The main objective of this paper is to investigate and analyse the thermo-hydro-mechanical（THM） coupling phenomena and their influences on the repository safety.In this paper,the high-level waste（HLW） disposal con...The main objective of this paper is to investigate and analyse the thermo-hydro-mechanical（THM） coupling phenomena and their influences on the repository safety.In this paper,the high-level waste（HLW） disposal concept in drifts in clay formation with backfilled bentonite buffer is represented numerically using the CODE BRIGHT developed by the Technical University of Catalonia in Barcelona.The parameters of clay and bentonite used in the simulation are determined by laboratory and in situ experiments.The calculation results are presented to show the hydro-mechanical（HM） processes during the operation phase and the THM processes in the after-closure phase.According to the simulation results,the most probable critical processes for the disposal project have been represented and analyzed.The work also provides an input for additional development regarding the design,assessment and validation of the HLW disposal concept.展开更多
Carbon capture and storage in deep geological formations is a method to reduce greenhouse gas emissions.Supercritical CO_(2) is injected into a reservoir and dissolves in the brine.Under the impact of pressure and tem...Carbon capture and storage in deep geological formations is a method to reduce greenhouse gas emissions.Supercritical CO_(2) is injected into a reservoir and dissolves in the brine.Under the impact of pressure and temperature(P-T)the aqueous species of the CO_(2)-acidified brine diffuse through the cap rock where they trigger CO_(2)-watererock interactions.These geochemical reactions result in mineral dissolution and precipitation along the CO_(2) migration path and are responsible for a change in porosity and therefore for the sealing capacity of the cap rock.This study focuses on the diffusive mass transport of CO_(2) along a gradient of decreasing PeT conditions.The process is retraced with a one-dimensional hydrogeochemical reactive mass transport model.The semigeneric hydrogeochemical model is based on chemical equilibrium thermodynamics.Based on a broad variety of scenarios,including different initial mineralogical,chemical and physical parameters,the hydrogeochemical parameters that are most sensitive for safe long-term CO_(2) storage are identified.The results demonstrate that PeT conditions have the strongest effect on the change in porosity and the effect of both is stronger at high PeT conditions because the solubility of the mineral phases involved depends on PeT conditions.Furthermore,modeling results indicate that the change in porosity depends strongly on the initial mineralogical composition of the reservoir and cap rock as well as on the brine compositions.Nevertheless,a wide range of conditions for safe CO_(2) storage is identified.展开更多
基金financed and supported by the German research institute "Gesellschaft für Anlagen-und Reaktorsicherheit (GRS) mbH"
文摘The main objective of this paper is to investigate and analyse the thermo-hydro-mechanical（THM） coupling phenomena and their influences on the repository safety.In this paper,the high-level waste（HLW） disposal concept in drifts in clay formation with backfilled bentonite buffer is represented numerically using the CODE BRIGHT developed by the Technical University of Catalonia in Barcelona.The parameters of clay and bentonite used in the simulation are determined by laboratory and in situ experiments.The calculation results are presented to show the hydro-mechanical（HM） processes during the operation phase and the THM processes in the after-closure phase.According to the simulation results,the most probable critical processes for the disposal project have been represented and analyzed.The work also provides an input for additional development regarding the design,assessment and validation of the HLW disposal concept.
基金We would like to thank the anonymous reviewers for their constructive reviews that considerably improved the manuscript.
文摘Carbon capture and storage in deep geological formations is a method to reduce greenhouse gas emissions.Supercritical CO_(2) is injected into a reservoir and dissolves in the brine.Under the impact of pressure and temperature(P-T)the aqueous species of the CO_(2)-acidified brine diffuse through the cap rock where they trigger CO_(2)-watererock interactions.These geochemical reactions result in mineral dissolution and precipitation along the CO_(2) migration path and are responsible for a change in porosity and therefore for the sealing capacity of the cap rock.This study focuses on the diffusive mass transport of CO_(2) along a gradient of decreasing PeT conditions.The process is retraced with a one-dimensional hydrogeochemical reactive mass transport model.The semigeneric hydrogeochemical model is based on chemical equilibrium thermodynamics.Based on a broad variety of scenarios,including different initial mineralogical,chemical and physical parameters,the hydrogeochemical parameters that are most sensitive for safe long-term CO_(2) storage are identified.The results demonstrate that PeT conditions have the strongest effect on the change in porosity and the effect of both is stronger at high PeT conditions because the solubility of the mineral phases involved depends on PeT conditions.Furthermore,modeling results indicate that the change in porosity depends strongly on the initial mineralogical composition of the reservoir and cap rock as well as on the brine compositions.Nevertheless,a wide range of conditions for safe CO_(2) storage is identified.
