Validation of direct pore scale modeling approaches to wettability
byRaul Verma, Matteo Icardi, Masa Prodanovic
Year:2015
Bibliography
Raul Verma, Matteo Icardi, Masa Prodanovic, Validation of direct pore scale modeling approaches to wettability, submitted March 2015
Abstract
Understanding of pore-scale physics for multiphase flow in porous media is essential for accurate description of various flow phenomena. In particular, capillarity and wettability strongly influence capillary pressure-saturation and relative permeability relationships. Wettability is quantified by the con- tact angle of the fluid-fluid interface at the pore walls. In this work we com- pare the interface capturing method implemented in a popular open-source finite volume computational fluid dynamics solver with a new formulation of the level set method that models capillarity-dominated flow and is less computationally expensive. The methods fundamentally differ in the way they mesh porous geometry and capture interfaces, as well as in the num- ber of equations solved and other implementation and algorithmic details. Both methods are able to solve curvature-driven flow and implement arbi- trary contact angles at pore walls. The methods are tested in rhomboidal packings of spheres for a range of contact angles and for different rhom- boidal configurations. Predictions are validated against the semi-analytical solutions obtained by Mason and Morrow (1994). We specifically focus on evaluating the accuracy of each method (algebraic VOF and level-set) and benefits and limitations of employing a less computationally intense method for semi-equilibrium capillary-dominated flows vs. the full approximation of the Navier-Stokes equation applicable also to inertial and viscous flows. Consequences for larger and more complex problems are also considered.
Keywords
Validation of direct pore scale modeling approaches to wettability