Velocity estimation for seismic data exhibiting focusing-effect AVO (Part 3)

Ioan Vlad, Biondo Biondi, and Paul Sava

nick@sep.stanford.edu, biondo@sep.stanford.edu, paul@sep.stanford.edu

ABSTRACT

Given a satisfactory image perturbation, Target Image Fitting (TIF) Wave Equation Migration Velocity Analysis (WEMVA) successfully produces a velocity model that completely eliminates focusing-effect AVO anomalies through prestack depth migration. However, TIF WEMVA ceases to converge to the desired result when the Born approximation is not fulfilled because the starting guess is too far from the correct velocity. Fortunately, there are several possible remedies to this problem. Extracting the image perturbation proves somewhat more complicated than expected, but new possible solutions based on differential semblance have been identified.