Hunt for oil and gas
Wednesday, 9th January, 2019
By Myles Burt
Gas and oil seems to be fool’s gold in the Far West, but only because of a lack of exploration.
As past evidence shows, gas and oil may be closer to home than previously thought, according to local Geologist Kingsley Mills.
The NSW Department of Planning and Environment announced last year it was preparing a regional assessment for the exploration of gas resources in the Bancannia Trough and Pondie Range.
But Mr Mills can reaffirm the Bancannia Trough as a significant area of interest, having mapped much of the area for the government in the 1990s.
“That’s why I came to Broken Hill, because it was the last part of the state that hadn’t been mapped,” Mr Mills said.
“We didn’t really understand what was out there, it was so remote from Sydney, they knew a lot about Broken Hill because that was discovered as a metal province.
“Very few people went across the trough and looked at that area.”
Over his time there, Mr Mills discovered small amounts of trilobite fossils in what was once a volcanic arc dating back 500 million years.
It was a good sign that could further hint at the existence of gas and oil deposits deep beneath the surface.
“The fossils are good because they tell you that there were marine rocks which you need for most petroleum deposits, they’re formed from marine accumulations,” Mr Mills said.
“Most of the Darling Basin rocks, the quartz sandstones were formed when there were very big rivers flowing in from Western Australia and South Australia.
“These enormous meandering rivers, a bit like the Ganges.
“Most of the sediments here are deposited from a river or a series of rivers coming in from the west.”
Over the 1960s a few people went out drilling and mapping the Bancannia Trough, where three petroleum holes were drilled to explore for gas and oil, with one called the Bancannia South-1 that was drilled at 6km in depth and produced signs of gas.
Since then no further drilling exploration has been conducted, leaving the door open to the possibility of an untapped energy source.
“There’s limited knowledge to what’s really underneath the Bancannia Trough other than from the drill holes and the Mutawintji area,” Mr Mills said.
“That’s the problem, they’re expensive to drill.
“Americans look at it and say oh you’ve only got three holes.
“Over in America, they’d have 30 holes.
“The Mutawintji National Park is quite important, because it’s the one place were the Bancannia Trough is actually exposed.”
The Bancannia Trough is of particular interest as the area shares similar geological traits to Moomba, a major gas field in outback South Australia owned by Santos.
“There probably are Devonian rocks underneath Moomba so there is that sort of comparison,” Mr Mills said.
“Of course you’re getting gas up here (Moomba) so why aren’t they getting gas down here (Far West).”
Mr Mills said there have been rumours and stories about gas and oil in the Far West.
He said a northern property owner had spoken about accidentally striking oil when drilling a bore back in the 40s or 50s.
“The oil filled their earth tank,” Mr Mills said.
“Whether that’s true I don’t know, I think a lot of these things get enhanced in the local pubs.
“Anyway there were sort of indications that there could be petroleum, there is gas in some of the water bores as it bubbles out as gas.
“There is evidence of gas.
“It’s probably more part of the Cretaceous basin rather than the Devonian basin.”
As geologists sit and ponder on these theories, Mr Mills said the only way to truly know whether Broken Hill sits near a cradle of gas is to simply “drill more holes”.
“There could well be, there’s an arm of gas bearing rocks in the form of the Bancannia Trough,” Mr Mills said.