One Multi-level Data Acquisition Strategy for Parallel Pre-stack Kirchhoff Depth Migration

3D pre-stack Kirchhoff depth migration is one of important means for petroleum prospecting. During the imaging processing, it needs a large of ray travel time data. How to optimize the obtaining the required ray travel time data is very important to the efficiency of parallel processing the pre-stack depth migration. In this paper, in order to solve the problem of how effectively to obtain the required ray travel time, we advance one multi-level data acquisition and exchange strategy by enhancing the reusability of ray travel time. Moreover, this paper also tests the actual cases which analyze the allocated memory size, the temporary file size, as well as the various combinations of different allocated memory and temporary file size, in order to investigate the impact on the efficiency of ray travel time acquisition. The final actual test results show that the method proposed in this paper is efficient, when the number of nodes is 8, 92% performance improvement of ray travel time data acquisition may be achieved.