, destruction of phyllosilicate framework, and the much lower zeta potential of hydrogen peroxide solution-shale system. It could mean that the injection of fracturing water with strong oxidizing aqueous solution may

  8. Refining shale-oil distillates

    Energy Technology Data Exchange (ETDEWEB)

    Altpeter, J

    1952-03-17

    A process is described for refining distillates from shale oil, brown coal, tar, and other tar products by extraction with selective solvents, such as lower alcohols, halogen-hydrins, dichlorodiethyl ether, liquid sulfur dioxide, and so forth, as well as treating with alkali solution, characterized in that the distillate is first treated with completely or almost completely recovered phenol or cresotate solution, the oil is separated from the phenolate with solvent, for example concentrated or adjusted to a determined water content of lower alcohol, furfural, halogen-hydrin, dichlorodiethyl ether, liquid sulfur dioxide, or the like, extracted, and the raffinate separated from the extract layer, if necessary after distillation or washing out of solvent, and freeing with alkali solution from residual phenol or creosol.

  9. Shale gas, a hazardous exploitation

    International Nuclear Information System (INIS)

    Maincent, G.

    2011-01-01

    In march 2010 three authorizations to search for shale gases were delivered in France in the regions of Montelimar, Nant and Villeneuve-de-Berg. A general public outcry has led the government to freeze the projects till a complete assessment of the impact on the environment is made. The fears of the public are based on the feedback experience in the Usa where some underground waters were polluted. The source of pollution is twofold: first the additives used in the injected fluids (methanol as an anti-microbic agent, hydrochloric acid to dissolve natural cements or glycol ethylene as a deposit inhibitor) and secondly metal particles of copper, zinc or lead trapped in the clay layers and released by the injection of the fluids. It appears also that the injection of high pressure fluids near a crack can induce earth tremors by reactivating the crack. (A.C.)

  10. The Resurgence of Shale Oil

    International Nuclear Information System (INIS)

    Cornot-Gandolphe, Sylvie

    2017-09-01

    This study addresses the resilience factors of the American production of light tight oil, in particular regarding the evolution of the financial model, and the regulatory changes with the authorisation of exports for crude oil. The paper also evaluates the development perspectives of the production on the medium and long term. US production of light tight oil (LTO, commonly known as 'shale oil') experienced a spectacular expansion between 2010 and 2014, becoming the largest source of growth in world oil production. At the start of 2015, however, the sustainability of its business model became questionable. Oil prices had collapsed and uncertainty about future US production was at its height. The sharp drop in the number of drill holes as of January 2015 raised fears of a rapid fall in US petroleum output. The LTO business model, based largely on the use of debt, reinforced this projection. Independent producers were heavily indebted, and were no longer able to invest in new wells. LTO production would therefore run out of steam. Two years later, LTO has passed its first test successfully. While output of shale gas has clearly fallen, cuts have been modest and much less than had been feared, given the falls in capital spending (CAPEX) and the number of drill holes. Productivity improvements as well as cost reductions have permitted a halving of the LTO equilibrium price. Independent producers have refocused their activities on the most productive basins and sites. The essential role played by the Permian Basin should be stressed at this point. In two years, it has become a new El dorado. Despite the fall in drill holes through to May 2016, production has continued to rise and now amounts to a quarter of American oil output. Furthermore, independents have drawn extra value from their well inventories, which include drilled, but also uncompleted wells. Lastly, the impressive number of drilled wells prior to price cuts has allowed producers to maintain their output

  11. Low-field nuclear magnetic resonance characterization of organic content in shales

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.; Seymour, Joseph D.; Kirkland, Catherine; Vogt, Sarah J.

    2013-01-01

    Low-field nuclear magnetic resonance (LF-NMR) relaxometry is a non-invasive technique commonly used to assess hydrogen-bearing fluids in petroleum reservoir rocks. Longitudinal T1 and transverse T2 relaxation time measurements made using LF-NMR on conventional reservoir systems provides information on rock porosity, pore size distributions, and fluid types and saturations in some cases. Recent improvements in LF-SNMR instrument electronics have made it possible to apply these methods to assess highly viscous and even solid organic phases within reservoir rocks. T1 and T2 relaxation responses behave very differently in solids and liquids, therefore the relationship between these two modes of relaxation can be used to differentiate organic phases in rock samples or to characterize extracted organic materials. Using T1-T2 correlation data, organic components present in shales, such as kerogen and bitumen, can be examined in laboratory relaxometry measurements. In addition, implementation of a solid-echo pulse sequence to refocus some types of T2 relaxation during correlation measurements allows for improved resolution of solid phase photons. LF-NMR measurements of T1 and T2 relaxation time correlations were carried out on raw oil shale samples from resources around the world. These shales vary widely in mineralogy, total organic carbon (TOC) content and kerogen type. NMR results were correlcated with Leco TOC and geochemical data obtained from Rock-Eval. There is excellent correlation between NMR data and programmed pyrolysis parameters, particularly TOC and S2, and predictive capability is also good. To better understand the NMR response, the 2D NMR spectra were compared to similar NMR measurements made using high-field (HF) NMR equipment.

  12. Strength and Anisotropy in Tournemire Shale: Temperature, Pressure and Time Dependences

    Science.gov (United States)

    Bonnelye, A.; Schubnel, A.; Zhi, G.; David, C.; Dick, P.

    2017-12-01

    Time and temperature dependent rock deformation has both scientific and socio-economic implications for natural hazards, the oil and gas industry and nuclear waste disposal. During the past decades, most studies on brittle creep have focused on igneous rocks and porous sedimentary rocks. To our knowledge, only few studies have been carried out on the brittle creep behavior of shale. We conducted a series of creep experiments on shale specimens coming from the French Institute for Nuclear Safety (IRSN) underground research laboratory located in Tournemire, France, under two different temperatures (26°C, 75°C) and confining pressures (10 MPa, 80 MPa), for three orientations (σ1along, perpendicular and 45° to bedding). In these long-term experiments (approximately 10 days), stress and strains were recorded continuously, while ultrasonic acoustic velocities were recorded every 1 15 minutes. The brittle creep failure stress of our Tournemire shale samples was systematically observed 50% higher than its short-term peak strength, with larger final axial strain accumulated. During creep, ultrasonic wave velocities first decreased, and then increased gradually. The magnitude of elastic wave velocity variations showed an important orientation and temperature dependence: velocities measured perpendicular to bedding showed increased variation, variation that was enhanced at higher temperature and higher pressure. The case of complete elastic anisotropy reversal was observed for sample deformed perpendicular to bedding, with amount of axial strain needed to reach anisotropy reversal reduced at higher temperature. SEM observations highlight the competition between crack growth, sealing/healing, and possibly mineral rotation, pressure solution or anisotropic compaction during creep defromation. Our study highlights that the short-term peak strength has little meaning in shale material, which can over-consolidate importantly by `plastic' flow. In addition, we show that elastic

  13. Hydrogeology of the carbonate rocks of the Lebanon Valley, Pennsylvania

    Science.gov (United States)

    Meisler, Harold

    1963-01-01

    The Lebanon Valley, which is part of the Great Valley in southeastern Pennsylvania, is underlain by carbonate rocks in the southern part and by shale in the northern part. The carbonate rocks consist of alternating beds of limestone and dolomite of Cambrian and Ordovician age. Although the beds generally dip to the south, progressively younger beds crop out to the north, because the rocks are overturned. The stratigraphic units, from oldest to youngest, are: the Buffalo Springs Formation, Snitz Creek, Schaefferstown, Millbach, and Richland Formations of the Conococheague Group; the Stonehenge, Rickenbach, Epler, and Ontelaunee Formations of the Beekmantown Group; and the Annville, Myerstown, and Hershey Limestones.

  14. EVALUATION OF SHALE GAS POTENTIAL IN KAZAKHSTAN

    Directory of Open Access Journals (Sweden)

    Lidiya Parkhomchik

    2015-01-01

    Full Text Available The article considers the primary evaluation of the shale gas resource potential in Kazakhstan, as well as defines the most problematic issues for the large-scale shale gas production over the state. The authors pay special attention to the national strategy of the Kazakhstani government in the sphere of the unconventional energy sources production, defining the possible technological and environmental problems for the shale gas extraction. The article also notes that implementation of the fracking technologies in the country could cause both positive and negative effects on the economy of Kazakhstan. Therefore, further steps in this direction should be based on the meaningful and comprehensive geological data regarding the shale gas potential.

  15. Process for desulfurizing shale oil, etc

    Energy Technology Data Exchange (ETDEWEB)

    Escherich, F

    1922-12-17

    A process is described for the desulfurizing of shale oil or tar, with recovery of valuable oils and hydrocarbons, characterized in that the raw material is heated in an autoclave to a pressure of 100 atmospheres or more.

  16. Texture and anisotropy analysis of Qusaiba shales

    KAUST Repository

    Kanitpanyacharoen, Waruntorn; Wenk, Hans-Rudolf; Kets, Frans; Lehr, Christian; Wirth, Richard

    2011-01-01

    Scanning and transmission electron microscopy, synchrotron X-ray diffraction, microtomography and ultrasonic velocity measurements were used to characterize microstructures and anisotropy of three deeply buried Qusaiba shales from the Rub

  17. Triterpene alcohol isolation from oil shale.

    Science.gov (United States)

    Albrecht, P; Ourisson, G

    1969-03-14

    Isoarborinol, an intact pentacyclic unsaturated alcohol, was isolated from the Messel oil shale (about 50 x 106 years old). Complex organic substances, even those very sensitive to oxidation, reduction, or acidic conditions, can thus survive without alteration for long periods.

  18. Legal Regime of Shale Gas Extraction

    OpenAIRE

    Ovidiu – Horia Maican

    2013-01-01

    Some countries with large reserves intend to promote shale gas production, in order to reduce their dependency on imported gas. Shale gas will be an important new aspect in the world energy scene, with many effects. European Union wants secure and affordable sources of energy. Natural gas is the cleanest fossil fuel and a vital component of European Union's energy strategy. One of the most important aspects is that gas produces significantly cleaner energy than other fossil fuels. From a lega...

  19. The influence of shale gas on steamcracking

    Energy Technology Data Exchange (ETDEWEB)

    Rupieper, A. [Linde Engineering Dresden GmbH, Dresden (Germany)

    2013-11-01

    US shale gas reserves with more than 860 TCF (Source: U.S. Energy Information Administration study World Shale Gas Resources) account for 2 of the global largest reserves after China. In 7 areas of the US, these reserves are systematically explored, providing a significant amount of cheap natural gas source for decades. The ethane share, carried by such shale gas, can reach up to 16%. Ethane has been already in the past 2 most important feedstock for Steamcrackers, being the backbone of the Petrochemical Industry. Due to availability of vast shale gas, the US steamcracker industry is facing a shift from naphtha to shale gas ethane, as the margin of Ethylene produced from shale gas ethane is significantly larger than that of naphtha based Ethylene (app. + 630 USD/t Ethylene). As a consequence shale gas is ''the magic bullet'' incinerating investments into Steamcrackers and downstream plants for U.S petrochemical industry. Steamcracker Projects with an additional ethylene production capacity of more than 17 million tons/a by 2020 are announced or already under construction. Investments into downstream plants refining the C2 derivatives will follow or are already in planning/engineering phase. But the US market cannot absorb all related products, causing a significant export exposure, which will influence global trade flows for C2 derivatives and affect prices. This article presents the impact of shale gas ethane cracking on: - Trade flow of C2 derivatives; - By-product deficits; - Alternate C3+ derivative production routes; - Challenges related to engineering requirements and project execution for Steamcracker projects. (orig.)

  20. Experimental Investigation of Crack Extension Patterns in Hydraulic Fracturing with Shale, Sandstone and Granite Cores

    Directory of Open Access Journals (Sweden)

    Jianming He

    2016-12-01

    Full Text Available Hydraulic fracturing is an important method of reservoir stimulation in the exploitation of geothermal resources, and conventional and unconventional oil and gas resources. In this article, hydraulic fracturing experiments with shale, sandstone cores (from southern Sichuan Basin, and granite cores (from Inner Mongolia were conducted to investigate the different hydraulic fracture extension patterns in these three reservoir rocks. The different reactions between reservoir lithology and pump pressure can be reflected by the pump pressure monitoring curves of hydraulic fracture experiments. An X-ray computer tomography (CT scanner was employed to obtain the spatial distribution of hydraulic fractures in fractured shale, sandstone, and granite cores. From the microscopic and macroscopic observation of hydraulic fractures, different extension patterns of the hydraulic fracture can be analyzed. In fractured sandstone, symmetrical hydraulic fracture morphology could be formed, while some micro cracks were also induced near the injection hole. Although the macroscopic cracks in fractured granite cores are barely observed by naked eye, the results of X-ray CT scanning obviously show the morphology of hydraulic fractures. It is indicated that the typical bedding planes well developed in shale formation play an important role in the propagation of hydraulic fractures in shale cores. The results also demonstrated that heterogeneity influenced the pathway of the hydraulic fracture in granite cores.

  1. Thermal maturity of northern Appalachian Basin Devonian shales: Insights from sterane and terpane biomarkers

    Science.gov (United States)

    Hackley, Paul C.; Ryder, Robert T.; Trippi, Michael H.; Alimi, Hossein

    2013-01-01

    To better estimate thermal maturity of Devonian shales in the northern Appalachian Basin, eleven samples of Marcellus and Huron Shale were characterized via multiple analytical techniques. Vitrinite reflectance, Rock–Eval pyrolysis, gas chromatography (GC) of whole rock extracts, and GC–mass spectrometry (GCMS) of extract saturate fractions were evaluated on three transects that lie across previously documented regional thermal maturity isolines. Results from vitrinite reflectance suggest that most samples are immature with respect to hydrocarbon generation. However, bulk geochemical data and sterane and terpane biomarker ratios from GCMS suggest that almost all samples are in the oil window. This observation is consistent with the presence of thermogenic gas in the study area and higher vitrinite reflectance values recorded from overlying Pennsylvanian coals. These results suggest that vitrinite reflectance is a poor predictor of thermal maturity in early mature areas of Devonian shale, perhaps because reported measurements often include determinations of solid bitumen reflectance. Vitrinite reflectance interpretations in areas of early mature Devonian shale should be supplanted by evaluation of thermal maturity information from biomarker ratios and bulk geochemical data.

  2. An insight into the mechanism and evolution of shale reservoir characteristics with over-high maturity

    Directory of Open Access Journals (Sweden)

    Xinjing Li

    2016-10-01

    Full Text Available Over-high maturity is one of the most vital characteristics of marine organic-rich shale reservoirs from the Lower Paleozoic in the south part of China. The organic matter (OM in shale gas reservoirs almost went through the entire thermal evolution. During this wide span, a great amount of hydrocarbon was available and numerous pores were observed within the OM including kerogen and solid bitumen/pyrobitumen. These nanopores in solid bitumen/pyrobitumen can be identified using SEM. The imaging can be dissected and understood better based on the sequence of diagenesis and hydrocarbon charge with the shape of OM and pores. In terms of the maturity process showed by the various typical cases, the main effects of the relationship between the reservoir porosity and organic carbon abundance are interpreted as follows: the change and mechanism of reservoirs properties due to thermal evolution are explored, such as gas carbon isotope from partial to complete rollover zone, wettability alteration from water-wet to oil-wet and then water-wet pore surface again, electrical resistivity reversal from the increasing to decreasing stage, and nonlinearity fluctuation of rock elasticity anisotropy. These indicate a possible evolution pathway for shale gas reservoirs from the Lower Paleozoic in the southern China, as well as the general transformation processes between different shale reservoirs in thermal stages.

  3. Crack deflection in brittle media with heterogeneous interfaces and its application in shale fracking

    Science.gov (United States)

    Zeng, Xiaguang; Wei, Yujie

    Driven by the rapid progress in exploiting unconventional energy resources such as shale gas, there is growing interest in hydraulic fracture of brittle yet heterogeneous shales. In particular, how hydraulic cracks interact with natural weak zones in sedimentary rocks to form permeable cracking networks is of significance in engineering practice. Such a process is typically influenced by crack deflection, material anisotropy, crack-surface friction, crustal stresses, and so on. In this work, we extend the He-Hutchinson theory (He and Hutchinson, 1989) to give the closed-form formulae of the strain energy release rate of a hydraulic crack with arbitrary angles with respect to the crustal stress. The critical conditions in which the hydraulic crack deflects into weak interfaces and exhibits a dependence on crack-surface friction and crustal stress anisotropy are given in explicit formulae. We reveal analytically that, with increasing pressure, hydraulic fracture in shales may sequentially undergo friction locking, mode II fracture, and mixed mode fracture. Mode II fracture dominates the hydraulic fracturing process and the impinging angle between the hydraulic crack and the weak interface is the determining factor that accounts for crack deflection; the lower friction coefficient between cracked planes and the greater crustal stress difference favor hydraulic fracturing. In addition to shale fracking, the analytical solution of crack deflection could be used in failure analysis of other brittle media.

  4. Hydrological evaluation of five sedimentary rocks for high-level waste disposal

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Kanehiro, B.Y.

    1986-01-01

    Utilizing performance criteria that are based upon siting guidelines issued by DOE for postclosure as well as preclosure conditions, a preliminary hydrologic evaluation and ranking is being conducted to determine the suitability of five sedimentary rocks as potential host rocks for a high-level radioactive waste repository. Based upon both quantitative and qualitative considerations, the hydrological ranking of the rocks in order of their potential as a host rock for the disposal of radioactive wastes would be shale, anhydrock, sandstone, chalk, and carbonates, with the first three rocks being significantly better than the remaining two types

  5. Oil shale mines and their realizable production

    International Nuclear Information System (INIS)

    Habicht, K.

