Propagation of seismic waves in patchy‐saturated porous media: double‐porosity representation

Abstract

Propagation of harmonic plane waves is studied in a patchy‐saturated porous medium. Patchy distribution of the two immiscible fluids is considered in a porous frame with uniform skeletal properties. A composition of two types of patches, connected through continuous paths, constitutes a double‐porosity medium. Different compressibilities of pore‐fluids in two porous phases facilitate the wave‐induced fluid‐flow in this composite material. Constitutive relations are considered with frequency‐dependent complex elastic coefficients, which define the dissipative behaviour of porous aggregate due to the flow of viscous fluid in connected patches. Relevant equations of motion are solved to explain the propagation of three compressional waves and one shear wave in patchy‐saturated porous solids. A numerical example is solved to illustrate dispersion in phase velocity and quality factor of attenuated waves in patchy‐saturated porous materials. Role of fluid–solid inertial coupling in Darcy's law is emphasized to keep a check on the dispersion of wave velocities in the porous composite. Effects of patchy saturation on phase velocities and quality factors of attenuation are analysed using the double‐porosity formulation as well as the reduced single‐porosity equivalents.

Effects of petrophysical parameters on attenuation and dispersion of seismic waves in the simplified poroelastic theory: Comparison between the Biot's theory and viscosity‐extended theory

“…She obtained excellent agreement with Plona's measurements and Rasolofosaon's experimental work (Rasolofosaon, 1988). There are many other investigations of extended Biot's theory (Santos et al ., 1990a, 1990b; Pride et al ., 1992; Dvorkin and Nur, 1993; Dvorkin et al ., 1994; Cao et al ., 2017; Sharma, 2019).…”

Shear Wave Splitting and Polarization in Anisotropic Fluid-Infiltrating Porous Media: A Numerical Study

“…The propagation of shear (S) and compressive/pressure (P) waves in poroelastic materials are phenomena relevant for seismology [1][2][3][4][5][6], geotechnical earthquake engineering [7][8][9][10][11], reservoir management [12], and biomechanics of bones and tissues [13]. The shear wave is a polarized transversal wave that propagates within the solid skeleton perpendicularly to the direction of the wave propagation and it often propagates slower than the pressure wave.…”