Multiphase Flow Modelling in Multiscale Deformable Porous Media: An Open-Source Micro-Continuum Approach

Abstract:

Multiphase flow in deformable porous media is a ubiquitous process within hydrocarbon extraction, bioremediation, and carbon sequestration. Due to the technological prevalence of these phenomena, it has become increasingly important to characterize and predict the relationship between multiphase flow and solid mechanics, particularly in multiscale systems that contain both porous and solid-free domains. For example, when modeling flow through fractured porous media it is imperative to understand how fluid flow behaves inside the porous formation (~μm) while simultaneously understanding how fracture propagation affects the overall flow field (~mm). To that point, we present a novel modeling framework that allows us to effectively couple fluid and solid mechanics at different scales, simultaneously. Our approach is based on the derivation of a unique set of volume-averaged partial differential equations that asymptotically approach the Navier-Stokes Volume-of-Fluid equations in solid-free-regions and multiphase Biot Theory in porous regions. Through careful consideration of interfacial dynamics (relative permeability and capillary effects) and extensive benchmarking, we show that the resulting model captures the strong two-way coupling that is often exhibited between multiple fluids and soft porous materials. Thus, it can be used to represent uniform material deformation (swelling, compression) and failure (cracking, fracturing). The model’s open-source numerical implementation, hybridBiotInterFoam, effectively marks the extension of computational fluid mechanics into modeling multiscale multiphase flow in deformable porous systems. In this talk, we will discuss the model’s structure, open-sourced implementation, and application to simulate dynamic multiscale phenomena such as fracturing and flow-induced surface deformation.