Beach digs into SE fracking potential

Beach Energy is seeking permission from the State Government to sink two 4000-metre wells to gauge the practically of extracting tight and shale gas from a location about 2 kilometres south east and about 13km north west of Penola.

A spokesperson said the company had not proposed hydraulic fracturing at this stage, but it was drilling for natural gas trapped in shales or tight sands at more than 2600m - deeper than formations previously targeted for gas in the region.

This would also be at depths far greater than coal seam gas deposits being extracted interstate.

"But we are certainly not hiding from the fact that if drilling is successful, we may have to fracture-stimulate to get the gas to flow," the spokesperson said.

"That's a whole new application process, however, and we've committed to the SE community that we'd go back and consult on that stage of work, and every stage after that."

Livestock SA vice-chairman Jack England, Shepherds Hill, said the company answered a number of questions at two public meetings in mid-September, at Penola and Robe, with those they could not answer directed to the Department for Manufacturing, Innovation, Trade, Resources and Energy.

"Basically, because it's shale and tight gas, they will frack every two to three years, depending on the well life," Mr England said.

"All the fracking fluids won't be stored on site and are going to be removed.

"But the real thing that mining companies steer away from is that, even if the well has a high number of casings, there is always an outside layer."

This created risks because concrete might not bond with many of the hundreds of rock formations that bore holes intercept, giving rise to the risk of gas escaping - and groundwater contamination.

High-pressure gas deposits could also push liquids against the well casing.

Dennis Vice, Highbank Wines, Coonawarra, says Beach Energy gave few assurances about well integrity at the meeting.

"There's been quite a bit of controversy about this subject in Gippsland and the Hunter Valley," he said.

"They're going through three aquifers here and it doesn't seem like there's any real assurances about the integrity of the technology, such as deterioration of the casings and the like."

Monash University Environ-mental Engineering senior lecturer Gavin Mudd says there is a lot companies can do to overcome bonding conditions, including sending equipment and technology into the well to test for crack and hairline fractures.

It also included using cement with the appropriate chemical composition for the soils and groundwater quality because naturally occurring carbon dioxide, when combined with water, could create carbonic acid.

"What happens when you start putting carbonic acid next to steel?" Mr Mudd said.

"It corrodes it. You can also get corrosion from sulfate and high chloride - just look at peoples' houses by the sea.

"Part of the reason why one of the CityLink tunnels in Melbourne had so many problems is because of the grouting cement they were using, which is the same concept."

A DMITRE spokesperson said the assessment of Beach Energy's Environmental Impact Report and Statement of Environmental Objectives for exploratory drilling was ongoing.

"No petroleum projects are approved or otherwise until the conclusion of a rigorous risk assessment process, which involves robust consultation with potentially affected people and enterprises," the spokesperson said.

*Full report in Stock Journal, October 24 issue, 2013.