WIT Depth to be presented at Geophysical Society of Kansas

Wave Equation Simulation, Depth Imaging, and Velocity Analysis Over Shallow Salt

Modeling and depth migration techniques which use the "full" wave equation have a proven robustness to strong velocity structure, such as complex salt bodies in the Gulf of Mexico, and can in many cases out-perform Kirchhoff prestack depth migration or time migration. While Kansas is not normally viewed as a "sub-salt" play, from an imaging perspective, the salt collapse features found in many Kansas fields produce the velocity structure which makes depth migration in general, and wave equation depth migration (WEM) in particular, applicable.

In this talk we simulate and image--from variable topography--a 3D survey over a salt collapse feature, illustrating the effect of various survey geometries on the image quality. We'll present an efficient and general WEM angle decomposition scheme which enables AVA or azimuth-based prospecting in areas where time imaging fails. We'll go on to take the synthetic data through multiple iterations of depth velocity model building using an advanced WEM-based focusing scheme.