The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Thibault Candela - One of the best experts on this subject based on the ideXlab platform.
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evolution of the transport properties of fractures subject to thermally and mechanically activated Mineral Alteration and redistribution
Geofluids, 2016Co-Authors: Igor Faoro, Derek Elsworth, Thibault CandelaAbstract:Strong feedbacks link temperature (T), hydrologic flow (H), mechanical deformation (M), and chemical Alteration (C) in fractured rock. These processes are interconnected as one process affects the initiation and progress of another. Dissolution and precipitation of Minerals are affected by temperature and stress, and can result in significant changes in permeability and solute transport characteristics. Understanding these couplings is important for oil, gas, and geothermal reservoir engineering, for CO2 sequestration, and for waste disposal in underground repositories and reservoirs. To experimentally investigate the interactions between THMC processes in a naturally stressed fracture, we report on heated (25°C up to 150°C) flow-through experiments on fractured core samples of Westerly granite. These experiments examine the influence of thermally and mechanically activated dissolution of Minerals on the mechanical (stress/strain) and transport (permeability) responses of fractures. The evolutions of the permeability and relative hydraulic aperture of the fracture are recorded as thermal and stress conditions’ change during the experiments. Furthermore, the efflux of dissolved Mineral mass is measured periodically and provides a record of the net mass removal, which is correlated with observed changes in relative hydraulic fracture aperture. During the experiments, a significant variation of the effluent fluid chemistry is observed and the fracture shows large changes in permeability to the changing conditions both in stress and in temperature. We argue that at low temperature and high stresses, mechanical crushing of the asperities and the production of gouge explain the permeability decrease although most of the permeability is recoverable as the stress is released. While at high temperature, the permeability changes are governed by mechanical deformation as well as chemical processes, in particular, we infer dissolution of Minerals adjacent to the fracture and precipitation of kaolinite.
Feng Pan - One of the best experts on this subject based on the ideXlab platform.
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Forecasting evolution of formation water chemistry and long-term Mineral Alteration for GCS in a typical clastic reservoir of the Southwestern United States
International Journal of Greenhouse Gas Control, 2016Co-Authors: Feng Pan, Brian Mcpherson, Rich Esser, Ting Xiao, Martin S. Appold, Wei Jia, Nathan MoodieAbstract:Abstract Groundwater chemistry and rock properties can change dramatically following CO 2 injection in a geologic sequestration system. A favored target for subsurface sequestration is clastic reservoirs, due to their limited tendency to impact water quality or porosity and permeability due to dissolution or precipitation compared to carbonate reservoirs. However, most clastic reservoirs will exhibit geochemical changes, especially during the injection phase and over the long term. And, in most oil reservoirs targeted for enhanced recovery and concomitant CO 2 storage, water-alternating-gas, or so-called “WAG” injection schemes are preferred to maximize CO 2 mobility and minimize viscous fingering of CO 2 . Under WAG schemes, reactive transport processes and resulting water quality changes and rock property changes may differ when compared to continuous CO 2 injection (CCI) schemes. The purpose of this paper is to analyze and quantify the extent of geochemical changes to both water chemistry and rock properties, specifically for the “low hanging fruit” of CO 2 storage targets: a sandstone formation using a WAG injection scheme. Specifically, the objectives of this study are: (1) to evaluate the evolution of formation water chemistry and Mineral Alteration induced by WAG injection in a typical southwestern U.S. sandstone reservoir; (2) to quantify CO 2 trapping mechanisms and associated porosity and permeability evolution over the long term following injection; (3) to investigate whether different injection schemes (WAG vs. CCI designs) may affect the evolution of water chemistry and Mineral Alteration during the injection phase. Because it is not just a candidate formation, but rather is already undergoing CO 2 injection for enhanced oil recovery (EOR) and sequestration, the Morrow Sandstone Formation in the Anadarko Basin of Texas was selected as representative of a typical clastic CCS candidate. A numerical reactive transport model of a 5-spot well pattern in the Morrow Formation was developed and used to simulate WAG injection and subsequent geochemical processes. Initial conditions of flow and geochemistry were based on actual measurements from the Morrow Formation within the Farnsworth EOR field in northern Texas. The simulation design period included WAG injection for 25 years (injection phase) followed by 975 years of post-injection monitoring (arbitrary post-injection phase). Simulation results suggest that formation water chemistry (pH, aqueous species Ca 2+ , Mg 2+ , Fe 2+ , HCO 3 − ) dramatically changes after CO 2 arrival, and Mineral dissolution (with an increase in porosity and permeability) is greatest near the injection well during the injection phase. The simulated increase in porosity is approximately 2.7%, with a maximum permeability increase of almost 8.4% at the end of the injection phase. The possibility of halite Mineral precipitation, a phenomenon observed in many injection scenarios, was specifically examined. However, no simulations yielded halite precipitation. Mineral precipitation increases in the long term (hundreds of years), resulting in both increased CO 2 trapping by Mineralization as well as decreased porosity and permeability. Finally, the analysis of impacts of WAG injection during the injection phase suggests that the extent of CO 2 -rock geochemical interactions following WAG increases compared to CCI scenarios. Specifically, the extra water injected (in WAG) facilitates aqueous reactions compared to CCI, which “dries out” the formation. Changes in porosity and permeability for CCI schemes are much less than those for WAG schemes, a factor to consider with respect to how these different schemes may impact injectivity.
