A dual-porosity scheme for fluid/solid substitution
MetadataShow full item record
© 2016. Estimating the impact of solid pore fill on effective elastic properties of rocks is important for a number of applications such as seismic monitoring of production of heavy oil or gas hydrates. We develop a simple model relating effective seismic properties of a rock saturated with a liquid, solid, or viscoelastic pore fill, which is assumed to be much softer than the constituent minerals. A key feature of the model is division of porosity into stiff matrix pores and compliant crack-like pores because the presence of a solid material in thin voids stiffens the rock to a much greater extent than its presence in stiff pores. We approximate a typical compliant pore as a plane circular interlayer surrounded by empty pores. The effect of saturation of the stiff pores is then taken into account using generalized Gassmann's equations. The proposed model provides a good fit to measurements of the shear stiffness and loss factor of the Uvalde heavy-oil rock at different temperatures and frequencies. When the pore fill is solid, the predictions of the scheme are close to the predictions of the solid squirt model recently proposed by Saxena and Mavko. At the same time, the present scheme also gives a continuous transition to the classic Gassmann's equations for a liquid pore fill at low frequencies and the squirt theory at high frequencies.
Showing items related by title, author, creator and subject.
Saxena, N.; Mavko, G.; Hofmann, R.; Gurevich, Boris; Glubokovskikh, Stanislav; Aliyeva, S.; Dutta, O. (2016)Rock-physics models are often needed to interpret fluid signatures from subsurface seismic data. Over the last decade or so, generalized fluid- and solid-substitution equations have been derived for estimating the exact ...
Kong, L.; Gurevich, Boris; Zhang, Y.; Wang, Y. (2017)© 2017 European Association of Geoscientists & Engineers.In fractured reservoirs, seismic wave velocity and amplitude depend on frequency and incidence angle. Frequency dependence is believed to be principally caused by ...
Gurevich, Boris; Makarynska, D; Pervukhina, M. (2009)Mavko and Jizba propose a quantitative model for squirt dispersion of elastic-wave velocities between seismic and ultrasonic frequencies in granular rocks. Their central results are the expressions for the so-called ...