Australia became the world's second-largest LNG exporter after Qatar shut down production in March following damage to its facilities from Iranian strikes.
Global LNG flows out of the Middle East have also been upended by Iran's blockage of the Strait of Hormuz.
Chevron said it was working to restore production at its Gorgon and Wheatstone LNG facilities in Western Australia following outages that were likely due to Tropical Cyclone Narelle, a category three storm, which crossed the coast on Friday.
Gorgon is Australia's largest LNG export facility, producing 15.6 million tonnes a year with three processing trains, while the smaller Wheatstone consists of two trains producing 8.9 million tonnes.
Woodside also said production at its Karratha gas plant had been disrupted by the cyclone.
The gas plant is the onshore processing facility for the North West Shelf, Australia's oldest and second-largest LNG project, producing 14.3 million tonnes a year, down from 16.9 million tonnes a year after it shut down one of its five production trains.
MST Marquee analyst Saul Kavonic estimated the cyclone was disrupting more than 30 million tonnes a year of Australian LNG supply.
Combined with the shock from the Middle East, he said more than a quarter of global LNG supply was affected.
"This will exacerbate gas market tightness in Asia and Europe, especially if it takes more than a matter of days to normalise Australian production levels again," Kavonic said.
A Chevron Australia spokesperson said an outage occurred at the Wheatstone platform, about 225km off Australia's west coast, on Thursday, causing a suspension of onshore gas production.
"All personnel were demobilised from the Wheatstone Platform ahead of the cyclone passing, which has been operated remotely from our Perth office since Tuesday afternoon," the spokesperson said.
Three hours later, an outage shut down one of three LNG production trains at the Gorgon facility on Barrow Island, about 50km offshore.
"We will resume full production at both facilities once it is safe to do so," a Chevron Australia spokesperson said.
Woodside said production at the North West Shelf project would restart once it is able to send workers back to its offshore facilities.
It said operations were continuing at its Macedon domestic gas plant and its Pluto LNG facility.
"If there is any material impact to production or assets, Woodside will update the market," a spokesperson said.
