Waves in a Poroelastic Solid Saturated by a Three-Phase Fluid

Abstract

This work presents an analysis of the behavior of body waves in a multiphase system consisting of a poroelastic solid saturated by a three-phase fluid, taken to be oil, water and gas, with water being the wetting phase. The constitutive relations and the equations of motion include the effect of two capillary relations between the water and oil phases and the oil and gas phases, and three relative permeability functions. A plane wave analysis shows that four compressional waves and one shear wave can propagate in this multiphase system, all suffering dispersion and attenuation effects. The behavior of all waves as function of confining pressure, saturation of the fluid phases and frequency is analyzed in the numerical examples.