Anisotropic poromechanics of gas flow in sedimentary rocks

Solid deformation is always a crucial factor in the shale gas transport model. While previous studies always adopt the assumption of isotropic poroelastic deformation, anisotropic poroelastoplastic deformation is rarely considered, despite the anisotropy being a ubiquitous property of natural rocks. In this work, an anisotropic poromechanical model is established to analyze the matrix porosity and apparent permeability evolutions during the process of shale gas migration. A recently developed constitutive model appropriate for rocks exhibiting transverse isotropy in both the elastic and plastic responses is adopted in this work. Through the stress point simulation, a new double-U shape curve of apparent permeability is obtained, which cannot be reproduced from the assumption of isotropic poroelasticity.

Sep 5, 2023 — Sep 7, 2023