What to Expect from Prestack Time Migration

P063 WHAT TO EXPECT FROM PRESTACK TIME MIGRATION WALTER E. A. RIETVELD 1 BP – UTG Geophysics Chertsey Road Sunbury on Thames UK Abstract This paper attempts to shed light on the expected quality of prestack time migration. Prestack time migration has become a widely used tool in areas where we have slowly varying lateral velocities and good stratigraphic imaging is required. We will show that for low vertical velocity gradients prestack time migration will yield very accurate images of the subsurface. For stronger vertical gradients the longer offsets show residual move-out even if the correct velocities are used. At