ENGINEERS testing a geothermal drill rig at Karni Engineering in Merredin have come across an untapped water source between 300 and 400 metres underneath the town.
Globe Drill was testing its new GT3000, hailed as the world’s most powerful mobile drill, by drilling three kilometres into solid granite in Merredin, when they discovered the water flowing through an ancient granite fault line.
General manager Warren Strange, who invented and built the drill in partnership with Merredin’s Karni Engineering, said it was a significant find.
“It was unexpected to find a large water supply in this area and at this depth,” he said.
“The largest inflow was encountered at 327 metres and the water at this level seems fresher than the ground water discovered at shallower depths.
“However it is still quite salty and not suitable for drinking, but could be used for industrial or agricultural purposes.”
Mr Strange said it wasn’t yet known exactly where exactly the water was coming from, or how much of it there was.
“It seems to be quite a large supply as we have been pumping it to the surface and depositing it in a dam for days and the water level inside the hole still has not dropped,” he said.
He said water could flow thousands of kilometres in underground fault lines, so it was possible water from high rainfall areas, for example near the equator, could make its way to the drought-stricken Wheatbelt.
The WA Department of Water was notified and invited to conduct tests on the water.
However, within two or three days Globe Drill needed to seal off the fault to contain the water and continue with its drilling project.
Further testing will need to be carried out in the future, before the water can be used for anything.
“Further segregation testing of each inflow would be required to determine the exact salt levels of each inflow,” Mr Strange said.
“This is done by plugging off the hole above and below the faults and testing the water without contamination from the upper levels.”
However he said regardless of the salt content, a consistent water supply would be very useful for a future geothermal energy project, if the drill should succeed in finding sufficient geothermal heat three kilometres beneath Merredin.
Geothermal energy is generated by pouring water down a hole to a depth where the earth’s heat turns it into steam, which is used to generate electricity.
“Although our sole purpose here is to test the GT3000 drill rigs capabilities by drilling a deep test hole, if we discover any ground heat levels at depth we will let the relevant authorities know,” Mr Strange said.
“It would be wonderful if Merredin could produce its own geothermal power.”
The GT3000 is a world-first drill which uses a combination of percussion and rotary technology and is set to make geothermal drilling affordable.
Previously, drilling a hole deep enough to access geothermal heat (about four kilometres) has cost more than $30,000,000 and taken months to achieve.
“After proving the GT3000 rig capabilities, we are hopeful we will be able to drill a 4000 metre hole for under $10,000,000 and in under one third of the time traditional oil and gas rigs are taking,” Mr Strange said.
