InterPore2018 New Orleans

Multiphase micro-continuum models: an hybrid-scale approach

15 May 2018, 17:15

1h 30m

New Orleans

Poster MS 4.18: Coupling multi-physic at the pore-scale: experimental and numerical investigation Poster 2

Speaker

Cyprien Soulaine (Stanford University)

Description

Advances in imaging technologies and high-performance computing are making it possible to perform Direct Numerical Simulation (DNS) of flow processes at the pore scale; nevertheless, the restrictions on the physical size of the sample (porous rock) that can be fully resolved using Navier-Stokes-based DNS are quite severe. For samples on the order of a cm 3 , the complexity of the spatial heterogeneity of the pore space precludes Navier-Stokes-based DNS. Even for smaller sizes, some microstructures are below the instrument resolution and are not resolved in the image. To deal with this challenge of having a wide range of length scales -even for ’small’ systems, we describe a micro-continuum formalism, based on the Darcy-Brinkman-Stokes (DBS) equation where flow and transport phenomena are governed by Navier-Stokes equations in the resolved regions (voxels containing fluids only) and by Darcy in the unresolved (solid-fluid aggregates) regions [1]. This hybrid-scale modeling framework has been used successfully to compute the flow in a digital sandstone imaged with X-ray microtomography including sub-voxel porosity [2]. The micro-continuum DBS approach has also been used to simulate dissolution phenomena at the pore-scale under single-phase conditions [3].

In this work, the micro-continuum formulation is extended to multiphase flow where two-immiscible fluids share the pore-space involving surface tension force and moving contact lines at the mineral surfaces. The multiphase micro-continuum model is used to investigate multiphase system with reactive transport and is compared with microfluidic experiments.

References

[1] C. Soulaine and H.A. Tchelepi. Micro-continuum approach for pore-scale simulation of subsurface processes. Transport
in Porous Media, 113, 431–456, (2016).

[2] C. Soulaine, F. Gjetvaj, C. Garing, S. Roman, A. Russian, P. Gouze and H.A. Tchelepi. The impact of sub-resolution
porosity of X-ray microtomography images on the permeability. Transport in Porous Media, 113, 227-243, (2016).

[3] C. Soulaine, S. Roman, A. Kovscek and H.A. Tchelepi. Mineral dissolution and wormholing from a pore-scale per-
spective. Journal of Fluid Mechanics, 827, 457–483, (2017).