The Greater Western Flank Phase 3 and Lambert Deep gas project is located in  Commonwealth waters off the coast of north-western Australia. It is being developed to support the production of the North West Shelf (NWS) project that has been producing since 1984 and currently delivers approximately one-third of Australia’s oil and gas production.

Woodside Energy is the operator of the NWS project, while the other development partners are BHP Billiton, BP, Chevron, Japan Australia LNG (MIMI), Shell, and China National Offshore Oil Corporation (CNOOC).

The Greater Western Flank Phase 3 and the Lambert Deep gas project targets estimated recoverable gas reserves of 400 billion cubic feet (bcf). It involves the drilling and subsea tieback of new production wells to the existing infrastructure of the NWS project.

The NWS joint venture partners reached a final investment decision (FID) on the project in January 2020 followed by the award of key contracts in the second quarter of 2020. The first gas from the project is expected in 2022.

Location

The Greater Western Flank Phase 3 and the Lambert Deep gas project is located in offshore production blocks WA-5-L, WA-16-L, and WA-3-L in the Carnarvon Basin, approximately 126km north-west off the coast of Dampier in Western Australia. The water depths in the project area range from 80m to 130m.

Western Flank Phase 3 and the Lambert Deep development details

The offshore gas development project comprises four production wells, including three production wells in the Greater Western Flank field located in WA-5-L and one production well in the Lambert Deep field located in WA-16-L.

The gas production wells will be tied-back to the existing Angel platform located in WA-3-L via subsea Xmas trees, flexible flowlines, production manifolds, and service umbilicals.

The project also involves top-side modifications on the Angel platform.

Angel production platform

The Angel platform, commissioned in 2008, is a not normally manned (NNM) production platform connected to the North Rankine offshore complex through 50km of subsea pipeline and umbilicals.

The Angel offshore platform is installed in 80m-deep waters approximately 125km off the coast of Karratha. Currently connected with three production wells, the Angel platform produces up to 21,500 tonnes (t) of gas and up to 5,270t of condensate a day.

North West Shelf infrastructure facilities

The NWS assets include the North Rankin A and North Rankin B platforms, the Goodwyn Alpha (A) platform producing from the Goodwyn, Searipple and the Perseus field reservoirs, the Angel platform, and the Okha floating production storage and offloading (FPSO) unit which is connected to the Cossack, Wanaea, Lambert and the Hermes oil fields.

The dry gas and condensate produced from these offshore platforms is transported via subsea pipelines to the onshore Karratha gas plant that houses five LNG processing trains with a total export capacity of 16.9million tonnes per annum (Mtpa), apart from two domestic gas trains, six condensate stabilisation units, and three LPG fractionation units.

Contracts awarded for the Greater Western Flank Phase 3 and Lambert Deep gas project

TechnipFMC received an integrated engineering, procurement, construction, and installation (EPCI) contract for the Greater Western Flank Phase 3 and Lambert Deep gas development project from Woodside Energy in April 2020.

The scope of the contract includes design, manufacturing, delivery, and installation of subsea production system, risers, flowlines, and umbilicals.

The value of the contract is in the range of £60m ($75m) to £200m ($250m).

Greater Western Flank phases one and two

The Greater Western Flank Phase 1 (GWF-1) and the Greater Western Flank Phase 2 (GWF-2) are two previous subsea tie-back projects that came on stream in December 2015 and October 2018 respectively.

The GWF-1 project involved the subsea tieback of Goodwyn GH and Tidepole gas fields to the Goodwyn A platform, while the GWF-2 project involved the subsea tieback of Keast, Dockrell, Sculptor, Rankin, Lady Nora and Pemberton gas fields to the Goodwyn A platform though  35km of subsea pipeline.