Up- and Down-going Wave Multiples RTM Imaging for VSP

SUMMARY Vertical seismic profile (VSP) using reverse time migration (RTM) with up- and down-going wave separation can produce VSP images with improved image coverage compared to a conventional imaging result . We go beyond first order up- and down-going signal to use higher-order surface-related multiples as signal to maximize subsurface illumination. By separating up- and down-going waves, we reduce the interference between up- and down-going wave. We test our method on a synthetic data generated by a Born’s method on a fourlayer model with a normal fault. By applying up- and downgoing wave separation, we inject source wavelet and receiver data in different locations using mirror imaging and RTM process. The migrated image provides accurate velocity, depth and Q attenuation information to tie well-log and surface seismic data.