AVO分析和应用

A REVIEW OF AVO AND ITS APPLICATION

石油天然气总公司物探局研究院

Academy of Geophyscical Bureau, China National Oil and Gas Exploration and Development Carportion

随着对振幅随偏移距变化(AVO)效应研究的日益深入,AVO分析的可靠性成为人们越来越关心的问题。本文从寻找一种精确拟合大角度入射时反射系数随入射角变化的方法入手,提出一个与泊松比有关的二次多项式。并对方程中的声学项和剪切项在AVO效应中的作用进行了分析,以便在解释中避免误入陷井。最后了、以一个气藏的实际例子,说明AVO分析与具体地质情况相结合后的应用效果。

With the increasingly deepening in studying AVO(amplitude versus offset),the discussion focused on the reliability of AVO anlysis has stirred up an intense interest in geophysical community. The authors'attempt is to find out an approach by which reflection coefficients can vary with incidence when large incidence is best fitted. And proceeding from this ,a quadratic polynomial derivative of Poisson's ratio is produced. Also,the roles that acoustic terms and shearing terms in equation play in terms of AVO effect are examined so as to avoid misleading to pitfalls.Finally,an example taken from one gas pool is given,which illustrates the payoff resulted from AVO analysis integrated with specific geological settings.