Patent ID: 7110323

Claim:
A method for processing seismic data recorded with at least one source and receiver, using at least one structural horizon at a known depth Zn, a velocity model, and a plurality of non-primary reflections including Type I and Type II duplex waves, for the purpose of imaging steeply dipping vertical events, the method comprising the steps: i) forming a plurality of common receiver point gathers (“CRPG”) using said seismic data to create a CRPG wave-field; ii) continuing said CRPG wave-field using Type I duplex waves, for each said CRPG and for each discrete level Z i where i=0 to n, down to each said structural horizon Zn using said velocity model to determine a Type I amplitude. iii) calculating each Type I duplex wave travel time T i where i=0 to n, for each discrete level Z i ; and iv) forming a seismic image using said Type I amplitude corresponding to each said travel time T i for Type I duplex waves; v) forming a plurality of common source point gathers (“CSPG”) using said seismic data so as to create a CSPG wave-field; vi) continuing said CSPG wave-field using Type II duplex waves, for each said CSPG and for each discrete level Z i down to each said structural horizon, using said velocity model to determine a Type II amplitude; vii) calculating each Type II duplex wave travel time T i for each discrete level Z i ; and viii) forming a seismic image using said Type II amplitude corresponding to each said travel time T i for Type II duplex waves; ix) summing said seismic image using Type I duplex waves with said seismic image using Type II duplex waves, to form a seismic image of a target event.