| Abstract |
Geodynamics has been developing an Engineered Geothermal System (EGS) in the Cooper Basin, Australia since 2003. In this period, stimulation of the system has produced over 45900 seismic events, of which over 32500 events could be located. In November 2012, a large stimulation was carried out in the Habanero field. The intent of the stimulation was to expand the existing geothermal reservoir in the Habanero field and to gain a better understanding of the geothermal system. The stimulation was conducted through Habanero 4, situated approximately 680m North East of Habanero 1, which had been used for the original stimulations in 2003 and 2005. Over 34 Ml of water was injected into the existing “Main fracture” at a depth of 4077m over a 3 week period. During stimulation, 7 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 3 week stimulation period, over 27000 events were recorded, of which over 20700 events were located. Event magnitudes calibrated by recordings of the permanent network of Geosciences Australia were in the range of ML -1.6 and 3. Hypocenter locations indicate that seismicity occurred on the same sub horizontal layer structure identified in previous stimulations. The nature of the seismic cloud growth was consistent with the previous 2005 stimulation performed through Habanero 1. This paper aims to provide an overview of the seismicity produced through the 2012 stimulation of Habanero 4 and how it relates to previous stimulations of the Habanero field. |