Kinematic migration for determination of velocity model of the medium while solving practical problems of seismic exploration

Abstract

Seismic migration allows solving different problems of seismic exploration and depending on the properties of the wave field which take part during the processing is subdivided into two types: kinematic and dynamic. Kinematic migration allows to determine seismic velocities and interfaces in geological medium for further implementation of dynamic migration can be enabled while solving different problems of seismic exploration where fast information on a priori parameters of velocity model of the study medium is needed. Kinematic migration for both fields of refracted and reflected waves is based on the continuation of temporal field which is implemented by finite-differential solution of eikonal equation. The values of temporal field are determined by distinct scheme which has quadratic degree of approximation and conditional stability that is proved during the studies. In this case the algorithm of kinematic migration of the field of refracted waves envisages two reverse continuations of temporal fields observed from two opposite sources while algorithm of kinematic migration of the field of reflected waves includes both direct continuation of temporal field from dotted source and reverse continuation from seismic receivers. Particularly urgent problem in this direction is the study of feasibility of finite-differential kinematic migration in case of determination of velocity model of multiple-structured geological medium while processing seismic data observed in different range of distances from the source. Possibilities of application of elaborated finite-differential kinematic migration for solving practical problems of seismic exploration have been considered in the paper. Effectiveness of elaborated techniques is demonstrated by model and real examples.