Oil and gas mergers and acquisitions in and around Australia could reach $US27 billion ($37.9 billion) over the next few years, as producers shed assets after the oil price collapse to cut debt and European players transform their portfolios towards lower-carbon energy.

Up to $US10 billion of oil and gas assets are already up for sale, dominated by big-ticket assets such as Chevron's stake in the North West Shelf venture and ExxonMobil's and BHP's stakes in Bass Strait gas. Woodside Petroleum also has LNG interests on offer at Scarborough and Pluto in Western Australia.