Allseas Pioneering Spirit offshore vessel has completed the infield pipelay scope for BP’s ultra-deepwater GTA liquified natural gas project offshore Mauritania and Senegal. Two months after arriving in the field, production crew welded, scanned and field joint coated the final piece of pipe for the second 16-inch export gas line.

This on time project completion milestone was achieved few days after the announcement of the arrival of The floating liquefied natural gas (FLNG) vessel that is a core component of the Greater Tortue Ahmeyim (GTA) LNG project at its destination on the Mauritania and Senegal maritime border. The FLNG vessel, Gimi, is at the heart of the GTA Phase 1 development, operated by bp with partners, Kosmos Energy, PETROSEN and SMH.

Safely landed in a 2-metre target box at 2400 metre water depth, the pipeline will be recovered in J-mode configuration to install the termination assembly. To make this happen, the vessel aft has been fitted with a bespoke J-mode frame with a 1000-tonne load capacity. Designed, built and installed on board in only eight weeks by our engineering and fabrication teams, it typifies Allseas “can do” mentality.

The pipelay scope comprises approx. 75 km of 16-inch export lines and 10 km of 10-inch CRA infield lines, some of the pipeline infrastructure exceeding 2700 metres water depth at the deep end! To meet our own ambitious production rate, the main firing line and double jointing facilities on Pioneering Spirit have run in parallel throughout the campaign. Pioneering Spirit will conclude the offshore works by installing the six outstanding flowline termination assemblies.

“Our Agile approach was a key to quick and efficient start to the project and decision-making process throughout the offshore campaign. Thanks to great collaboration between the onshore and offshore teams, we’ve overcome all challenges faced during the project preparation and execution phases and met all milestones without delay.” Allseas Project Manager, Laurent Beghin said.

BP was in October 2023 awarded Allseas with a contract to perform the subsea pipelay scope for the GTA natural gas project. GTA Phase 1 is set to produce around 2.3 million tonnes of LNG per year. The innovative project is expected to produce LNG for more than 20 years, enabling Mauritania and Senegal to become a global LNG hub