Complex-salt Model Building Using a Combination of Interactive Beam Migration and Layer-stripping RTM

A new salt velocity model building methodology is proposed which allows effective testing of different salt interpretation scenarios. In this methodology, we combine the strength of efficiency from interactive beam migration with the accuracy of layer-stripping RTM to derive a more accurate salt geometry. Using interactive salt geometry editing and efficient beam migration, a large number of salt interpretation scenarios are quickly tested and narrowed down to a small number of likely salt interpretation cases. This is followed by a reduced number of layer-stripping RTM runs to single out the final salt velocity model. Redatuming the wavefield from surface to a user defined subsurface datum plays a pivotal role in this methodology; it enables improving the quality of beam migration and the efficiency of RTM.