基于MPI的三维波动方程有限元法并行正演模拟

3D wave-equation finite-element forward modeling based on message passing interface parallel computing

（中国石油大学（北京）资源与信息学院地质地球物理综合研究中心,北京102249）

Lab for Integrated Geology and Geophysics,China University of Petroleum (Beijing),Beijing 102249,China

在三维空间进行地震波动方程有限元正演模拟时,采用基于消息传递界面（MPI）的并行算法可以克服基于单PC机串行算法对数据容量和计算速度的局限。其基本原理是:将模拟区域剖分成多个小区域,每一个进程处理其中一个小区域；在运算过程中,各个进程之间互通相邻区域节点的物性参数和前一时刻的位移值,以备计算当前时刻区域内的位移值,共同实现整个模拟空间的正演模拟。在正演模拟时,采用质量矩阵近似方法来提高程序的并行性,压缩数据量和运算量,最佳并行效率的进程个数则依据并行系统能够满足程序内数据容量来确定。通过3层水平层状介质模型的数值模拟,对方法的可行性和有效性进行了验证。

In 3D spatial seismic wave-equation finite-element forward modeling,the parallel algorithm based on message passing interface (MPI) can overcome the limitation of data capacity and computation velocity in single PC with serial algorithm.The basic principles are as follows:the simulated area is divided into several small sub-regions,and each processor computes one small region;in computation,the physical property parameters and the displacement at the former moment of the nodes from neighboring regions are communicated in processors each other,to prepare for calculating the displacement of the region at current moment and realize forward modeling of the whole simulated space together.In forward modeling,mass matrix approximation method was adopted to improve the parallelism of the program,compress the data volume and calculated amount.Processor number for optimal parallel efficiency was set in terms of parallel system satisfying data capacity in program.Through the numerical simulation of three-layer horizontal layered medium model,the method was proved feasible and effective.