Allseas set for largest ever decom campaign in Australian history

ExxonMobil’s Australian subsidiary, Esso Australia, has awarded Swiss-based marine construction specialist Allseas a contract to remove up to 12 retired platforms from the Gippsland Basin in the Bass Strait.

According to Allseas, the 12 platforms have a combined weight of approximately 60,000 tonnes making it the largest offshore decommissioning assignment in Australian history. It will also be the first time the company’s giant Pioneering Spirit vessel will be working in the country.

The removal scope – covering up to 12 topsides and up to 11 steel jackets – is supposed to be executed in only 3–4 months starting in late 2027.

Once safely removed, the facilities will be transferred to barges or vessels for load-in to the Barry Beach Marine Terminal in Victoria for dismantling and recycling by a separate onshore contractor.

Work is already underway, with engineering and project management teams in Perth and Melbourne leading the effort, with specialist support from our Delft and Kuala Lumpur offices.