Pore-scale modeling of phase change in porous media

Abstract

The combination of high-resolution visualization techniques and pore-scale flow modeling is a powerful tool used to understand multiphase flow mechanisms in porous media and their impact on reservoir-scale processes. One of the main open challenges in pore-scale modeling is the direct simulation of flows involving multicomponent mixtures with complex phase behavior. Reservoir fluid mixtures are often described through cubic equations of state, which makes diffuse-interface, or phase-field, theories particularly appealing as a modeling framework. What is still unclear is whether equation-of-state-driven diffuse-interface models can adequately describe processes where surface tension and wetting phenomena play important roles. Here we present a diffuse-interface model of single-component two-phase flow (a van der Waals fluid) in a porous medium under different wetting conditions. We propose a simplified Darcy-Korteweg model that is appropriate to describe flow in a Hele-Shaw cell or a micromodel, with a gap-averaged velocity. We study the ability of the diffuse-interface model to capture capillary pressure and the dynamics of vaporization-condensation fronts and show that the model reproduces pressure fluctuations that emerge from abrupt interface displacements (Haines jumps) and from the breakup of wetting films.

Pore scale modelling of moisture transfer in building materials with the phase field method

“…The simulated density distribution at steady-state conditions is shown in Fig. 2 (b) for two different values of the parameter k. According to prior studies [4], the interface width δ becomes larger with increasing value of the parameter k. This fact is also visible by plotting the density and pressure profiles along the symmetry plane of the cavity (Fig. 3).…”

“…(1) turns into the wellknown diffusion equation. The bulk chemical potential, density and pressure are related via the following equations [4]:…”

“…An extended review of available formulations is reported in [5]. In prior studies on phase field modelling [4], the well-known van der Waals equation has been used:…”

Diffusion‐to‐Imbibition Transition in Water Sorption in Nanoporous Media: Theoretical Studies

“…If the model resolution is decreased while keeping κ constant, the value of the surface tension changes because the concentration gradient changes. As achieving such a high model resolution is prohibitive for a macroscopic modeling study, κ is typically scaled up by the square of the numerical model grid size to compensate for the decreased concentration gradient with decreasing model resolution so that the magnitude of the surface tension stays approximately same (Cihan et al., 2019; Cueto‐Felgueroso & Juanes, 2018). In addition to the model resolution, in macroscopic modeling studies of complex porous media, κ is expected to be a function of pore size distribution and connectivity.…”

Numerical Modeling of the Filtration Process During Oil Displacement by Gas

“…Cueto-Felgueroso L., Fu X. and Juanes R. in their work [1] considered simulation of flows involving multicomponent mixtures with complex phase behavior. Authors presented a diffuse-interface model of single-component two-phase flow in a porous medium under different wetting conditions.…”