几种P-SV转换波反射系数近似公式的比较

Comparison to several approximate reflection coefficient expressions of P-SV converted wave

石油大学CNPC物探重点实验室,北京 102200

Key Laboratory of Exploration in the University of Petroleum, Beijing 102200, China

多波多分量勘探利用了纵波和转换波的AVO属性来了解复杂的构造、岩性、裂隙裂缝的情况,以及确定地下流体的性质等。影响AVO属性的因素有很多,其反演的多解性很强,将纵波和转换波的AVO属性综合起来应用,就会大大减少多解性,还可以得到更多的岩石物理参数,并能提高一些参数的精度。AVO近似方程可以对单一的纵波、转换波,或纵、横波联合进行AVO岩性参数拟合反演。为此,对P-SV转换波反射系数近似公式进行了讨论和总结,并用理论模型对近似公式的特点和精度进行了分析。

Multiwave and multicomponent exploration is u-sing AVO attributes of compressional and converted waves to discriminate complex structures, lithology, and fractures as well as to determine underground fluids over past years. P and S waves, which are affected by different petrophysical parameters, appear different characteristics. Because P wave is related to Lame coefficients λ and μ,S wave is related just to μ. AVO influenced by several factors. AVO inversion exists multi resolution strongly. The simultaneous inversion of P-P and P-SV will not only reduces multi resolution but also gets more petrophysical parameters and improves precision of parameters greatly. Approximate expressions are applicable to AVO inversion, such as P-P, P-SV, jointed inversion P-P and P-SV. This article summarizes three styles of AVO attribution inversions of converted wave and analyzes feature and precision respectively, preparing for simultaneous inversion of P-P and P-SV.