Calibration of a Fractal Model Relating Porosity to Permeability and its Use for Modeling Hydrothermal Transport Processes in the Perth Basin, Australia

Numerical modeling of geothermal systems requires the best possible knowledge of porosity and permeability within the geothermal reservoir. The deep Jurassic Yarragadee Aquifer in the Perth Basin consists of various different lithofacies but is characterized by a high average permeability and the likely occurrence of free convection, making this Aquifer to a promising low-medium enthalpy geothermal reservoir unit.We define a log(permeability) - porosity model based on a combination of the Kozeny-Carman equation and fractal theory and calibrate it by nonlinear regression using a least-squares approach to the Yarragadee Aquifer in the Perth Basin. For the calibration, we use over 100 measurement pairs of porosity and permeability from three boreholes in the vicinity of our model domain. The calibrated model reasonably covers the control of lithofacies on permeability.