The Scarborough gas resource, located in Commonwealth waters approximately 375 kilometres off the Burrup Peninsula, forms part of the Greater Scarborough gas fields, comprising the Scarborough, North Scarborough, Thebe and Jupiter gas fields.

Woodside Energy Limited (Woodside), is proposing to develop the gas resource through new offshore facilities. All subsea and subsurface infield infrastructure and wells are located in Commonwealth waters.

These facilities are proposed to be connected to the mainland through an approximately 430 km trunkline (also refers to as the export pipeline) to an onshore facility. Woodside’s preferred concept is to process Scarborough gas through brownfield expansion of the existing Pluto LNG onshore facility (Pluto Train 2).

The proposed offshore development, referred to as ‘Scarborough’, targets the commercialisation of the Scarborough and North Scarborough gas fields, through the construction of a number of subsea, high-rate gas wells, tied back to a semi-submersible floating production unit (FPU) moored in approximately 900 metres of water close to the Scarborough field.

The trunkline from the FPU to the onshore Pluto LNG facility will be the only part of the offshore development which traverses State waters. The location at which the trunkline will cross into State waters is about 20 km north-west from the shore and in water depths of 31 metres.

The proposed development of Scarborough is an integral part of Woodside’s Burrup Hub vision for a regional gas hub which will secure economic growth and local employment opportunities for Western Australia. In addition to the development of the Scarborough and North Scarborough fields, the Thebe and Jupiter gas fields provide opportunities for future tieback to Scarborough infrastructure. As the proposed export trunkline route crosses the Carnarvon Basin, in close proximity to other undeveloped fields, Woodside is also engaging with other resource owners to explore opportunities for future development.

Woodside is targeting a final investment decision in 2020 and for start-up in 2023. Achieving these milestones is subject to all necessary joint venture approvals, regulatory approvals and appropriate commercial arrangements being finalised. The first drilling phase is targeted in 2020 followed by the installation of the trunkline in 2022, FPU installation in 2023 and phase 2 drilling (potentially including Thebe and Jupiter) in 2025. Decommissioning is expected to commence in 2055[1].
Key components of the proposed development of Scarborough include:
- Surface infrastructure – FPU in approximately 900 metres of water over the Scarborough reservoir
- Subsea infrastructure - infield infrastructure, including wellheads, manifolds, flowlines and umbilicals, export trunkline and communications lines
- Wells – drilling anticipated in two phases. Drilling of the Scarborough and North Scarborough gas fields, with potential for future fields (including Thebe and Jupiter gas fields) to be tied back to the facility
- Trunkline installation – installation of a 32-inch gas trunkline to extend for a total of 430 kilometres using piling to support anchoring of pipelay vessel and trenching and backfill (for nearshore only).

The environmental context of the proposed development of Scarborough has been described according to zones of relevance to the project and comprise the project area and the environment that may be affected (EMBA).
The project area includes three zones:
- Offshore project area (the area covered by WA-1-R, WA-62-R, WA-61-R, and WA-63-R)
- The trunkline project area (the proposed trunkline route with a 1 km buffer either side)
- The borrow grounds project area (the proposed location for the borrow grounds from which stabilisation material from the export pipeline will be sourced).

Studies and reviews of the Exmouth Plateau and North West Shelf have been compiled and/or undertaken to provide an understanding of the physical, biological and socio-economic environmental conditions within the project area. These studies contribute to long-term datasets for the region and the majority have been made available in the public domain.

The environment that may be affected (EMBA) by Scarborough is the largest spatial extent where unplanned events could have an environmental consequence on the surrounding environment has also been described.

The offshore project proposal has defined environmental performance outcomes for all receptors that may be impacted by the activity from planned and unplanned events.

[1]If additional or third-party reservoirs have been tied into Scarborough Project infrastructure, this could increase the project’s economic life and therefore delay decommissioning activities.