Inpex coming aboard Australia’s huge multibillion-dollar gas project

May 15, 2026, by Melisa Cavcic

Japan’s exploration and production (E&P) company Inpex has set the wheels in motion to join an offshore development project, which is described as Australia’s largest untapped conventional gas resource.

Browse to North-West Shelf project development concept; Source: Woodside

The Japanese player, through its subsidiary, Inpex Mirai Upstream, has entered into a sales and purchase agreement (SPA) to acquire a 10.67% participating interest that PetroChina International Investment (CNPC) holds in the Woodside-operated Browse joint venture, including titles covering the Brecknock, Calliance, and Torosa gas fields offshore Western Australia.

The completion of the transaction is conditional on several matters, including regulatory and Browse joint venture approvals. The Browse fields, which were discovered between 1971 and 2000, are estimated to contain a combined contingent resource of about 13.9 trillion cubic feet of dry gas and approximately 390 million barrels of condensate.

As a result, the development of Browse has the potential to make a significant contribution to energy security in Australia and in the Asia-Pacific region, as confirmed by an economic impact assessment by Deloitte Access Economics.

This assessment estimates that the Browse to North West Shelf (NWS) project could contribute a long-term uplift of around A$147 billion ($102.9 billion) in gross state product for Western Australia and more than A$141 billion ($98.7 billion) in gross domestic product (GDP) nationally.

$30 billion mega gas project set to enrich Australia’s countrywide GDP by $98.7 billion

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Located almost 300 kilometers offshore in deep waters, the Browse gas project is intended to backfill the NWS as supply from existing fields declines. The capital expenditure for this offshore energy development could reach $25 – $30 billion between 2019 and 2063, based on energy analysts’ projections.

The addition of Browse will enrich Inpex’s Australian energy portfolio, which already includes Ichthys LNG, where it acts as operator, and participating interests in the Prelude FLNG, Darwin LNG, Van Gogh, and Ravensworth projects.