Effect of fracture fill on elastic waves in fractured porous rocks

Abstract

When a porous medium is permeated by open fractures, wave-induced flow between pores and fractures can cause attenuation and dispersion of the passing wave. Most studies of this phenomenon assume that pores and fractures are saturated with the same fluid. Here we develop a model for wave propagation in a porous medium with aligned fractures where pores and fractures are filled with different fluids. The model is based on the theory of wave propagation in a periodically layered poroelastic medium. The results are consistent with earlier studies when both pores and fractures are saturated with liquids, but also show significant dispersion and attenuation when the pores are filled with a liquid while the fractures are dry or gas-saturated.