Propagation of Wave in a Viscous Fluid-Saturated Porous Solid and Study of Reflection and Transmission from a Boundary

摘要

To describe the viscous fluid-saturated porous solid, based on Biot's two-phase media theory, a viscous-porous model is proposed in view of the liquid viscoelastic constitutive relation, and, the elastic wave equations, expression of phase velocity and inverse quality factor are also presented. A new slow S-wave with slow velocity will appear in this model, which is a kind of diffusive wave with great attenuation and mostly propagates in the fluid. Numerical analyzes are performed here to study the changing of the velocity and inverse quality factors of the four waves with frequency and porosity, meanwhile which is compared to Biot's model since some differences exist. Combining boundary condition, the reflection coefficient and transmission coefficient for the viscous fluid-saturated porous solid are derived for the first time. The numerical results reveal that using this model to study multi-wave's AVO characters can provide some basis for obtaining the fluid's information in the reservoir.