Targeting Faults for Geothermal Fluid Production: Exploring for Zones of Enhanced Permeability

Abstract

Fault structures can potentially deliver increased geothermal fluid production by boosting the bulk permeability and fluid storage of a production zone. However, the hydromechanical properties of faults are inherently heterogeneous and anisotropic, thereby, making it challenging to distinguish between permeable and impermeable faults. This discussion paper outlines the key features that determine fault permeability and how the probability of locating zones of enhanced fault permeability can be derived from preliminary fault stress state modelling. It is proposed that preliminary fault stress state modelling for early stage exploration projects or in areas of unknown or complex geology can reduce the uncertainty and risk of exploring for fault-related geothermal targets.