Simultaneous anisotropic prestack depth migration of P-S VSP and surface seismic data

M. Gratziella Kirtland Grech, Donald C. Lawton

A general prestack depth migration algorithm has been developed to investigate combined depth imaging of VSP and surface seismic data. The migration, which can handle vertical and tilted transverse isotropy, as well as pure P- and S-modes and converted-waves, has been tested on synthetic data from a flat reflector. The results show that the integration of the VSP migrated section with the surface seismic one yields a better image than that from VSP migration alone - it images a larger portion of the reflector and shows enhanced reflection continuity and focusing. Similar imaging improvements were observed when the integrated P-P VSP and surface seismic depth-migrated section was added to the corresponding P-S VSP and surface seismic depth-migrated section.