叠前深度偏移处理方法和实例

The method and example of prestack depth migration processing

胜利油田物探公司研究所, 东营 257100

Research Institute,Geophysical Exploration Company,Shengli Petroleum Administration, Dongying 257100

本文针对SH地区潜山复杂介质构造成像, 开展了叠前深度偏移处理的研究, 提出以精细速度分析、建立正确的速度—深度模型为核心的叠前深度偏移处理的方法流程。该流程以Kirchhoff偏移理论为基础, 用交互方式实现地质与地球物理的综合及处理与解释的一体化。利用文中提出的处理流程在SH地区对数条测线进行了二维叠前深度偏移, 与原常规叠后时间偏移剖面相比, 具有归位正确、能解决速度陷阱以及真实反映地下构造形态等特点。同时, 还用实例指出二维叠前深度偏移的三维效应问题。

In view of the structural imaging of complicated media in buried hills of the SH area, we carry out the research on the prestack depth migration processing, and put forward the method and process of the prestack depth migration processing which centers around fine velocity analysis and velocity-depth mod-el building. The process is based on the Kirchhoff migration theory, realizing the integration of geology and geophysics as well as the integration of processing and interpretation. The process has been used to perform 2-D prestack depth migration for several lines in the SH area. Compared with the conventional poststack time migration, the method can accurately reduce events, solve velocity pitfalls, and truly re-flect subsurface structure shapes. Moreover, we point out the 3-D effect problem of 2-D prestack depth migration via real examples.