This decision follows speculation early last year that the joint venture was considering boosting capacity at the project to lower production costs.

The Gorgon gas project received environmental approval for two 5 million tonne per annum trains at the end of last year.

“Developing three LNG production trains in quick succession improves project economics and addresses mounting industry cost pressures,” WA Business News quoted a Chevron spokesman as saying.

Chevron as operator expects to lodge a formal environmental assessment to the Western Australian Environmental Protection Authority early this year.

Over the next 12 months, the partners plan to work with government to secure approvals for the extra train, begin front-end engineering and design, as well as considering early works on Barrow Island.

Estimated to contain more than 40 trillion cubic feet of gas, the Gorgon gas fields are 200km offshore in up to 1300m of water.

The project life is expected to be 60 years.