Fractures with weakly and strongly correlated aperture distributions were used to explore a fundamental scaling relationship between fracture stiffness and fluid flow in a fracture. Computational models were used to analyze fluid flow through a fracture undergoing deformation and chemical alteration. Fracture stiffness captures the deformation of the fracture void geometry and enables collapse of the numerical flow-stiffness data, from multiple length scales, to a single scaling function. Simulations of wave propagation across fractures with varying contact area but with fixed asperity spacing show that elastic wave transmission is also sensitive to the fracture geometry. The hydro-mechanical scaling relationship provides a path forward for the remote characterization of fluid flow through fractured rock.
Long term safety and optimization of subsurface engineering activities require geophysical monitoring methods that can delineate and characterize evolving fractures and fracture systems. Fractures and other discontinuities pose serious challenges for seismic detection because such mechanical discontinuities span many orders of magnitude in size, are structurally complex and are subjected to complicated mechanical, hydraulic and geochemical processes that alter fractures over time. Thus, both the interrelationship among fracture properties (Fig. 1) and the scaling behavior of these relationships are needed for the optimal design of geophysical monitoring systems and for simulations used to interpret geophysical data to predict subsurface performance.