Wavefield Simulation With The Pseudo-Spectral Method In Anisotropic Viscoelastic And Porous Media

Effective media theory has to be close to describing actual medium, which is required by more and more researches on complicated earth medium model with the improvement of geological layers studies and seismic wave dynamics. Studies on simulation of seismic wavefield in complex medium is helpful for people to understand the seismic wave propagation in actual medium and perform geological interpretation and reservoir predication with field seismic data. Thus, in order to describe and identify reservoirs more accurately, several characteristics of actual earth medium must be considered comprehensively, such as anisotropy, viscoelasticity and porosity, etc.In this paper,a new media model is presented, the anisotropic- viscoelastic and porous media. According to solid anisotropic theory, Biot theory and viscoelastic theory, viscidity into the rock framework of two- phase anisotropic medium is introduced to establish the constitutive relationship. Finally, the wave equations in 3D anisotropic viscoelastic and porous media are derived. Using pseudo-spectral method, forward modeling in several different 2D medium is achieved, including anisotropic medium, anisotropic viscoelastic medium, anisotropic two-phase medium and anisotropic viscoelastic porous medium. Numerical simulation results are clear with obvious boundary absorption.The anisotropic viscoelastic porous medium established in this paper can show the anisotropy, viscoelasticity and porosity of the actual stratum exactly which can be seen from analysis and comparison of the results. And also, the pseudo-spectral method is approved as an effective forward method.