Pre-stack Reverse Time Migration of Undulating Surface Based on Layered Irregular Grid Finite Difference Method

Seismic exploration in the conditions of complex surface topography in western China is a world-wide problem. A complex surface and weathering zone has a great influence on the results of seismic processing. The traditional rectangular grid finite difference method is difficult to adapt to the fluctuation of surface topography, but the difference method based on triangular grid can be used directly for forward modeling on models with complex top surfaces and migration without statics preprocessing. In this paper, we propose a layered irregular grid finite difference method, and apply it to acoustic wave finite difference pre-stack reverse-time migration. Tests on model data verify that the method introduced here can achieve perfect results in application.