Efficient and simple simulation method for matching stress‐permeability test results

Abstract In the process of pressure‐relief mining in high gas coal seams and hydraulic fracturing deep coalbed methane, a large number irregular fractures are generated inside coal, which becomes main path for migration. The stress sensitivity directly affects migration characteristics coal. For better matching stress‐permeability test results, fluid–solid coupling simulation method with joint stiffness changing (JSCM), accommodates fracture (or joint) through acting on fracture, is proposed. permeability under different states was matched compared laboratory experiment. This has following advantages traditional fixing (JSFM). (1) JSCM does not need to set residual aperture, can match wider range stresses, so there no upper limit principle. (2) results than JSFM. A parameter‐determining given flow results. Based JSCM, an confining axial stresses determined. show that occurrence segmental dip angles persistent determines flow. With increase stress, aperture horizontal section reduced, causing decrease seepage capacity. It whole fracture. While vertical greatly reduced rate reducing greatly.