Relation Between First Arrival Time and Permeability in Self-Affine Fractures with Areas in Contact

Laurent Talon (1) , Harold Auradou (1) , Alex Hansen (1, 2)

1 FAST - Fluides, automatique, systèmes thermiques
2 Physics NTNU - Department of Physics [Trondheim]

We demonstrate that the first arrival time in dispersive processes in self-affine fractures are governed by the same length scale characterizing the fractures as that which controls their permeability. In one-dimensional channel flow this length scale is the aperture of the bottle neck, i.e., the region having the smallest aperture. In two dimensions, the concept of a bottle neck is generalized to that of a minimal path normal to the flow. The length scale is then the average aperture along this path. There is a linear relationship between the first arrival time and this length scale, even when there is strong overlap between the fracture surfaces creating areas with zero permeability. We express the first arrival time directly in terms of the permeability.

Mots clés: Fracture; Permeability; First Arrival Time; Dispersion; Critical Path; Fracture

Domaines: Dynamique des Fluides [physics.flu-dyn]; Hydrologie; Milieux et Changements globaux

Laurent Talon, Harold Auradou, Alex Hansen. Relation Between First Arrival Time and Permeability in Self-Affine Fractures with Areas in Contact. EPL - Europhysics Letters, 2012, pp.1. ⟨10.1209/0295-5075/97/68009⟩. ⟨hal-00673739⟩