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Impacts of hydrological heterogeneities on caprock Mineral Alteration and containment of CO2 in geological storage sites
International Journal of Greenhouse Gas Control, 2014Co-Authors: Hailong Tian, Gaofan Yue, Feng Pan, Brian Mcpherson, Prashanth MandalapartyAbstract:Abstract For long-term geological CO 2 storage, heterogeneity of hydrological parameters (i.e., porosity and permeability in this study) leads to the development of heterogeneities in physical parameters within the reservoir that are critical to the risk assessment and monitoring requirements of the project. Caprock heterogeneity is also a critical aspect of CO 2 storage planning because of the implications for storage integrity and associated risk assessment. The objectives of this study are: (1) to assess the effects of heterogeneity on caprock Mineral Alteration and associated evolution of sealing quality; (2) to elucidate how hydrologic heterogeneities affect CO 2 migration within caprock, and (3) to characterize the relative roles (importance) of porosity heterogeneity incorporated into permeability heterogeneity versus permeability heterogeneity only. A 2-dimensional (2D) model of the Xingouzui formation in the Jianghan Basin of China was developed for this analysis. Heterogeneity in porosity was parameterized employing a specific empirical relationship between permeability and porosity obtained by regression analysis of the field data in the Jianghan Basin. Homogeneous Mineral compositions of reservoir and caprock from the Jianghan Basin were used in all simulations. Three model permutations were evaluated, including a homogeneous case, a case with heterogeneity in permeability only, and a case with heterogeneity in both porosity and permeability. Simulation results indicated significant differences among these cases with respect to forecasted Mineral Alterations, associated evolution of caprock sealing quality, and CO 2 migration within the caprock. The impacts of hydrological heterogeneities depend not only on Mineralogical composition but also on time scale. The relative roles of porosity heterogeneity and permeability heterogeneity were similar, though porosity variability led to slightly more retarded vertical CO 2 migration and increased horizontal propagation, and enhanced Mineral dissolution resulting in weakened caprock sealing quality.
Nathan Moodie - One of the best experts on this subject based on the ideXlab platform.
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Forecasting evolution of formation water chemistry and long-term Mineral Alteration for GCS in a typical clastic reservoir of the Southwestern United States
International Journal of Greenhouse Gas Control, 2016Co-Authors: Feng Pan, Brian Mcpherson, Rich Esser, Ting Xiao, Martin S. Appold, Wei Jia, Nathan MoodieAbstract:Abstract Groundwater chemistry and rock properties can change dramatically following CO 2 injection in a geologic sequestration system. A favored target for subsurface sequestration is clastic reservoirs, due to their limited tendency to impact water quality or porosity and permeability due to dissolution or precipitation compared to carbonate reservoirs. However, most clastic reservoirs will exhibit geochemical changes, especially during the injection phase and over the long term. And, in most oil reservoirs targeted for enhanced recovery and concomitant CO 2 storage, water-alternating-gas, or so-called “WAG” injection schemes are preferred to maximize CO 2 mobility and minimize viscous fingering of CO 2 . Under WAG schemes, reactive transport processes and resulting water quality changes and rock property changes may differ when compared to continuous CO 2 injection (CCI) schemes. The purpose of this paper is to analyze and quantify the extent of geochemical changes to both water chemistry and rock properties, specifically for the “low hanging fruit” of CO 2 storage targets: a sandstone formation using a WAG injection scheme. Specifically, the objectives of this study are: (1) to evaluate the evolution of formation water chemistry and Mineral Alteration induced by WAG injection in a typical southwestern U.S. sandstone reservoir; (2) to quantify CO 2 trapping mechanisms and associated porosity and permeability evolution over the long term following injection; (3) to investigate whether different injection schemes (WAG vs. CCI designs) may affect the evolution of water chemistry and Mineral Alteration during the injection phase. Because it is not just a candidate formation, but rather is already undergoing CO 2 injection for enhanced oil recovery (EOR) and sequestration, the Morrow Sandstone Formation in the Anadarko Basin of Texas was selected as representative of a typical clastic CCS candidate. A numerical reactive transport model of a 5-spot well pattern in the Morrow Formation was developed and used to simulate WAG injection and subsequent geochemical processes. Initial conditions of flow and geochemistry were based on actual measurements from the Morrow Formation within the Farnsworth EOR field in northern Texas. The simulation design period included WAG injection for 25 years (injection phase) followed by 975 years of post-injection monitoring (arbitrary post-injection phase). Simulation results suggest that formation water chemistry (pH, aqueous species Ca 2+ , Mg 2+ , Fe 2+ , HCO 3 − ) dramatically changes after CO 2 arrival, and Mineral dissolution (with an increase in porosity and permeability) is greatest near the injection well during the injection phase. The simulated increase in porosity is approximately 2.7%, with a maximum permeability increase of almost 8.4% at the end of the injection phase. The possibility of halite Mineral precipitation, a phenomenon observed in many injection scenarios, was specifically examined. However, no simulations yielded halite precipitation. Mineral precipitation increases in the long term (hundreds of years), resulting in both increased CO 2 trapping by Mineralization as well as decreased porosity and permeability. Finally, the analysis of impacts of WAG injection during the injection phase suggests that the extent of CO 2 -rock geochemical interactions following WAG increases compared to CCI scenarios. Specifically, the extra water injected (in WAG) facilitates aqueous reactions compared to CCI, which “dries out” the formation. Changes in porosity and permeability for CCI schemes are much less than those for WAG schemes, a factor to consider with respect to how these different schemes may impact injectivity.
Brian Mcpherson - One of the best experts on this subject based on the ideXlab platform.
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Forecasting evolution of formation water chemistry and long-term Mineral Alteration for GCS in a typical clastic reservoir of the Southwestern United States
International Journal of Greenhouse Gas Control, 2016Co-Authors: Feng Pan, Brian Mcpherson, Rich Esser, Ting Xiao, Martin S. Appold, Wei Jia, Nathan MoodieAbstract:Abstract Groundwater chemistry and rock properties can change dramatically following CO 2 injection in a geologic sequestration system. A favored target for subsurface sequestration is clastic reservoirs, due to their limited tendency to impact water quality or porosity and permeability due to dissolution or precipitation compared to carbonate reservoirs. However, most clastic reservoirs will exhibit geochemical changes, especially during the injection phase and over the long term. And, in most oil reservoirs targeted for enhanced recovery and concomitant CO 2 storage, water-alternating-gas, or so-called “WAG” injection schemes are preferred to maximize CO 2 mobility and minimize viscous fingering of CO 2 . Under WAG schemes, reactive transport processes and resulting water quality changes and rock property changes may differ when compared to continuous CO 2 injection (CCI) schemes. The purpose of this paper is to analyze and quantify the extent of geochemical changes to both water chemistry and rock properties, specifically for the “low hanging fruit” of CO 2 storage targets: a sandstone formation using a WAG injection scheme. Specifically, the objectives of this study are: (1) to evaluate the evolution of formation water chemistry and Mineral Alteration induced by WAG injection in a typical southwestern U.S. sandstone reservoir; (2) to quantify CO 2 trapping mechanisms and associated porosity and permeability evolution over the long term following injection; (3) to investigate whether different injection schemes (WAG vs. CCI designs) may affect the evolution of water chemistry and Mineral Alteration during the injection phase. Because it is not just a candidate formation, but rather is already undergoing CO 2 injection for enhanced oil recovery (EOR) and sequestration, the Morrow Sandstone Formation in the Anadarko Basin of Texas was selected as representative of a typical clastic CCS candidate. A numerical reactive transport model of a 5-spot well pattern in the Morrow Formation was developed and used to simulate WAG injection and subsequent geochemical processes. Initial conditions of flow and geochemistry were based on actual measurements from the Morrow Formation within the Farnsworth EOR field in northern Texas. The simulation design period included WAG injection for 25 years (injection phase) followed by 975 years of post-injection monitoring (arbitrary post-injection phase). Simulation results suggest that formation water chemistry (pH, aqueous species Ca 2+ , Mg 2+ , Fe 2+ , HCO 3 − ) dramatically changes after CO 2 arrival, and Mineral dissolution (with an increase in porosity and permeability) is greatest near the injection well during the injection phase. The simulated increase in porosity is approximately 2.7%, with a maximum permeability increase of almost 8.4% at the end of the injection phase. The possibility of halite Mineral precipitation, a phenomenon observed in many injection scenarios, was specifically examined. However, no simulations yielded halite precipitation. Mineral precipitation increases in the long term (hundreds of years), resulting in both increased CO 2 trapping by Mineralization as well as decreased porosity and permeability. Finally, the analysis of impacts of WAG injection during the injection phase suggests that the extent of CO 2 -rock geochemical interactions following WAG increases compared to CCI scenarios. Specifically, the extra water injected (in WAG) facilitates aqueous reactions compared to CCI, which “dries out” the formation. Changes in porosity and permeability for CCI schemes are much less than those for WAG schemes, a factor to consider with respect to how these different schemes may impact injectivity.
