The company said temperature logging of three recently completed Frome Project drill holes has recorded relatively high bottom-hole temperatures.
Drillhole Frome-3 had the highest bottom of hole temperature of 45 degrees Celsius at a depth of 440 metres, supported by nearby holes, Frome-2 and Frome-9, which have slightly lower, but still markedly elevated bottom of hole temperature readings.
“These results indicate high geothermal gradients, comparable with temperature gradients found in the Cooper Basin, some 500km to the north,” Geothermal Resources said.
“It is therefore inferred that suitably high temperatures [over 200C] are likely to be present at around 4000 metres and within economic drilling depths.”
Ranking of the thermal profiles for the three holes shows an area of at least 400 square kilometres where temperatures over 40 degrees exist at 500m indicating a potentially large geothermal heat reservoir at depth, it said.
Conductivity measurements will be undertaken on core samples in order to calculate hypothetical heat flows in due course.
Geothermal Resources chairman, Dr Bob Johnson, said the highest temperatures related closely to predicted locations of buried granite bodies, thus confirming the company’s geological model for the region.
“Our next step will be to drill and log some further shallow holes to pin-point the area of highest heat flow, which is where we will drill our deeper test holes into the large granite geothermal reservoirs,” he said.
The Frome project is some 120km west of Broken Hill where there is a national electricity grid connector.
Between Broken Hill and the Frome Project area lie several potential mining projects including the large Havilah Resources-Glencore Kalkaroo copper-gold-molybdenum project, which is currently in feasibility stage.
This drilling is being supported both by a South Australian PACE grant and by a $2.4 million REDI (Renewable Energy Development Initiative) grant from the Federal Government.
Geothermal Resources is 63.6% owned by Havilah Resources.
