Reflection and Transmission of Elastic Waves at the Permeable Interface Between Fractured Porous Solid Saturated with Two Immiscible Pore Fluids and a Liquid Medium

Resumo

The reflection and transmission of elastic waves at a permeable interface between a fluid half-space and a fractured porous solid (FPS) half-space saturated with two immiscible pore fluids, are examined within the framework of Volume Average Theory for porous solids. The FPS comprises a solid matrix saturated with two immiscible fluids within pores and a connected network of fractures in which five types of wave modes exist. Five transmitted waves in the FPS medium are attenuating waves. Energy partition across the interface is examined through the computation of reflection and transmission coefficients. Parametric analysis is conducted to evaluate the effects of partial pore opening at the interface, fractures, frequency, incidence angle, and pores permeabilities. The results of wave characteristics and energy distribution are highly sensitive to pore opening at the interface and multiphase fluid interactions within the fractured porous solid, thus offering key insights for subsurface imaging, reservoir evaluation, and acoustic monitoring.