摄动法是分析沿井中各向异性地层传播的弹性波的有效方法之一。应用摄动模型可以计算各向异性目的层与未摄动的各向同性参考层间弹性常数差异引起的波散曲线的变化。参考地层的等价各向同性常数根据与选择挠曲波的传播方向和偏振方向对应的恰当的纵、横波速度求取。未摄动解的选择原则是使 Perturbation method is one of the effective methods to analyze elastic waves propagating along an anisotropic formation in a well. The perturbation model can be used to calculate the variation of the dispersion curve caused by the difference of elastic constants between the anisotropic target layer and the non-perturbed isotropic reference layer. Equivalent isotropic constants for the reference formation are derived from the appropriate longitudinal and shear wave velocities corresponding to the propagation direction and polarization direction of the chosen flexural wave. The principle of unbiased solution is to make it