A fully coupled fracture equivalent continuum-dual porosity model for hydro-mechanical process in fractured shale gas reservoirs

Abstract

A fully coupled fracture equivalent continuum-dual porosity model is proposed to investigate hydro-mechanical coupling phenomena in fractured porous media. An improved fracture tensor is then developed to transform the local discontinuities at cell level to the anisotropic continuum at macro-scale. This model is incorporated into a set of nonlinear partial differential equations and numerically solved by multi-time-step finite element algorithm. The approach is then applied to a field-scale simulation of shale gas reservoir. Results indicate that the proposed method can be applied to insights into the field-scale hydro-mechanical coupling with high-density fractures in any arbitrary orientation within manageable computational cost.