A new algorithm for converted wave pre-stack migration

Xinxiang Li, John C. Bancroft

A method for converted wave pre-stack time migration is presented. This methodsplits the Kirchhoff time migration into two steps using the concept of equivalent offset. Migration gathers are first constructed, and these gathers provide accurate migration velocity information. The second step consists of normal moveout (NMO) correction and conventional CDP stacking applied on migration gathers.

The main difficulty in implementing this method is the accurate computing of theequivalent offsets. Different from P-P wave case, we use an approximate solution for the converted wave case. Synthetic and real data experiments prove that this methodcan provide very good imaging results.