Study on 2D / 3C wave propagation in two-phase anisotropic media using the rotated staggered-grid method

Based on two-phase Biot model,the 2D / 3C velocity-stress elastic wave equation of the two-phase TTI media was deduced. The solution of this equation using high accuracy rotated staggered-grid (RSG) finite difference time do- main (FDTD) method was presented. The unsplit convolutional perfectly matched layer ( CPML) method was intro- duced into this method. To test this method,elastic waves propagation in two-phase homogeneous TTI media was simu- lated. The results obtained from RSG-FDTD simulation show that four types of wave,the fast S-wave,the low S-wave,the fast P-wave and the slow P-wave propagation in the two-phase TTI media can be clearly simulated. The shear wave split- ting,the wave fronts corners and the phenomena of trifurcation can be seen obviously. The CPML has a perfect absorption effect on the boundary reflection. Compared with the standard stagger-grid (SSG),the RSG method is stable and can provide accurate solutions. The RSG-FDTD method is a practical technique for seismic wave simulation.