Compensating Visco-Acoustic Effects in Anisotropic Resverse-Time Migration

Anelastic properties of the earth cause frequency dependent energy attenuation and phase distortion in seismic wave propagation. It is preferred that these unwanted effects be corrected in a prestack depth migration. Zhang et al (2010) introduced a visco-acoustic wave equation in the time domain for isotropic media. This paper extends the visco-acoustic wave equation for anisotropic case, and develops visco-acoustic reverse time migration algorithm for VTI medium. To validate the proposed wave equation, wave propagation is simulated on a homogeneous viscous VTI medium using a finite difference method. The wavefield snapshot shows predicted frequency dependent attenuation and dispersion. Synthetic and field data examples are also given.