    1994-01-01

    The production of Estonian oil shale depends on its marketing opportunities. The realizable production is a function of the oil shale price, which in turn depends on production costs. The latter are dependent on which mines are producing oil shale and on the volume of production. The purpose of the present article is to analyze which mines should operate under various realizable production scenarios and what should be their annual output so that the total cost of oil shale production (including maintenance at idle mines) is minimized. This paper is also targeted at observing the change in the average production cost per ton of oil shale depending on the realizable output. The calculations are based on data for the first four months of 1993, as collected by N. Barabaner (Estonian Academy of Sciences, Institute of Economy). The data include the total production volume and production cost from the mines of RE 'Eesti Polevkivi' (State Enterprise 'Estonian Oil Shale'). They also project expenses from mine closings in case of conservation. The latter costs were allocated among mines in direct proportion to their respective number of employees. (author)

  6. Senate hearings whet interest in oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Remirez, R

    1967-06-05

    Recent oil shale hearings by the U.S. Senate disclosed the proposed leasing rules for federal oil-shale lands. In addition, Oil Shale Corp. announced that the first commercial shale-oil processing plant would be on stream in 1970. Both these announcements are expected to create a stronger interest in what is possibly the greatest untapped natural wealth in the U.S. According to the leasing rules, development leases would involve the following phases: (1) the contractor would have a 10-yr limit to conduct a research and development program on the leased territory; and (2) upon completion of a successful research program, the Interior Department will make available to lease at least enough land to sustain commercial operation. The terms that applicants will have to meet are included in this report. At the Senate hearing, discussions ranged from opinions indicating that development of oil shale recovery was not immediately necessary to opinions urging rapid development. This report is concluded with a state-of-the-art review of some of the oil shale recovery processes.

  7. Environmental control costs for oil shale processes

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-10-01

    The studies reported herein are intended to provide more certainty regarding estimates of the costs of controlling environmental residuals from oil shale technologies being readied for commercial application. The need for this study was evident from earlier work conducted by the Office of Environment for the Department of Energy Oil Shale Commercialization Planning, Environmental Readiness Assessment in mid-1978. At that time there was little reliable information on the costs for controlling residuals and for safe handling of wastes from oil shale processes. The uncertainties in estimating costs of complying with yet-to-be-defined environmental standards and regulations for oil shale facilities are a critical element that will affect the decision on proceeding with shale oil production. Until the regulatory requirements are fully clarified and processes and controls are investigated and tested in units of larger size, it will not be possible to provide definitive answers to the cost question. Thus, the objective of this work was to establish ranges of possible control costs per barrel of shale oil produced, reflecting various regulatory, technical, and financing assumptions. Two separate reports make up the bulk of this document. One report, prepared by the Denver Research Institute, is a relatively rigorous engineering treatment of the subject, based on regulatory assumptions and technical judgements as to best available control technologies and practices. The other report examines the incremental cost effect of more conservative technical and financing alternatives. An overview section is included that synthesizes the products of the separate studies and addresses two variations to the assumptions.

  8. Radioactivities (dose rates) of rocks in Japan

    International Nuclear Information System (INIS)

    Matsuda, Hideharu; Minato, Susumu

    1995-01-01

    The radioactive distribution (radiation doses) of major rocks in Japan was monitored to clarify the factors influencing terrestrial gamma-ray absorbed dose rates. The rock samples were reduced to powder and analyzed by well-type NaI(Tl) scintillation detector and pulse height analyzer. Terrestrial gamma-ray dose rates were estimated in terms of gamma radiation dose rate 1 m above the ground. The radioactivity concentration was highest in acidic rock which contains much SiO 2 among igneous rock, followed by neutral rock, basic rock, and ultrabasic rock. The radioactive concentration was 30-40% lower in acidic and clastic rocks than those of the world average concentration. Higher radioactive concentration was observed in soils than the parent rocks of sedimentary rock and metamorphic rock. The gamma radiation dose rate was in proportion to the radioactive concentration of the rocks. To clarify the radioactive effect in the change course of rocks into soils, comparative measurement of outcrop and soil radioactive concentrations is important. (S.Y.)

  9. Controlled sample program publication No. 1: characterization of rock samples

    International Nuclear Information System (INIS)

    Ames, L.L.

    1978-10-01

    A description is presented of the methodology used and the geologic parameters measured on several rocks which are being used in round-robin laboratory and nuclide adsorption methodology experiments. Presently investigators from various laboratories are determining nuclide distribution coefficients utilizing numerous experimental techniques. Unfortunately, it appears that often the resultant data are dependent not only on the type of groundwater and rock utilized, but also on the experimentor or method used. The Controlled Sample Program is a WISAP (Waste Isolation Safety Assessment Program) attempt to resolve the apparent method and dependencies and to identify individual experimenter's bias. The rock samples characterized in an interlaboratory Kd methodology comparison program include Westerly granite, Argillaceous shale, Oolitic limestone, Sentinel Gap basalt, Conasauga shale, Climax Stock granite, anhydrite, Magenta dolomite and Culebra dolomite. Techniques used in the characterization include whole rock chemical analysis, X-ray diffraction, optical examination, electron microprobe elemental mapping, and chemical analysis of specific mineral phases. Surface areas were determined by the B.E.T. and ethylene glycol sorption methods. Cation exchange capacities were determined with 85 Sr, but were of questionable value for the high calcium rocks. A quantitative mineralogy was also estimated for each rock. Characteristics which have the potential of strongly affecting radionuclide Kd values such as the presence of sulfides, water-soluble, pH-buffering carbonates, glass, and ferrous iron were listed for each rock sample

  10. Elastic-Brittle-Plastic Behaviour of Shale Reservoirs and Its Implications on Fracture Permeability Variation: An Analytical Approach

    Science.gov (United States)

    Masoudian, Mohsen S.; Hashemi, Mir Amid; Tasalloti, Ali; Marshall, Alec M.

    2018-05-01

    Shale gas has recently gained significant attention as one of the most important unconventional gas resources. Shales are fine-grained rocks formed from the compaction of silt- and clay-sized particles and are characterised by their fissured texture and very low permeability. Gas exists in an adsorbed state on the surface of the organic content of the rock and is freely available within the primary and secondary porosity. Geomechanical studies have indicated that, depending on the clay content of the rock, shales can exhibit a brittle failure mechanism. Brittle failure leads to the reduced strength of the plastic zone around a wellbore, which can potentially result in wellbore instability problems. Desorption of gas during production can cause shrinkage of the organic content of the rock. This becomes more important when considering the use of shales for CO2 sequestration purposes, where CO2 adsorption-induced swelling can play an important role. These phenomena lead to changes in the stress state within the rock mass, which then influence the permeability of the reservoir. Thus, rigorous simulation of material failure within coupled hydro-mechanical analyses is needed to achieve a more systematic and accurate representation of the wellbore. Despite numerous modelling efforts related to permeability, an adequate representation of the geomechanical behaviour of shale and its impact on permeability and gas production has not been achieved. In order to achieve this aim, novel coupled poro-elastoplastic analytical solutions are developed in this paper which take into account the sorption-induced swelling and the brittle failure mechanism. These models employ linear elasticity and a Mohr-Coulomb failure criterion in a plane-strain condition with boundary conditions corresponding to both open-hole and cased-hole completions. The post-failure brittle behaviour of the rock is defined using residual strength parameters and a non-associated flow rule. Swelling and shrinkage

  11. Research on borehole stability of shale based on seepage-stress-damage coupling model

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ran

    2014-01-01

    Full Text Available In oil drilling, one of the most complicated problems is borehole stability of shale. Based on the theory of continuum damage mechanics, a modified Mohr-Coulomb failure criterion according to plastic damage evolution and the seepage-stress coupling is established. Meanwhile, the damage evolution equation which is based on equivalent plastic strain and the permeability evolution equation of shale are proposed in this paper. The physical model of borehole rock for a well in China western oilfield is set up to analyze the distribution of damage, permeability, stress, plastic strain and displacement. In the calculation process, the influence of rock damage to elastic modulus, cohesion and permeability is involved by writing a subroutine for ABAQUS. The results show that the rock damage evolution has a significant effect to the plastic strain and stress in plastic zone. Different drilling fluid density will produce different damage in its value, range and type. This study improves the theory of mechanical mechanism of borehole collapse and fracture, and provides a reference for the further research of seepage-stress-chemical-damage coupling of wall rock.

  12. Shale Fracture Analysis using the Combined Finite-Discrete Element Method

    Science.gov (United States)

    Carey, J. W.; Lei, Z.; Rougier, E.; Knight, E. E.; Viswanathan, H.

    2014-12-01

    Hydraulic fracturing (hydrofrac) is a successful method used to extract oil and gas from highly carbonate rocks like shale. However, challenges exist for industry experts estimate that for a single $10 million dollar lateral wellbore fracking operation, only 10% of the hydrocarbons contained in the rock are extracted. To better understand how to improve hydrofrac recovery efficiencies and to lower its costs, LANL recently funded the Laboratory Directed Research and Development (LDRD) project: "Discovery Science of Hydraulic Fracturing: Innovative Working Fluids and Their Interactions with Rocks, Fractures, and Hydrocarbons". Under the support of this project, the LDRD modeling team is working with the experimental team to understand fracture initiation and propagation in shale rocks. LANL's hybrid hydro-mechanical (HM) tool, the Hybrid Optimization Software Suite (HOSS), is being used to simulate the complex fracture and fragment processes under a variety of different boundary conditions. HOSS is based on the combined finite-discrete element method (FDEM) and has been proven to be a superior computational tool for multi-fracturing problems. In this work, the comparison of HOSS simulation results to triaxial core flooding experiments will be presented.

  13. Source rock hydrocarbons. Present status

    International Nuclear Information System (INIS)

    Vially, R.; Maisonnier, G.; Rouaud, T.

    2013-01-01

    This report first presents the characteristics of conventional oil and gas system, and the classification of liquid and gaseous non conventional hydrocarbons, with the peculiar case of coal-bed methane. The authors then describe how source rock hydrocarbons are produced: production of shale oils and gases (horizontal drilling, hydraulic fracturing, exploitation) and of coal-bed methane and coal mine methane. In the next part, they address and discuss the environmental impact of source rock hydrocarbon production: installation footprint, water resource management, drilling fluids, fracturing fluids composition, toxicity and recycling, air pollution, induced seismicity, pollutions from other exploitation and production activities. They propose an overview of the exploitation and production of source rock gas, coal-bed gas and other non conventional gases in the world. They describe the current development and discuss their economic impacts: world oil context and trends in the USA, in Canada and other countries, impacts on the North American market, on the world oil industry, on refining industries, on the world oil balance. They analyse the economic impacts of non conventional gases: development potential, stakes for the world gas trade, consequence for gas prices, development opportunities for oil companies and for the transport sector, impact on CO 2 emissions, macro-economic impact in the case of the USA

  14. Screening methodology for site selection of a nuclear waste repository in shale formations in Germany

    International Nuclear Information System (INIS)

    Hoth, P.; Krull, P.; Wirth, H.

    2004-01-01

    The radioactive waste disposal policy in the Federal Republic of Germany is based on the principle that all types of radioactive waste must be disposed of in deep geological formations. Because of the favourable properties of rock salt and the existence of thick rock salt formations in Germany, so far most of the research in the field of radioactive waste disposal sites was focused on the study of the use of rock salt. In addition, German research organisations have also conducted generic research and development projects in alternative geological formations (Wanner and Brauer, 2001), but a comprehensive evaluation of their utilisation has been only done for parts of the crystalline rocks in Germany. Research projects on argillaceous rocks started relatively late, so that German experience is mainly connected to German research work with the corresponding European Underground Research Laboratories and the exploration of the former Konrad iron mine as a potential repository site for radioactive waste with negligible heat generation. The German Federal Government has signed in 2001 an agreement with national utility companies to end electricity generation by nuclear power. This decision affected the entire German radioactive waste isolation strategy and especially the repository projects. The utility companies agreed upon standstill of exploration at the Gorleben site and the Federal Ministry for the Environment tries to establish a new comprehensive procedure for the selection of a repository site, built upon well-founded criteria incorporating public participation. Step 3 of the planning includes the examination of further sites in Germany and the comparison with existing sites and concepts. Under these circumstances, argillaceous rock (clay and shale) formations are now a special area of interest in Germany and the development of a screening methodology was required for the evaluation of shales as host and barrier rocks for nuclear waste repositories. (author)

  15. Carbon Isotope Analyses of Individual Hydrocarbon Molecules in Bituminous Coal, Oil Shale and Murchison Meteorite

    Directory of Open Access Journals (Sweden)

    Kyoungsook Kim

    1998-06-01

    Full Text Available To study the origin of organic matter in meteorite, terrestrial rocks which contain organic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Murchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molecular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of δ(13C, -20.1%_0 - -54.4%_0 compared to bituminous coal, -25.2%_0 - -34.3%_0. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of δ(13C from -13%_0 to +30%_0. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

  16. Dissolution of cemented fractures in gas bearing shales in the context of CO2 sequestration

    Science.gov (United States)

    Kwiatkowski, Kamil; Szymczak, Piotr

    2016-04-01

    Carbon dioxide has a stronger binding than methane to the organic matter contained in the matrix of shale rocks [1]. Thus, the injection of CO2 into shale formation may enhance the production rate and total amount of produced methane, and simultaneously permanently store pumped CO2. Carbon dioxide can be injected during the initial fracking stage as CO2 based hydraulic fracturing, and/or later, as a part of enhanced gas recovery (EGR) [2]. Economic and environmental benefits makes CO2 sequestration in shales potentially very for industrial-scale operation [3]. However, the effective process requires large area of fracture-matrix interface, where CO2 and CH4 can be exchanged. Usually natural fractures, existing in shale formation, are preferentially reactivated during hydraulic fracturing, thus they considerably contribute to the flow paths in the resulting fracture system [4]. Unfortunately, very often these natural fractures are sealed by calcite [5]. Consequently the layer of calcite coating surfaces impedes exchange of gases, both CO2 and CH4, between shale matrix and fracture. In this communication we address the question whether carbonic acid, formed when CO2 is mixed with brine, is able to effectively dissolve a calcite layer present in the natural fractures. We investigate numerically fluid flow and dissolution of calcite coating in natural shale fractures, with CO2-brine mixture as a reactive fluid. Moreover, we discuss the differences between slow dissolution (driven by carbonic acid) and fast dissolution (driven by stronger hydrochloric acid) of calcite layer. We compare an impact of the flow rate and geometry of the fracture on the parameters of practical importance: available surface area, morphology of dissolution front, time scale of the dissolution, and the penetration length. We investigate whether the dissolution is sufficiently non-uniform to retain the fracture permeability, even in the absence of the proppant. The sizes of analysed fractures

  17. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  18. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO2 enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 7, 1997--February 6, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Morea, M.F.

    1998-06-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO{sub 2} enhanced oil recovery project in the antelope Shale in Buena Vista Hills Field. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization during Phase 1 of the project will be performed using data collected in the pilot pattern wells. During this period the following tasks have been completed: laboratory wettability; specific permeability; mercury porosimetry; acoustic anisotropy; rock mechanics analysis; core description; fracture analysis; digital image analysis; mineralogical analysis; hydraulic flow unit analysis; petrographic and confocal thin section analysis; oil geochemical fingerprinting; production logging; carbon/oxygen logging; complex lithologic log analysis; NMR T2 processing; dipole shear wave anisotropy logging; shear wave vertical seismic profile processing; structural mapping; and regional tectonic synthesis. Noteworthy technological successes for this reporting period include: (1) first (ever) high resolution, crosswell reflection images of SJV sediments; (2) first successful application of the TomoSeis acquisition system in siliceous shales; (3) first detailed reservoir characterization of SJV siliceous shales; (4) first mineral based saturation algorithm for SJV siliceous shales, and (5) first CO{sub 2} coreflood experiments for siliceous shale. Preliminary results from the CO{sub 2} coreflood experiments (2,500 psi) suggest that significant oil is being produced from the siliceous shale.

  19. Igneous Rocks

    Science.gov (United States)

    Doe, Bruce R.

