On the anisotropy, thermoplasticity, and multiscale poromechanics of shale

Abstract

We synthesize the framework reported in previous works for hydromechanical analysis of coupled fluid flow-solid deformation in shale accommodating the following important features: (a) double porosity concept allowing Darcy flow to occur through the distributed microfractures and non-Darcy flow to prevail through the much smaller nanopores, (b) structural anisotropy in the mechanical response, and (c) thermal effects in the mechanical constitutive description. The work involves coupling of fluid flow with solid deformation by idealizing the shale as a deformable mixture of two overlapping porosity subdomains.