Woodside eyes FPU subsea infrastructure work next year for giant Australian gas project

Australian energy player Woodside has handed out an environment plan (EP) to the country’s offshore regulator for a floating production unit (FPU) work associated with subsea infrastructure activities, including the Commonwealth waters portion of an export trunkline at a natural gas project off the coast of Australia.

The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) has confirmed Woodside’s submission of the Scarborough offshore facility and trunkline operations environment plan, proposing to undertake the FPU-associated subsea infrastructure that encompasses the Commonwealth waters section of the export trunkline, which runs between the Scarborough FPU and onshore gas plant approximately 375 km west-north-west of Dampier in Western Australia.

The planned activities are proposed within production licenses WA-61-L and WA-62-L, and pipeline license WA-32-PL. These activities entail the hook-up of the Scarborough FPU to pre-installed moorings and subsea gathering system; start-up and commissioning activities of the FPU and associated subsea wells, flowlines, and infrastructure; and routine production and associated activities for up to 13 subsea wells, consisting of up to eight wells in Phase 1 and five wells in Phase 2.

In addition, these operations cover the export of dry gas to the onshore gas plant through the gas export trunkline (ETL); inspection, monitoring, maintenance, and repair (IMMR) activities for the FPU, subsea infrastructure, and ETL; gravimetry surveys. The installation, hook-up, commissioning, and start-up are around twelve months, after which the operation of the FPU and export trunkline will be continuous, 24 hours per day, 365 days per year, with a planned field life from start-up of operations of about 30 years.

Based on the EP, the earliest start-up date for hook-up and offshore commissioning activities is anticipated in the second half of 2025 pending approvals, vessel availability, and weather constraints. During the hookup and commissioning an accommodation support vessel (ASV) may be utilized alongside the FPU to accommodate a higher number of personnel required during these activities.

The Scarborough energy project was 67% complete at the end of June 2024. The delivery of the first LNG cargo is expected in 2026, generating more than A$50 billion ($33.43 billion) in direct and indirect taxes for Australia’s economy, over 3,000 jobs during the construction phase, and creating or sustaining almost 600 jobs on average during operations. Woodside recently sealed a deal with the Australian Conservation Foundation (AFC) to end a two-year legal challenge regarding a primary environmental approval for the project.

Located 375 km off the Pilbara coast of Western Australia, the Scarborough gas project in the Carnarvon Basin entails new offshore facilities connected by an approximately 430 km pipeline to a second LNG train at the existing Pluto LNG onshore facility. All wells will be tied back to a semi-submersible FPU moored in 950 meters of water close to the Scarborough field.

As the total project cost estimate recently increased to $12.5 billion, representing $8.2 billion as the Australian player’s share for the integrated Scarborough energy project, this is a 4% jump from the previous cost estimate of $12 billion when a final investment decision (FID) was disclosed in November 2021.

Woodside pinpoints the scope maturation of the Pluto Train 1 modifications project as the main culprit for the cost hike. Out of 51 modules required for the Scarborough project’s Pluto Train 2, 29 have been delivered to the site, with 25 modules set in position at the end of the quarter.