Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications
Geological sequestration of CO2 is critical for deep decarbonization, but the geomechanical stability of coal reservoirs remains a major challenge. This study integrates nanoindentation, XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical d...
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| Format: | Article |
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Elsevier
2025-06-01
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| Series: | International Journal of Mining Science and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2095268625000837 |
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| author | Peng Liu Jingtao Yang Baisheng Nie Ang Liu Wei Zhao Hao Xu Hengyi He |
| author_facet | Peng Liu Jingtao Yang Baisheng Nie Ang Liu Wei Zhao Hao Xu Hengyi He |
| author_sort | Peng Liu |
| collection | DOAJ |
| description | Geological sequestration of CO2 is critical for deep decarbonization, but the geomechanical stability of coal reservoirs remains a major challenge. This study integrates nanoindentation, XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO2 injection. The main results show that 4 d of ScCO2 treatment caused 50.47%–80.99% increase in load–displacement deformation and 26.92%–76.17% increase in creep depth at peak load, accompanied by 55.01%–63.38% loss in elastic modulus and 52.83%–74.81% reduction in hardness. The degradation exhibited biphasic kinetics, characterized by rapid surface-driven weakening (0–2 d), followed by stabilized matrix-scale pore homogenization (2–4 d). ScCO2 preferentially dissolved carbonate minerals (dolomite), driving pore network expansion and interfacial debonding, while silicate minerals resisted dissolution but promoted structural homogenization. These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes. The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO2 enhanced coalbed methane recovery. |
| format | Article |
| id | doaj-art-97bae8866ecc40d6827b03b0e35cbc03 |
| institution | Matheson Library |
| issn | 2095-2686 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | International Journal of Mining Science and Technology |
| spelling | doaj-art-97bae8866ecc40d6827b03b0e35cbc032025-07-11T04:31:12ZengElsevierInternational Journal of Mining Science and Technology2095-26862025-06-01356961973Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implicationsPeng Liu0Jingtao Yang1Baisheng Nie2Ang Liu3Wei Zhao4Hao Xu5Hengyi He6State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China; Corresponding author.Department of Energy and Mineral Engineering, G3 Center and Energy Institute, The Pennsylvania State University, University Park, PA 16802, USASchool of Emergency Management and Safety Engineering, China University of Mining & Technology-Beijing, Beijing 100083, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, ChinaGeological sequestration of CO2 is critical for deep decarbonization, but the geomechanical stability of coal reservoirs remains a major challenge. This study integrates nanoindentation, XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO2 injection. The main results show that 4 d of ScCO2 treatment caused 50.47%–80.99% increase in load–displacement deformation and 26.92%–76.17% increase in creep depth at peak load, accompanied by 55.01%–63.38% loss in elastic modulus and 52.83%–74.81% reduction in hardness. The degradation exhibited biphasic kinetics, characterized by rapid surface-driven weakening (0–2 d), followed by stabilized matrix-scale pore homogenization (2–4 d). ScCO2 preferentially dissolved carbonate minerals (dolomite), driving pore network expansion and interfacial debonding, while silicate minerals resisted dissolution but promoted structural homogenization. These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes. The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO2 enhanced coalbed methane recovery.http://www.sciencedirect.com/science/article/pii/S2095268625000837CO2 sequestrationNanoindentationReservoirs stabilityCoal mechanics |
| spellingShingle | Peng Liu Jingtao Yang Baisheng Nie Ang Liu Wei Zhao Hao Xu Hengyi He Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications International Journal of Mining Science and Technology CO2 sequestration Nanoindentation Reservoirs stability Coal mechanics |
| title | Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications |
| title_full | Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications |
| title_fullStr | Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications |
| title_full_unstemmed | Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications |
| title_short | Time-evolution of ScCO2-weakened coal integrity: Chemo-hydromechanical coupling and geological sequestration implications |
| title_sort | time evolution of scco2 weakened coal integrity chemo hydromechanical coupling and geological sequestration implications |
| topic | CO2 sequestration Nanoindentation Reservoirs stability Coal mechanics |
| url | http://www.sciencedirect.com/science/article/pii/S2095268625000837 |
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