Allseas pipelay vessel winds down gas pipeline gig in Australian waters

Switzerland-headquartered offshore pipeline installation, heavy lift, and subsea construction contractor Allseas has confirmed the end of a pipeline assignment for one of its vessels on a natural gas development project off the coast of Australia.

Following brushes with the law, the Barossa gas export pipeline (GEP) project received the court’s blessing in January 2024, giving Australia’s Santos the green light to proceed with planned work for which Allseas secured a contract in September 2019.

Thanks to this, the Swiss player’s Audacia pipelay vessel was able to install its largest-ever PLET in S-mode while laying the 262-kilometre-long Barossa GEP with the help of its support team of vessels, encompassing Fortitude, Alegria, Felicity, and Fortress.

According to Allseas, its Audacia team has completed the 262-kilometer gas export pipeline in the southern Timor Sea with assistance from the rest of the Australian fleet by installing the second PLET.

“Operating in one of the most remote environments in the world, with a supply chain stretching thousands of kilometres, and faced with high humidity and extreme tidal fluctuations, our dedicated teams delivered,” highlighted the Swiss firm.

Audacia signed off on the offshore campaign by passing the baton to the Fortitude team to survey and test the newly installed export pipeline. This 26-inch diameter pipeline will connect the Barossa field development to the future Darwin Pipeline Duplication, transporting natural gas to the Darwin LNG facility in Australia’s Northern Territory.

The FID for the project, taken in 2021, set the ball rolling for the $600 million investment in the Darwin LNG life extension and pipeline tie-in projects to extend the facility life for around 20 years. The Barossa project is owned by a joint venture between Santos (operator, 50%), SK E&S (32.5%), and JERA (12.5%).

With the first gas targeted for the first half of 2025, the Barossa development project will consist of a floating production storage and offloading (FPSO) unit, subsea production wells, supporting subsea infrastructure, and a gas export pipeline tied into the existing Bayu-Undan to Darwin LNG pipeline.

A 4.6 billion fixed 15-year FPSO contract, with additional ten-year extension options, put BW Offshore in charge of building the FPSO BW Opal, which will be used for natural gas production from the Australian field.

“Allseas has been installing complex pipeline systems in Australian waters for more than 20 years, but Barossa marks our inaugural project in the Northern Territory, with the promise of many more on the horizon,” emphasized Allseas.

A few months ago, the Swiss player’s Pioneering Spirit vessel crossed the finish line at BP’s ultra-deepwater Greater Tortue Ahmeyim (GTA) LNG project offshore Mauritania and Senegal, which recently welcomed the arrival of the FPSO destined to work on the giant gas field.