Macroscopic behavior of gas flow with adsorption through a fractured porous medium

Pascale Royer (1) , Jean-Louis Auriault (1) , T. Strzelecki (2)

1 3SR - Laboratoire sols, solides, structures - risques [Grenoble]
2 UWr - University of Wrocław [Poland]

A fractured porous medium is a double-porosity medium, i.e. it consists of two interacting porous systems whose permeabilities are very different. One of the two porous structures is associated with the fractures and the other one with the porous matrix. Thus, when looking for a macroscopic equivalent description, three separated scales whose characteristic lengths are very different may be under consideration: the pore-scale, the fracture-scale and the macroscopic scale. Modeling gas flow with adsorption through double-porosity media is of particular interest in mining engineering. lndeed, coal is a multiple-porosity system that naturally contains gas. Gas adsorption within coal skeleton is strongly connected to the occurence of a coal-outburst. To prevent outbursts and also to draw up reliable safety measures, an accurate knowledge of coal-gas system behavior is required. A three-scale homogenization method bas been first used in [1] and (2] for the investigation of incompressible fluid flow in a deformable fractured porous medium. The local descriptions at both porescale and fracture-scale are expressed by Navier-Stokes equations. This upscaling method allows to convey the influence of the local effects to the macroscopic level. This technique bas been taken up again for modeling gas flow through a rigid fractured porous matrix while considering the strong compressibility of the fluid [3], (4], (5], [6]. Here, the adsorption phenomenon is implemented to gas-flow equations at both local scales through additionnai boundary conditions. Then, the macroscopic behavior is derived via the same three-scale homogenization method.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des solides [physics.class-ph]

Pascale Royer, Jean-Louis Auriault, T. Strzelecki. Macroscopic behavior of gas flow with adsorption through a fractured porous medium. Mechanics Research Communications, 1996, 23 (1), pp.67 - 73. ⟨10.1016/0093-6413(95)00079-8⟩. ⟨hal-01713983⟩