Production, Injection and Closed-Loop Testing at Habanero EGS Project

Geodynamics Limited (GDY) has been developing an Enhanced Geothermal System (EGS) in hot granites beneath the Cooper Basin, Australia, since 2002. Four wells have been drilled at the Habanero site to depths exceeding 4,200 m and all four wells have penetrated a major fault which forms the reservoir. The temperature in the reservoir has been measured at 244°C at ~4,220 m below the surface. In November 2012, the latest well, Habanero 4, was stimulated and production tested. The stimulation was done with water and injection rates of up to 53 kg/s were achieved. Following this stimulation, a maximum production flow rate of 39 kg/s was achieved in open flow mode. Commencing in April 2013, Habanero 4 and Habanero 1 were operated in closed-loop mode, with Habanero 4 as the producer and Habanero 1 as the injector. Circulation was established and maintained with the aid of a surface pump, re-injecting the produced geothermal brine back into the reservoir. The heat produced was used to power a 1 MWe pilot power station. The results of these production, injection and closed-loop tests will be discussed and compared to earlier tests conducted at Habanero. Combining the results of production, injection and closed–loop tests, the likely performance of future wells at Habanero will be discussed.