分层映射法起伏自由地表弹性波正演模拟与波场分离

发布时间：2018-03-17 12:44

本文选题：分层映射　切入点：自由边界条件　出处：《石油地球物理勘探》2016年02期 　论文类型：期刊论文

【摘要】：传统有限差分方法在处理起伏自由地表时存在一些问题;传统映射法通过将起伏地表映射为水平地表克服上述缺点,但在变换的同时会破坏原有地下构造,导致波传播的不准确和虚假反射的产生。为此,通过改进传统映射法,提出了分层映射法起伏自由地表弹性波正演模拟与波场分离方法,在实现算法的基础上,对几个典型起伏地表模型进行了正演模拟试算,结果表明:1分层映射法不仅可以将起伏地表映射为水平地表,而且也可以将地下起伏地层映射为水平地层。相对于传统矩形网格以及常规映射法,分层映射法对双复杂构造具有更好的适应性。2通过对比分层映射法、传统映射法、传统有限差分法的正演模拟试算结果表明,分层映射法具有更高的模拟精度和抑制频散能力。3基于分层映射法的起伏自由地表弹性波波场分离能够准确地将纵、横波分离,可为起伏自由地表弹性波偏移成像方法提供关键的技术支持。
[Abstract]:The traditional finite difference method has some problems in dealing with the undulating free surface, the traditional mapping method overcomes the above shortcomings by mapping the undulating surface to the horizontal surface, but it will destroy the original underground structure while transforming. In this paper, by improving the traditional mapping method, the forward simulation of elastic wave and the separation of wave field from the undulating free surface are proposed by improving the traditional mapping method, which is based on the realization of the algorithm, which leads to the inaccuracy of wave propagation and the generation of false reflection. The forward simulation of several typical undulating surface models has been carried out. The results show that not only the undulating surface can be mapped to horizontal surface by the 1: 1 stratified mapping method, Compared with the traditional rectangular grid and the conventional mapping method, the stratified mapping method has a better adaptability to the double complex structures by comparing the stratified mapping method, the traditional mapping method, the traditional mapping method, the traditional mapping method, the traditional mapping method, the traditional mapping method, the traditional mapping method, the traditional mapping method and the traditional mapping method. The forward simulation results of the traditional finite difference method show that the layered mapping method has higher simulation accuracy and ability to suppress dispersion. 3 the elastic wave field separation of undulating free surface based on stratified mapping method can accurately separate longitudinal and shear waves. It can provide key technical support for undulating free surface elastic wave migration imaging method.
【作者单位】：中国石油大学(华东)地球科学与技术学院地球物理系;中国石油青海油田天然气开发公司;中国石油东方地球物理公司研究院库尔勒分院;
【基金】：国家“973”课题项目(2014CB239006,2011CB202402) 国家自然科学基金项目(41104069,41274124) 中石化课题(KJWX-2014-05) 中央高校科研业务费专项基金项目(R1401005A)联合资助
【分类号】：P631.4

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