SYSTEM AND METHOD FOR VELOCITY ANALYSIS IN THE PRESENCE OF CRITICAL REFLECTIONS

摘要

A method is described for processing residual moveout in seismic image data gathers representing critical reflections. The method includes receiving seismic image data arranged as a function of an angle or offset parameter including a high-velocity-contrast event with post-critical. The method also includes applying a wavelet de- stretch filter (32) to the seismic data to correct wavelet stretching. The method also includes applying a fan-filter (33) to remove coherent noise in the one or more post-critical traces; picking residual moveout (34) of the high-velocity-contrast event; adjacent-trace differencing (35) to detect the impact of phase change at critical reflections in residual moveouts, and applying a median-filter (36) to the residual moveout to reduce the impact of phase change of the high-velocity-contrast event in the one or more post-critical traces. The median-filtered and reconstructed residual moveout (37) is used for improving a velocity model (38A) used for generating the seismic image gathers (30A).