A new independent review has increased AWE's Waitsia gas field – one of the most prospective in Australia – to 811 petajoules.
The evaluation of the field by RISC has concluded that Waitsia's proven and probable reserves are 78 per cent higher than previous estimates.
In its third quarter results, the group had already lifted its its proven and probable reserves by a quarter, to 228 petajoules of gas.
The latest review of the project has also lifted AWE's 3P reserves – that is proven, probable and possible – to 1,219.6 petajoules.
"The Waitsia Stage 2 development project is planned to deliver 100 terajoules a day for at least 10 years," AWE chief executive David Biggs said.
This is equivalent to production rates of more than a petajoule a fortnight.
"The additional reserves identified by this review are more than double the reserves required for this project and provide opportunities for significantly increased near term field production and longer field life."
The new is also a boon for Beach Energy, which acquired a 50 per cent stake in the project after its acquisition of Lattice Energy earlier this year.
Beach bought Lattice from Origin for $1.585 billion, setting Beach up as a major supplier of gas to the east coast markets.
"The [Waitsia] project remains on track for the joint venture to be in a position to make a final investment decision (FID) from the end of 2017," Mr Biggs said.
Waitsia is believed to be one of the largest onshore gas finds in Australia in decades.