The Problems of Pre-stack Reverse Time Migration and Solutions with GPU Implementation

Pre-stack reverse time migration (RTM) is a very useful tool for seismic imaging. But it has not been widely used because of the highly intensive computation cost, imaging noise and massy memory demand. In this paper, we illustrate the implementation process of RTM and analyze the stability condition and dispersion relation of finite difference (FD) method. For the problem of intensive computation cost, we use the Graphic Processing Unit (GPU) architecture to realize RTM and get an order of magnitude higher speedup ratio compared to the traditional CPU architecture. Compared to the one way wave equation migration methods, RTM does not have the imaging dip limit and the imaging effect is significantly improved. We use the random boundary condition method to realize RTM using GPU/CPU collaborative computation which avoids the communication between GPU and CPU and the additional amount of computation could be partially remedied by reducing the communication cost.