Dispersion and Attenuation of Elastic Waves in a Viscous Fluid-Saturated Anisotropic Porous Solid

• Published in: Chinese journal of geophysics 2008-01, Vol.51 (1), p.143-151
• Main Authors: WEI, Xiu‐Cheng, LU, Ming‐Hui, BA, Jing, YANG, Hui‐Zhu
• Format: Article
• Language: English
• Subjects: Anisotropy; Dispersion and attenuation; Permeability; Porous medium; Viscous fluid
• ISSN: 0898-9591; 2326-0440
• DOI: 10.1002/cjg2.1203

Based on Biot's theory, considering the viscous and elastic strain of a porous fluid material and the interaction torque between the fluid and solid constituents, a viscous fluid‐saturated anisotropic porous media model is proposed in this paper. In addition to 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 a slow SV wave and a slow SH wave in this model. Numerical simulation is carried out to analyze 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.