Pore-Scale Modeling of the Effect of Wettability on Two-Phase Flow Properties for Newtonian and Non-Newtonian Fluids

Abstract

The Darcy-scale properties of reservoir rocks, such as capillary pressure and relative permeability, are controlled by multiphase flow properties at the pore scale. In the present paper, we implement a volume of fluid (VOF) method coupled with a physically based dynamic contact angle to perform pore-scale simulation of two-phase flow within a porous medium. The numerical model is based on the resolution of the Navier–Stokes equations as well as a phase fraction equation incorporating a dynamic contact angle model with wetting hysteresis effect. After the model is validated for a single phase, a two-phase flow simulation is performed on both a Newtonian and a non-Newtonian fluid; the latter consists of a polymer solution displaying a shear-thinning power law viscosity. To investigate the effects of contact angle hysteresis and the non-Newtonian nature of the fluid, simulations of both drainage and imbibition are carried out in order to analyze water and oil saturation—particularly critical parameters such as initial water saturation (Swi) and residual oil saturation (Sor) are assessed in terms of wettability. Additionally, the model sensitivities to the consistency factor (χ), the flow behavior index (n), and the advancing and receding contact angles are tested. Interestingly, the model correctly retrieves the variation in Sor and wettability and predicts behavior over a wide range of contact angles that are difficult to probe experimentally.

Analysis of Polygonal Vortex Flows in a Cylinder with a Rotating Bottom

“…In the present work, VOF method is combined with a constant contact angle treatment (found appropriate in a number of applications-e.g., [66]) for the moving water boundaries on vertical walls and rotating bottom. Alternative treatment of the contact angle parameter can also be considered-e.g., recently published work [67] on application of dynamic contact angle formulation along with VOF method.…”

Pore-scale simulation of viscous instability for non-Newtonian two-phase flow in porous media

“…The Volume-of-Fluid (VoF) method, implemented in OpenFOAM [30] using interFoam solver, is used to simulate immiscible and incompressible two-phase fluid flow in a porous medium involving non-Newtonian fluids. The details of the VoF method implemented in OpenFOAM for two-phase flow displacement can be found at [31,32,33,34,35,26]. The shear viscosity (η) of the polymeric non-Newtonian fluid is defined using shear stress-dependent Meter model (Eq.…”

Feasibility Evaluation of CFD Approach for Inhalation Exposure Assessment: Case Study for Biocide Spray

“…The CFD can be used to predict the flow behavior in ventilated indoor and calculating the concentration of pollutant by solving the partial differential equations with 3D tensor based on the physics law [14]. In general, the dynamic behavior of particle/aerosol have been predicted with discrete particle method (DPM) and a volume-tracking represented by the volume of fluid (VOF) method in CFD [23][24][25][26][27]. By adopting a numerical method based on the VOF method, various phase flow behaviors, gas-liquid and gas-gas interactions can be accurately described [25][26][27].…”

“…In general, the dynamic behavior of particle/aerosol have been predicted with discrete particle method (DPM) and a volume-tracking represented by the volume of fluid (VOF) method in CFD [23][24][25][26][27]. By adopting a numerical method based on the VOF method, various phase flow behaviors, gas-liquid and gas-gas interactions can be accurately described [25][26][27]. The DPM has been used to track the dynamic behavior of solid particle in air [23,24].…”