Presentation materials
Terzaghiโs Principle states that the total stress acting on a porous material can be decomposed linearly into a part that acts on the solid porous structure and the fluid pressure. The result of the Terzaghiโs Principle is that the stress-strain relationship for porous media does not have to be re-constructed for every possible fluid pressure โ increasing the fluid pressure linearly effects...
We consider a shale gas reservoir with multimodal distribution composed of networks of natural and hydraulic fractures along with nano and micropores dispersed within the organic and inorganic matters.
Under the long term pseudo-steady state regime, characterized by the absence of pressure variability in the matrix, mass transfer between matrix and fractures can be approximated by the...
In mechanized tunneling, grouting mortars are necessary for the backfilling of the annular gap, which is the cavity between the surrounding soil and the lining segments. An adequate grouting mortar should ensure a force-fitting connection in order to minimize surface settlements above the tunnel lining. The specific application prescribes two contrary requirements towards the rheology of the...
Diffuse interface methods are popular methods for modeling two-phase flow at the pore scale. These methods are based on the minimization of Helmholtz free energy of the fluid system and approximate the interface between the phases by a transition region of finite thickness. The mathematical model is a coupled system of time-dependent Cahn-Hilliard and Navier-Stokes equations. Contact angle...
We have given experimental grounding for the remarkable observation made 30 years ago by Furuberg et al. [1] of an unusual dynamic scaling for the pair correlation function
We study experimentally and numerically drainage situation in a disordered porous medium. We show how the fractal dimension associated to capillary fingering, the Bond number and fluctuations amplitude in capillary thresholds allow to compute the residual saturation under various gravitational fields, and in various disordered distributions for the capillary thresholds. We also show how these...
When a more viscous fluid displaces a less viscous one in porous media, viscous pressure drop stabilizes the displacement front against capillary pressure fluctuation. For this favorable viscous ratio conditions, previous studies focused on the front instability under slow flow conditions but did not address competing effects of wettability and flow rate. Here we study how this competition...
In several applications, morphology evolves over time, e.g. in the formation of pores in porous polymer membranes or in the formation of porous particles during spray polymerization of suspensions in a drying chamber. For example, during the preparation of porous polymer membranes by phase inversion process, a homogeneous polymer solution phase separates at contact with a coagulation bath due...
Gas hydrates are crystalline solids formed when water molecules form a cage-like structure and trap a large number of gas molecules within. Gas hydrates are thermodynamically stable under conditions of low temperature and high pressure and occur in nature typically in permafrost regions and marine off-shores. If warmed or depressurized, hydrates destabilize and dissociate into water and...
Surfactant flooding is one of the mechanisms used to enhance oil recovery from oil reservoirs. Surfactants mainly reduce interfacial tension, increase oil mobility thus allowing better displacement of oil by injected water. One of the main challenges in this process is the loss of surfactant due to adsorption on reservoir rocks. The first adsorbed layer of surfactant is mostly governed by...
Geological storage of CO2 in subsurface saline aquifers is a promising way to reduce CO2 emissions. During this process, CO2 first dissolves into pure brine, forming an acidic and denser mixture that falls down under the gravity and reacts with the rock [1, 2]. From the fundamental science point of view, the above process is indeed flow and reactive transport processes in porous...
Up scaling techniques allowing to use coarser meshes have rigorous fundations as well as the underlying heterogeneous porous medium presents some statistical homogeneity. In that situation, homogenization theory works well and provides closure problems, the solution of which gives rises to up scaled paramters. These assumptions break down in presence of a front corresponding for example to...