    “Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

  20. Gasification of oil shale by solar energy

    International Nuclear Information System (INIS)

    Ingel, Gil

    1992-04-01

    Gasification of oil shales followed by catalytic reforming can yield synthetic gas, which is easily transportable and may be used as a heat source or for producing liquid fuels. The aim of the present work was to study the gasification of oil shales by solar radiation, as a mean of combining these two energy resources. Such a combination results in maximizing the extractable fuel from the shale, as well as enabling us to store solar energy in a chemical bond. In this research special attention was focused upon the question of the possible enhancement of the gasification by direct solar irradiation of the solid carbonaceous feed stock. The oil shale served here as a model feedstock foe other resources such as coal, heavy fuels or biomass all of which can be gasified in the same manner. The experiments were performed at the Weizman institute's solar central receiver, using solar concentrated flux as an energy source for the gasification. The original contributions of this work are : 1) Experimental evidence is presented that concentrated sunlight can be used effectively to carry out highly endothermic chemical reactions in solid particles, which in turn forms an essential element in the open-loop solar chemical heat pipe; 2) The solar-driven gasification of oil shales can be executed with good conversion efficiencies, as well as high synthesis gas yields; 3)There was found substantial increase in deliverable energy compared to the conventional retorting of oil shales, and considerable reduction in the resulting spent shale. 5) A detailed computer model that incorporates all the principal optical and thermal components of the solar concentrator and the chemical reactor has been developed and compared favorably against experimental data. (author)

  1. PRINCIPLE ROCK TYPES FOR RADIOACTIVE WASTE REPOSITORIES

    Directory of Open Access Journals (Sweden)

    Sibila Borojević Šostarić

    2012-07-01

    Full Text Available Underground geological storage of high- and intermediate/low radioactive waste is aimed to represent a barrier between the surface environment and potentially hazardous radioactive elements. Permeability, behavior against external stresses, chemical reacatibility and absorption are the key geological parameters for the geological storage of radioactive waste. Three principal rock types were discussed and applied to the Dinarides: (1 evaporites in general, (2 shale, and (3 crystalline basement rocks. (1 Within the Dinarides, evaporite formations are located within the central part of a Carbonate platform and are inappropriate for storage. Offshore evaporites are located within diapiric structures of the central and southern part of the Adriatic Sea and are covered by thick Mesozoic to Cenozoic clastic sediment. Under very specific circumstances they can be considered as potential site locations for further investigation for the storage of low/intermediate level radioactive wast e. (2 Thick flysch type formation of shale to phyllite rocks are exposed at the basement units of the Petrova and Trgovska gora regions whereas (3 crystalline magmatic to metamorphic basement is exposed at the Moslavačka Gora and Slavonian Mts. regions. For high-level radioactive waste, basement phyllites and granites may represent the only realistic potential option in the NW Dinarides.

  2. Multi-physics and multi-scale characterization of shale anisotropy

    Science.gov (United States)

    Sarout, J.; Nadri, D.; Delle Piane, C.; Esteban, L.; Dewhurst, D.; Clennell, M. B.

    2012-12-01

    Shales are the most abundant sedimentary rock type in the Earth's shallow crust. In the past decade or so, they have attracted increased attention from the petroleum industry as reservoirs, as well as more traditionally for their sealing capacity for hydrocarbon/CO2 traps or underground waste repositories. The effectiveness of both fundamental and applied shale research is currently limited by (i) the extreme variability of physical, mechanical and chemical properties observed for these rocks, and by (ii) the scarce data currently available. The variability in observed properties is poorly understood due to many factors that are often irrelevant for other sedimentary rocks. The relationships between these properties and the petrophysical measurements performed at the field and laboratory scales are not straightforward, translating to a scale dependency typical of shale behaviour. In addition, the complex and often anisotropic micro-/meso-structures of shales give rise to a directional dependency of some of the measured physical properties that are tensorial by nature such as permeability or elastic stiffness. Currently, fundamental understanding of the parameters controlling the directional and scale dependency of shale properties is far from complete. Selected results of a multi-physics laboratory investigation of the directional and scale dependency of some critical shale properties are reported. In particular, anisotropic features of shale micro-/meso-structures are related to the directional-dependency of elastic and fluid transport properties: - Micro-/meso-structure (μm to cm scale) characterization by electron microscopy and X-ray tomography; - Estimation of elastic anisotropy parameters on a single specimen using elastic wave propagation (cm scale); - Estimation of the permeability tensor using the steady-state method on orthogonal specimens (cm scale); - Estimation of the low-frequency diffusivity tensor using NMR method on orthogonal specimens (example

  3. Thermal maturity and petroleum kitchen areas of Liassic Black Shales (Lower Jurassic) in the central Upper Rhine Graben, Germany

    Science.gov (United States)

    Böcker, Johannes; Littke, Ralf

    2016-03-01

    In the central Upper Rhine Graben (URG), several major oil fields have been sourced by Liassic Black Shales. In particular, the Posidonia Shale (Lias ɛ, Lower Toarcian) acts as excellent and most prominent source rock in the central URG. This study is the first comprehensive synthesis of Liassic maturity data in the URG area and SW Germany. The thermal maturity of the Liassic Black Shales has been analysed by vitrinite reflectance (VRr) measurements, which have been verified with T max and spore coloration index (SCI) data. In outcrops and shallow wells (oil window (ca. 0.50-0.60 % VRr). This maturity is found in Liassic outcrops and shallow wells in the entire URG area and surrounding Swabian Jura Mountains. Maximum temperatures of the Posidonia Shale before graben formation are in the order of 80-90 °C. These values were likely reached during Late Cretaceous times due to significant Upper Jurassic and minor Cretaceous deposition and influenced by higher heat flows of the beginning rift event at about 70 Ma. In this regard, the consistent regional maturity data (VRr, T max, SCI) of 0.5-0.6 % VRr for the Posidonia Shale close to surface suggest a major burial-controlled maturation before graben formation. These consistent maturity data for Liassic outcrops and shallow wells imply no significant oil generation and expulsion from the Posidonia Shale before formation of the URG. A detailed VRr map has been created using VRr values of 31 wells and outcrops with a structure map of the Posidonia Shale as reference map for a depth-dependent gridding operation. Highest maturity levels occur in the area of the Rastatt Trough (ca. 1.5 % VRr) and along the graben axis with partly very high VRr gradients (e.g. well Scheibenhardt 2). In these deep graben areas, the maximum temperatures which were reached during upper Oligocene to Miocene times greatly exceed those during the Cretaceous.

  4. Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Water Leak-Off Process during Hydraulic Fracturing in Shale Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2017-11-01

    Full Text Available The water leak-off during hydraulic fracturing in shale gas reservoirs is a complicated transport behavior involving thermal (T, hydrodynamic (H, mechanical (M and chemical (C processes. Although many leak-off models have been published, none of the models fully coupled the transient fluid flow modeling with heat transfer, chemical-potential equilibrium and natural-fracture dilation phenomena. In this paper, a coupled thermo-hydro-mechanical-chemical (THMC model based on non-equilibrium thermodynamics, hydrodynamics, thermo-poroelastic rock mechanics, and non-isothermal chemical-potential equations is presented to simulate the water leak-off process in shale gas reservoirs. The THMC model takes into account a triple-porosity medium, which includes hydraulic fractures, natural fractures and shale matrix. The leak-off simulation with the THMC model involves all the important processes in this triple-porosity medium, including: (1 water transport driven by hydraulic, capillary, chemical and thermal osmotic convections; (2 gas transport induced by both hydraulic pressure driven convection and adsorption; (3 heat transport driven by thermal convection and conduction; and (4 natural-fracture dilation considered as a thermo-poroelastic rock deformation. The fluid and heat transport, coupled with rock deformation, are described by a set of partial differential equations resulting from the conservation of mass, momentum, and energy. The semi-implicit finite-difference algorithm is proposed to solve these equations. The evolution of pressure, temperature, saturation and salinity profiles of hydraulic fractures, natural fractures and matrix is calculated, revealing the multi-field coupled water leak-off process in shale gas reservoirs. The influences of hydraulic pressure, natural-fracture dilation, chemical osmosis and thermal osmosis on water leak-off are investigated. Results from this study are expected to provide a better understanding of the

  5. Integrated acoustic, mineralogy, and geomechanics characterization of the Huron shale southern West Virginia, USA

    Energy Technology Data Exchange (ETDEWEB)

    Franquet, J.A.; Mitra, Arijit; Warrington, D.S.; Moos, Daniel; Lacazette, Alfred [Society of Petroleum Engineers (Canada)

    2011-07-01

    Successful hydraulic fracturing and horizontal drilling are the key to exploiting unconventional shale gas reservoirs. Acoustic anisotropy, in-situ stress, mineralogy and organic matter content are important factors in well completion design. This paper explores an integrated acoustic, mineralogy and geomechanics characterization of the Huron shale, located in south west Virginia, USA. The study consisted of acquiring the borehole acoustic and mineralogy logging data, in addition to conventional logs, from a vertical well prior to hydraulic fracturing and microseismic monitoring. The acoustic data were processed for borehole Stoneley reflective indicators and radial velocity variations. Substantial transverse acoustic anisotropy was noticed and used to acquire vertical and horizontal dynamic elastic properties. A micromechanical constitutive model, arrived at through mineralogy and petrophysical analysis, was used to produce the stress-strain behavior of the rock. This stress profile, with accurate mineralogy and petrophysical analysis, provides important information for best selection of lateral wells and helps in the identification of natural fracture barriers.

  6. Experimental and Model Studies on Loading Path-Dependent and Nonlinear Gas Flow Behavior in Shale Fractures

    Science.gov (United States)

    Li, Honglian; Lu, Yiyu; Zhou, Lei; Tang, Jiren; Han, Shuaibin; Ao, Xiang

    2018-01-01

    Interest in shale gas as an energy source is growing worldwide. Because the rock's natural fracture system can contribute to gas production, it is important to understand the flow behavior of natural fractures in shale. Previous studies on the flow characteristics in shale fractures were limited and did not consider the effect of nonlinearity. To understand the basic mechanics of the gas flow behavior in shale fractures, laboratory investigations with consideration of the fluid pressure gradient, the confining stress, the loading history and the fracture geometry were conducted in this paper. Izbash's equation was used to analyze the nonlinearity of the flow. The results show that the behavior of the friction factors is similar to that shown in flow tests in smooth and rough pipes. The increase of the confining stress and the irreversible damage to the shale decreased the hydraulic aperture and increased the relative roughness. Thus, turbulent flow could appear at a low Reynolds number, resulting in a significant pressure loss. The limits of the cubic law and the existing correction factor for transmissivity are discussed. It is found that the previous friction models overestimate the friction factor in the laminar regime and underestimate the friction factor in the turbulent regime. For this reason, a new friction model based on a linear combination of the Reynolds number and the relative roughness was developed.

  7. Shale gas characterization of the Dinder and Blue Nile Formations in the Blue Nile Basin, East Sudan

    Science.gov (United States)

    Shoieb, Monera Adam; Sum, Chow Weng; Bhattachary, Swapan Kumar; Abidin, Nor Syazwani Zainal; Abdelrahim, Omer Babiker

    2016-11-01

    The development of gas and oil in unconventional plays in United State and Northern Europe has affected the finances and the energy security. Geochanical properties of shale rocks can have a major impact on the efficiency of shale gas exploration. The goal of this study is to evaluate shale gas potentiality in the Blue Nile Basin, using samples from existing drilled wells. All the samples were analyzed in detail with the following organic geochemical techniques: total organic carbon (TOC), Rock-eval pyrolysis, to determine the quality and quantity of the organic matter. The total organic carbon (TOC) values for the shale intervals vary from 0.6 to 4.5weight% in FARASHA-1 Well, while in TAWAKUL-1 Well range from 0.4 to 2.4weight%, suggesting that fair to good source generative potential, as revealed by the S2 v's TOC plot. Hydrogen index (HI) values range from 12 to 182 mg HC/g TOC in the two wells, indicating type III and IV derived-input in the samples and their potential to generate gas. However, the Blue Nile and Dinder Formation have Tmax values in the range of 437 to 456°C, indicating early maturity in the oil window. Thus, higher maturity levels have affected the hydrocarbon generation potential and HI of the samples.

  8. The Oxidative Metabolism of Fossil Hydrocarbons and Sulfide Minerals by the Lithobiontic Microbial Community Inhabiting Deep Subterrestrial Kupferschiefer Black Shale

    Directory of Open Access Journals (Sweden)

    Agnieszka Włodarczyk

    2018-05-01

    Full Text Available Black shales are one of the largest reservoirs of fossil organic carbon and inorganic reduced sulfur on Earth. It is assumed that microorganisms play an important role in the transformations of these sedimentary rocks and contribute to the return of organic carbon and inorganic sulfur to the global geochemical cycles. An outcrop of deep subterrestrial ~256-million-year-old Kupferschiefer black shale was studied to define the metabolic processes of the deep biosphere important in transformations of organic carbon and inorganic reduced sulfur compounds. This outcrop was created during mining activity 12 years ago and since then it has been exposed to the activity of oxygen and microorganisms. The microbial processes were described based on metagenome and metaproteome studies as well as on the geochemistry of the rock. The microorganisms inhabiting the subterrestrial black shale were dominated by bacterial genera such as Pseudomonas, Limnobacter, Yonghaparkia, Thiobacillus, Bradyrhizobium, and Sulfuricaulis. This study on black shale was the first to detect archaea and fungi, represented by Nitrososphaera and Aspergillus genera, respectively. The enzymatic oxidation of fossil aliphatic and aromatic hydrocarbons was mediated mostly by chemoorganotrophic bacteria, but also by archaea and fungi. The dissimilative enzymatic oxidation of primary reduced sulfur compounds was performed by chemolithotrophic bacteria. The geochemical consequences of microbial activity were the oxidation and dehydrogenation of kerogen, as well as oxidation of sulfide minerals.

  9. Relationship between Mineral and Organic Matter in Shales: The Case of Shahejie Formation, Dongying Sag, China

    Directory of Open Access Journals (Sweden)

    Xiang Zeng

    2018-05-01

    Full Text Available Types of organic matter and mineral associations and microstructures of shales can reflect the depositional mechanism and sedimentary environment. Therefore, analysis of organic matter and mineral associations is a prerequisite for research on fine-grained sedimentary rocks. Shales from the Eocene Shahejie Formation in the Dongying Sag of China were selected to classify their lithofacies and to investigate the characteristics of their organic matter and mineral associations. This analysis identified six lithofacies (e.g., laminated shales and massive mudstones; in all the lithofacies, clay minerals exhibit a positive correlation with detrital minerals, thus indicating that they were derived from the same source. The comprehensive analysis of mineral and organic matter associations reveals that detrital minerals were deposited with low-hydrogen index (HI OM. The deposition of detrital minerals was mainly a physical process. Clay minerals can undergo deposition in one of two ways due to their surface charge: they can either aggregate with high-HI OM via chemical deposition, thus forming organic-rich laminae, or they can be deposited together with low-HI OM via physical deposition, thus forming clay-rich laminae or a massive matrix. Carbonate minerals, which often coexist with high-HI OM, are biological sediments. The analysis of the sedimentary characteristics of these organic matter and mineral associations indicates that the sedimentary processes differ between various lithofacies: e.g., the discontinuous laminated shale represents the product of biophysical processes. Differences in depositional mechanisms are also present in each sub-member. Therefore, it is important to analyze the properties of minerals and organic matter, as well as their associations, to more deeply understand the classification of lithofacies and the depositional processes of shales and mudstones.

  10. Breakdown pressures and characteristic flaw sizes during fluid injection experiments in shale at elevated confining pressures.

    Science.gov (United States)

    Chandler, M.; Mecklenburgh, J.; Rutter, E. H.; Taylor, R.; Fauchille, A. L.; Ma, L.; Lee, P. D.

    2017-12-01

    Fracture propagation trajectories in gas-bearing shales depend on the interaction between the anisotropic mechanical properties of the shale and the anisotropic in-situ stress field. However, there is a general paucity of available experimental data on their anisotropic mechanical, physical and fluid-flow properties, especially at elevated confining pressures. A suite of mechanical, flow and elastic measurements have been made on two shale materials, the Whitby mudrock and the Mancos shale (an interbedded silt and mudstone), as well as Pennant sandstone, an isotropic baseline and tight-gas sandstone analogue. Mechanical characterization includes standard triaxial experiments, pressure-dependent permeability, brazilian disk tensile strength, and fracture toughness determined using double-torsion experiments. Elastic characterisation was performed through ultrasonic velocities determined using a cross-correlation method. Additionally, we report the results of laboratory-scale fluid injection experiments for the same materials. Injection experiments involved the pressurisation of a blind-ending central hole in a dry cylindrical sample. Pressurisation is conducted under constant volume-rate control, using silicon oils of varying viscosities. Breakdown pressure is not seen to exhibit a strong dependence on rock type or orientation, and increases linearly with confining pressure. In most experiments, a small drop in the injection pressure record is observed at what is taken to be fracture initiation, and in the Pennant sandstone this is accompanied by a small burst of acoustic energy. The shale materials were acoustically quiet. Breakdown is found to be rapid and uncontrollable after initiation if injection is continued. A simplified 2-dimensional model for explaining this is presented in terms of the stress intensities at the tip of a pressurised crack, and is used alongside the triaxial data to derive a characteristic flaw size from which the fractures have initiated

  11. Investigation of water-soluble organic matter extracted from shales during leaching experiments

    Science.gov (United States)

    Zhu, Yaling; Vieth-Hillebrand, Andrea; Wilke, Franziska D. H.; Horsfield, Brian

    2017-04-01

    The huge volumes and unknown composition of flowback and produced waters cause major public concerns about the environmental and social compatibility of hydraulic fracturing and the exploitation of gas from unconventional reservoirs. Flowback and produced waters contain not only residues of fracking additives but also chemical species that are dissolved from the shales themselves during fluid-rock interaction. Knowledge of the composition, size and structure of dissolved organic carbon (DOC) as well as the main controls on the release of DOC are a prerequisite for a better understanding of these interactions and its effects on composition of flowback and produced water. Black shales from four different geological settings and covering a maturity range Ro = 0.3-2.6% were extracted with deionized water. The DOC yields were found to decrease rapidly with increasing diagenesis and remain low throughout catagenesis. Four DOC fractions have been qualitatively and quantitatively characterized using size-exclusion chromatography. The concentrations of individual low molecular weight organic acids (LMWOA) decrease with increasing maturity of the samples except for acetate extracted from the overmature Posidonia shale, which was influenced by hydrothermal brines. The oxygen content of the shale organic matter also shows a significant influence on the release of organic acids, which is indicated by the positive trend between oxygen index (OI) and the concentrations of formate and acetate. Based on our experiments, both the properties of the organic matter source and the thermal maturation progress of the shale organic matter significantly influence the amount and quality of extracted organic compounds during the leaching experiments.

