Abstract：There is a variety of salt domes with complex shapes and large thickness in the working area,which cause serious seismic ray distortion and pull-up of underlying strata,and impact sub-salt seismic reflections and accurate structure imaging.The comparison between post-stack time migration and pre-stack depth migration results indicates that 3D pre-stack depth migration can successfully image the sub-salt carbonate rocks and restore the true shape of the underlying structures.This paper analyzes pre-stack depth migration with theoretical model and real data applications,and demonstrates that 3D pre-stack depth migration can eliminate the pull-up impact from salt domes on the underlying strata and achieve accurate images of sub-salt targets.The drilling results confirm that sub-salt structures from pre-stack depth migration are reliable,the success rate of drilling is improved,and the exploration risk is reduced.
