Senegal - Mauritania: Allseas wins a contract to lay pipelines on the GTA project

Oil major BP has selected offshore installation contractor Allseas to complete the laying of subsea pipelines for its Greater Tortue Ahmeyim (GTA) ultra-deepwater natural gas project offshore Mauritania and Senegal.

Allseas will start laying the offshore pipelines at the beginning of December 2023 using the world's largest construction vessel, the Pioneering Spirit. Installation assistance will be provided by Allseas' offshore construction support vessel, the Oceanic .

The contract, worth an undisclosed amount, covers the installation of around 75 kilometers of the two 16-inch export pipelines with field termination assemblies (FTAs) in water depths of between 1,500 and 2,800 meters, and four 10-inch CRA inland lines with FTAs. up to two kilometers long in 2,800 meters of water.

According to Allseas, commercial and technical teams from Allseas and BP "worked tirelessly" to assess the technical feasibility of installing the pipelines and subsea structures, initially designed to be installed with a J-lay solution.

"This agreement demonstrates both our willingness and our ability to undertake highly complex pipe-laying projects with accelerated planning and execution times," says Pieter Heerema, General Manager of Allseas.

"We are delighted to be working with BP on this project, this opportunity re-establishes the partnership between our two companies and creates a platform on which to develop and strengthen the future collaboration between BP and Allseas."

The installation of mixed-diameter pipelines and subsea structures in ultra-deep waters is ideally suited to the Allseas S-lay vessel, Pioneering Spirit , with a record 2,000-ton voltage retention capacity. To install the 10 FTAs, the vessel will be equipped with a special 1,000-ton J-mode installation frame, designed in-house and built at Allseas' Heijningen fabrication yard in the Netherlands.

"As a pioneer of dynamically positioned S-lay technology, characterized by its fast installation speeds in all water depths, Allseas has installed over 27,500 kilometers of pipelines worldwide," said Allseas.