Acoustoelasticity for a Dissipative Fluid-Saturated Porous Rock: Fid-Bau Portal

Acoustoelasticity for a Dissipative Fluid-Saturated Porous Rock

Wang, Huaqing / Dong, Tengchao / Tian, Jiayong

Acoustoelastic theory for a dissipative fluid-saturated porous rock (FSPR) is investigated based on the finite deformation theory of the continuum and poroelastic theory. The assumption of a small dynamic motion superimposed on a largely static pre-deformation of the FSPR yields natural, initial, and final configurations. The consideration of homogeneous pre-deformation, dissipation induced by the Poiseuille-type fluid-solid relative motion, the plane harmonic form of the small dynamic motion according to the constitutive relations and equations of motion of the dissipative FSPR gives acoustoelastic equations, which provide the analytical formulations for the relation of the velocities of the fast longitudinal wave, the fast shear wave, the slow shear wave, and the slow longitudinal wave with the solid-skeleton stresses and the fluid pore-pressure. Taking a rock under open-pore jacketed condition as an example, the detailed discussions about the characteristic of wave dispersion and attenuation for the shear waves are shown that the characteristic of wave dispersion and attenuation for the dissipative FSPR is usually influenced by the pre-deformation. The pre-deformation has little effect on the characteristic of wave dispersion and attenuation for dissipative FSPR only when the components of the applied initial principal stresses are equal.