Interval velocity analysis and depth migration using common reflection point gathers

摘要

A method for performing velocity analysis while eliminating the effects on weak signals caused by strong signals includes migrating each event of the pre-stack trace to a single location instead of all possible locations. This correct location is determined by ray-tracing through a velocity model. The input trace is divided into many windows, and each window is migrated to a place determined by ray-tracing the center of the window through the model. If the velocity model is accurate, each event will be migrated to the proper location yielding an accurate depth section with no migration artifacts. As a by-product, if the model is not accurate, the post-migrated parts (PMP's) provide a clean velocity analysis.