A spectral element time domain (SETD) method based on poroelastic linear slip conditions for 3D wave propagation in fractured porous media

Abstract

In this study, we present a spectral element time domain (SETD) method for the simulation of wave propagation in fractured porous media. To avoid volumetric meshing of the extremely thin-layer fractures, we incorporate the fractures into spectral element model by treating them as geometrical interfaces, where the interaction between solid deformation and pore fluid flow is described by the poroelastic linear-slip conditions across the fractures. For different kinds of fractures (i.e. permeable, open, and impermeable), the explicit time schemes are presented for solving the stress tensor and fluid pressure over the fracture surfaces, which are subsequently implemented into the SETD framework to involve both elastic scattering and wave-induced fluid flow (WIFF) effects. Through various numerical examples, the proposed algorithm is shown to be able to accurately and effectively simulate and characterize the wave propagation in 3D porous media containing discrete and intersecting fractures with different permeabilities.