Allseas’ Offshore Construction Vessel Completes GTA Infield Pipelay Scope

Pioneering Spirit 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.

Safely landed in a 2-meter target box at 2,400 meter 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 1,000-ton load capacity. Designed, built and installed on board in only eight weeks by their engineering and fabrication teams, it typifies Allseas “can do” mentality.

The pipelay scope comprises approximately 75 km of 16-inch export lines and 10 km of 10-inch CRA infield lines, some of the pipeline infrastructure exceeding 2,700 meters water depth at the deep end. To meet Allseas’ 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.

Allseas Project Manager Laurent Beghin says, “Our Agile approach was key to a 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.”