f Observation of Seismic Anisotropy from VSP Measurements and Compensation for the Effect in Migration of Seismic Data

Results of refraction data studies show that horizontal velocities usually are higher than vertical (Sheriff). Isotropic prestack depth migration results show that the effect of anisotropy has practical significance also for reflection data; optimal migration velocities are usually higher than velocities derived from borehole data. Also the differences found beween dixinverted stacking velocities and velocities from borehole data are explained as partly caused by anisotropy (Thomsen).