  12. A multi-radioisotope approach to dating sedimentation : applying Re-Os organic-rich shale and U-Pb authigenic xenotime dating to the Shannon and Pennine Basins

    OpenAIRE

    Stanislawska, Maja Anna

    2013-01-01

    Sedimentary rocks are the most abundant hthologies on the Earth, covering over 70% of the planet’s surface. Quantitative dating of sedimentary rocks (especially those devoid of fossils) is critical to understanding the past events and rates and duration of processes that shaped the Earth. Recent advances in geochronology of sedimentary rocks, such as Re-Os dating of organic-rich shales and U-Pb dating of authigenic xenotime, allow precise depositional and early diagenetic ages to be obtained,...

  13. Isotope reversals in hydrocarbon gases of natural shale systems and well head production data

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U.; Schloemer, S.; Stiller, E. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Marquardt, D. [Rijksuniversiteit Utrecht (Netherlands)

    2013-08-01

    Relationships between gas geochemical signatures and the thermal maturity of source rocks containing aquatic organic matter are based on on pyrolysis experiments and have been successfully used in conventional hydrocarbon exploration since long. We demonstrate how these models can be applied to the evaluation of unconventional shale resources. For this purpose hydrocarbon gases have been extracted from low and high mature source rocks (type II kerogens) using laboratory desorption techniques. We determined the molecular composition of the gases as well as the carbon isotope ratios of methane to propane. In the extracted gases we observe an increase of {sup 13}C content in methane with increasing dry gas ratio (C1/{Sigma}C1-6). The carbon isotope ratios of ethane and propane initially increase with increasing dryness but start to become isotopically lighter above a dry gas ratio of 0.8. We show that oil-to-gas cracking explains the observed gas geochemical data, and that mixing between gases from different processes is a key factor to describe natural hydrocarbon systems of shales. However, data from published case studies using well head gases which show 'isotope roll-over' effects indicate that the isotopic reversal observed in well head samples deviate from those observed in natural shale systems in a fundamental way. We show that isotope reversals related to well head gases are best explained by an additional isotope fractionation effect induced through hydraulic fracturing and gas migration from the shale to the well head. Although, this induced isotope fractionation is an artifact which obscures isotopic information of natural systems to a large extend, we suggest a simple classification scheme which allows distinguishing between hot and cool spot areas using well head or mud line gas data. (orig.)

  14. Characterisation of organic carbon in black shales of the Kachchh ...

    Indian Academy of Sciences (India)

    46

    2Petroleum Geochemistry and Microbiology Group, National Geophysical Research Institute, .... gypsiferous shale of the Naredi Formation of early Eocene age (Biswas 1992). The shale .... This inference also helps us to explain the existence.

  15. White Rock

    Science.gov (United States)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  16. Integration of rock physical signatures with depositional environments: A case study from East Coast of India

    Science.gov (United States)

    Mondal, Samit; Yadav, Ashok; Chatterjee, Rima

    2018-01-01

    Rock physical crossplots from different geological setup along eastern continental margin of India (ECMI) represent diversified signatures. To characterize the reservoirs in rock physics domain (velocity/modulus versus porosity) and then connecting the interpretation with geological model has been the objectives of the present study. Petrophysical logs (total porosity and volume of shale) from five wells located at sedimentary basins of ECMI have been analyzed to quantify the types of shale such as: laminated, dispersed and structural in reservoir. Presence of various shale types belonging to different depositional environments is coupled to define distinct rock physical crossplot trends for different geological setup. Wells from three different basins in East Coast of India have been used to capture diversity in depositional environments. Contact model theory has been applied to the crossplot to examine the change in rock velocity with change in reservoir properties like porosity and volume of shale. The depositional and diagenetic trends have been shown in the crossplot to showcase the prime controlling factor which reduces the reservoir porosity. Apart from that, the effect of geological factors like effective stress, sorting, packing, grain size uniformity on reservoir properties have also been focused. The rock physical signatures for distinct depositional environments, effect of crucial geological factors on crossplot trends coupled with established sedimentological models in drilled area are investigated to reduce the uncertainties in reservoir characterization for undrilled potentials.

  17. Extraction of hydrocarbons from high-maturity Marcellus Shale using supercritical carbon dioxide

    Science.gov (United States)

    Jarboe, Palma B.; Philip A. Candela,; Wenlu Zhu,; Alan J. Kaufman,

    2015-01-01

    Shale is now commonly exploited as a hydrocarbon resource. Due to the high degree of geochemical and petrophysical heterogeneity both between shale reservoirs and within a single reservoir, there is a growing need to find more efficient methods of extracting petroleum compounds (crude oil, natural gas, bitumen) from potential source rocks. In this study, supercritical carbon dioxide (CO2) was used to extract n-aliphatic hydrocarbons from ground samples of Marcellus shale. Samples were collected from vertically drilled wells in central and western Pennsylvania, USA, with total organic carbon (TOC) content ranging from 1.5 to 6.2 wt %. Extraction temperature and pressure conditions (80 °C and 21.7 MPa, respectively) were chosen to represent approximate in situ reservoir conditions at sample depth (1920−2280 m). Hydrocarbon yield was evaluated as a function of sample matrix particle size (sieve size) over the following size ranges: 1000−500 μm, 250−125 μm, and 63−25 μm. Several methods of shale characterization including Rock-Eval II pyrolysis, organic petrography, Brunauer−Emmett−Teller surface area, and X-ray diffraction analyses were also performed to better understand potential controls on extraction yields. Despite high sample thermal maturity, results show that supercritical CO2 can liberate diesel-range (n-C11 through n-C21) n-aliphatic hydrocarbons. The total quantity of extracted, resolvable n-aliphatic hydrocarbons ranges from approximately 0.3 to 12 mg of hydrocarbon per gram of TOC. Sieve size does have an effect on extraction yield, with highest recovery from the 250−125 μm size fraction. However, the significance of this effect is limited, likely due to the low size ranges of the extracted shale particles. Additional trends in hydrocarbon yield are observed among all samples, regardless of sieve size: 1) yield increases as a function of specific surface area (r2 = 0.78); and 2) both yield and surface area increase with increasing

  18. Shale disposal of U.S. high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Sassani, David Carl; Stone, Charles Michael; Hansen, Francis D.; Hardin, Ernest L.; Dewers, Thomas A.; Martinez, Mario J.; Rechard, Robert Paul; Sobolik, Steven Ronald; Freeze, Geoffrey A.; Cygan, Randall Timothy; Gaither, Katherine N.; Holland, John Francis; Brady, Patrick Vane

    2010-05-01

    a few meters of the repository, that can be reasonably characterized. Within a few centuries after waste emplacement, overburden pressures will seal fractures, resaturate the dehydrated zones, and provide a repository setting that strongly limits radionuclide movement to diffusive transport. Coupled hydrogeochemical transport calculations indicate maximum extents of radionuclide transport on the order of tens to hundreds of meters, or less, in a million years. Under the conditions modeled, a shale repository could achieve total containment, with no releases to the environment in undisturbed scenarios. The performance analyses described here are based on the assumption that long-term standards for disposal in clay/shale would be identical in the key aspects, to those prescribed for existing repository programs such as Yucca Mountain. This generic repository evaluation for shale is the first developed in the United States. Previous repository considerations have emphasized salt formations and volcanic rock formations. Much of the experience gained from U.S. repository development, such as seal system design, coupled process simulation, and application of performance assessment methodology, is applied here to scoping analyses for a shale repository. A contemporary understanding of clay mineralogy and attendant chemical environments has allowed identification of the appropriate features, events, and processes to be incorporated into the analysis. Advanced multi-physics modeling provides key support for understanding the effects from coupled processes. The results of the assessment show that shale formations provide a technically advanced, scientifically sound disposal option for the U.S.

  19. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F.; Weck, Philippe F.; Sassani, David Carl; Zheng, Liange; Rutqvist, Jonny; Steefel, Carl I.; Kim, Kuhhwi; Nakagawa, Seiji; Houseworth, James; Birkholzer, Jens T.; Caporuscio, Florie Andre; Cheshire, Michael; Rearick, Michael; McCarney, Mary K.; Zavarin, Mavrik; Benedicto, Ana; Kersting, Annie B.; Sutton, Mark.; Jerden, James L.; Frey, Kurt E.; Copple, Jacqueline M.; Ebert, William L.

    2014-08-01

    Radioactive waste disposal in shale/argillite rock formations has been widely considered given its desirable isolation properties (low permeability), geochemically reduced conditions, anomalous groundwater pressures, and widespread geologic occurrence. Clay/shale rock formations are characterized by their high content of clay minerals such as smectites and illites where diffusive transport and chemisorption phenomena predominate. These, in addition to low permeability, are key attributes of shale to impede radionuclide mobility. Shale host-media has been comprehensively studied in international nuclear waste repository programs as part of underground research laboratories (URLs) programs in Switzerland, France, Belgium, and Japan. These investigations, in some cases a decade or more long, have produced a large but fundamental body of information spanning from site characterization data (geological, hydrogeological, geochemical, geomechanical) to controlled experiments on the engineered barrier system (EBS) (barrier clay and seals materials). Evaluation of nuclear waste disposal in shale formations in the USA was conducted in the late 70’s and mid 80’s. Most of these studies evaluated the potential for shale to host a nuclear waste repository but not at the programmatic level of URLs in international repository programs. This report covers various R&D work and capabilities relevant to disposal of heat-generating nuclear waste in shale/argillite media. Integration and cross-fertilization of these capabilities will be utilized in the development and implementation of the shale/argillite reference case planned for FY15. Disposal R&D activities under the UFDC in the past few years have produced state-of-the-art modeling capabilities for coupled Thermal-Hydrological-Mechanical-Chemical (THMC), used fuel degradation (source term), and thermodynamic modeling and database development to evaluate generic disposal concepts. The THMC models have been developed for shale

  20. Thermocatalytical processing of coal and shales

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available The article investigates the questions of thermocatalytical conversion of organic mass of coal (OMC, it is shown that in the absence of a catalyst process is carried out by a radical process. Accumulated data on the properties for radicals of different structure and therefore different reaction capacity enables us to understand and interpret the conversion of OMC. Thermal conversion of OMC regarded as a kind of depolymerization, accompanied by decomposition of the functional groups with the formation of radicals, competing for hydrogen atom. Catalyst can change the direction and conditions of the process. Modern catalysts can reduce the process pressure up to 50 atm., with a high degree of coal conversion. We consider examples of simultaneous conversion of coal and shale, shale and masut, shale and tar.

  1. Assessment of potential unconventional lacustrine shale-oil and shale-gas resources, Phitsanulok Basin, Thailand, 2014

    Science.gov (United States)

    Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Mercier, Tracey J.; Tennyson, Marilyn E.; Pitman, Janet K.; Brownfield, Michael E.

    2014-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey assessed potential technically recoverable mean resources of 53 million barrels of shale oil and 320 billion cubic feet of shale gas in the Phitsanulok Basin, onshore Thailand.

  2. Thermal effects in shales: measurements and modeling

    International Nuclear Information System (INIS)

    McKinstry, H.A.

    1977-01-01

    Research is reported concerning thermal and physical measurements and theoretical modeling relevant to the storage of radioactive wastes in a shale. Reference thermal conductivity measurements are made at atmospheric pressure in a commercial apparatus; and equipment for permeability measurements has been developed, and is being extended with respect to measurement ranges. Thermal properties of shales are being determined as a function of temperature and pressures. Apparatus was developed to measure shales in two different experimental configurations. In the first, a disk 15 mm in diameter of the material is measured by a steady state technique using a reference material to measure the heat flow within the system. The sample is sandwiched between two disks of a reference material (single crystal quartz is being used initially as reference material). The heat flow is determined twice in order to determine that steady state conditions prevail; the temperature drop over the two references is measured. When these indicate an equal heat flow, the thermal conductivity of the sample can be calculated from the temperature difference of the two faces. The second technique is for determining effect of temperature in a water saturated shale on a larger scale. Cylindrical shale (or siltstone) specimens that are being studied (large for a laboratory sample) are to be heated electrically at the center, contained in a pressure vessel that will maintain a fixed water pressure around it. The temperature is monitored at many points within the shale sample. The sample dimensions are 25 cm diameter, 20 cm long. A micro computer system has been constructed to monitor 16 thermocouples to record variation of temperature distribution with time

  3. Laboratory weathering of combusted oil shale

    International Nuclear Information System (INIS)

    Essington, M.E.

    1991-01-01

    The objective of this study was to examine the mineralogy and leachate chemistry of three combusted oil shales (two Green River Formation and one New Albany) in a laboratory weathering environment using the humidity cell technique. The mineralogy of the combusted western oil shales (Green River Formation) is process dependent. In general, processing resulted in the formation of anhydrite, lime, periclase, and hematite. During the initial stages of weathering, lime, periclase, and hematite. During the initial stages of weathering, lime, periclase, and anhydrite dissolve and ettringite precipitates. The initial leachates are highly alkaline, saline, and dominated by Na, hydroxide, and SO 4 . As weathering continues, ettringite precipitates. The initial leachates are highly alkaline, saline, and dominated by Na, hydroxide, and SO 4 . As weathering continues, ettringite dissolves, gypsum and calcite precipitate, and the leachates are dominated by Mg, SO 4 , and CO 3 . Leachate pH is rapidly reduced to between 8.5 and 9 with leaching. The combusted eastern oil shale (New Albany) is composed of quartz, illite, hematite, and orthoclase. Weathering results in the precipitation of gypsum. The combusted eastern oil shale did not display a potential to produce acid drainage. Leachate chemistry was dominated by Ca and SO 4 . Element concentrations continually decreased with weathering. IN a western disposal environment receiving minimal atmospheric precipitation, spent oil shale will remain in the initial stages of weathering, and highly alkaline and saline conditions will dominate leachate chemistry. In an eastern disposal environment, soluble salts will be rapidly removed from the spent oil shale to potentially affect the surrounding environment

  4. Preparing hydraulic cement from oil-shale slag

    Energy Technology Data Exchange (ETDEWEB)

    1921-11-19

    A process for the preparation of hydraulic cementing material from oil shale or oil-shale slag according to Patent 411,584 is characterized by the fact that the oil-shale slag is added to burnt marl, blast-furnace slag, and the like, whereupon the mixture is milled to dust in the known way.

  5. Rapid gas development in the Fayetteville shale basin, Arkansas

    Science.gov (United States)

    Advances in drilling and extraction of natural gas have resulted in rapid expansion of wells in shale basins. The rate of gas well installation in the Fayetteville shale is 774 wells a year since 2005 with thousands more planned. The Fayetteville shale covers 23,000 km2 although ...

  6. Reducing the greenhouse gas footprint of shale gas

    International Nuclear Information System (INIS)

    Wang Jinsheng; Ryan, David; Anthony, Edward J.

    2011-01-01

    Shale gas is viewed by many as a global energy game-changer. However, serious concerns exist that shale gas generates more greenhouse gas emissions than does coal. In this work the related published data are reviewed and a reassessment is made. It is shown that the greenhouse gas effect of shale gas is less than that of coal over long term if the higher power generation efficiency of shale gas is taken into account. In short term, the greenhouse gas effect of shale gas can be lowered to the level of that of coal if methane emissions are kept low using existing technologies. Further reducing the greenhouse gas effect of shale gas by storing CO 2 in depleted shale gas reservoirs is also discussed, with the conclusion that more CO 2 than the equivalent CO 2 emitted by the extracted shale gas could be stored in the reservoirs at significantly reduced cost. - Highlights: ► The long-term greenhouse gas footprint of shale gas is smaller than that of coal. ► Carbon capture and storage should be considered for fossil fuels including shale gas. ► Depleted shale gas fields could store more CO 2 than the equivalent emissions. ► Linking shale gas development with CO 2 storage could largely reduce the total cost.

  7. Extraction of hydrocarbon products from shales and coals

    Energy Technology Data Exchange (ETDEWEB)

    Reed, V Z

    1918-05-17

    A process is disclosed of extracting hydrocarbon oil matter from petroleum-bearing shales and coals which comprises subjecting a mass of such shale or coal, before distillation to the solvent action of material containing an acid, permitting the solvent material to pass through the mass of shale or coal, and recovering the combined solvent and extracted matter.

  8. Method of concentrating oil shale by flotation

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M

    1941-01-28

    A method is described of concentrating oil shale by flotation. It is characterized by grinding the shale to a grain size which, roughly speaking, is less than 0.06 mm. and more conveniently should be less than 0.05 mm., and followed by flotation. During the process the brown foam formed is separated as concentrate, while the black-brown to all-black foam is separated as a middle product, ground fine again, and thereafter floated once more. The patent contains five additional claims.

  9. Analysis of the kerogen of oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Quass, F W; Down, A L

    1939-01-01

    Comments are given on the method developed by F. W. Quass for reducing the amount of mineral matter present in certain coals and oil shales (torbanites). The method consisted of grinding oil shale with water in a porcelain ball mill in the presence of oil. The oil formed a paste with the carbonaceous material, and a greater portion of the mineral matter remained suspended in the water and was separated. Ultimate analyses of the enriched samples indicated that the percent of carbon was higher, the percent of hydrogen and oxygen was lower, and the ratio of carbon to hydrogen and carbon to oxygen increased in the enriched samples.

