We developed a new methodology to compute hydraulic transmissibility between karst-conduits and rock matrix in carbonate reservoirs. Such a parameter quantifies the mass exchange between these two geological objects and can be explored in EDKM-type models (Embedded Discrete Karst Model) via non-neighboring connections. The upscaling procedure adopted hinges on the karst index concept, whose...
Information about sub-surface formations is typically scarce and plagued by uncertainties. Especially when dealing with fractured formations, this strongly impacts the predictive power of numerical simulations. Isolated fractures for example may represent long-ranging highly conductive flow conduits having a strong impact on flow and transport. Furthermore, as fractures can reach extensions...
Despite the amount of research on flow and transport in single fractures and fracture networks, there is a gap in knowledge between the field data describing natural fractures and the models that represent them. Natural fracture networks exhibit ranges of fracture lengths, connectivity, and aperture distributions, which directly affect the flow and transport behavior within the network. The...
Understanding material failure is critical for designing stronger and lighter structures by identifying weaknesses that could be mitigated, predicting the integrity of engineered systems under stress to prevent unexpected breakdowns, and evaluating fractured subsurface reservoirs to ensure the long-term stability of the reservoir walls, fluid containment, and surrounding geological formations....
Coastal erosion is a growing concern for many coastal regions worldwide, and salt weathering has been identified as a contributing factor to this phenomenon. This research focuses on the ongoing erosion of the French Basque Country coastline, particularly between the connecting sections of Saint-Jean-de-Luz and Hendaye which are characterized by Santonian flysch rock cliffs.
The objective of...
Mineral dissolution during groundwater flow is a crucial phenomenon that has received continued interest for decades as a main drive of various subsurface processes, such as carbon mineralization, karstification, and the formation of complex rock patterns in caves. In fractured media and dissolving porous media, fluid inertia can play an important role in shaping fluid flow and dissolution...
To achieve the goal of limiting the global temperature increase to below 2°C and avoid the adverse effects of climate change, the removal of CO2 from the atmosphere requires the simultaneous application of carbon capture, utilization, and storage (CCUS) methods. Among these, carbon mineralization is a promising approach that can securely trap a substantial amount of CO2. Ultramafic rocks, such...
Chemical reactions induced by fluids that are out of chemical equilibrium with the minerals on fracture surfaces lead to mineral dissolution and/or precipitation along fracture surfaces and alterations in the fracture aperture. Incorporating the influence of localized chemical alterations into continuum models requires effective constitutive models that relate changes in mechanical aperture to...
Numerical modeling of coupled thermal, hydraulic, and mechanical (THM) processes is crucial for understanding and capturing the complex interactions in enhanced geothermal systems (EGS). We describe the development of the numerical approach for coupling those processes to improving the predictive capabilities for the EGS testbed site, part of the Center for Understanding Subsurface Signals and...
Fractures and fracture networks are critical pathways for subsurface flow and reactive transport in rock. In particular, fracture intersections, where fluids with different properties mix and react, serve as biogeochemical reaction hotspots. Recent studies have highlighted the importance of intersection geometry in influencing mixing dynamics. Although geologic fractures are subjected to...
Recently, Krauklis waves (Krauklis, 1962)—guided waves that propagate mostly as pressure pulses within fluid-filled, high-permeability fractures—have gained attention as a geophysical tool for subsurface fracture characterization. Strongly dispersive velocity and attenuation of these waves are sensitive to the hydraulic conductivity (permeability) of the fractures. This property may give...
Accurately modelling fracture networks in low-permeability formations like caprocks requires an understanding of the complexity of a single fracture geometry and its impact on flow. Fractures are often oversimplified as planar, ignoring the variability that influences flow behaviour. Most fracture geometry research focuses on granites and sandstones, while caprock fractures remain...
Predicting what permeability enhancements are feasible in a geothermal system (EGS) and the potential seismic activity they may trigger is challenging. Geomechanical simulations are computationally expensive because they require a discretized fracture network with a relevant level of complexity and a quantification of frictional sliding and tensile opening of individual fractures therein. Yet,...
Fractures are voids in rock, defined by rough surfaces in partial contact, that often create complex flow and transport networks. Flow and transport in fractured systems is complicated by coupled processes such as colloid transport, water-rock interactions, and geomechanics. Understanding these coupled processes is essential for permeability and injectivity management in oil and gas...
Humanity's innate drive for discovery has fueled exploration beyond Earth's boundaries, from landing on the Moon to ambitious missions targeting other planets and celestial bodies. Achieving these goals requires meticulous planning and engineering. Engineering uncertainty tolerances are gaining importance, mainly as mission objectives demand transporting larger payloads, such as...
Hydraulic fracturing is a technique that involves injecting fluids into rock formations at high pressure to create cracks or hydro-fractures. While hydro-fracture can occur naturally during seismic events, hydraulic fracturing is a human-engineered process used to increase the permeability of low-permeability rock formations. This technique is widely applied in engineering applications such as...
In this work, we have studied numerically the fracture initiation conditions induced by non-Newtonian polymer solution in the granular media. Computational Fluid Dynamics (CFD) coupled with the Discrete Element Method (DEM) technique is used to model fluid flow through porous media. The power law used to describe the polymer solution flow. The associated parameters are considered in the drag...
We perform a set of high-fidelity simulations of geochemical reactions within three-dimensional discrete fracture networks (DFN) and use various machine learning techniques to determine the primary factors controlling mineral dissolution. The DFN are partially filled with quartz that gradually dissolves until quasi-steady state conditions are reached. At this point, we measure the quartz...
