Effect of scale-dependent permeability on the propagation of seismic waves in fluid saturated rocks

Wave-induced local fluid flow at different scales, which contributes most to the wave velocity and attenuation, is determined not only by the compressibility of rock but also by its permeability properties. To investigate the potential relationship between permeability and seismic attributes, a wave propagation theory for fluid-saturated media with infinituple-porosity is extended to include rock textures (inclusions) with scale-dependent permeability. The effects of permeabilities, radii and elastic moduli of inclusions on wave dispersion and attenuation were first investigated. The results show that the stiffness moduli of the inclusions dominate, while for the same moduli, the permeability of the inclusions also exerts an influence at seismic frequencies. To validate the model, the results are compared with laboratory measurements on tight sandstones (1 Hz-106 Hz) and field measurements on marine sediments (50 Hz-400 kHz). The agreement confirms that the proposed model can be used to analyse and interpret the observed wave propagation and attenuation in a wide frequency range.