摘要
本文提出了基于共炮检距数据体的适用于大规模三维地震数据体的Kirchhoff叠前深度偏移(PSDM)并行实现方案。其基本思路为:①利用任意介质中的动态规划法三维旅行时计算方法提供旅行时场;②按照炮检距组织数据;③根据机器物理内存大小分配成像深度段;④对共炮检距数据分深度段进行基于消息传递接口(MPI)的进程并行处理;⑤对单进程作业进一步利用OpenMp并行同时实现多个单道的成像处理。此方案可充分利用节点内存,减少数据输入/输出(I/O)量。该方案是将单个炮检距的某个深度段的成像空间和需要的所有炮的对应深度段的旅行时场调入内存中,每一深度层的成像均在内存中进行,而且Inline和Crossline方向的偏移孔径可以自适应地根据偏移速度和成像深度进行选择,并采用空变反假频技术,可较大地提高成像精度。成像结果按体偏移形式输出,同时也可以输出成像道集。该方案在内存利用、数据I/O量和计算效率上达到最佳平衡。并行方式充分采用MPI+OpenMp混合编程模式,可高效、高精度地处理大规模三维地震数据。理论和实际数据的偏移成像结果均证明了本文方案的正确性和高效性。
This paper presents an implementation strategy of Kirchhoff integral prestack depth migration(PSDM) for large-scale seismic data sets,which is based on the 3D traveltime calculation method for arbitrary velocity variations.The strategy includes several key points: ①Common-offset data sets are the input data of the Kirchhoff PSDM algorithm.②One depth layer of image volume are resided in the inner memory,which thickness is dependent on the physics memory of the computer.③The MPI plus OpenMp implementation strategy is proposed by taking consider of share memory and decreasing input and output(I/O) amount.And,the self-adaptive migration aperture can be chosen because the current layer travel-times of all shots are inputted into the inner memory.The frequency-selective operator across aperture also guarantees the imaging accurate.The scheme can output the common image point gathers(CIGs) in a convenient way.All these points guarantee the balance of I/Oand computation and make our Kirchhoff PSDM to be high efficient and accurate.The imaging results of the synthetic and real data demonstrate that the presented methods are correct and effective.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2012年第3期404-410,355+518,共7页
Oil Geophysical Prospecting
基金
国家高技术研究发展"863"计划项目(2006AA09Z323)
国家重点基础研究发展"973"计划项目(2006CB202402)联合资助
胜利油田物探研究院的资助
中国石化集团公司科技部的资助
