Removing fault shadow distortions by fault‐constrained tomography

Abstract

Fault Shadows manifest a serious challenge to successful seismic imaging. The major part of this problem is caused by rapid lateral velocity changes within fault zones. Seismic rays traveling through fault areas experience geometrical and traveltime distortions which result in poor seismic images and non‐hyperbolic moveout anomalies in areas below such fault planes (Fault Shadow Zones). Fault Constrained Tomography (FCT) is a special depth processing technique developed to solve this problem by building detailed high resolution interval velocity model for such zones. Combined with Pre‐Stack Depth Migration (PSDM) this technique allows to remove Fault Shadow distortions from seismic images.