Pre-stack depth migration (Pre-SDM) is essential for seismic exploration in structured zones with strong velocity variations, such as the Gulf of Mexico (GOM) and the Gulf of Guinea (GOG).In such areas, where seismic targets are commonly located below intrusive salt bodies, the quality of Pre-SDM is very sensitive to the accuracy of the salt interpretation.
The advantages aside,3D Pre-Stack Depth migration remains a difficult and computationally expensive process that requires a great deal of interpretative input and QC. We present an innovative method which allows the geophysicist to quickly assess the “imaging potential” of sub-salt prospects without a full 3D iterative Pre-SDM. Once potential prospects are identified, we may continue with classical techniques in targeted zones. We first briefly outline the principles of the method and then demonstrate its benefits with a few real data examples.