Abstract：In the case of violent lateral velocity variation in medium or complicated subsurface geologic structure,the conventional time migration can hardly image seismic reflector accurately,while depth migration can solve the problem satisfactorily.In this method,the complex subsurface geologic structure can be nicely reconstructed by converging diffraction-wave equation and making time shift correction of refraction-term equation.We may have simple 45°and 60°high-order wave equations bytaking low-order equation system as approximate diffraction wave equation and revising approximate coefficients,so that steep dip ref1ection waves may migrate tocorrect positions.The refraction-term equation is coped with by using time shift algorithrn based on the equation property,instead of the usual finite difference method that results in unstable continuation.Theoretical model and real data results show that this method is an accurate and efficient depth migration method.
金胜汶, 马在田, 宜明理. 时移法大倾角深度偏移方法[J]. 石油地球物理勘探, 1995, 30(1): 11-17.
Jin Shengwen, Ma Zaitian, Yi Mingli. Steep-dip depth migration using time shift algorithm. OGP, 1995, 30(1): 11-17.
