Nonlinear fluid flow regimes in fractured shale:Impact of confining stresses and water-supercritical CO_(2) interactionsOA
The coupled chemo-mechanical impact of supercritical CO_(2)-H_(2)O(ScCO_(2)-H_(2)O)reactions on fracture geometry and nonlinear flow regimes in deep shale under confining pressures remains inadequately quantified.This study systematically investigates the effects of ScCO_(2)-H_(2)O-shale interactions on fracture morphology and flow properties under confining pressures from 15 MPa to 40 MPa by integrating XRD(X-ray diffraction),micro-CT,3D surface profilometry,and multistage steady-state flow experiments.The results demonstrate that ScCO_(2)-H_(2)O exposure drives pyrite/feldspar dissolution and localized clay precipitation,resulting in fracture branching and macroscopic aperture regularization.Critically,confining pressure dictates the net hydraulic response:under low confining pressure(15-25 MPa),dissolution dominates,enhancing permeability,flow efficiency(Q/VP),and pre-linear flow behavior(n<1).At high confining pressures(30-40 MPa)mechanical compaction and mineral precipitation amplify flow resistance,shifting the flow regime toward quasi-linear behavior,as inertial effects become negligible compared to dominant viscous forces and increased flow resistance.Confining pressure thus critically mediates the dissolution-precipitation balance during ScCO_(2)-H_(2)O treatment,with an optimal window of 15-25 MPa identified for enhancing conductivity while minimizing clogging risk.These findings provide a quantitative framework for predicting stress-dependent flow evolution in chemically altered shale fractures.
Bingbin Xie;Jingqiang Tan;Qiao Lyu;Chenger Hu;Xindong Li;Yonggang Ding;Gan Feng
Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,School of Geosciences and Info-physics,Central South University,Changsha,410083,ChinaKey Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,School of Geosciences and Info-physics,Central South University,Changsha,410083,ChinaState Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation,Hainan University,Haikou,570228,ChinaCollege of Environment and Resources,Xiangtan University,Xiangtan,411105,ChinaKey Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,School of Geosciences and Info-physics,Central South University,Changsha,410083,ChinaKey Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,School of Geosciences and Info-physics,Central South University,Changsha,410083,ChinaCollege of Water Resources&Hydropower,Sichuan University,Chengdu,610065,China
能源科技
Shale gasScCO_(2)-H_(2)O interactionsNonlinear flowCCUSFracture geometry
《Natural Gas Industry B》 2026 (1)
P.44-59,16
support from the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC1021)the Natural Science Foundation of Sichuan Province(Grant No.2025YFHZ0323).-。
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