Automatic Migration Velocity Analysis Using Reverse Time Migration

The objective of this paper is to describe an automatic velocity analysis method based on Reverse Time Migration and Differential Semblance Optimization. The velocity analysis is based on the solution of a nonlinear least squares problem aiming at the focusing of offset domain common image point gathers constructed by Reverse Time Migration. Because the method is based on the solution of the two-way wave equation, it can deal with strong and sharp velocity contrasts both in a stable and accurate manner. It is therefore expected that this method will help improve seismic imaging over complex geological settings. We illustrate the method with a simple synthetic 2D seismic example.