Browse Gas and Condensate Project, offshore Australia

Browse Gas and Condensate Project in Australia will involve the development of the largest untapped conventional gas resource in the country.

The proposed project will involve developing the Brecknock, Calliance and Torosa fields located in the offshore Browse Basin.

The concept definition phase of the project commenced in September 2018. As of July 2022, the targeted final investment decision (FID) has been delayed due to the impact of Covid-19 pandemic.

Browse Project is operated by Woodside Energy on behalf of the Browse Joint Venture (BJV).

The interest holders in BJV are Woodside Browse (30.60%), Shell Australia (27%), BP Developments Australia (17.33%), Japan Australia LNG (MIMI Browse) (14.40%), and PetroChina International Investment (Australia) (10.67%).

In April 2023, Shell signed an agreement to sell its interest in the Browse Project to BP. The completion of the deal is subject to regulatory approvals.

The offshore project execution may commence mid-2020s, subject to market conditions, all necessary regulatory approvals, joint venture approvals and commercial agreements.

It would have a production capacity of 11.4 million tonnes per annum (MTPA) of LNG/LPG and domestic gas with operations for up to 44 years.

Location details and Hydrocarbon resources

The Brecknock, Calliance, and Torosa fields are located approximately 425km north of Broome in the offshore Browse Basin. The region is around 290km off Kimberley coastline of Western Australia.

The fields were discovered in 1979, 2000, and 1971, respectively.

The three fields mainly host gas with contingent resources (2C, 100%) of 13.9 trillion cubic feet (tcf) of dry gas, and around 390 million barrels of condensate.

Browse development concept

The Browse JV selected the Browse to North West Shelf Project development concept for the project.

The proposed development will include two 1,100 million standard cubic feet per day (MMscfd) (annual daily export average) Floating Production Storage and Offloading (FPSO) facilities.

The two FPSOs will be equipped with a subsea production system and will transport gas to existing North West Shelf (NWS) Project infrastructure through an 85km spur line and nearly 900km long pipeline (Browse Trunkline). This pipeline will be connected near the existing North Rankin Complex (NRC) in Commonwealth waters.

Project details

The project will include up to 50 wells for hydrocarbon extraction at the Brecknock, Calliance and Torosa over the life of the development, along with ancillary subsea infrastructure including manifolds and flowlines.

A wellhead will be installed at the top of each well to hold production well casing and enable installation of the Christmas tree with well control facilities.

The wells will also be equipped with Surface Controlled Subsurface Safety Valves (SCSSVs).

The project plans to arrange production wells around drill centres to optimise the layout of the subsea infrastructure.

The wells will be connected to manifolds by well jumpers to enable flow of reservoir fluids. These manifolds will connect wells to Corrosion Resistant Alloy (CRA) clad/lined flowlines, which will be tied to the FPSOs.

Flowline End Termination (FLET) or riser base manifold will be used to connect flowlines and FPSOs. The umbilicals will be tied back to the FPSOs via a system of flexible risers.

The subsea infrastructure will be powered, monitored, and controlled from the FPSOs leveraging a network of electro-hydraulic control umbilical and Subsea Distribution Units (SDUs).

The related subsea infrastructure will include piles, mooring lines for the FPSO mooring, and piles for permanent moorings for the MODU/Light Well Intervention Vessel (LWIV).

The FPSO facilities will perform stabilisation of condensate as well as store it before it is transferred to condensate tankers for delivery to market. The recovered gas will also be processed at FPSOs and then exported via the inter-field spur line and BTL to existing NWS Project infrastructure.

Around 18 mooring piles will be installed per FPSO.

Each of the FPSOs will feature a ship shaped hull. They will be capable of storing 1 million barrels of condensate.

The FPSOs facilities will include depletion compression (post RFSU), water treatment and overboard disposal, acid gas removal, condensate stabilisation and compartmentalised storage, mercury removal, hydrocarbon and water dew pointing, and export gas compression.

The other facilities of FPSO are utilities such as cooling water, desalination, and power generation.

The vessels will be capable of accommodating up to 60 people during routine operations and 180 people during major maintenance activities.

The 42inch carbon steel Browse Trunkline, which will export gas, will run approximately 900km southwest from the Calliance/Brecknock FPSO facility to the tie-in point with the NWS Project infrastructure near North Rankin Complex (NRC) in Commonwealth waters.

It will be capable of exporting 2,150MMscf/d (annual daily average).

The 34-inch 85km-long carbon steel inter-field spur line will have a capacity of 1,100MMscf/d (annual daily average). This line will connect FPSO at Torosa to the Browse Trunkline near the Calliance/Brecknock FPSO.

The Browse Project and the North West Shelf (NWS) Project Extension will entail a capital expenditure of A$36bn ($24.45bn) in Western Australia between 2019-2063. This will include A$27.3bn on the Browse project.

Decommissioning

The proposed Browse Project is expected to have a life of around 44 years.

At the end of project life, the infrastructure will be decommissioned in accordance with the relevant legislation and practice of the time. This is expected to include well suspension, plugging and abandoning wells and removing the subsea infrastructure.

The infrastructure that will be installed above the seabed will be designed to enable their removal.