Hot Rock (ASX: HRL) has been encouraged by the results of Panax Geothermals’ (ASX: PAX) maiden geothermal well, Salamander-1, which recorded a bottom of hole temperature (BHT) of 156°C at a depth of 4,015m for the Hot Sedimentary Aquifer (NYSE:HSA) system in the Penola Trough of the Otway Basin in South Australia.
Salamander-1 well tested the geothermal reservoir comprising the Pretty Hill Formation which exists throughout HRL’s extensive permits covering the Otway Basin in Victoria.
The area of Penola Trough tested in South Australia extends 13km eastward into HRL’s permits, GEP6 and 23. Water has been recorded in the wells but unfortunately no flow tests were carried out because no significant hydrocarbons were intersected.
Executive Chairman of HRL, Mark Elliott, said “Panax’s temperature result from their first geothermal well is very significant in that it provides compelling evidence for the potential of HSA style geothermal projects in Australia and in particular in the Otway Basin."
"HSA projects have been operating commercially in the USA for over 25 years. HRL looks forward to drill testing one of its best projects, the Koroit Project later this year followed by the Penola Trough,” he added.
The highest temperature was recorded from Glenaire ST1 well which was drilled in 2006 into the centre of the Penola Trough and intersected the top 189m of the Pretty Hill Formation providing a BHT of 152oC at a depth of 3,702m.
Salamander-1 well’s BHT result of 156°C compares favourably with Glenaire ST1’s BHT of 152°C recorded at a 300m shallower depth. This comparison confirms the potential of HSA systems in the Otway Basin for geothermal power generation based on temperature.
There is extensive Pretty Hill Formation below 3000m in the Penola Trough, which should provide geothermal reservoir fluid at temperatures above 130°C suitable for geothermal binary cycle plants.
HRL is currently undertaking a geothermal resource estimation study of the Penola Trough, which will be released this quarter.
Disclosure: The author holds no positions in the company