Petratherm and its joint venture partners Beach Energy and TRUenergy Geothermal have begun fracture stimulation of the deep well at the Paralana 2 geothermal energy project in South Australia, a key step in proving that a geothermal reservoir can be created at deep levels.


 The stimulation process involves the injection of water into the geothermal reservoir in the subsurface. The volumes and rates of injection of water are dependent on the micro-seismic response measured by the installed micro-seismic array.


The primary aim of the hydraulic stimulation work is to demonstrate the ability to propagate fractures beyond 500 metres from the Paralna 2 well.


In addition, the fracture stimulation works aim to connect to and enhance the existing natural fractures identified during drilling of the Paralana 2 well, which contain over-pressured brines below 3670 metres. The operating micro-seismic array at the Paralana site will map in three dimensions the growth and nature of the fracture field during the fracture stimulation process.


The fracture stimulation and associated micro-seismic work will assist the joint venture’s understanding of the sub-surface heat exchange potential for potential commercial geothermal power production at Paralana. Results will also determine the optimum site for the drilling of Paralana 3, the planned deep geothermal production well to follow.


The operation, which began last week, will take approximately ten days with the actual injection of water being conducted over a period of three to five days. Passive seismic monitoring will be used to monitor the development of fracturing.