The 721Bcf total includes both 2P and 2C resources for the Waitsia conventional gas discovery and the Senecio, Irwin and Synaphea tight gas fields.

Waitsia's resource has been boosted by 67% from the 290Bcf announced in May to 484Bcf of 2C contingent gas from Kingia and High Cliff Sandstones, putting it on par with the largest field in the basin at Dongara, which has so far produced 500Bcf out of the total Perth Basin's historical production of 700Bcf.

Thanks to the Waitsia-2 appraisal well the JV has booked initial gross 2P reserves of 178Bcf and gross 2C contingent resources of 306Bcf.

AWE has confirmed it is looking to rapid development scenarios that could see the field in production within nine months.

Managing director Bruce Clement said the data gathered from Waitsia-2, the second appraisal well drilled, allowed AWE to increase the company's previous estimates.

"Gas marketing is making good progress and the joint venture has applied for a licence to construct a pipeline from the Senecio-3 and Waitsia-1 wells to the Xyris production facility, located near the Waitsia-2 well," Clement said.

"The Waitsia field, together with AWE's other onshore North Perth Basin gas discoveries, represents an exciting new project for the company.

"The volume of gas is substantial and should provide AWE with a highly valuable long-term domestic gas business in WA," he said.

Waitsia-2's data, integrated with the information from the Senecio-3 discovery well and Waitsia-1, indicates better than 11% porosity and an average field wide porosity of 14.5% for the Kingia/High Cliff Sandstone reservoirs over the entire Waitsia field.

The deep zone, previously ignored in past, flowed at commercial rates in Senecio-3, and is considered largely derisked.

The contingent resources cover the undrilled sectors in the south and east of the field, which will eventually need to be drilled to confirm reservoir assumptions, however so far all of AWE's pressure modelling for the field has proven to be correct and it has a high degree of confidence in the field's size.

The preliminary full-field development plan involves the drilling and completion of 17 more vertical or deviated production wells, with connection to the existing centralised gas processing facility.

It is envisaged that export to domestic markets at a plateau rate of about 85 million cubic feet per day would use existing nearby gas pipelines.

The gas has 93% methane and requires only minimal processing.

In addition, further contingent resources have been estimated for lesser quality gas bearing reservoir intervals in the Kingia and High Cliff Sandstone formations which have porosity in the range 7-11%.

AWE operates L1 and L2 for Origin in a 50/50 joint venture.

AWE's good news came as the company's otherwise strong annual performance for 2014-15 was marred by impairments.

The company reported annual production of 5.1MMboe, close to the top of its guidance, sales revenue of $284 million and a net loss after tax of $230 million, which included $158 million of non-cash impairments after tax.

After adjusting for non-recurring items, AWE's underlying net loss after tax was $52 million.

Managing director Bruce Clement said it was a year of significant achievements, with sales revenue was only 2% below guidance, which was a "substantial achievement" given the lower realised average oil price during the year.

"At year end, AWE had significantly increased its net 2P Reserves by 23MMboe, or 25% up over the previous year, to 114MMboe. This equates to more than 22 years of production at current rates," he said.

"Similarly, AWE increased its net 2C Contingent Resources by 44 MMboe, or 57%, to 121 mmboe, and the majority of these assets have the potential to be reclassified as 2P within the short to medium term."

The impairments were the flagged $106 million writedown for reduction in remaining reserves at Yolla after the recent drilling and further $51 million after tax hit for the mature Tui and Cliff Head oil fields in New Zealand and Western Australia respectively.

Clement said the company was aiming to maintain its financial discipline and preserve balance sheet strength in this low oil price environment.

He has reduced the 2015-16 budget, and has flagged further farm-outs and sales of non-core assets, but says the long-stated production target of 10MMboe by the end of 2018 remains achievable.

AWE shares closed up $0.94 following Friday's announcement, but fell almost 5% this morning.