Anisotropic Prestack Depth Migration and Model Building

A-01 ANISOTROPIC PRESTACK DEPTH MIGRATION AND MODEL BUILDING R. BLOOR P. WHITFIELD and K. FISK WesternGeco 10001 Richmond Avenue Houston TX 77042 USA Summary 1 The majority of the subsurface is anisotropic to some extent but in most cases the processing of seismic data ignores anisotropy. Ignoring anisotropy can result in significant mispositioning of events due to biased velocity values and in prestack space difficulty in aligning events at different offsets. Well mis-ties and vertical seismic profile (VSP) data can help constrain the nature and quantity of anisotropy. Incorporating anisotropy in depth imaging can result in more accurate seismic images.