REVERSE-TIME MIGRATION WITH CORRECT EXTRAPOLATION OF PRESSURE AND SHEAR WAVES FOR BOREHOLE SEISMIC CASE
Reverse-time migration (RTM) is a well-proven method for surface seismic prospecting. However in borehole seismic (Vertical seismic profiling, VSP) direct usage of surface RTM method generates nonexistent interfaces (artifacts) due to ambiguity of primary/shear wave definition. These artifacts are often stable and cannot be wiped out after summation over all shots and often complicate the interpretation. This paper proposes a modified RTM algorithm that uses a different functional treat ing pressureand shear waves separately. Application of the new RTM method helps eliminate the ambiguity artifacts.