弹性各向同性介质的AVO响应对Thomsen各向异性参数的差值是敏感的。该方程描述了P-P波反射。它指出,各向同性特性(纵波速度、横波速度和密度)的差值越小穿过反射界面的δ的差值和ε的差值越大,则各向异性对AVO信号的影响越大。正如Banik(1987)所述,在中、小入射角情况下,δ的差值是最重要的影响因素。而ε的差值则对大入射角振幅的影响极大。因而,采用Rutherford和William的各向同性含气砂岩的分类方法时,如Ⅰ类含气砂岩上覆横向同性页岩时, The AVO response of elastic isotropic media is sensitive to the difference in Thomsen’s anisotropy parameters. This equation describes the P-P wave reflection. It points out that anisotropy has a greater effect on the AVO signal when the difference between isotropic properties (P-wave velocity, shear-wave velocity and density) is smaller as the difference between δ and ε across the reflective interface increases. As described by Banik (1987), the difference in δ is the most important factor at medium and small angles of incidence. The difference of ε has a great impact on the amplitude of large incident angle. Therefore, when using the classification method of isotropic gas sands by Rutherford and William, such as class I gas sands overlaying transversely homogeneous shales,