High-resolution streamline models of flow in fractured porous media using discrete fractures: Implications for upscaling of permeability anisotropy

This paper reviews the equivalent permeability tensor concept for flow in 2D fractured porous media and adds new fundamental insight from a series of systematic flow simulations. Flow models with discrete fractures based on complex analysis methods (CAM), scaled for permeability anisotropy, provide unique, high-resolution examples of streamline deflection and delays or gains in the time-of-flight due to the presence of fractures in fractured porous media. The results of our study provide guidance for advanced studies of flow in fractured porous media, with immediate practical conclusions for drainage studies of geothermal and hydrocarbon reservoirs. The practical implications of the new model tool and improved understanding of flow in fractured porous media are not limited to applications in energy extraction projects in fractured reservoirs. The flow of igneous melts through the Earth's crust, and ore formation in natural (hydraulic) fracture systems, commonly preserved in exhumed Precambrian Cratons, may equally well benefit from the same techniques. Such applications may need added terms to account for thermal effects (not developed further in our present study). Nonetheless, the multidisciplinary nature of flow studies in fractured rock bodies warrants a concise exposé of our discrete fracture flow models, with instructive examples that may serve to open up new insights in a variety of application areas.