oa Multiple Removal by Wavepath Migration

Multiple removal by wavepath migration is used for discriminating primary reflections from multiple reflections during the migration process. Both the take-off and incidence angles are computed from the data so that rays can be traced from both the source and the receiver positions. An event is a primary reflections as long as the rays intersect and the intersection point has a reflection traveltime equal to the observed traveltime. In contrast，an event is a multiple reflection if the intersection point of the rays has a reflection traveltime different from he observed traveltime. Numerical results for a three-layer model show that multiple removal by wavepath migration can clearly resolve the true interfaces and effectively remove the false structures generated by multiple energy. Numerical results show that the method can effectively remove the migration artifacts generated by surface-related multiples. When near-offset data are not used, the migrated images is nearly free of multiple-related artifacts. However, the method becomes less effective with decreasing source-receiver offset of the traces.