含黏滞流体各向异性孔隙介质中弹性波的频散和衰减

基于Biot理论，考虑液相的黏弹性变形和固液相接触面上的相对扭转，提出了含黏滞流体VTI孔隙介质模型.从理论上推导出，在该模型中除存在快P波、慢P波、SV波、SH波以外，还将存在两种新横波－慢SV波和慢SH波.数值模拟分析了6种弹性波的相速度、衰减、液固相振幅比随孔隙度、频率的变化规律以及快P波、快SV波的衰减随流体性质、渗透率、入射角的变化规律.结果表明慢SV波和慢SH波主要在液相中传播，高频高孔隙度时，速度较高；大角度入射时，快P波衰减表现出明显的各向异性，而快SV波的衰减则基本不变；储层纵向和横向渗透率存在差异时，快SV波衰减大的方向渗透率高.

Dispersion and attenuation of elastic waves in a viscous fluid-saturated anisotropic porous solid

Based on Biot's theory, considering the viscous and elastic strain of a porous fluid material and the interaction torque between fluid and solid constituents, a viscous fluid saturated anisotropic porous media model is proposed in this paper. Besides the fast P wave, the slow P wave, the SV wave and the SH wave, there exist two new kinds of shear waves, named as slow SV wave and slow SH wave, in this model. Numerical simulation analyzes the rules of the phase velocity and attenuation of the six kinds of elastic waves varying with porosity and frequency, and the attenuation of the fast P wave and the fast SV wave varying with fluid property, permeability and incidence angle. The results show that the slow SV wave and the slow SH wave are mainly propagating in the porous fluid and the phase velocity of the two kinds of waves are fast in the porous media with high porosity at high frequency; the attenuation of the fast P wave shows evident anisotropy at large incidence angle, whereas, the attenuation of the fast SV wave has little variation; the direction of the highest attenuation of the fast SV wave can denote the orientation of the maximum permeability when the permeability in the z direction is not equal to the permeability in the x direction.