Reflection of elastic waves at an interfaces between two porous half-spaces filled with different fluids

Abstract

The problem about the refraction of elastic waves at the interface of two half-spaces (rocks) filled with immiscible fluids is solved with the use of modified boundary conditions of the dynamics of saturated porous media [Nagy and Nayfeh, 1995]. The solution is obtained within the framework of the Frenkel’-Biot theory with allowance for the surface tension at the interface of fluids for a porous medium formed by two half-spaces, which differ only in the properties of the fluids filling them. Practically important cases of the reflection from the fluid-gas (water-air) and fluid-fluid (oil-water) interfaces are considered in detail. The calculations are performed for both harmonic waves and pulses. The possibility to determine in principle the structural factor characterizing the pore-space geometry of rocks from measured dynamic parameters of reflected waves is shown.