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Pore-Scale Modeling Of Two-Phase Flows At Various Surface Tensions And Wetting Contact Angles

2017; Volume: 4; Linguagem: Inglês

1390-9304

T.R. Zakirov, Khramchenkov Maxim Georgievich,

Lattice Boltzmann Simulation Studies

The paper studies the features of two-phase flows in a porous medium at different values of surface tension and contact angles of wetting. As an example, an artificially created digital two-dimensional model of a porous medium with a random distribution of impermeable obstacles of rhomboid, quadratic and rectangular shape is considered. In order to model the multiphase flow, the Boltzmann lattice equations and the color field gradient model are used. Computational experiments are carried out to displace the wetting phase saturating the porous space at the initial instant of time by injecting a nonwetting liquid at various interfacial tensions and the wetting properties of a skeleton. Based on the calculations, it was found that at very low values of the capillary pressure in the porous medium, the fingers and isolated globules of the injected non-wetting phase are formed in comparison with the hydrodynamic drop. At comparable values of capillary and hydrodynamic pressures, the uncharged liquid uniformly fills the pore space, but a significant part of the wetting phase remains stationary. It was shown that the result of the capillary resistance decrease is the flow rate increase of the wetting liquid through an outlet section. The intensification of the flow is mainly manifested after the breakthrough of injected liquid from the sample and it is increased at capillary pressure decrease.