Woodside has agreed to acquire half of BHP Billiton's Scarborough area assets in the Carnarvon Basin in offshore Western Australia.

Under the agreement, the company will acquire a 25% interest in WA-1-R and a 50% interest in WA-62-R, which together contain the Scarborough gasfield.

Furthermore, a 50% interest will be acquired in WA-61-R and WA-63-R, which contain the Jupiter and Thebe gasfields.

Woodside will operate WA-61-R, WA-62-R and WA-63-R, while ExxonMobil will be the operator of WA-1-R.

"The Scarborough, Thebe and Jupiter field assets are estimated to contain a gross 8.7 trillion cubic feet of gas resources."

Upon completion of the transaction, Woodside will pay $250m to BHP Billiton and also make a contingent payment of $150m upon a positive final investment decision to develop the Scarborough field.

The Scarborough, Thebe and Jupiter field assets are estimated to contain a gross 8.7 trillion cubic feet of gas resources at the 2C confidence level.

Woodside said that its net share of the resources is estimated to be 2.6 trillion cubic feet of gas.

Woodside CEO Peter Coleman said that the addition of Carnarvon Basin volumes to the Australian portfolio will complement the company’s growth strategy in addition to leveraging its deep water and LNG capabilities.

Coleman said: "We look forward to working with ExxonMobil and BHP Billiton following completion of the transaction to progress commercialisation of these world-class resources."

Subject to pre-emption rights and customary regulatory approvals, the deal is slated for completion by the year-end.