  10. Phosphate-rich sedimentary rocks: significance for organic facies and petroleum exploration

    Energy Technology Data Exchange (ETDEWEB)

    Waples, D W

    1982-03-01

    Phosphorus-bearing rocks and sediments can be divided into two genetically distinct classes: phosphatic shales or limestones and phosphorites. Phosphatic shales are primary sediments in which phosphate nodules or micronodules have formed diagenetically by precipitation of calcium phosphates derived mainly from organic phosphorus. The nodules form in reducing environments at shallow depths within the sediments, where loss of phosphate by diffusion to the overlying water column is minimized. Highly biogenic sediments containing large amounts of organic matter and some fine clastic debris provide ideal environments for the formation of phosphate nodules. Phosphorites, in contrast, represent concentrated accumulations of reworked phosphate nodules which originated in phosphatic shales or limestones. Currents, wave action, recrystallization, and erosion and resedimentation are important mechanisms in the concentration process. Phosphatic shales and limestones may become excellent oil source rocks if thermal maturity is achieved. They are useful facies indicators for anoxic or nearly anoxic depositional environments, and are often associated with restricted basins, or, during certain geologic periods, with broad shelves developed during transgressions. Phosphorites, in contrast, are often correlated with sea-level regressions or uplifts. They are modest source rocks because of their low organic carbon contents and the fact that they were reworked under oxidizing conditions. Nevertheless, because phosphorites are derived from, and often grade into, phosphatic shales, they also are of potential utility in the search for oil source beds.

  11. Mineralogy controls on reactive transport of Marcellus Shale waters.

    Science.gov (United States)

    Cai, Zhang; Wen, Hang; Komarneni, Sridhar; Li, Li

    2018-07-15

    Produced or flowback waters from Marcellus Shale gas extraction (MSWs) typically are highly saline and contain chemicals including trace metals, which pose significant concerns on water quality. The natural attenuation of MSW chemicals in groundwater is poorly understood due to the complex interactions between aquifer minerals and MSWs, limiting our capabilities to monitor and predict. Here we combine flow-through experiments and process-based reactive transport modeling to understand mechanisms and quantify the retention of MSW chemicals in a quartz (Qtz) column, a calcite-rich (Cal) column, and a clay-rich (Vrm, vermiculite) column. These columns were used to represent sand, carbonate, and clay-rich aquifers. Results show that the types and extent of water-rock interactions differ significantly across columns. Although it is generally known that clay-rich media retard chemicals and that quartz media minimize water-rock interactions, results here have revealed insights that differ from previous thoughts. We found that the reaction mechanisms are much more complex than merely sorption and mineral precipitation. In clay rich media, trace metals participate in both ion exchange and mineral precipitation. In fact, the majority of metals (~50-90%) is retained in the solid via mineral precipitation, which is surprising because we typically expect the dominance of sorption in clay-rich aquifers. In the Cal column, trace metals are retained not only through precipitation but also solid solution partitioning, leading to a total of 75-99% retention. Even in the Qtz column, trace metals are retained at unexpectedly high percentages (~20-70%) due to precipitation. The reactive transport model developed here quantitatively differentiates the relative importance of individual processes, and bridges a limited number of experiments to a wide range of natural conditions. This is particularly useful where relatively limited knowledge and data prevent the prediction of complex rock

  12. Fracture Patterns within the Shale Hills Critical Zone Observatory

    Science.gov (United States)

    Singha, K.; White, T.; Perron, J.; Chattopadhyay, P. B.; Duffy, C.

    2012-12-01

    Rock fractures are known to exist within the deep Critical Zone and are expected to influence groundwater flow, but there are limited data on their orientation and spatial arrangement and no general framework for systematically predicting their effects. Here, we explore fracture patterns within the Susquehanna-Shale Hills Critical Zone Observatory, and consider how they may be influenced by weathering, rock structure, and stress via field observations of variable fracture orientation within the site, with implications for the spatial variability of structural control on hydrologic processes. Based on field observations from 16-m deep boreholes and surface outcrop, we suggest that the appropriate structural model for the watershed is steeply dipping strata with meter- to decimeter-scale folds superimposed, including a superimposed fold at the mouth of the watershed that creates a short fold limb with gently dipping strata. These settings would produce an anisotropy in the hydraulic conductivity and perhaps also flow, especially within the context of the imposed stress field. Recently conducted 2-D numerical stress modeling indicates that the proxy for shear fracture declines more rapidly with depth beneath valleys than beneath ridgelines, which may produce or enhance the spatial variability in permeability. Even if topographic stresses do not cause new fractures, they could activate and cause displacement on old fractures, making the rocks easier to erode and increasing the permeability, and potentially driving a positive feedback that enhances the growth of valley relief. Calculated stress fields are consistent with field observations, which show a rapid decline in fracture abundance with increasing depth below the valley floor, and predict a more gradual trend beneath ridgetops, leading to a more consistent (and lower) hydraulic conductivity with depth on the ridgetops when compared to the valley, where values are higher but more variable with depth. Hydraulic

  13. Rock stresses (Grimsel rock laboratory)

    International Nuclear Information System (INIS)

    Pahl, A.; Heusermann, S.; Braeuer, V.; Gloeggler, W.

    1989-01-01

    On the research and development project 'Rock Stress Measurements' the BGR has developed and tested several test devices and methods at GTS for use in boreholes at a depth of 200 m and has carried out rock mechanical and engineering geological investigations for the evaluation and interpretation of the stress measurements. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on hollow cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure and vertical stresses which agree well with the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are generally lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (orig./HP) [de

  14. Computerized X-ray Microtomography Observations and Fluid Flow Measurements of the Effect of Effective Stress on Fractured Reservoir Seal Shale

    Science.gov (United States)

    Welch, N.; Crawshaw, J.; Boek, E.

    2014-12-01

    The successful storage of carbon dioxide in geologic formations requires an in-depth understanding of all reservoir characteristics and morphologies. An intact and substantial seal formation above a storage reservoir is required for a significant portion of the initial sealing mechanisms believed to occur during carbon dioxide storage operations. Shales are a common seal formation rock types found above numerous hydrocarbon reservoirs, as well as potential saline aquifer storage locations. Shales commonly have very low permeability, however they also have the tendency to be quite fissile, and the formation of fractures within these seals can have a significant detrimental effect on the sealing potential of a reservoir and amount to large areas of high permeability and low capillary pressures compared to the surrounding intact rock. Fractured shales also have an increased current interest due to the increasing development of shale gas reservoirs using hydraulic fracturing techniques. This work shows the observed changes that occur within fractured pieces of reservoir seal shale samples, along with quarry analogues, using an in-situ micro-CT fluid flow imaging apparatus with a Hassler type core holder. Changes within the preferential flow path under different stress regimes as well as physical changes to the fracture geometry are reported. Lattice Boltzmann flow simulations were then performed on the extracted flow paths and compared to experiment permeability measurements. The preferential flow path of carbon dioxide through the fracture network is also observed and compared to the results two-phase Lattice Boltzmann fluid flow simulations.

  15. A microfluidic investigation of gas exsolution in glass and shale fracture networks

    Science.gov (United States)

    Porter, M. L.; Jimenez-Martinez, J.; Harrison, A.; Currier, R.; Viswanathan, H. S.

    2016-12-01

    Microfluidic investigations of pore-scale fluid flow and transport phenomena has steadily increased in recent years. In these investigations fluid flow is restricted to two-dimensions allowing for real-time visualization and quantification of complex flow and reactive transport behavior, which is difficult to obtain in other experimental systems. In this work, we describe a unique high pressure (up to 10.3 MPa) and temperature (up to 80 °C) microfluidics experimental system that allows us to investigate fluid flow and transport in geo-material (e.g., shale, Portland cement, etc.) micromodels. The use of geo-material micromodels allows us to better represent fluid-rock interactions including wettability, chemical reactivity, and nano-scale porosity at conditions representative of natural subsurface environments. Here, we present experimental results in fracture systems with applications to hydrocarbon mobility in fractured rocks. Complex fracture network patterns are derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in the different materials. We discuss results from two-phase gas (CO2 and N2) injection experiments designed to enhance oil recovery. In these experiments gas was injected into micromodels saturated with oil and allowed to soak for approximately 12 hours at elevated pressures. The pressure in the system was then decreased to atmospheric, causing the gas to expand and/or dissolve out of solution, subsequently mobilizing the oil. In addition to the experimental results, we present a relatively simple model designed to quantify the amount of oil mobilized as a function of decreasing system pressure. We will show comparisons between the experiments and model, and discuss the potential use of the model in field-scale reservoir simulations.

  16. Thermal Inertia of Rocks and Rock Populations

    Science.gov (United States)

    Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

    2001-01-01

    The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

  17. Evaluating possible industrial applications of combustible shales and shale ash wastes

    Directory of Open Access Journals (Sweden)

    Н. К. Кондрашева

    2016-08-01

    Full Text Available Today energy consumption is constantly growing while explored reserves of easily accessible oil are depleting, which is a reason why most countries tend to diversify their energy mix, develop non-hydrocarbon energy sources and use domestic types of fuel, including the low grade ones. Thereby interest is raised to such a source of hydrocarbons as combustible shales. Combustible shales appear to be one of the highest-potential types of organic raw materials, which may offset and in future even substitute oil products and gas. The paper is investigating behavior and structure of combustible shales during heat treatment in order to identify their possible industrial applications. A synchronous thermal analysis has been held, chemical composition of combustible shales’ mineral fraction and optimal conditions for shale fines briquetting have been determined.

  18. Distillation of shale and other bituminous substances. [shale granules wetted, mixed with lime, heated; sulfur recovered

    Energy Technology Data Exchange (ETDEWEB)

    Noad, J

    1912-09-23

    A process is described for the treatment of shale and other bituminous substances containing sulfur and recovering desulfurized distillates. The process consists of first grinding the shale and mixing the granules obtained with a convenient liquid. The shale granules coated or covered with liquid and mixed with slacked lime are fed into a retort with a series of steps or their equivalent, made to descend, step by step, in such manner that they are continually agitated and heated. The volatile constituents escape through the coating or sheath of lime and are carried away at the upper part of the retort to a convenient condensing apparatus, the sulfur being retained by the sheath of lime and is discharged at the bottom of the retort with the spent shale and other impurities.

  19. Geochemistry of the Oruatemanu Formation, Arrow Rocks, Northland, New Zealand

    International Nuclear Information System (INIS)

    Hori, R.S.; Higuchi, Y.; Fujiki, T.; Maeda, T.; Ikehara, M.

    2007-01-01

    We investigated the geochemical characteristics of sedimentary rocks from the Upper Permian - Middle Triassic Oruatemanu Formation on Arrow Rocks, Waipapa Terrane, New Zealand. The sedimentary rocks consist of limestone, tuffaceous shale, vari-coloured bedded chert, hemipelagic shale and green siliceous mudstone (= green argillite), in ascending order, a typical oceanic plate sequence. Shale and green argillite have higher Zr/Nb ratios than do chert and tuffaceous shales, and show similar REE patterns to PAAS (Post-Archean average Australian shale). In contrast, chert sequences from the basal part and intercalated tuff layers have high TiO 2 contents and Zr/Nb ratios similar to those of basaltic rocks from Arrow Rocks. These geochemical characteristics suggest that the sedimentary environment of the Oruatemanu Formation changed upward, from an open sea setting to the continental margin of Gondwanaland. Chemical compositions of bedded cherts from Arrow Rocks indicate a mixing of biogenic silica, detritus from continents and basaltic materials. In the interval from Upper Permian to Lower Middle Triassic this mixing shows remarkable secular variations. We detected geochemical signals of two Oceanic Anoxic Events (OAEs), one at the Permian/Triassic (P/T) boundary, and the other at the middle Upper Induan level. We name them the OAEα (P/T OAE) and OAEβ (Upper Induan OAE). These OAE horizons are enriched in S, U and other heavy metals (e.g. Mo and Cr), and also have high V/(V+Ni) ratios. Based on a comparison between enrichment factors of Cr and other redox-sensitive trace elements (e.g. Zn, Pb, Co, Cu), the Upper Induan OAEβ is considered to be more intense than the P/T boundary OAEα. This result is not in agreement with the superanoxia model previously proposed. In addition, OAEβ corresponds well with the radiolarian faunal turnover from Permian to Triassic forms documented from the Oruatemanu Formation in this volume. These results may suggest that peak time and

  20. Regional geological assessment of the Devonian-Mississippian shale sequence of the Appalachian, Illinois, and Michigan basins relative to potential storage/disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lomenick, T.F.; Gonzales, S.; Johnson, K.S.; Byerly, D.

    1983-01-01

    The thick and regionally extensive sequence of shales and associated clastic sedimentary rocks of Late Devonian and Early Mississippian age has been considered among the nonsalt geologies for deep subsurface containment of high-level radioactive wastes. This report examines some of the regional and basin-specific characteristics of the black and associated nonblack shales of this sequence within the Appalachian, Illinois, and Michigan basins of the north-central and eastern United States. Principal areas where the thickness and depth of this shale sequence are sufficient to warrant further evaluation are identified, but no attempt is made to identify specific storage/disposal sites. Also identified are other areas with less promise for further study because of known potential conflicts such as geologic-hydrologic factors, competing subsurface priorities involving mineral resources and groundwater, or other parameters. Data have been compiled for each basin in an effort to indicate thickness, distribution, and depth relationships for the entire shale sequence as well as individual shale units in the sequence. Included as parts of this geologic assessment are isopach, depth information, structure contour, tectonic elements, and energy-resource maps covering the three basins. Summary evaluations are given for each basin as well as an overall general evaluation of the waste storage/disposal potential of the Devonian-Mississippian shale sequence,including recommendations for future studies to more fully characterize the shale sequence for that purpose. Based on data compiled in this cursory investigation, certain rock units have reasonable promise for radioactive waste storage/disposal and do warrant additional study.

  1. Regional geological assessment of the Devonian-Mississippian shale sequence of the Appalachian, Illinois, and Michigan basins relative to potential storage/disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Gonzales, S.; Johnson, K.S.; Byerly, D.

    1983-01-01

    The thick and regionally extensive sequence of shales and associated clastic sedimentary rocks of Late Devonian and Early Mississippian age has been considered among the nonsalt geologies for deep subsurface containment of high-level radioactive wastes. This report examines some of the regional and basin-specific characteristics of the black and associated nonblack shales of this sequence within the Appalachian, Illinois, and Michigan basins of the north-central and eastern United States. Principal areas where the thickness and depth of this shale sequence are sufficient to warrant further evaluation are identified, but no attempt is made to identify specific storage/disposal sites. Also identified are other areas with less promise for further study because of known potential conflicts such as geologic-hydrologic factors, competing subsurface priorities involving mineral resources and groundwater, or other parameters. Data have been compiled for each basin in an effort to indicate thickness, distribution, and depth relationships for the entire shale sequence as well as individual shale units in the sequence. Included as parts of this geologic assessment are isopach, depth information, structure contour, tectonic elements, and energy-resource maps covering the three basins. Summary evaluations are given for each basin as well as an overall general evaluation of the waste storage/disposal potential of the Devonian-Mississippian shale sequence,including recommendations for future studies to more fully characterize the shale sequence for that purpose. Based on data compiled in this cursory investigation, certain rock units have reasonable promise for radioactive waste storage/disposal and do warrant additional study

  2. Formation and destruction mechanism as well as major controlling factors of the Silurian shale gas overpressure in the Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Shuangjian Li

    2016-08-01

    Full Text Available Taking the Well JY1 and Well PY1 in the Eastern Sichuan Basin as examples, the formation mechanism of shale gas overpressure was studied by using the cross plot of acoustic versus density logging data. During the processes of hydrocarbon generation and the uplifting, the pressure evolution of fluids in shale gas layers was reconstructed by fluid inclusions and PVTSIM software. The major factors controlling the evolution of shale gas overpressure were established according to the study of fracture, the timing of the uplifting, and episodes of tectonic deformation. Our results showed that the main mechanism of overpressure in the Silurian shale gas reservoirs in the Sichuan Basin was the fluid expansion, which was caused by hydrocarbon generation. Since the Yanshanian, the strata were uplifted and fluid pressure generally showed a decreasing trend. However, due to the low compression rebound ratio of shale gas reservoir rocks, poor connectivity of reservoir rocks, and low content of formation water and so on, such factors made fluid pressure decrease, but these would not be enough to make up the effects of strata erosion resulting in a further increase in fluid pressure in shale gas reservoirs during the whole uplifting processes. Since the Yanshanian, the Well PY1 zone had been reconstructed by at least three episodes of tectonic movement. The initial timing of the uplifting is 130 Ma. Compared to the former, the Well JY1 zone was firstly uplifted at 90 Ma, which was weakly reconstructed. As a result, low-angle fractures and few high resistance fractures developed in the Well JY1, while high-angle fractures and many high resistance fractures developed in the Well PY1. In totality, the factors controlling the overpressure preservation in shale gas reservoirs during the late periods include timing of late uplifting, superposition and reconstruction of stress fields, and development of high-angle fractures.

  3. An Image-based Micro-continuum Pore-scale Model for Gas Transport in Organic-rich Shale

    Science.gov (United States)

    Guo, B.; Tchelepi, H.

