Seismic Real-Time Monitoring of a Massive Hydraulic Stimulation of a Geothermal Reservoir in the Cooper Basin, Australia

Geodynamics Limited has been developing an Enhanced Geothermal System (EGS) at Habanero in the Cooper Basin, Australia, since 2003.

In November 2012, a large hydraulic stimulation was carried out in the Habanero field. The intent of the stimulation was to expand the existing EGS geothermal reservoir. Over 34 ML of water was injected into the existing “Main Fracture” at a depth of 4,077 m total vertical depth (TVD) over a three week period.

During stimulation, seven seismic stations were used to transfer data in real time to the central processing office with an additional 17 stations recording in an offline mode and incorporated into the workflow in post-processing. In this three week stimulation period, over 27,000 events were recorded, of which over 20,700 events in the magnitude range of ML −1.6 and 3 were located in real time. Hypocenter locations indicate that seismicity occurred on the same sub-horizontal layer structure identified in previous stimulations.

With peak seismicity rates of approx. 2,700 events per day, highly automatized processing played a decisive role. The seismic monitoring campaign is a unique showcase for successful and reliable real-time processing and traffic-light system operation at extremely high seismicity rates.