Geodynamics reports hottest EGS well in the world at Cooper Basin

Drilling crew of Geodynamics at work (source: Geodynamics)

Alexander Richter 7 Sep 2010

Australian Geodynamics provided this week an overview over its Innamincka ‘Deeps’ Joint Venture project in the Cooper Basin, Australia, stating among others the “confirmation of the hottest drilled Enhanced Geothermal System geothermal well in the world”.

In the release the company, Operator of the Innamincka ‘Deeps’ Joint Venture, reports “that it has successfully indentified fractures in the upper section of the granite in its Jolokia well at the Cooper Basin, using a purpose built imaging tool.

This is the first time that an imaging tool has been successfully deployed to log a well bore in the high temperature and high pressure conditions prevalent in the granite reservoirs of the Innamincka ‘Deeps’ Joint Venture. Geodynamics was able to obtain images in the upper section of the wellbore (Figure 1) and useful temperature data to a depth of 4,575m using the imaging tool. This data together with other data from drilling operations and logs is being used to evaluate the fracture network at depth in the Jolokia 1 well.

Logging results have revealed potential fractures deeper within the granite at higher temperatures which are believed to be comparable to the imaged shallower fractures and these will be targeted for stimulation to enhance the existing natural network of fractures and create an underground reservoir.

The logs also confirmed that the temperature at Jolokia is approximately 8 degrees hotter than the company’s Habanero site (at the same depth), making Jolokia 1 the hottest EGS geothermal well in the world at this depth. Temperatures in Jolokia at 4,900 m are around 278 °C.
Well completion operations continue as the company progresses with its next major stage of work to hydraulically stimulate the identified fractures at Jolokia. The work currently being undertaken has two defined stages. These are to install a 7 “ liner from the surface to the granite, followed by stimulation of the granite reservoir.

The hydraulic fracture stimulation program is now expected to be completed during October. This represents a short delay due to slower than expected progress in installing the 7” liner in the one-off completion at Jolokia and continued heavy rain in the region. In addition, the Company continues to take a measured and cautious approach to completing the well. An announcement will be made as soon as stimulation program results are available.

The successful stimulation of Jolokia and demonstration of key flow and temperature targets from the reservoir will represent a major validation point by demonstrating the Joint Venture’s ability to stimulate the granite and thereby create an underground heat exchanger at a location 9 km away from the original site at Habanero. The fractured granite, once coupled with another well will then complete the demonstration of circulation as has been previously demonstrated at Habanero.”

Source: Company announcement via e-mail