In its second quarter activities report, the South Australian-based company today said eight holes would be drilled to at least 500m depth at the Frome project, 120km west of Broken Hill.

Geothermal Resources said this would be done to take temperature measurements of standing water at the bottom of each drillhole so that the temperature gradient can be estimated. This in turn will yield vital information concerning the likely geothermal energy potential of the predicted buried uranium-rich granites in the region.

In order to expedite the drilling of these holes Havilah, which owns 63.6% of Geothermal Resources, has offered the company the use of two drill rigs that it has on long-term contract.

“Rather than drill a large diameter hole with a powerful percussion drilling rig as originally planned, it has now been decided to use the Havilah contracted drilling rigs to drill the holes in two stages, so that work can commence immediately,” Geothermal Resources said.

The first stage will use a percussion drill rig to drill and case a pre-collared hole to roughly 200m depth. The second stage will use a diamond drill rig to continue on from the bottom of this hole to at least 500m depth if possible.

Initially three drillholes will be completed, with the remaining five holes planned for the first half of 2007 to be drilled as soon as possible, the company said.

“Apart from being able to commence drilling almost immediately, there is the added advantage that the diamond drilling will produce rock cores, which can be used to undertake essential thermal conductivity measurements and hence determine the insulating properties of the blanketing sediments,” it said.

The drilling is being supported by a $2.4 million renewable energy development initiative (REDI) grant from the Federal Government.

Geothermal Resources said it is also continuing to investigate the feasibility of measuring downhole standing water temperatures in a number of deep mineral and oil exploration holes in the region.

A survey is planned in the next few weeks to determine if the holes remain open so that a temperature logging probe can be lowered down the holes, it said.