    2017-12-01

    Gas production from unconventional source rocks, such as ultra-tight shales, has increased significantly over the past decade. However, due to the extremely small pores ( 1-100 nm) and the strong material heterogeneity, gas flow in shale is still not well understood and poses challenges for predictive field-scale simulations. In recent years, digital rock analysis has been applied to understand shale gas transport at the pore-scale. An issue with rock images (e.g. FIB-SEM, nano-/micro-CT images) is the so-called "cutoff length", i.e., pores and heterogeneities below the resolution cannot be resolved, which leads to two length scales (resolved features and unresolved sub-resolution features) that are challenging for flow simulations. Here we develop a micro-continuum model, modified from the classic Darcy-Brinkman-Stokes framework, that can naturally couple the resolved pores and the unresolved nano-porous regions. In the resolved pores, gas flow is modeled with Stokes equation. In the unresolved regions where the pore sizes are below the image resolution, we develop an apparent permeability model considering non-Darcy flow at the nanoscale including slip flow, Knudsen diffusion, adsorption/desorption, surface diffusion, and real gas effect. The end result is a micro-continuum pore-scale model that can simulate gas transport in 3D reconstructed shale images. The model has been implemented in the open-source simulation platform OpenFOAM. In this paper, we present case studies to demonstrate the applicability of the model, where we use 3D segmented FIB-SEM and nano-CT shale images that include four material constituents: organic matter, clay, granular mineral, and pore. In addition to the pore structure and the distribution of the material constituents, we populate the model with experimental measurements (e.g. size distribution of the sub-resolution pores from nitrogen adsorption) and parameters from the literature and identify the relative importance of different

  4. RUSSIA DOESN’T SUPPORT «SHALE REVOLUTION»

    Directory of Open Access Journals (Sweden)

    S. S. Zhiltsov

    2015-01-01

    Full Text Available Growth of volumes of production of shale gas in the USA compelled Russia to pay attention to this type of resourses. The interest to shale gas in Russia was limited to discussions at the level of experts and reflection of importance of this problem in statements of politicians. In the next years in Russia don't plan production of shale gas commercially. It is connected with existence in Russia of considerable reserves of traditional natural gas, absence of exact data of reserves of shale gas, high costs of production, and also environmental risks which accompany development of fields of shale gas.

  5. Multiple Approaches to Characterizing Pore Structure in Natural Rock

    Science.gov (United States)

    Hu, Q.; Dultz, S.; Hamamoto, S.; Ewing, R. P.

    2012-12-01

    Microscopic characteristics of porous media - pore shape, pore-size distribution, and pore connectivity - control fluid flow and chemical transport, and are important in hydrogeological studies of rock formations in the context of energy, environmental, and water resources management. This presentation discusses various approaches to investigating pore structure of rock, with a particular focus on the Barnett Shale in north Texas used for natural gas production. Approaches include imbibition, tracer diffusion, porosimetry (MIP, vapor adsorption/desorption isotherms, NMR cyroporometry), and imaging (μ-tomography, Wood's metal impregnation, FIB/SEM). Results show that the Barnett Shale pores are predominantly in the nm size range, with a measured median pore-throat diameter of 6.5 nm. But small pore size is not the major contributor to low gas recovery; rather, the low gas diffusivity appears to be caused by low pore connectivity. Chemical diffusion in sparsely-connected pore spaces is not well described by classical Fickian behavior; anomalous behavior is suggested by percolation theory, and confirmed by results of imbibition tests. Our evolving complementary approaches, with their several advantages and disadvantages, provide a rich toolbox for tackling the pore structure characteristics in the Barnett Shale and other natural rocks.

  6. New adsorbents from oil shales. Preparation, characterization and U, Th isotope adsorption tests

    International Nuclear Information System (INIS)

    Khouya, E.; Andres, Y.; Naslain, R.; Pailler, R.; Nourredine, A.

    2004-01-01

    New activated adsorbents for radionuclides have been produced from Moroccan oil shales by pyrolysis of the natural material at 550 deg C flowed by a KMnO 4 activation. The texture and composition of the native rock and the adsorbents were studied before their use in tests for adsorption of radionuclides from standard solutions prepared from uranylnitrate and thorium nitrate in equilibrium with their daughters. The distribution coefficients between solutions containing U, Th and Ra and the adsorbents were evaluated by means of specific activities, measured by γ-ray spectrometry. The adsorbents were observed to eliminate U, Th, Ra, Ac and Tl from aqueous solutions. (author)

  7. Electromagnetic De-Shaling of Coal

    NARCIS (Netherlands)

    De Jong, T.P.R.; Mesina, M.B.; Kuilman, W.

    2003-01-01

    The efficiency with which an electromagnetic sensor array is able to distinguish density and ash content of coal and shale mixtures was determined experimentally. The investigated sensor was originally designed for automatic metal detection and sorting in industrial glass recycle processing, where

  8. Method of treating oil-bearing shale

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, N H

    1926-04-14

    The process is given for treating shale or other oil-bearing mineral which consists of the application of dry heat to render the oil soluble and subjects the product of the heat treatment to an operation to extract the soluble oils.

  9. Epistemic values in the Burgess Shale debate

    DEFF Research Database (Denmark)

    Baron, Christian

    2009-01-01

    Focusing primarily on papers and books discussing the evolutionary and systematic interpretation of the Cambrian animal fossils from the Burgess Shale fauna, this paper explores the role of epistemic values in the context of a discipline (paleontology) striving to establish scientific authority w...

  10. Evaluation of waste disposal by shale fracturing

    International Nuclear Information System (INIS)

    Weeren, H.O.

    1976-02-01

    The shale fracturing process is evaluated as a means for permanent disposal of radioactive intermediate level liquid waste generated at the Oak Ridge National Laboratory. The estimated capital operating and development costs of a proposed disposal facility are compared with equivalent estimated costs for alternative methods of waste fixation

  11. Quantitative effects of the shale oil revolution

    International Nuclear Information System (INIS)

    Belu Mănescu, Cristiana; Nuño, Galo

    2015-01-01

    The aim of this paper is to analyze the impact of the so-called “shale oil revolution” on oil prices and economic growth. We employ a general equilibrium model of the world oil market in which Saudi Arabia is the dominant firm, with the rest of the producers as a competitive fringe. Our results suggest that most of the expected increase in US oil supply due to the shale oil revolution has already been incorporated into prices and that it will produce an additional increase of 0.2% in the GDP of oil importers in the period 2010–2018. We also employ the model to analyze the collapse in oil prices in the second half of 2014 and conclude that it was mainly due to positive unanticipated supply shocks. - Highlights: • We analyze the impact of the “shale oil revolution” on oil prices and economic growth. • We employ a general equilibrium model of the oil market in which Saudi Arabia is the dominant firm. • We find that most of the shale oil revolution is already priced in. • We also analyze the decline in oil prices in the second half of 2014. • We find that unanticipated supply shocks played the major role in the fall.

  12. Shale Gas Development and Drinking Water Quality.

    Science.gov (United States)

    Hill, Elaine; Ma, Lala

    2017-05-01

    The extent of environmental externalities associated with shale gas development (SGD) is important for welfare considerations and, to date, remains uncertain (Mason, Muehlenbachs, and Olmstead 2015; Hausman and Kellogg 2015). This paper takes a first step to address this gap in the literature. Our study examines whether shale gas development systematically impacts public drinking water quality in Pennsylvania, an area that has been an important part of the recent shale gas boom. We create a novel dataset from several unique sources of data that allows us to relate SGD to public drinking water quality through a gas well's proximity to community water system (CWS) groundwater source intake areas.1 We employ a difference-in-differences strategy that compares, for a given CWS, water quality after an increase in the number of drilled well pads to background levels of water quality in the geographic area as measured by the impact of more distant well pads. Our main estimate finds that drilling an additional well pad within 1 km of groundwater intake locations increases shale gas-related contaminants by 1.5–2.7 percent, on average. These results are striking considering that our data are based on water sampling measurements taken after municipal treatment, and suggest that the health impacts of SGD 1 A CWS is defined as the subset of public water systems that supplies water to the same population year-round. through water contamination remains an open question.

  13. Process of distillation of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Saxton, A L

    1968-08-16

    In an oil-shale distillation apparatus with a single retort, in which separate zones of preheating, distillation, combustion, and cooling are maintained, the operation is conducted at a presssure higher than the atmospheric pressure, preferably at a gage pressure between about 0.35 and 7.0 bars. This permits increasing the capacity of the installation.

  14. Furnace for distillation of shales, etc

    Energy Technology Data Exchange (ETDEWEB)

    Germain-Clergault, M

    1863-07-09

    Practical experience and continuous operation of 55 retorts for 5 years of the system of vertical retorts patented in 1857 (French Patent 18,422) has shown the advantages resulting from this furnace which gives over a mean yield of 5% of Auton shale, which is /sup 1///sub 2/% more than the old systems with a fuel economy varying from 15 to 20%.

  15. Total and the Algerian shale gas

    International Nuclear Information System (INIS)

    Chapelle, Sophie; Petitjean, Olivier; Maurin, Wilfried; Balvet, Jacqueline; Combes, Maxime; Geze, Francois; Hamouchene, Hamza; Hidouci, Ghazi; Malti, Hocine; Renaud, Juliette; Simon, Antoine; Titouche, Fateh

    2015-01-01

    This publication proposes a rather detailed and discussed overview of the movement of mobilisation of Algerian people (notably those living in the Sahara) against projects of exploration and exploitation of shale gases in Algeria by the Total group. The authors also recall and comment the long and heavy history of hydrocarbon management in Algeria, the role of international firms and of western interests (notably French interests) in this country, and the position of Total regarding the stake related to shale gases. The authors outline problems created by shale gas exploitation regarding water consumption and waste waters. They also notice that the safety of wells is at the centre of the protest. Problems raised by hydraulic fracturing are reviewed: seismic activity, chemical pollution, air pollution and greenhouse gases, landscape destruction. The attitude of the Algerian government is commented. Then, the authors try to identify and describe the action of Total in the Algerian shale gas sector, discuss the possible French influence, and outline the presence of Total all over the world in this sector

  16. Naval Petroleum and Oil Shale Reserves

    International Nuclear Information System (INIS)

    1992-01-01

    During fiscal year 1992, the reserves generated $473 million in revenues, a $181 million decrease from the fiscal year 1991 revenues, primarily due to significant decreases in oil and natural gas prices. Total costs were $200 million, resulting in net cash flow of $273 million, compared with $454 million in fiscal year 1991. From 1976 through fiscal year 1992, the Naval Petroleum and Oil Shale Reserves generated more than $15 billion in revenues and a net operating income after costs of $12.5 billion. In fiscal year 1992, production at the Naval Petroleum Reserves at maximum efficient rates yielded 26 million barrels of crude oil, 119 billion cubic feet of natural gas, and 164 million gallons of natural gas liquids. From April to November 1992, senior managers from the Naval Petroleum and Oil Shale Reserves held a series of three workshops in Boulder, Colorado, in order to build a comprehensive Strategic Plan as required by Secretary of Energy Notice 25A-91. Other highlights are presented for the following: Naval Petroleum Reserve No. 1--production achievements, crude oil shipments to the strategic petroleum reserve, horizontal drilling, shallow oil zone gas injection project, environment and safety, and vanpool program; Naval Petroleum Reserve No. 2--new management and operating contractor and exploration drilling; Naval Petroleum Reserve No. 3--steamflood; Naval Oil Shale Reserves--protection program; and Tiger Team environmental assessment of the Naval Petroleum and Oil Shale Reserves in Colorado, Utah, and Wyoming

  17. Fundamental Study of Disposition and Release of Methane in a Shale Gas Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Xiong, Yongliang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Repository Performance; Criscenti, Louise J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Ho, Tuan Ahn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Storage and Transportation Technology; Ilgen, Anastasia G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Matteo, Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Kruichak, Jessica N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Mills, Melissa M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Dewers, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geomechanics; Gordon, Margaret E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Materials, Devices and Energy Technologies; Akkutlu, Yucel [Texas A & M Univ., College Station, TX (United States). Dept. of Petroleum Engineering

    2016-09-01

    simulations also indicate that a significant fraction (3 - 35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. We have successfully established experimental capabilities for measuring gas sorption and desorption on shale and model materials under a wide range of physical and chemical conditions. Both low and high pressure measurements show significant sorption of CH4 and CO2 onto clays, implying that methane adsorbed on clay minerals could contribute a significant portion of gas-in-place in an unconventional reservoir. We have also studied the potential impact of the interaction of shale with hydrofracking fluid on gas sorption. We have found that the CH4-CO2 sorption capacity for the reacted sample is systematically lower (by a factor of ~2) than that for the unreacted (raw) sample. This difference in sorption capacity may result from a mineralogical or surface chemistry change of the shale sample induced by fluid-rock interaction. Our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs.

  18. Brazilian Tensile Strength of Anisotropic Rocks: Review and New Insights

    Directory of Open Access Journals (Sweden)

    Tianshou Ma

    2018-01-01

    Full Text Available Strength anisotropy is one of the most distinct features of anisotropic rocks, and it also normally reveals strong anisotropy in Brazilian test Strength (“BtS”. Theoretical research on the “BtS” of anisotropic rocks is seldom performed, and in particular some significant factors, such as the anisotropic tensile strength of anisotropic rocks, the initial Brazilian disc fracture points, and the stress distribution on the Brazilian disc, are often ignored. The aim of the present paper is to review the state of the art in the experimental studies on the “BtS” of anisotropic rocks since the pioneering work was introduced in 1964, and to propose a novel theoretical method to underpin the failure mechanisms and predict the “BtS” of anisotropic rocks under Brazilian test conditions. The experimental data of Longmaxi Shale-I and Jixi Coal were utilized to verify the proposed method. The results show the predicted “BtS” results show strong agreement with experimental data, the maximum error is only ~6.55% for Longmaxi Shale-I and ~7.50% for Jixi Coal, and the simulated failure patterns of the Longmaxi Shale-I are also consistent with the test results. For the Longmaxi Shale-I, the Brazilian disc experiences tensile failure of the intact rock when 0° ≤ βw ≤ 24°, shear failure along the weakness planes when 24° ≤ βw ≤ 76°, and tensile failure along the weakness planes when 76° ≤ βw ≤ 90°. For the Jixi Coal, the Brazilian disc experiences tensile failure when 0° ≤ βw ≤ 23° or 76° ≤ βw ≤ 90°, shear failure along the butt cleats when 23° ≤ βw ≤ 32°, and shear failure along the face cleats when 32° ≤ βw ≤ 76°. The proposed method can not only be used to predict the “BtS” and underpin the failure mechanisms of anisotropic rocks containing a single group of weakness planes, but can also be generalized for fractured rocks containing multi-groups of weakness planes.

  19. China organic-rich shale geologic features and special shale gas production issues

    Directory of Open Access Journals (Sweden)

    Yiwen Ju

    2014-06-01

    Full Text Available The depositional environment of organic-rich shale and the related tectonic evolution in China are rather different from those in North America. In China, organic-rich shale is not only deposited in marine environment, but also in non-marine environment: marine-continental transitional environment and lacustrine environment. Through analyzing large amount of outcrops and well cores, the geologic features of organic-rich shale, including mineral composition, organic matter richness and type, and lithology stratigraphy, were analyzed, indicating very special characteristics. Meanwhile, the more complex and active tectonic movements in China lead to strong deformation and erosion of organic-rich shale, well-development of fractures and faults, and higher thermal maturity and serious heterogeneity. Co-existence of shale gas, tight sand gas, and coal bed methane (CBM proposes a new topic: whether it is possible to co-produce these gases to reduce cost. Based on the geologic features, the primary production issues of shale gas in China were discussed with suggestions.

  20. Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems

    Science.gov (United States)

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Lewan, Mike; Sun, Xun; Baez, Luis; Beeney, Ken; Sonnenberg, Steve

    2013-01-01

    A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linearly correlated with the CH4 sorption capacity in both organic-rich shales and clay-rich rocks. The presence of organic matter is a primary control on gas adsorption in shale-gas systems, and the gas-sorption capacity is determined by total organic carbon (TOC) content, organic-matter type, and thermal maturity. A large number of nanopores, in the 2–50 nm size range, were created during organic-matter thermal decomposition, and they significantly contributed to the surface area. Consequently, methane-sorption capacity increases with increasing thermal maturity due to the presence of nanopores produced during organic-matter decomposition. Furthermore, CH4 sorption on clay minerals is mainly controlled by the type of clay mineral present. In terms of relative CH4 sorption capacity: montmorillonite ≫ illite – smectite mixed layer > kaolinite > chlorite > illite. The effect of rock properties (organic matter content, type, maturity, and clay minerals) on CH4 adsorption can be quantified with the heat of adsorption and the standard entropy, which are determined from adsorption isotherms at different temperatures. For clay-mineral rich rocks, the heat of adsorption (q) ranges from 9.4 to 16.6 kJ/mol. These values are considerably smaller than those for CH4 adsorption on kerogen (21.9–28 kJ/mol) and organic-rich shales (15.1–18.4 kJ/mol). The standard entropy (Δs°) ranges from -64.8 to -79.5 J/mol/K for clay minerals, -68.1 to -111.3 J/mol/K for kerogen, and -76.0 to -84.6 J/mol/K for organic-rich shales. The affinity of CH4 molecules for sorption on organic matter

  1. Shale as a radioactive waste repository: the importance of vermiculite

    Energy Technology Data Exchange (ETDEWEB)

    Komarneni, S; Roy, D M; Pennsylvania State Univ., University Park; USA). Materials Research Labs.)

