Darwin LNG plant leaked methane for decades, group claims

A liquefied natural gas export plant in the Northern Territory leaked methane for almost two decades, according to a local environmental group.

A storage tank at the Darwin LNG site emitted as much as 184 kilograms of methane an hour from 2006, the Environment Centre NT said, citing emails from ConocoPhillips — which operated the hub until Santos acquired its interests in 2019 — to the Northern Territory state government.

While the amount released by the tank accounted for just a fraction of the plant’s reported pollution, tackling fugitive emissions of methane — the main component of natural gas — is seen as important in helping slow climate change.

The hydrocarbon traps more than 80 times more heat than carbon dioxide over a 20-year period.

“Methane is one of the most actionable levers to slow climate warming,” said Sean Bay, a researcher at Melbourne’s La Trobe University. “Fixing leaks like this should be a top priority.”

The emails were obtained by the Environment Centre NT under freedom of information laws and were first reported by the Australian Broadcasting Corporation.

Before an initial survey by a drone in 2019, the fugitive emissions were assumed to be negligible, Conoco said in one of the emails.

Conoco said it “transparently engaged with the regulator and operated the facility under relevant regulatory approvals.” Santos said the tank “remains fit and safe for service” and that all regulatory approvals and an ongoing monitoring program are in place.

Darwin LNG went idle when it ran out of supply in late 2023, but is set to be replenished by Santos’ $US4.5 billion Barossa gas field. The development - criticised for its high carbon dioxide content - is viewed as a key asset for the Abu Dhabi National Oil Co.-led group that is pursuing a $US19 billion takeover of the Australian producer.

Santos operates Darwin LNG and owns about 43 per cent of the venture. The other shareholders in the venture are SK Innovation E&S, Inpex, Eni, Jera Co. and Tokyo Gas Co.