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Impacts of hydrological heterogeneities on caprock Mineral Alteration and containment of CO2 in geological storage sites
International Journal of Greenhouse Gas Control, 2014Co-Authors: Hailong Tian, Gaofan Yue, Feng Pan, Brian Mcpherson, Prashanth MandalapartyAbstract:Abstract For long-term geological CO 2 storage, heterogeneity of hydrological parameters (i.e., porosity and permeability in this study) leads to the development of heterogeneities in physical parameters within the reservoir that are critical to the risk assessment and monitoring requirements of the project. Caprock heterogeneity is also a critical aspect of CO 2 storage planning because of the implications for storage integrity and associated risk assessment. The objectives of this study are: (1) to assess the effects of heterogeneity on caprock Mineral Alteration and associated evolution of sealing quality; (2) to elucidate how hydrologic heterogeneities affect CO 2 migration within caprock, and (3) to characterize the relative roles (importance) of porosity heterogeneity incorporated into permeability heterogeneity versus permeability heterogeneity only. A 2-dimensional (2D) model of the Xingouzui formation in the Jianghan Basin of China was developed for this analysis. Heterogeneity in porosity was parameterized employing a specific empirical relationship between permeability and porosity obtained by regression analysis of the field data in the Jianghan Basin. Homogeneous Mineral compositions of reservoir and caprock from the Jianghan Basin were used in all simulations. Three model permutations were evaluated, including a homogeneous case, a case with heterogeneity in permeability only, and a case with heterogeneity in both porosity and permeability. Simulation results indicated significant differences among these cases with respect to forecasted Mineral Alterations, associated evolution of caprock sealing quality, and CO 2 migration within the caprock. The impacts of hydrological heterogeneities depend not only on Mineralogical composition but also on time scale. The relative roles of porosity heterogeneity and permeability heterogeneity were similar, though porosity variability led to slightly more retarded vertical CO 2 migration and increased horizontal propagation, and enhanced Mineral dissolution resulting in weakened caprock sealing quality.
M. Jullien - One of the best experts on this subject based on the ideXlab platform.
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Impact of iron-reducing bacteria on the properties of argillites in the context of radioactive waste geological disposal
Applied Clay Science, 2013Co-Authors: L. Esnault, M. Libert, F. Marsal, Olivier Bildstein, C. Mustin, M. JullienAbstract:The presence of indigenous microorganisms in deep clayey geological formations raises the issue, regarding radioactive waste geological disposal, of the influence of bacterial activity on the confinement properties of materials, including the clayey host rock. Iron-reducing bacteria (IRB) activity is assessed in batch experiments in the presence of argillite samples from an in situ experimental laboratory at Tournemire (Aveyron, France). The results show the availability of structural Fe(III) from the clay Minerals for biochemical reactions (bioreduction). In laboratory conditions, a significant impact of IRB on the Alteration of clay Minerals, mainly the illite-smectite mixed layer (I-Sm), is indeed observed. Such reactions may locally modify the physicochemical conditions and the stability of clay Minerals (essentially smectites) prevailing in such deep facilities. More generally, bacterial activity could play an important role on clay Mineral Alteration and in situ experiments need to be performed in order to quantify the reaction rates and show the representative of these phenomena in the framework of the safety assessment of waste disposal.