    1979-01-01

    Cesium sorption and fixation properties of thirty shale minerals and shales were investigated in search of a criterion for the suitability of shales for a radioactive waste repository. Shales and illites containing vermiculite fixed the largest proportion of total Cs sorbed (up to 91%) against displacement with 0.1 N KCl. For example, a slate sample fixed 33% of the total Cs sorbed while its weathered counterpart in which chlorite had altered to vermiculite fixed 89% of the total Cs sorbed. Since Cs is one of the most soluble and hazardous radioactive ions, its containment is of great importance in safe radioactive waste disposal. Presence of vermiculite in a shale body may therefore, serve as one criterion in the selection of a suitable shale for radioactive waste disposal if and when shales in geologically stable areas are selected for repositories.

  2. Rock Physical Interpretation of the Relationship between Dynamic and Static Young's Moduli of Sedimentary Rocks

    Science.gov (United States)

    Takahashi, T.

    2017-12-01

    The static Young's modulus (deformability) of a rock is indispensable for designing and constructing tunnels, dams and underground caverns in civil engineering. Static Young's modulus which is an elastic modulus at large strain level is usually obtained with the laboratory tests of rock cores sampled in boreholes drilled in a rock mass. A deformability model of the entire rock mass is then built by extrapolating the measurements based on a rock mass classification obtained in geological site characterization. However, model-building using data obtained from a limited number of boreholes in the rock mass, especially a complex rock mass, may cause problems in the accuracy and reliability of the model. On the other hand, dynamic Young's modulus which is the modulus at small strain level can be obtained from seismic velocity. If dynamic Young's modulus can be rationally converted to static one, a seismic velocity model by the seismic method can be effectively used to build a deformability model of the rock mass. In this study, we have, therefore, developed a rock physics model (Mavko et al., 2009) to estimate static Young's modulus from dynamic one for sedimentary rocks. The rock physics model has been generally applied to seismic properties at small strain level. In the proposed model, however, the sandy shale model, one of rock physics models, is extended for modeling the static Young's modulus at large strain level by incorporating the mixture of frictional and frictionless grain contacts into the Hertz-Mindlin model. The proposed model is verified through its application to the dynamic Young's moduli derived from well log velocities and static Young's moduli measured in the tri-axial compression tests of rock cores sampled in the same borehole as the logs were acquired. This application proves that the proposed rock physics model can be possibly used to estimate static Young's modulus (deformability) which is required in many types of civil engineering applications

  3. Sedimentology and facies analysis of Devonian Rocks, southern district of Mackenzie, North West Territories, Canada

    NARCIS (Netherlands)

    Meijer Drees, N.C.

    1989-01-01

    The Devonian rock succession in the southern part of the District of Mackenzie consists of interbedded evaporites and carbonates, fossiliferous carbonates and shales. Inthe study areathe Devonian succession unconformably overlies LowerPaleozoic orPrecambrian strata and thins in a northeastward

  4. The challenge of shale to the post-oil dreams of the Arab Gulf

    International Nuclear Information System (INIS)

    Sultan, Nabil

    2013-01-01

    Growth patterns in the Gulf Cooperation Council (GCC) countries suggest that demand for energy in this region is likely to increase in the years to come and this situation ultimately means that more of the region’s natural resources will need to be devoted to meeting this demand. For some of the GCC countries, the option to meet future power demands through alternative sources of energy such as nuclear power was deemed an attractive proposition. Furthermore, real investments and plans to use other alternative energy sources such as solar, wind, hydrogen and geothermal are also gaining momentum in the region. However, relatively recent developments in the technology used for extracting gas and oil from shale rock formations places a big question mark on the GCC countries’ energy plans including those relating to alternative and renewable sources of energy. This article examines the GCC’s new energy drive and explores the economic and political motivations behind it. Furthermore, the article also examines the potential impact of shale gas and oil extraction on this region’s abundant fossil-based resources and the ramifications of such impact (if it materialises) for the GCC countries’ alternative energy plans, future wealth and their political stability. - Highlights: • Shale gas (and oil) could potentially affect future oil prices. • Gas could be the future transport fuel. • Arab Gulf countries could be the victims

  5. Water pollution risk associated with natural gas extraction from the Marcellus Shale.

    Science.gov (United States)

    Rozell, Daniel J; Reaven, Sheldon J

    2012-08-01

    In recent years, shale gas formations have become economically viable through the use of horizontal drilling and hydraulic fracturing. These techniques carry potential environmental risk due to their high water use and substantial risk for water pollution. Using probability bounds analysis, we assessed the likelihood of water contamination from natural gas extraction in the Marcellus Shale. Probability bounds analysis is well suited when data are sparse and parameters highly uncertain. The study model identified five pathways of water contamination: transportation spills, well casing leaks, leaks through fractured rock, drilling site discharge, and wastewater disposal. Probability boxes were generated for each pathway. The potential contamination risk and epistemic uncertainty associated with hydraulic fracturing wastewater disposal was several orders of magnitude larger than the other pathways. Even in a best-case scenario, it was very likely that an individual well would release at least 200 m³ of contaminated fluids. Because the total number of wells in the Marcellus Shale region could range into the tens of thousands, this substantial potential risk suggested that additional steps be taken to reduce the potential for contaminated fluid leaks. To reduce the considerable epistemic uncertainty, more data should be collected on the ability of industrial and municipal wastewater treatment facilities to remove contaminants from used hydraulic fracturing fluid. © 2012 Society for Risk Analysis.

  6. Mud Lake, a modern analog of oil shale deposition in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, J.D.

    1987-01-01

    Mud Lake in north-central Florida was identified by Bradley as an analog of oil shale-type kerogen deposition. This lake supports an abundant diatom and algal flora which is unique in that the accumulating algal ooze does not decay as long as it stays oxygenated. This same material does not nutritionally support many invertebrates, owing to its flocculent consistency and apparent indigestibility, although fish are abundant and an occasional crocodile is found in the lake. Accumulation of the algal ooze is very slow at roughly 1 foot per 52,000 years based on radiocarbon dates. An understanding of oil shale depositional conditions could be translated into a predictive model for location and recognition of hydrocarbon generating source rocks. When oil shales are mentioned the first association is likely to be that with the Eocene Green River Formation of the Western US. Conditions leading to deposition and preservation of this massive quantity of organic debris is difficult to comprehend, but recognition of modern analogs provide an available area for study and comparison.

  7. Know thy reservoir : multi-disciplinary shale gas solution integrates cased hole evaluation interpretation and stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2009-11-15

    This article discussed Schlumberger's efforts in making shale gas a priority. Shale gas plays require maximum reservoir exposure to be economic. The exploitation of shale gas has been solved through the use of long horizontal wells that are fractured in multiple zones along their length. Companies have invested heavily into research to find increasingly novel ways to reduce costs and extract more molecules of gas from the ultra-low permeability rock. The tools and techniques that Schlumberger has developed for well stimulation and completion were described. Schlumberger was extremely focused on improving its ability to understand the Horn River reservoir and improve completion practices. Openhole logging was discussed as an option. Schlumberger in conjunction with its in-house data and consulting services group, also devised a method to log a lateral well after it had been cased, cemented, and the rig had been released. It was concluded that using such instruments as spectroscopy logging, epithermal neutron porosity logging and multidimensional shear sonic logging tools, Schlumberger could provide all the necessary measurements post-casing. 2 refs., 3 figs.

  8. Multivariate analysis of ATR-FTIR spectra for assessment of oil shale organic geochemical properties

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.

    2013-01-01

    In this study, attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR) was coupled with partial least squares regression (PLSR) analysis to relate spectral data to parameters from total organic carbon (TOC) analysis and programmed pyrolysis to assess the feasibility of developing predictive models to estimate important organic geochemical parameters. The advantage of ATR-FTIR over traditional analytical methods is that source rocks can be analyzed in the laboratory or field in seconds, facilitating more rapid and thorough screening than would be possible using other tools. ATR-FTIR spectra, TOC concentrations and Rock–Eval parameters were measured for a set of oil shales from deposits around the world and several pyrolyzed oil shale samples. PLSR models were developed to predict the measured geochemical parameters from infrared spectra. Application of the resulting models to a set of test spectra excluded from the training set generated accurate predictions of TOC and most Rock–Eval parameters. The critical region of the infrared spectrum for assessing S1, S2, Hydrogen Index and TOC consisted of aliphatic organic moieties (2800–3000 cm−1) and the models generated a better correlation with measured values of TOC and S2 than did integrated aliphatic peak areas. The results suggest that combining ATR-FTIR with PLSR is a reliable approach for estimating useful geochemical parameters of oil shales that is faster and requires less sample preparation than current screening methods.

  9. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    Lamminen, S.

    1995-01-01

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  10. Stratigraphy of Slick Rock district and vicinity, San Miguel and Dolores Counties, Colorado

    Science.gov (United States)

    Shawe, Daniel R.; Simmons, George C.; Archbold, Norbert L.

    1968-01-01

    The Slick Rock district covers about 570 square miles in western San Miguel and Dolores Counties, in southwestern Colorado. It is at the south edge of the salt-anticline region of southwestern Colorado and southeastern Utah and of the Uravan mineral belt.Deposition of Paleozoic sedimentary rocks in the district and vicinity was principally controlled by development of the Paradox Basin, and of Mesozoic rocks by development of a depositional basin farther west. The Paleozoic rocks generally are thickest at the northeast side of the Paradox Basin in a northwest- trending trough which seems to be a wide graben in Precambrian igneous and metamorphic basement rocks; Mesozoic rocks generally thicken westward and southwestward from the district.Sedimentary rocks rest on a Precambrian basement consisting of a variety of rocks, including granite and amphibolite. The surface of the Precambrian rocks is irregular and generally more than 2,000 feet below sea level and 7,000-11,000 feet below the ground surface. In the northern part of the district the Precambrian surface plunges abruptly northeastward into the trough occupying the northeast side of the Paradox Basin, and in the southern part it sags in a narrow northeasterly oriented trough. Deepening of both troughs, or crustal deformation in their vicinity, influenced sedimentation during much of late Paleozoic and Mesozoic time.The maximum total thickness of sedimentary rocks underlying the district is 13,000 feet, and prior to extensive erosion in the late Tertiary and the Quaternary it may have been as much as about 18,000 feet. The lower 5,000 feet or more of the sequence of sedimentary rocks consists of arenaceous strata of early Paleozoic age overlain by dominantly marine carbonate rocks and evaporite beds interbedded with lesser amounts of clastic sediments of late Paleozoic age. Overlying these rocks is about 4,500 feet of terrestrial clastic sediments, dominantly sandstone with lesser amounts of shale, mudstone

  11. Compact rock material gas permeability properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

    2014-09-15

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

  12. Knudsen-Like Scaling May Be Inappropriate for Gas Shales

    KAUST Repository

    Patzek, Tadeusz

    2017-10-02

    Summary We assert that a classification of gas flow regimes in shales that is widely accepted in the petroleum industry, may be inconsistent with the physics of high-pressure gas flow in capillaries. This classification follows from the 1946 work by Brown et al. (1946) that deals with the flow of gases in large industrial metal pipes, elbows and orifices under vacuum, with gas pressures of the order of 1 mm Hg or less. In another pioneering paper that year, Tsien (1946) analyzed the hypersonic flight of rockets in the thermosphere (above 50 miles of altitude), and established the widely accepted Knudsen flow regimes for the high-Reynolds, high-Mach flow of rarified gases. We show why both these papers are not quite applicable to flow of compressed gas in the hot, high-pressure shale pores with rough surfaces. In addition, it may be inappropriate to use the capillary tube metaphor to describe shale micropores or microcracks, simply because each is fed with gas by dozens or hundreds of intricately connected nanopores, which themselves may be slits rather than circular cylinders, and are charged with the dense, liquid-like gas. In the small-scale, low-velocity flows of gases, failure of the standard Navier-Stokes description (the standard Darcy law in petroleum engineering) can be quantified by the Knudsen number, ratio of the mean free path, λ, of gas molecules at the reservoir pressure and temperature to the characteristic pore radius, R. We carefully enumerate the multiple restrictive conditions that must hold for the slip-flow boundary condition to emerge. We also describe the dependence of the slip correction factor on the gas pressure and temperature, as well as the median pore size and rock roughness. In the derivation, we revisit the original approaches of Helmholtz and von Piotrowski (1860) and Maxwell, Niven (1890), which were somehow lost in the multiple translations from physics to petroleum engineering. For example, in Barnett mudrocks, naturally

  13. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Glenn Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wolery, Thomas J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jerden, James L. [Argonne National Lab. (ANL), Argonne, IL (United States); Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States); Cruse, Terry [Argonne National Lab. (ANL), Argonne, IL (United States); Ebert, William L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-04

    Deep geological disposal of nuclear waste in clay/shale/argillaceous rock formations has received much consideration given its desirable attributes such as isolation properties (low permeability), geochemically reduced conditions, slow diffusion, sorbtive mineralogy, and geologically widespread (Jové Colón et al., 2014). There is a wealth of gained scientific expertise on the behavior of clay/shale/ argillaceous rock given its focus in international nuclear waste repository programs that includes underground research laboratories (URLs) in Switzerland, France, Belgium, and Japan. Jové Colón et al. (2014) have described some of these investigative efforts in clay rock ranging from site characterization to research on the engineered barrier system (EBS). Evaluations of disposal options that include nuclear waste disposition in clay/shale/argillaceous rock have determined that this host media can accommodate a wide range of waste types. R&D work within the Used Fuel Disposition Campaign (UFDC) assessing thermal effects and fluid-mineral interactions for the disposition of heat-generating waste have so far demonstrated the feasibility for the EBS and clay host rock to withstand high thermal loads. This report represents the continuation of disposal R&D efforts on the advancement and refinement of coupled Thermal-Hydrological-Mechanical-Chemical (THMC), hydrothermal experiments on clay interactions, used fuel degradation (source term), and thermodynamic modeling and database development. The development and implementation of a clay/shale/argillite reference case described in Jové Colón et al. (2014) for FY15 will be documented in another report (Mariner et al. 2015) – only a brief description will be given here. This clay reference case implementation is the result of integration efforts between the GDSA PA and disposal in argillite work packages. The assessment of sacrificial zones in the EBS is being addressed through experimental work along with 1D reactive

  14. Shale gas development impacts on surface water quality in Pennsylvania

    Science.gov (United States)

    Olmstead, Sheila M.; Muehlenbachs, Lucija A.; Shih, Jhih-Shyang; Chu, Ziyan; Krupnick, Alan J.

    2013-01-01

    Concern has been raised in the scientific literature about the environmental implications of extracting natural gas from deep shale formations, and published studies suggest that shale gas development may affect local groundwater quality. The potential for surface water quality degradation has been discussed in prior work, although no empirical analysis of this issue has been published. The potential for large-scale surface water quality degradation has affected regulatory approaches to shale gas development in some US states, despite the dearth of evidence. This paper conducts a large-scale examination of the extent to which shale gas development activities affect surface water quality. Focusing on the Marcellus Shale in Pennsylvania, we estimate the effect of shale gas wells and the release of treated shale gas waste by permitted treatment facilities on observed downstream concentrations of chloride (Cl−) and total suspended solids (TSS), controlling for other factors. Results suggest that (i) the treatment of shale gas waste by treatment plants in a watershed raises downstream Cl− concentrations but not TSS concentrations, and (ii) the presence of shale gas wells in a watershed raises downstream TSS concentrations but not Cl− concentrations. These results can inform future voluntary measures taken by shale gas operators and policy approaches taken by regulators to protect surface water quality as the scale of this economically important activity increases. PMID:23479604

  15. Comparative acute toxicity of shale and petroleum derived distillates.

    Science.gov (United States)

    Clark, C R; Ferguson, P W; Katchen, M A; Dennis, M W; Craig, D K

    1989-12-01

    In anticipation of the commercialization of its shale oil retorting and upgrading process, Unocal Corp. conducted a testing program aimed at better defining potential health impacts of a shale industry. Acute toxicity studies using rats and rabbits compared the effects of naphtha, Jet-A, JP-4, diesel and "residual" distillate fractions of both petroleum derived crude oils and hydrotreated shale oil. No differences in the acute oral (greater than 5 g/kg LD50) and dermal (greater than 2 g/kg LD50) toxicities were noted between the shale and petroleum derived distillates and none of the samples were more than mildly irritating to the eyes. Shale and petroleum products caused similar degrees of mild to moderate skin irritation. None of the materials produced sensitization reactions. The LC50 after acute inhalation exposure to Jet-A, shale naphtha, (greater than 5 mg/L) and JP-4 distillate fractions of petroleum and shale oils was greater than 5 mg/L. The LC50 of petroleum naphtha (greater than 4.8 mg/L) and raw shale oil (greater than 3.95 mg/L) also indicated low toxicity. Results demonstrate that shale oil products are of low acute toxicity, mild to moderately irritating and similar to their petroleum counterparts. The results further demonstrate that hydrotreatment reduces the irritancy of raw shale oil.

