Anisotropic Wave Separation Elastic Reverse Time Migration Based on the Pseudo-Decoupled Wave Equations in VTI Media

Abstract

Seismic exploration risk can be decreased by high-precision migration techniques. Imaging anisotropic multicomponent seismic data in areas with developed cracks and sedimentation is challenging. We introduce an efficient anisotropic wave separation elastic reverse time migration (RTM) to image anisotropic multicomponent seismic data in this letter. The elastic waves are decomposed into P- and S-waves for subsequent anisotropic wave separation elastic RTM (AWSERTM) to reduce crosstalk noise and improve imaging accuracy. In this new method, the pseudo-decoupled wave equations of transverse isotropic (TI) media with a vertical symmetry axis vertical transversely isotropic (VTI) are derived based on the decomposition of the anisotropic elastic stiffness parameters into anisotropic P- and S-wave stiffness parameters. Forward and backward anisotropic P- and S-waves can then be efficiently obtained by numerical solution of the pseudo-decoupled wave equations using the finite difference (FD) method. Combining the vector imaging condition, the high-quality AWSERTM’s results can be obtained. Synthetic examples from the modified HESS VTI model demonstrate the correctness and progressiveness of the proposed method.