Biot slow waves in isotropic rocks based on BISQ model

摘要

Biot slow waves in isotropic rocks based on BISQ model is investigated. The low frequency approximate expression for velocity and attenuation of Biot low wave is presented. By comparing with Biot model, BISQ model predicts as follows. The attenuation of Biot slow waves is very large at low frequency range and decreases with the characteristic squirt flow length ( R ) increasing. The velocity dispersion is weak. The velocity low frequency limit is not zero and decreases with R increasing. The ratio of pore fluid-displacement to skeleton-displacement is similar to attenuation. The phase is obviously different. The seepage flow induced by Biot slow waves at the fluid-rocks interface is much larger than that by BISQ model. Two interesting conclusions induced from BISQ model are that there is no squirt mechanism in inviscid fluid-saturated porous media and there is no "dynamic compatibility" phenomenon in inviscid fluid-saturated porous media.