The Laminaria and Corallina oil fields and the associated production platform, located in the Timor Sea, Australia, are planned to be decommissioned by the Australian government in phases.

The offshore fields had been producing through the Northern Endeavour floating production, storage and offloading (FPSO) facility since they entered into operations in November 1999.

The Australian government took the responsibility of decommissioning the FPSO facility and the remediation of the offshore oil fields in December 2020, after their owner the Northern Oil and Gas Australia (NOGA) group of companies entered into liquidation in the month of February of same year.

A law was passed by the government in March 2022 to recover the costs to be incurred for the decommissioning of Laminaria and Corallina fields and associated infrastructure through a temporary levy on offshore petroleum production.

The Laminaria and Corallina oil fields produced in more than 200 million barrels of oil before the production was ceased in 2019.

Location

The Laminaria and Corallina oil fields are located in the production licence areas AC/L5 and WA-18-L respectively, in the Bonaparte Basin, Timor Sea, Australia.

The fields are approximately 550km off the coast of Darwin and the water depth in the Laminaria and Corallina fields is approximately 350m and 410m, respectively.

The Northern Endeavour FPSO and the subsea wells are located in the AC/L5 licence.

Laminaria and Corallina oil fields decommissioning project details

The Laminaria and Corallina oil fields decommissioning and their remediation will be carried out in three phases over several years.

In the phase one, the FPSO will be decommissioned and disconnected from the subsea equipment, while the phase two involves permanent plugging and well abandonment.

The scope of work in the phase one will include the demobilisation of the FPSO from the field, installation of temporary barriers between the reservoir and the environment, and disconnection of risers and moorings.

Removal of subsea infrastructure and remediation of the Laminaria and Corallina fields will be undertaken in the phase three.

Northern Endeavour FPSO details

The 274m-long, 50m-wide double-hulled Northern Endeavour FPSO vessel is permanently moored between the Laminaria and Corallina fields in the Timor Sea and the water depth in the area is approximately 380m.

The FPSO had a crude oil storage capacity of 1.4 million barrels and a capacity to process approximately 170,000 barrels of oil a day, before the production operations were ended in 2019.

The vessel employs a Bottom Mounted Internal Turret (BMIT) mooring system.

Laminaria and Corallina oil field development details

The Laminaria and Corallina fields’ development involved subsea tieback to the Northern Endeavour FPSO, with the subsea infrastructure consisting of subsea manifolds, flowlines, umbilicals and dynamic risers.

Woodside, Shell and BHP were the initial developers of the Laminaria and Corallina oil fields, which contained 317 million barrels of oil, as per the original estimates. Woodside was the operator of the field development project and the Northern Endeavour FPSO.

The the Laminaria and Corallina oil fields recorded a peak production of 180,000 barrels of oil a day during their operational period. Woodside announced the decommissioning plan for the fields in July 2015.

In April 2016, the two offshore fields and the FPSO were acquired by NOGA from Woodside and Talisman.

NOGA planned to extend the life of the fields by improving operational efficiency, infill drilling and utilising FPSO to develop neighbouring fields, before it was placed into voluntary administration in September 2019.

Contractors involved

Petrofac Facilities Management was awarded a contract worth up to £181.3m ($236m) by the Australian government to execute phase one of the decommissioning of the Northern Endeavour FPSO vessel in April 2022.

Monadelphous and Linch-pin are the supply chain partners to Petrofac for the project.

Upstream Production Solutions (Upstream PS), a wholly owned subsidiary of GR Engineering Services, was contracted by NOGA to operate and maintain the Northern Endeavour FPSO and associated infrastructure in May 2016.

The company was awarded a new contract by the Australian government for the FPSO vessel in February 2020. The contract included ensuring the safety and integrity of the FPSO and the protection of the marine environment.