Simulation of Fracture-Matrix Interaction using Micro-Continuum Approaches
French National Centre for Scientific Research, France
Cyprien Soulaine is an Associate Scientist at CNRS, the French National Centre for Scientific Research, working at the Institute of Earth Sciences of Orléans, France. He develop hybrid-scale models for coupled processes in porous and fractured media. He considers a wide variety of scales ranging from nanometers to kilometers. Cyprien’s interest in pore-scale physics led to the development of computational microfluidics for geosciences. His research is very broad and applications include carbon dioxide storage in the subsurface, hydrogen production, water resources management, and superfluid quantum turbulence in porous media. Before, joining CNRS, Cyprien spent 5 years at Stanford University in Energy Resources Engineering department as a Research Associate in the group of Prof. Tchelepi. He has a PhD in Fluid Dynamics from Institut Polytechnique de Toulouse, France.
Introduction of the Lecture
Naturally occurring porous media involve a wide range of spatial scales. Image-based simulations offer an appealing framework to investigate fracture-matrix interactions in reactive environments. However, the large contrast of characteristic length-scales involved in fractured porous media – the typical pore sizes of the rock matrix and the fracture aperture differ by several orders of magnitude – limits the use of very high-resolution images that fully resolve both the fracture and the matrix microstructure. Nevertheless, the presence of the surrounding porous matrix can impact the evolution of the fracture aperture by the development of a weathered zone at the vicinity of the fracture-matrix interface and must be included in the modeling. Here, we use micro-continuum simulations to compare the evolution of a fracture geometry under various conditions.
Micro-continuum models are a versatile and powerful approach to simulate multi-scale coupled processes in porous media [1,2]. The governing equations are rooted in the elementary physical principles and combined with appropriate sub-grid models for describing processes in the unresolved porosity . Micro-continuum approaches are intrinsically two-scale allowing simulations in fractures (Stokes flow) surrounded by a porous matrix (Darcy’s law) . Conditions at the interface between the two domains are included in the partial differential equations and automatically satisfied. The technique is also powerful to move fluid / solid boundaries in the presence of geochemical processes.
Despite its early age micro-continuum approach for pore-scale processes has already demonstrated its strength in image-based simulations and coupled physics. State-of-the-art micro-continuum models handle hydro-bio-geochemical processes [4,5,6], two-phase flow [7,8], and poromechanics . In this talk, we give an overview of micro-continuum models applied to fracture-matrix interactions and we discuss our most recent developments.
References Soulaine and Tchelepi, Micro-continuum approach for pore-scale simulation of subsurface processes, Transport In Porous Media, 2016, 113, 431-456  Steefel, Beckingham, Landrot “Micro-continuum approaches for modeling pore-scale geochemical processes” Rev Mineral Geochem 80, 217-246 (2015)  Soulaine, Gjetvaj, Garing, Roman, Russian, Gouze, Tchelepi, The impact of sub-resolution porosity of X-ray microtomography images on the permeability, Transport in Porous Media, 2016, 113(1), 227-243  Noiriel and Soulaine “Pore-scale imaging and modelling of reactive flow in evolving porous media: tracking the dynamics of the fluid-rock interface” Transport in Porous Media 140, 181-213 (2021)  Soulaine, Roman, Kovscek, Hamdi, Mineral dissolution and wormholing from a pore-scale perspective, Journal of Fluid Mechanics, 2017, 827, 457–483  Soulaine, Pavuluri, Claret, Tournassat “porousMedia4Foam: Multi-scale open-source platform for hydro-geochemical simulations with OpenFOAM®” Environmental Modelling and Software 145, 105199 (2021)  Soulaine, Creux, Tchelepi, Micro-Continuum Framework for Pore-Scale Multiphase Fluid Transport in Shale Formations, Transport in Porous Media, 2019  Carrillo, Bourg, Soulaine “Multiphase Flow Modeling in Multiscale Porous Media: An Open-Source Micro-Continuum Approach” Journal of Computational Physics (2020), 8, 100073  Carrillo and Bourg, A Darcy-Brinkman-Biot Approach to Modeling the Hydrology and Mechanics of Porous Media Containing Macropores and Deformable Microporous Regions, Water Resources Research, 2019