Prestack depth migration by means of controlled illumination

Abstract

The prestack depth migration process involves a huge amount of computations required for the extrapolation process of the prestack data. Especially for 3-D surveys, full prestack migration takes too much computation time to be economic yet. We propose an efficient as well as an accurate procedure that enables us to migrate prestack data in a target‐oriented way using the method of controlled illumination. Use of controlled illumination combined with depth migration is a special case of the more general concept of “areal” shot‐record migration. The method differs from conventional plane‐wave stacking methods in the sense that in the approach of controlled illumination the control of the source wavefield is put at the target, and by the fact that it is always followed by depth migration. It is shown that controlling the complexity of the incident wavefield at the target level leads to a high‐quality image in an efficient way.