波动方程保幅叠前深度偏移与AVO响应  

Wave equation preserved-amplitude prestack depth migration and AVO response

作　　者：刘定进[1] 印兴耀[2] 陆树勤[1] 杨瑞娟[1] 王丽[1] 

机构地区：[1]江苏油田分公司物探技术研究院,江苏南京210046 [2]中国石油大学地球资源与信息学院,山东东营257061

出　　处：《中国石油大学学报（自然科学版）》2009年第4期45-51,共7页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家'973'计划项目(2007CB209605);江苏油田博士后科研项目(JD08001)

摘　　要：从全声波方程出发,基于严格的解耦理论进行单程波保幅分解,得到直观、高效率的直接面对地震波传播波场的压力分量进行延拓的单程波动方程;按照叠前深度偏移方法中的波场双重向下延拓理论实现共炮域公式到CMP(共中心点)域公式的转换,推导出由双平方根方程定义的保幅单程波动方程,从而将振幅误差补偿作为偏移的一部分在偏移过程中实现,使得地震成像在给出正确位置的同时也给出真实振幅。在此基础上获得的CRP(共反射点)道集在保证真实振幅的前提下,有效解决了绕射波干涉、反射点弥散、与倾角有关的NMO等问题,使AVO响应更加清晰,提高了AVO资料的分析精度。The high efficient and direct-viewing one-way wave equation, which was started from full acoustic wave equation, was derived by using one-way wave＇s preserved-amplitude decomposition based on strict decoupling theory. This kind of one- way wave equation is to do continuation for pressure components of seismic wavefield directly. The formula transformation from common-shot domain to common midpoint （ CMP ） domain was achieved according to the theory of wavefield double downward continuation in prestack depth migration. Then the preserved-amplitude one-way wave equation defined by double- square-root equation was derived. So the amplitude error compensation as one part of migration can be realized during migra- tion period. Furthermore, this method has a special function that can give true amplitudes as well as the correct locations at the same time. Under the condition of preserving true amplitudes, the common reflection point（CRP） gathers based on this method efficiently solve diffracted wave interference, reflection point dispersion and NMO problem connected with angle of dip. This method makes AVO response clearer and improves the precision of AVO analysis.

关 键 词：叠前深度偏移 保幅偏移 单程波动方程 双平方根 AVO 

分 类 号：P631.4[天文地球—地质矿产勘探]