Origin caps old exploration holes after CSG water bubbles up
A PROPERTY on Green swamp Rd in Chinchilla had to have four historic coal exploration drilling holes capped after salty CSG water seeped onto farmland and caused gas to bubble to the surface of Charleys Creek.
An Origin Energy spokesman said the company first became aware of the issue on Thursday, July 23, where coal exploration drilling holes had caused CSG water and gas to surface.
Origin confirmed the holes were capped last Wednesday, August 23.
"We have remediated four of these old coal exploration holes with the authorisation from Department of Natural Resources, Mines and Energy - they have now been plugged and abandoned to gas industry regulations and standards," he said.
"While we aren't responsible for the ongoing management of these old coal exploration bores, we are prepared to work with our landowners and government on a case-by-case basis to remediate from an environmental and safety perspective.
"What we have shown is that we are prepared to work with our landowners and government on a case-by-case basis to step in and remediate from an environmental and safety perspective."
When asked if recent CSG development in the Chinchilla area had caused the issue to arise, the spokesman said, "there is no gas development on this property and no fracking has occurred in this area".
The spokesman said since being capped, the gas bubbling to the surface of Charley's Creek, which runs through the township, had stopped.
"We also sampled and tested water quality in dams and in the nearby creek, providing this information to the landowner and government," he said.
As old exploration drilling holes are not lined, the spokesman said a path is sometimes provided for groundwater and gas to move between the shallow geology in the Chinchilla region, which sometimes caused gas to rise to the surface.
"The underlying geology in this area is rich in shallow natural gas resources associated with coal formations," he said.
"Any of these old coal bores which don't have sufficient isolations in place may also provide pathways between gas bearing coals and shallow porous formations connected to underlying dams and creek beds.
There are still hundreds of old gas exploration holes in the region which remain uncapped, the spokesman said, "exactly how many is a question for government or the coal companies who are responsible for drilling them".
The four old gas exploration drilling holes that were capped by Origin are currently managed by the Australian based coal producer, Yancoal.
A Yancoal spokesman said they were not aware of the issue until Wednesday, July 29, when the Department of Natural Resources, Mines and Energy notified the company of a request made by Origin Energy to undertake remediation works.
"Yancoal is providing appropriate assistance to the affected landholders and Government, as well as Origin Energy," he said.
"These exploration holes were drilled in 2007 on a coal exploration tenement that was subsequently acquired and is currently managed by Yancoal - the land has never been mined for coal.
"They overlap a production tenement for Coal Seam Gas operated by Origin Energy on behalf of a Joint Venture, Australia Pacific Liquified Natural Gas (APLNG).
The spokesman said Yancoal is not aware of any other issues with remaining uncapped exploration holes in the area.