Chevron would not provide details of the well and its target, but according to the Australian analysts said it looked as if Chandon-1 had intersected a structure that could contain up to 4 trillion cubic feet of gas.

Woodside’s Pluto discovery, announced in April last year and closer to shore than Chandon, is estimated to contain about 3.5Tcf of gas.

The Gorgon project has gas reserves of about 40Tcf, including the Jansz field, which is estimated to contain 20Tcf.

Earlier this year, Chevron told potential customers in Japan that Gorgon’s delivery start-up had been pushed backed to 2012.

Chevron said yesterday that while it owned 100% of the Chandon permit, under an agreement signed last year covering Gorgon, Exxon and Shell would each take 25% of the discovery.

Chandon-1 was drilled in water 1200m deep in the WA-268-P block to 3100m by the semi-submersible rig Jack Bates.

The rig is now drilling Clio-1, closer to Barrow.