f Imaging Subsalt Structural Targets by 3D Prestack Depth Migration

We present a case history on delineating subsalt structures in the Gulf of Mexico. Strong lateral velocity variations associated with salt diapirism makes depth migration imperative to accurately image subsalt structures. Non-hyperbolic moveouts of subsap reflection events in CMP gathers makes CMP stack undesirable as input to depth migration, and requires depth migration before stack. Moreover, the three-dimensional character of the boundary between the salt body and surrounding strata requires 3-D imaging strategies.