Solving the Fault Shadow Problem in the Wilcox Trend of South Texas

Imaging distortions in the footwall of faults in the Wilcox trend of South Texas are shown to be caused by velocity effects associated with the truncation of overlying high-velocity Queen City Sandstone and low-velocity Reklaw. The thinning of these units across the fault give rise to appreciable velocity sags and pull-ups. Moreover, this variability in the thickness of velocity bodies gives rise to nonhyperbolic reflections which create apparent disruptions in footwall reflections. The only imaging solution which is free of these artifacts is prestack depth migration. A synthetic example is used to demonstrate fault shadow Imaging artifacts and their elimination by depth imaging. Identical artifacts are identified on a real data set and the imaging Improvements from prestack depth imaging are demonstrated.