But Chevron faced so many engineering problems with the technology that three years after Gorgon began production, the injection system was still not operational.
The carbon capture system was finally switched on last August, though is understood to be not yet operating to full capacity.
The Australia Institute “conservatively” estimated Gorgon vented 10-12 million tonnes of carbon dioxide during the three years, comparing this to the 10 million tonnes the domestic airline industry produced in a normal year.
Chevron argued to the WA government those three years should not count under approvals, as not all of its gas trains were operational, but the WA EPA reviewed the approvals and disagreed.
On Friday WA Environment Minister Stephen Dawson made a long-awaited announcement that he backed the authority’s reading and confirmed emissions would be counted from July 2016 for train one and July 2018 for trains one and two.
The decision was a blow to Chevron, making it essentially impossible to meet its emissions reduction targets and puts the company in the crosshairs of regulators.
The government has just one year left to consider its options before Gorgon’s first five-year period expires.
Previously the WA Environmental Protection Authority has suggested gas companies offset their emissions through carbon credits, and The Australia Institute’s analysis says at the market rate of $15 a tonne for Australian carbon credit, Chevron would be up for $160 to $200 million.
This would be a fraction of their cash profit and less than the $340 million Chevron owed the Australian Tax Office after being prosecuted for tax evasion in 2017, The Australia Institute’s climate and energy program director Richie Merzian said.
He said Chevron’s failure to bury its emissions from the Gorgon site in 2017-18 resulted in more than half of Australia’s increase in annual in emissions and he criticised the has sector’s move to carbon capture technology.
“Carbon capture and storage has been a long-running marketing tool to try to bury the fossil fuel industry’s dirty reputation,” he said.
“If Gorgon is the benchmark project for CCS technology, we hold little hope for it to play a major role in any low-emission economy.”
A Chevron spokeswoman said the company was still reviewing the decision but it was continuing to look at how it could reduce emissions across the business.
“Managing greenhouse gas emissions is an integral part of how Chevron plans and executes its business and we continue to evaluate all opportunities to minimise emissions over the full life of our facilities,” she said.
The federal government’s Technology Investment Roadmap, released last month, highlighted gas as a key fuel for the future and embraced the controversial carbon capture and storage technology as a key area for investment to offset the gas industry’s emissions.
A Department of Water and Environmental Regulation spokesman said the agency would continue to monitor Chevron’s compliance with its conditions and if it is found to be in non-compliance after July 2021, it would consider its regulatory options.
Hamish Hastie is WAtoday’s business reporter.
Emma Young covers breaking news with a focus on science and environment, health and social justice for WAtoday.