A new report has found that methane leakage and fugitive emissions from unconventional gas fields are likely to be much higher than industry estimates, largely because it is neither accounting for nor reporting on them.
A review of current and future methane emissions from Australian unconventional oil and gas production was commissioned by The Australia Institute and written by four authors from the University of Melbourne Energy Institute.
The report found that United States unconventional gas fields’ leakage rates were 10 to 25 times higher than the figures the Australian government logs with the United Nations Framework on Climate Change (UNFCC), which is overseeing the Paris Agreement to voluntarily cut carbon emissions.
It concluded that if the rate of Australia’s leaks were comparable to those in the US, Australia would not be able to meet its emission reduction commitments.
Furthermore, The Australia Institute’s Mark Ogge said “Australian gas fields may well have higher levels of leakage than US gas fields as the gas is far closer to the surface, and depressurising of coal seams over vast areas increases the risk of migratory emissions”.
He criticised the industry’s current practice, which is to take a measurement only at the well head and ignore surrounding infrastructure, saying it could not provide an accurate reading of fugitive emissions.
Report author and former Australian Energy Market Operator Gas Principal Tim Forcey said: “While the industry in Australia has claimed that fugitive emissions amount to only 0.1% of gas production, actual measurements made at US gas fields found leakage rates to be up to 17% of production, or 170 times the Australian assumption.
“This report identifies significant weaknesses in the way Australia measures methane emissions and identifies major sources of emissions during the ‘production’ phase of unconventional gas that are effectively set to zero in Australian reporting.”
The report applauds the Australian CSG-LNG industry for pledging to limit methane emissions to no more than 0.1% of total gas production but says the reporting has to be accurate.
The report notes that the National Greenhouse Gas inventory reports methane emissions based on “default emission factors”, none of which relate specifically to the production of coal seam gas in Australia.
The US uses satellite and aircraft-based systems to detect methane emissions and quantify emission rates. These technologies have discovered a few “super emitters” from oil and gas producing areas.
But as Australia does not deploy such methods, the report says “the occurrence or otherwise of ‘super-emitters’ in Australia is unknown”.
The authors, who assume the industry will continue to expand, are critical of the industry fudging its measurements, saying there has been ample time to get this right. Gas reporting requirements have been in place since 2009 and the unconventional gas industry has been operating “at significant scale” since 2010 and yet “there has been no comprehensive, rigorous, independently verifiable audit of gas emissions”.