多分量地震数据的成像技术

Imaging techniques of multi-component seismic data

从水平叠加成像、叠前时间偏移以及叠前深度偏移三个方面总结了多分量地震成像技术的发展现状.在水平叠加成像方面,分析了转换波与纵波在道集抽取方面的差异,总结了常用的转换点计算公式,着重对比了由炮检坐标映射地下的转换点以及由地表的网格节点映射地下的反射点两种共转换点道集抽取方式各自的优缺点以及应用化程度.概述了各向同性与各向异性叠前时间偏移技术的基本原理,总结了多分量偏移技术发展以及配套软件的工业应用现状,并对最近发展的层匹配多分量偏移技术进行了介绍.最后,从射线理论以及波场延拓理论的角度总结了多分量叠前深度偏移的发展现状与存在的问题,介绍了标量偏移与矢量偏移的差异,并提出了深度域速度建模存在的问题.

In this paper,we summarize the development situation of the imaging techniques of multi-component seismic data from the horizontal stack,prestack time migration and prestack depth migration.In the horizontal stack,we point out the difference between PP-and PS-waves on the gather formation and present commonly used equations for the conversion point calculation of PS-waves.We give the details of the common conversion point gather formation method performed by mapping source and receiver coordinates to the subsurface conversion point and the method performed by mapping the imaging grid from the ground to the reflection depth.We compare the pros and cons of the two methods and show some successful industrial applications.Then,we summarize the fundamental principles and software development situations of multi-component isotropic and anisotropic migrations.We introduce detailed procedures of layer-matched multi-component migration and present its application prospect.In the end,we summarize the development situations and problems about multi-component depth migration from the prospects of ray-tracing and wave field extrapolation theories.We point out the difference between scalar migration and vector migration as well as the main problem existing in the velocity model construction for prestack depth migration.