Anomalous Solute and Heat Diffusion in Fault Structures

Abstract

A structure associated with large-scale faults can contribute to control fluid flow in a geothermal reservoir. The fracture density at the damage zone in the fault zone decays with distance from the main conduit. A fractional advection-dispersion equation (fADE) and a fractional heat transfer equation (fHTE) describe diffusion processes of solute and heat into the surrounding rocks through fractal geometry and have been developed to characterize mass and heat transfer in the fault-related structure. This study conducted numerical simulation and column flow experiments to generate tracer responses and temperature profiles. The results reveal that permeability patterns in the surrounding rocks affect on the reservoir responses. Both numerical and experimental results simulating tracer response with a fault-related structure show a gradual decrease in concentration of tracer. The fADE and fHTE solutions were found to be in reasonable agreement with the tracer responses and the temperature profiles for a fault zone model.