Chevron Australia completes Thevenard Island decommissioning

Chevron Australia has completed onshore decommissioning works at Thevenard Island which houses the Chevron-operated Thevenard Island Joint Venture oil and gas site about 22 km from Onslow.

Decommissioning plugged 11 onshore production wells, 3 water disposal wells, 1 exploration well. and safely dismantled and removed three 150,000-bbl oil storage tanks in addition to production tanks, separator vessels, flowlines, associated process infrastructure, ancillary accommodation, and utilities including the controlled toppling of the 38-m communications tower.

In total, the project resulted in the removal of more than 5,000 tonnes of scrap metal from the island for recycling.  Chevron Corp. engaged several contractors including Liberty Industrial, AGC, Bhagwan Marine, TAMS Group, Golder Associates, and Astron Environmental Services to assist with the decommissioning process.

The island is a nature reserve adjacent to a tourism operator, and the rehabilitation process included working with local partners NTC Contracting, Workpower, and the Onslow Indigenous Sea Rangers to plant more than 120,000 native seeds. Monitoring of rehabilitation will be carried out over the next few years.

Thevenard Island started producing oil in 1989 with about 150 million bbl oil produced over its 25-year life until production ceased in 2014. The area will be returned to the Western Australia government once it is restored to a condition similar and compatible with the adjacent environment.

Decommissioning of the Chevron Australia-operated Barrow Island Joint Venture (BWIJV) oil site and associated infrastructure on Barrow Island is expected to start in 2025.