Grid Tomography Velocity Modeling For Pre-stack Depth Migration And Its Application In WLH Area

Pre-stack depth migration can effectively improve the imaging problems of complex tectonic areas and regions with high velocity transverse change.With the continuous depth of seismic exploration,pre-stack depth migration is also widely used,which has become a common processing section in the exploration and development process of major oil and gas fields.But it is not to be ignored that accurate velocity model is a necessary condition for pre stack depth migration imaging,and the precision of velocity model will have a great influence on the imaging effect of pre-stack depth migration,so the key of pre-stack depth migration is speed modeling.In this paper,the principle of pre-stack depth migration and the method of speed modeling are studied.After comparing and analyzing some of the main speed modeling methods at present,the principle of grid velocity modeling and the technology of grid velocity modeling are studied,and the research results are applied in the WLH area in order to improve the precision of speed modeling.And efficiency,improving the imaging effect of pre-stack depth migration in this area.The WLH work area studied in this paper is complex in structure,unclear in breakpoint,large in dip angle,sharp in lateral variation of velocity,and difficult in migration imaging.After applying the technology of grid velocity modeling,the velocity of approaching the real formation medium can be accurately reversed.The common reflection point set is leveled and the residual velocity difference is small,and the ideal effect of pre stack depth migration imaging is obtained.