Introducing a New Method in Velocity Analysis by using Focal Transform

Abstract

Many steps in seismic processing are affected, directly or indirectly, by the quality of the velocity function obtained through velocity analysis. Improving the quality of the velocity function can affect the whole processing procedure. In this paper, focal transformation is introduced as an effective tool in velocity analysis. This method is based on the fact that the shape of a hyperbolic event in the focal domain depends on the difference between the shape of the hyperbolic event in the operator and the hyperbolic event in the CMP gather. Measuring the difference between the operator and the CMP gather can be used to determine the velocity of each event in the CMP gather. Focal transform velocity analysis is tested on a synthetic CMP gather set and a real data set. A comparison of the results of the focal transformation method with that of the semblance method demonstrates that a higher resolution in the velocity analysis is achieved when using the focal transformation than when employing the semblance method.