Hydraulic Fracturing at the Olympic Dam Geothermal Energy Project

Abstract

Australia’s first mini hydraulic-fracturing program of a hot granite in a slim hole was carried out early this year by Green Rock Energy Limited at its Olympic Dam Engineered Geothermal System (EGS) Project. The viability of EGS projects are critically dependant on being able to establish a sufficient water flow rate through fractures in the hot granites between injection and production wells. Success depends on the capacity to successfully engineer by fracture stimulation a network of sustainable permeable fractures connecting the wells in the granite. The mini hydraulic-fracturing program was undertaken in Blanche No 1 well drilled to a depth of 1.935 km. This was done in order to provide the engineering data and confidence required before undertaking the more expensive drilling and fracture stimulation program to connect the injection and production wells by opening fractures at the greater depths where the granites are hotter.