  16. Can the US shale revolution be duplicated in Europe?

    International Nuclear Information System (INIS)

    Saussay, Aurelien

    2015-04-01

    Over the past decade, the rapid increase in shale gas and shale oil production in the United States has profoundly changed energy markets in North America, and has led to a significant decrease in American natural gas prices. The possible existence of large shale deposits in Europe, mainly in France, Poland and the United Kingdom, has fostered speculation on whether the 'shale revolution', and its accompanying macro-economic impacts, could be duplicated in Europe. However, a number of uncertainties, notably geological, technological and regulatory, make this possibility unclear. We present a techno-economic model, SHERPA (Shale Exploitation and Recovery Projection and Analysis), to analyze the main determinants of the profitability of shale wells and plays. We calibrate our model using production data from the leading American shale plays. We use SHERPA to estimate three shale gas production scenarios exploring different sets of geological and technical hypotheses for the largest potential holder of shale gas deposits in Europe, France. Even considering that the geology of the potential French shale deposits is favorable to commercial extraction, we find that under assumptions calibrated on U.S. production data, natural gas could be produced at a high breakeven price of $8.6 per MMBtu, and over a 45 year time-frame have a net present value of $19.6 billion - less than 1% of 2012 French GDP. However, the specificities of the European context, notably high deposit depth and stricter environmental regulations, could increase drilling costs and further decrease this low profitability. We find that a 40% premium over American drilling costs would make shale gas extraction uneconomical. Absent extreme well productivity, it appears very difficult for shale gas extraction to have an impact on European energy markets comparable to the American shale revolution. (author)

  17. Features of the first great shale gas field in China

    Directory of Open Access Journals (Sweden)

    Ruobing Liu

    2016-04-01

    Full Text Available On the 28th of November 2012, high shale gas flow was confirmed to be 203 × 103 m3 in Longmaxi Formation; this led to the discovery of the Fuling Shale Gas Field. On the 10th of July in 2014, the verified geological reserves of the first shale gas field in China were submitted to the National Reserves Committee. Practices of exploration and development proved that the reservoirs in the Fuling Shale Gas Field had quality shales deposited in the deep-shelf; the deep-shelf had stable distribution, great thickness with no interlayers. The shale gas field was characterized by high well production, high-pressure reservoirs, good gas elements, and satisfactory effects on testing production; it's from the mid-deep depth of the quality natural gas reservoirs that bore high pressure. Comprehensive studies on the regional sedimentary background, lithology, micropore structures, geophysical properties, gas sources, features of gas reservoirs, logging responding features, and producing features of gas wells showed the following: (1 The Longmaxi Formation in the Fuling Shale Gas Field belongs to deep-shelf environment where wells developed due to organic-rich shales. (2 Thermal evolution of shales in Longmaxi Formation was moderate, nanometer-level pores developed as well. (3 The shale gas sources came from kerogens the Longmaxi Formation itself. (4 The shale gas reservoirs of the Fuling Longmaxi Formation were similar to the typical geological features and producing rules in North America. The findings proved that the shale gas produced in the Longmaxi Formation in Fuling was the conventional in-situ detained, self-generated, and self-stored shale gas.

  18. Geomechanical characterization of the Montney Shale northwest Alberta and northeast British Columbia, Canada

    Science.gov (United States)

    Davey, Heather

    there is a strong formation influence on the progression of hydraulic fractures. The locations of interfaces between changes in rock properties and/or stress state are locations where the hydraulic fracture character will also change. It was found that energy is dissipated in heterogeneous/brittle zones, while hydraulic growth occurs in homogenous zones. However, at the intersection of a homogenous zone with a brittle zone, both hydraulic fracture growth and energy dissipation is possible. Here relatively higher production is observed. Stress shadowing amplifies the effects of energy dissipation in brittle zones. Understanding the geological factors that have the greatest influence on stimulation has proven to be a useful method of predicting productivity and efficiency in shale reservoirs. The results of this geomechanical study are calibrated with diagnostic fracture injection tests, microseismic, spinner gas data, and time-lapse multicomponent seismic to corroborate the predictions of reservoir performance in the Montney Shale.

  19. Chemical and Mineralogical Features of Smectite from the Morron de Mateo Bentonite Deposit (Cabo de Gata, Almeria) in Relation to the Parent Rocks and the Alteration Processes Occurred After the Bentonite Formation: Analogies and Implications for the Engineered Clayey Barrier of a Deep Geological Rad waste Repository

    International Nuclear Information System (INIS)

    Pelayo, M.; Labajo, M. A.; Garcia Romero, L.; Perez del Villar, L.

    2009-01-01

    The Morron de Mateo bentonite deposit is being studied as a natural analogue of the thermal and geochemical effects on the clayey barrier of a Deep Geological Rad waste Repository (DGRR) after its closure, in relation to the radioactive decay of the fission products and the container corrosion. This bentonite deposit and their host rocks were intruded by a rhyodacitic volcanic dome that induced a hydrothermal metasomatic process affecting the bioclastic calcarenite beds close to the dome. Bentonite from the NE sector of the deposit have been chemically and mineralogically characterized. Pyroclastic rocks (white tuffs), epyclastic rocks (mass flow) and andesitic breccia all of them hydrothermally altered, have been studied at the site. Samples are composed of feldspars, quartz and amphybols, as inherited minerals, and phyllosilicates, zeolites, crystoballite and calcite, as new formed minerals. White tuffs have the highest phyllosilicate contents, mainly dioctahedral smectite of montmorillonite type. Epyclastic rocks and andesitic breccia have a highest proportion of inherited minerals, the new formed phillosilicates being di octahedral smectite of beidellite type and an ordered interlayer chlorite/smectite mineral, of corrensite type. Smectite from the epyclastic rocks have higher Fe and Mg contents and chemical variability, as a consequence of nature of their parent rocks. The presence of corrensite in the epyclastic rocks suggests that in the Morron de Mateo area a propilitic alteration process occurred after bentonite formation, which transformed Fe-Mg-rich smectite into corrensite. This transformation was probably favoured by the sub volcanic intrusion, which also produced a temperature increase in the geological media and a supply of Fe-Mg-rich solutions, which also were the responsible for the metasomatic transformations observed in the calcarenite beds. (Author) 57 refs

  20. Is Estonian oil shale beneficial in the future?

    International Nuclear Information System (INIS)

    Reinsalu, Enno

    1998-01-01

    Oil shale mining production reached its maximum level of 31.35·10 6 tonnes per year in 1980. After the eighties there was a steady decline in mining. The first scientific prognoses of the inescapable decrease in oil shale mining were published in 1988. According to this, the Estonian oil shale industry would vanish in the third decade of the next century. From the beginning of the nineties, the consumption and export of electricity have dropped in Estonia. The minimum level of oil shale mining was 13.5·10 6 tonnes per year. This occurred in 1994/1995. Some increase in consumption of electric power and oil shale began at the end of 1995. Oil shale processing began to increase gradually in 1993. Oil shale is the most important fuel in Estonia today. In 1997, oil shale provided 76% of Estonia's primary energy supply and accounted for 57% of its economic value. Oil shale is the cheapest fuel in Estonia. Nowadays, oil shale provides an essential part of the fuel supply in Estonia because it is considerably cheaper than other fuels. Oil shale costs EEK 12.16 per G J. At the same time, coal costs EEK 23.41 per G J and peat costs EEK 14.80 per G J (year 1997). There are three important customers of oil shale: the electric power company Eesti Energia, the oil processing company Kiviter and the factory Kunda Nordic Cement. In 1995, the power company utilised 81% of the oil shale mass and 77% of its heating value. The state energy policy inhibits increases in the oil shale price even though the mining infrastructure is decaying. Government price policies subside oil shale processing. The energy of oil shale processing is 1.9 times cheaper than the heating value of raw oil shale for power stations. It could be considered as a state subsidisation of oil and cement export at the expense of electricity. The subsidy assigned to oil processing was of EEK 124·10 6 and to the cement industry of EEK 8.4·10 6 in year 1997 (based on heating value). State regulation of prices and

  1. Noble Gases as tracers of fluid migration in the Haynesville shale and overlying strata

    Science.gov (United States)

    Byrne, D. J.; Barry, P. H.; Lawson, M.; Ballentine, C. J.

    2017-12-01

    Noble gases are ideal tracers of physical processes and fluid provenance in crustal systems. Due to their inert nature, they are unaffected by chemical alteration, redox, or biological phenomena that fractionate other geochemical tracers. Noble gas analysis has been used to quantify fluid provenance, interactions, and ages in petroleum systems [1,2], but the effects of hydrocarbon migration on noble gas signatures have not been directly observed. The Haynesville Shale (East Texas & Louisiana), is exploited commercially for unconventional shale gas, but also acts as the source-rock for overlying conventional reservoirs. We present noble gas isotope and abundance data in samples collected from 9 natural gas wells sourced from the Haynesville Shale, as well as 21 from reservoirs in the overlying Cotton Valley (n=7), Travis Peak (n=9), and James (n=5) groups. Using a stratigraphic model, we observe systematic changes in the noble gas signatures as the fluids migrate from the Haynesville source rock to the overlying conventional accumulations. Helium isotope ratios (3He/4He) are strongly radiogenic in the Haynesville and stratigraphically older conventional reservoirs, with the younger reservoirs showing evidence of a mantle helium input. Argon isotope ratios (40Ar/36Ar) are strongly correlated with high 3He/4He, suggesting a similar provenance for radiogenic 40Ar and mantle 3He. Concentrations of groundwater-derived 36Ar are consistently higher in the conventional reservoirs than in the Haynesville shale, reflecting the greater interaction with groundwater during migration. However, 20Ne/36Ar ratios are not significantly different, suggesting that solubility-dependent partitioning is not simply dependent on vertical or horizontal migration distance. Krypton and xenon abundances are higher than expected for groundwater in all samples, a phenomenon that has been observed in many other hydrocarbon accumulations [3]. The excess Xe/Kr ratio is highest in the Haynesville

  2. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  3. Waste-rock interactions and bedrock reactions

    International Nuclear Information System (INIS)

    White, W.B.

    1977-01-01

    The experimental program is designed to discover possible reactions between shale repository rocks and radioactive wastes. The canister can be regarded in three ways: (a) As a source of heat that modifies the mineralogy and therefore the physical properties of the surrounding rock (dry heat). (b) As a source of heat that activates reactions between minerals in the surrounding rock and slowly percolating ground water. (c) As a source of reaction materials of different composition from the surrounding rock and which therefore may react to form completely new ''minerals'' in a contact aureole around the canister. The matrix of interactions contains two composition axes. The waste compositions are defined by the various prototype waste forms usually investigated: glass, calcine, ''spent fuel'' and the ceramic supercalcine. The temperatures and pressures at which these reactions take place must be investigated. Thus each node on the ''wiring diagram'' is itself a matrix of experiments in which the T and to some extent P are varied. Experiments at higher pressure and temperature allow reactions to take place on a laboratory time scale and thus identify what could happen. These reactions are then followed downward in temperature to determine both phase boundaries and kinetic cut-offs below which equilibrium cannot be achieved on a laboratory time scale

  4. American shale gas in the European air

    International Nuclear Information System (INIS)

    Chauveau, L.

    2015-01-01

    Belgian scientists have detected ethane in atmosphere samples from Switzerland. The origin of this ethane is highly likely to be linked to the production of shale gas in Northern America. These concentrations of ethane have been increasing by 5% a year since 2009 while they had been steadily decreasing by about 1% a year over the 2 previous decades. These releases of ethane are massive since they are detected in Europe while ethane's lifetime in the atmosphere is only 2 months. Ethane is exclusively released from natural gas leaks during extraction operations or tank filling. A measurement campaign involving infrared spectrometry stations around the world have shown that ethane is released only in the northern hemisphere. It also appears that the beginning of the increase coincides with the beginning of the industrial exploitation of shale gas in the U.S. (A.C.)

  5. Adsorption of xenon and krypton on shales

    Science.gov (United States)

    Podosek, F. A.; Bernatowicz, T. J.; Kramer, F. E.

    1981-01-01

    A method that uses a mass spectrometer as a manometer is employed in the measurement of Xe and Kr adsorption parameters on shales and related samples, where gas partial pressures were lower than 10 to the -11th atm, corresponding adsorption coverages are only small fractions of a monolayer, and Henry's Law behavior is expected and observed. Results show heats of adsorption in the 2-7 kcal/mol range, and Henry constants at 0-25 C of 1 cu cm STP/g per atmosphere are extrapolated. Although the adsorption properties obtained are variable by sample, the range obtained suggests that shales may be capable of an equilibrium adsorption with modern air high enough to account for a significant fraction of the atmospheric inventory of Xe, and perhaps even of Kr. This effect will nevertheless not account for the factor-of-25 defficiency of atmospheric Xe, in comparison with the planetary gas patterns observed in meteorites.

  6. Organic material of the Messel oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, B.; Littke, R.

    1986-05-01

    According to chemism, the Messel oil shales belong to the Kerogen type II, formed by algae with additions of huminite detritus, i.e. residues of higher plants. This has been confirmed by the organo-petrographic studies reported. The oil shale deposits are characterised by their content of organic materials, the occurrence of a cream-coloured inertinite maceral, and of siderite. Hence, two facies can be clearly discriminated, the lower one containing relatively much organic material and the cream-coloured inertinite, but no siderite, and the upper facies exhibiting just the opposite. As the detritus is finely grained and quite uniform in content of huminite and silicate material, and only few spores and pollen have been found, there is reason to assume that the two facies represent sediments formed far from the border of the lake.

  7. Study on the Low-Temperature Oxidation Law in the Co-Mining Face of Coal and Oil Shale in a Goaf—A Case Study in the Liangjia Coal Mine, China

    Directory of Open Access Journals (Sweden)

    Gang Wang

    2018-01-01

    Full Text Available The low-temperature oxidation law of coal and rock mass is the basis to study spontaneous combustion in goafs. In this paper, the low-temperature oxidation laws of coal, oil shale, and mixtures of coal and oil shale were studied by using laboratory programmed heating experiments combined with a field beam tube monitoring system. The results from the programmed heating experiments showed that the heat released from oil shale was less than that from coal. Coal had a lower carbon monoxide (CO-producing temperature than oil shale, and the mixture showed obvious inhibiting effects on CO production with an average CO concentration of about 38% of that for coal. Index gases were selected in different stages to determine the critical turning point temperature for each stage. The field beam tube monitoring system showed that the temperature field of the 1105 co-mining face of coal and oil shale in the goaf of the Liangjia Coal Mine presented a ladder-like distribution, and CO concentration was the highest for coal and lower for the mixture of coal and oil shale, indicating that the mixture of coal with oil shale had an inhibiting effect on CO production, consistent with the results from the programmed heating experiments.

  8. Seismic based characterization of total organic content from the marine Sembar shale, Lower Indus Basin, Pakistan

    Science.gov (United States)

    Aziz, Omer; Hussain, Tahir; Ullah, Matee; Bhatti, Asher Samuel; Ali, Aamir

    2018-02-01

    The exploration and production of unconventional resources has increased significantly over the past few years around the globe to fulfill growing energy demands. Hydrocarbon potential of these unconventional petroleum systems depends on the presence of significant organic matter; their thermal maturity and the quality of present hydrocarbons i.e. gas or oil shale. In this work, we present a workflow for estimating Total Organic Content (TOC) from seismic reflection data. To achieve the objective of this study, we have chosen a classic potential candidate for exploration of unconventional reserves, the shale of the Sembar Formation, Lower Indus Basin, Pakistan. Our method includes the estimation of TOC from the well data using the Passey's ΔlogR and Schwarzkofp's methods. From seismic data, maps of Relative Acoustic Impedance (RAI) are extracted at maximum and minimum TOC zones within the Sembar Formation. A geostatistical trend with good correlation coefficient (R2) for cross-plots between TOC and RAI at well locations is used for estimation of seismic based TOC at the reservoir scale. Our results suggest a good calibration of TOC values from seismic at well locations. The estimated TOC values range from 1 to 4% showing that the shale of the Sembar Formation lies in the range of good to excellent unconventional oil/gas play within the context of TOC. This methodology of source rock evaluation provides a spatial distribution of TOC at the reservoir scale as compared to the conventional distribution generated from samples collected over sparse wells. The approach presented in this work has wider applications for source rock evaluation in other similar petroliferous basins worldwide.

  9. Preferred orientation of phyllosilicates: Comparison of fault gouge, shale and schist

    International Nuclear Information System (INIS)

    Wenk, Hans-Rudolf; Kanitpanyacharoen, Waruntorn; Voltolini, Marco

    2010-01-01

    Samples of fault gouge from the San Andreas Fault drill hole (SAFOD), a shale from the North Sea sedimentary basin and schists from metamorphic rocks in the Alps have been analyzed with high energy synchrotron X-rays to determine preferred orientation of mica and clay minerals. The method relies on obtaining 2D diffraction images which are then processed with the crystallographic Rietveld method, implemented in the software MAUD, allowing for deconvolution of phases and extraction of their orientation distributions. It is possible to distinguish between detrital illite/muscovite and authigenic illite/smectite, kaolinite and chlorite, and muscovite and biotite, with strongly overlapping peaks in the diffraction pattern. The results demonstrate that phyllosilicates show large texture variations in various environments, where different mechanisms produce the rock microfabrics: fault gouge fabrics are quite weak and asymmetric with maxima for (001) in the range of 1.5-2.5 multiples of random distribution (m.r.d.). This is attributed to heterogeneous deformation with randomization, as well as dissolution-precipitation reactions. Shale fabrics have maxima ranging from 3 to 9 m.r.d. and this is due to sedimentation and compaction. The strongest fabrics were observed in metamorphic schists (10-14 m.r.d.) and developed by deformation as well as recrystallization in a stress field. In the analyzed samples, fabrics of co-existing quartz are weak. All phyllosilicate textures can be explained by orientation of (001) platelets, with no additional constraints on a-axes.

  10. Use for refuse of shale carbonization

    <