ConocoPhillips is nearing a decision on its choice of contractor to provide a subsea production system as it gets busy with the issue of which contractors will be responsible for the significant subsea elements of its Barossa gas project off northern Australia.

The US operator is currently absorbed in discussions with contractors which have bid to supply the subsea production system.

It is understood the majors of this sector — Aker Solutions, GE-controlled Baker Hughes, TechnipFMC and OneSubsea — are in contention for a contract to supply christmas trees, wellheads, a control system, subsea well intervention system, manifolds and other structures.

ConocoPhillips previously said it intends to award this contract in early 2019.

In addition, the operator has also completed pre-qualification exercises for the engineering, procurement, construction and installation of the subsea umbilicals, flowlines and risers, and the subsea gas export pipeline.

For these opportunities, sources said ConocoPhillips in April will issue an invitation to tender to selected contractors.

The SURF component will consist of umbilicals, risers and flowlines including flowline end terminations and in-line tees.

Pipeline-end terminations at either end of the gas export pipeline will allow for connection to a floating production, storage and offloading vessel and to the existing Bayu-Undan pipeline.

As for the export pipeline, the 260-kilometre 26-inch carbon steel line will have a concrete coating for stability and mechanical protection. It will be installed using the S-lay method.

Contract awards are targeted for the end of this year.

Another major contract earmarked for award in the fourth quarter of 2019 is the development drilling assignment. A semi-submersible rig will be required to drill, complete and flow six subsea production wells in water depths of between 240 metres and 260 metres.

ConocoPhillips recently requested information from interested drillers on their ideas about the proposed well delivery and sequencing of the work; as well as identifying efficiency and design opportunities.

Meanwhile, the centrepiece of the Barossa development is an FPSO, which is the subject of a design competition between Japan's Modec and a grouping of TechnipFMC and Samsung Heavy Industries. Modec will offer a technical and commercial solution for a leased FPSO while TechnipFMC-Samsung will offer an FPSO solution on a turnkey basis.

The FPSO will be 350 metres long and 60 metres wide. The topsides will weigh between 25,000 and 35,000 tonnes, and the vessel will be capable of processing 800 million cubic feet per day of gas and 6000 barrels per day of condensate.

The two rivals will submit their proposals for the FPSO contract later this year.

Barossa's dry gas will be exported to the Darwin liquefied natural gas facility.