Numerical Investigation of the Structure of Fracture Network Impact on the Fluid Flow through a Poroelastic Medium

Abstract

Two-dimensional single-phase flow of a weakly compressible fluid through a deformable fractured-porous medium is considered. A poroelastic model is used for coupled simulation of the fluid flow and the related changes in the stress state of the medium. Fracture network is simulated using the discrete fracture model. The fractures in the region under consideration have random location and orientations, and the fracture length distribution follows a power law. The dependence of the hydraulic properties of fractured porous media on its stress-strain state and the structure of the fracture network is studied. Numerical study was performed for various realizations of fracture network obtained using multiple random generation. It is found that the permeability of the fractured porous medium is determined mainly by the structure of the fracture system characterized by the percolation parameter. According to the simulations results, hydraulic properties are significantly affected by the stress-strain state only for connected fracture systems. An approximation is proposed to define the dependence of the equivalent permeability of a fractured-porous medium on the following parameters: the connectivity of the fracture system, the stress-strain state of the medium, and fracture properties such as stiffness and aperture.