基于有理式近似的高精度波场传播算子  

High-accuracy wave-field extrapolation operator based on rational approximation

作　　者：白敏[1,2] 陈小宏[1,2] 熊晓军[3] 吴娟[1,2] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)CNPC物探重点实验室,北京102249 [3]成都理工大学地球物理学院,四川成都610059

出　　处：《石油地球物理勘探》2013年第2期176-180,332+155,共5页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目(U1262207和41074098)资助

摘　　要：以地震波单程波传播方程为基础,利用有理式展开方法,推导出一种新的高精度波场传播算子。该算子波场延拓满足分裂步框架,采用快速傅里叶变换(FFT)进行计算。频散曲线分析以及数值试验的对比研究表明:本文方法的波场成像能力明显优于裂步傅里叶法(SSF),可以达到与傅里叶有限差分法(FFD)类似的波场成像效果。计算效率方面,其波场延拓只需三次FFT计算和一次插值,仅比SSF多了一次FFT和插值,但比FFD(计算量相当于五次FFT)少了两次FFT。这种算子不仅精度高,稳定性好,而且计算效率高,具有重要的理论意义和实际应用价值。Based on one-way wave equation,we propose a new wave-field extrapolation operator of high-accuracy using rational expansion method.This operator uses split-step framework and Fast Fourier Transforms(FFT) in wave-field continuation.Analysis results of dispersion curves and numerical experiments show that the imaging capability of this operator is significantly better than split-step Fourier method(SSF).Its imaging capability is nearly as good as Fourier Finite Difference method(FFD).In the aspect of computing efficiency,the operator only needs 3 FFTs and one interpolation,which is one more FFT and interpolation than conventional SSF(needs 2 FFTs) in computation,but two FFTs less than FFD(equivalent to 5 FFTs).It is not only highly accurate,unconditionally stable,but also highly efficient in migration imaging.This method is of important theoretical and practical significance.

关 键 词：单程波动方程 波场延拓 有理式近似 地震偏移 精度分析 

分 类 号：P631[天文地球—地质矿产勘探]