The geometrical properties of fracture corridors

Abstract

Fracture corridors are densely fractured zones that may form preferential drains for fluids in the surface and subsurface. Their accurate characterization and modeling are of utmost importance to predictive hydrodynamic models. This paper details their key geometrical attributes and shows that they can be predicted, based on a comprehensive study of surface and subsurface data.The spacing, length and width of fracture corridors all exhibit multifractal characteristics, with a very good consistency between the different data sources. Their width appears to be limited to a maximum of ∼250–300 m, while their fracture density is correlated to their width by a negative power law relationship, but with a significant variability at all scales. The constitutive fractures in the corridors also show multifractal properties. The fracture spacings typically fall in the cm-m range regardless of the corridor size, and moderately increase with increasing corridor size. The fracture heights increase more significantly with increasing corridor size, but with a constant distribution when normalized to the corridor height. All these elements are indicative of typically scale-independent fracture corridor development mechanisms, consistent with a recent model.The data acquired form a key resource from which a new method and tools are proposed for the modeling of fracture corridors in surface and subsurface contexts, with applications to aquifers, hydrocarbon reservoirs or underground CO2 storage sites.