THE EFFECT OF GEOMETRICAL AND TOPOLOGICAL CHANGES ON THE FLUID FLOW THROUGH LARGE-SCALE DISCRETE FRACTURE NETWORKS
Pouria Aghajannezhad, Mathieu Sellier, Sid Becker
Abstract
This study presents a computationally efficient approach for modelling fluid flow at low Reynolds numbers in large scale Discrete Fracture Networks (DFN). Different three dimensional configurations of two hundred fractures were randomly generated. In this investigation, the influence of surface roughness and geometrical changes of fractures on the hydraulic resistance was studied. The fluid flow behaviour with different arrangements of fractures was modelled. The validity of the approach was evaluated by solving the full Navier-Stokes equations (NSE) for a network consisting of nine fractures. Very good agreement was found between the HS approximation and the full NSE (average deviation of 0.12%). Our findings suggest that increasing the surface roughness causes a rise in hydraulic resistance. Further- more, the number of active fractures in the networks was found to be more influential on the flow resistance than the connection length of fractures. All simulations were carried out for Reynolds numbers smaller than 10.