Slow waves propagation in BISQ poroelastic model

Abstract

The slow compressional wave (P2wave) in porous media based on BISQ model is investigated. The lowfrequency approximate expression for velocity and attenua t ion of P2wave is presented. Compared with Biot model, BISQ model predicts tha t the attenuation of P2 waves is very large at low frequency and decreases with increasing characteristic squirt flow length (R), the velocity lowfrequency limit is not zero and decreases with increasingR, variation of the ratio of pore fluiddisplacement to bulkdisplacement is similar to that of attenuation and its phase is diffe rent from that of Biot model. The seepage flow induced by P2 wave at the fluidporous media interface is larger than that of Biot model. For the sake of contrast, the p roperties of the fast compressional wave are also presented. Two conclusions are induced from the BISQ model: there is no squirt mechanism in inviscid fluid-satura ted porous media and there is no “dynamic compatibility” phenomenon in viscid fluid-saturated porous media.