P-SV波和SS波反射系数之间的近似关系

Approximate Relationships between Reflection Coefficients of P-SV Wave and SS Wave

本文通过对Aki&Richards给出的P SV波反射系数的一阶近似 ,给出了一个新的描述P SV波和SS波反射系数之间关系的近似公式。在 4个不同类型的含油气砂岩模型上的定量计算表明 :新的近似关系能够反映SS波阻抗和P SV波反射系数之间的内在关系 ,而且形式简单、近似效果好、适用范围广 ,适合于SS波阻抗的定量反演和理论研究 ;如果再结合PP波AVO信息 ,还可以简单、准确地进行多参数反演。另外 ,在 2 0°以内 ,利用该近似关系 ,纯SS波零偏移距剖面和P SV转换波剖面之间可以相互转换。

Based on small-angle approximation of the reflection coefficient of P-SV wave given by Aki & Richards, this paper presents a new approximate relationship of reflection coefficients between P-SV wave and SS wave. The quantitative results from four different gas sand models show that the new equation not only can describe the inherent relationship between the impedance of SS wave and the reflection coefficient of P-SV wave but also has a simple form, a good approximation effect and a wide range of application. It is therefore suitable for the impedance quantitative inversion and theoretical researches and, in combination with PP-wave AVO, can make multiple parameters inversion easier and more reliable. In addition, within 20°, the pure SS wave Zero-offset section and the P-SV wave section can be transformed into each other through the new relationship.