P-SV波AVO方法研究进展

为有效地利用AVO(amplitude versus offset)信息来反演岩性参数和预测油气储层，详细介绍了P—SV转换波AVO方法的研究现状和主要进展，并针对几种具有代表性的方法的基本思路、方法特点及参数反演等方面进行了对比和评述。同时，给出了两个不同形式的近似公式，并讨论了利用这两种近似公式进行AVO分析的思路和参数反演的方法，通过对比和讨论可以得出：不同近似的主要目的是为了提高近似精度并体现不同的岩性参数对反射系数的影响、敏感程度及其在参数反演中的意义；根据弹性模量和波速之间的关系，目前所有的PP波和P—SV波反射系数近似公式都可以统一表示成射线参数幂级数的形式，这些结论对于AVO理论研究和参数反演都具有重要意义。

Progress in research on the method of P-SV wave AVO

In order to utilize AVO information to inverse lithology parameters and to predict the reservoir bed effectively, the state of the art and the mainly progresses about P-SV converted-wave AVO methods are presented thoroughly in this paper. Furthermore, we review and discuss the basic assumptions and features of several classical formulas, as well as the aspects on parameter inversion for the corresponding approximation. At the same time, we also give two new approximation equations of P-SV wave reflection coefficient and discuss the methods of AVO analysis and parameters inversion by using the new formulae. It is found that the mainly purpose of each approximation is to improve the precision and to emphasize the influence of different elastic parameters, the role that each formula plays in parameter inversion. Also found is that from the relationship of elastic parameters to velocities one can transform one approximation to the others. Further, the all PP wave and P-SV wave reflection coefficients presently can be unified as power series of ray parameter. The conclusions of the present paper should be significant for AVO theory research and parameter inversion.