Applications of the Boundary Absorption Using A Perfectly Matched Layer for Elastic Wave Simulation in Poroelstic Media

Abstract

AbstractIn elastic wave numerical modeling for a porous medium, artificial boundaries should be treated so that they have minimum effects on the modeling results. In this paper, a high‐order velocity‐stress staggered‐grid finite‐difference scheme, with a perfectly matched layer (PML) absorbing boundary condition was proposed for simulating wave propagation in poroelastic media. The construction of the perfectly matched layer was discussed in detail, and the implementation of the high‐order finite‐difference scheme of the PML boundary conditions was also studied. The numerical results were validated by using analytical solutions in a homogeneous porous model. The performance of the PML for body waves with various incidence angles and various absorbing thicknesses was demonstrated. Also, free surface Raleigh waves were investigated for their absorptions. The PML was compared with two kinds of absorption boundary conditions to confirm the efficiency of the PML method. Our numerical results show that the PML can greatly absorb or reduce outgoing waves, not only for body waves, but also for surface waves. The PML method is one of the best absorption boundary conditions for porous elastic wave modeling. This work will play an important role in investigating elastic wave response of inhomogeneous porous media, especially in studying borehole sonic logging response of heterogeneous porous media.