ABSTRACT
The equations for dilatational waves in a porous medium consisting of a solid and two almost incompressible and immiscible fluids are constructed. The solutions of these wave equations appear to be coupled porosity and saturation waves. The porosity wave described previously is an almost incompressible fluid flow process where a dynamic change in the porosity of a porous medium is coupled to a dynamic pressure change in the fluid, which in turn induces the fluid to flow. The saturation wave is a fluid flow process where a dynamic change occurs in the proportion of two incompressible fluids in a porous medium, that is, the saturation is coupled to the pressure in each fluid. Laboratory studies have demonstrated that porosity waves can enhance fluid flow and displacement; furthermore, they can generate saturation waves, which are highly dispersional and can suppress viscous fingering. The theory of porosity waves and the theory of saturation waves have been developed separately.
