Seismic imaging systems and methods employing tomographic migration-velocity analysis using common angle image gathers

Abstract

In at least some embodiments, the system obtains shot gathers for a survey region and migrates the shot gather data with an initial velocity model to obtain angle-domain common image gathers. The system processes the common image gathers to determine depth residuals and corresponding angle-dependent time deviations throughout a seismic survey region. The system solves a set of tomographic equations which employ ray theory to establish a relationship between a travel time deviation and the depth residual of a reflector in the depth-offset ray parameter (z,p) domain. The resulting updates are applied to the velocity model and can be used to re-migrate the shot gather data. The system generates a representation of the survey region that can be displayed to a user.