From decommissioning to expansion, Woodside shares offshore oil and gas initiatives

Trion, 180 km from the Mexican coast and 30 km south of the US/Mexico maritime border, will produce via 24 subsea wells to a semisubmersible FPU with a production capacity of 100,000 bbl/d of oil, offloading to an FSO.

Woodside says it is targeting first oil in 2028.

During the first half, the detailed design of the FPU was finalized, with construction of three topside modules and the living quarters progressing, and fabrication completed of the platform’s turbo machinery and equipment. 

Construction of the FSO, to be provided by SBM Offshore, is due to start later this year, while fabrication is underway for the disconnectable turret mooring as well as the FSO and FPU anchor piles.

All subsea equipment, trees and topside control systems have been ordered and all main contracts now awarded, including those for drilling and completion services, the gas pipeline installation, FSO operating and maintenance, and support vessels.

Since March, all project costs have been split 60% by Woodside (operator) and 40% by PEMEX (sole project partner).

In the US Gulf, the bp-led partnership has taken FID on the Atlantis Major Facility Expansion project, which calls for two new water injector wells and upgrades to the semisubmersible platform’s topsides water injection system to raise water injection capacity.

The partners (Woodside, 44%) are aiming for first water injection from the new facilities in 2027.

Another of the company’s ventures in US waters is the Mad Dog oil and gas field development, which produces through the offshore A-Spar and the Argos platform. The latter was installed for Mad Dog Phase 2, an ongoing development of the field’s southern flank.

Infill drilling and completion activity continued throughout first-half 2025 to support both production facilities, with the Mad Dog Southwest Extension recently brought online, delivering first oil 25 months post-completion of the appraisal well.

Offshore Trinidad

Concept select engineering and subsurface studies continue for the Calypso project in 2,100 m water depth, 220 km offshore Trinidad. Calypso comprises various gas discoveries in Block 23(a) and Block TTDAA 14, and it is close to existing infrastructure.

Offshore Australia

Offshore Western Australia, the retrieval of the decommissioned Echo Yodel umbilical should get underway later this year.

Woodside continues to review decommissioning workscopes for the Minerva, Stybarrow and Griffin fields. It has identified potential safety issues with the as-left condition on some closed sites that could impact execution, and those challenges were the main cause of a $445-million pre-tax ($218 million post-tax) restoration expense being recognized in the company’s profit and loss results.

At Bass Strait offshore southeast Australia, however, the Gippsland Basin joint venture (ExxonMobil and Woodside) has safely completed P&A so far of more than 200 wells, including the Bream B and Kingfish A platform wells earlier this year.

Detailed engineering and execution planning continues for the planned Bass Strait offshore platform removal campaign in 2027.