Senegal - Mauritania: Allseas completes pipe-laying work for the GTA project

Swiss-based offshore contractor Allseas has completed the laying of inland pipelines for BP's Greater Tortue Ahmeyim FLNG project offshore Mauritania and Senegal.

In October 2023, British energy giant BP selected Allseas to complete the remainder of the FLNG project's subsea pipelay, replacing former Houston-based contractor McDermott.

Allseas announced in December that it had begun offshore pipelay work using what it considers to be the world's largest construction vessel, the Pioneering Spirit. Allseas' offshore construction support vessel, Oceanic, provided installation assistance.

"Two months after arriving in the field, the production team welded, scanned and field coated the final piece of pipe for the second 16-inch export gas line," Allseas said in a statement on Tuesday.

The contract covered the installation of approximately 75 kilometers of two 16-inch export pipelines with on-site termination assemblies in water depths ranging from 1,500 to 2,800 meters, as well as four 10-inch CRA inland lines with FTAs of up to two kilometers in length over 2,800 meters.

"To meet our own ambitious production pace, Pioneering Spirit's main firing line and double assembly facilities ran in parallel throughout the campaign. Pioneering Spirit will conclude the offshore work by installing the six outstanding flowline termination assemblies," said Allseas.

Tortue FLNG has arrived on the GTA site

BP recently announced that Golar LNG's converted FLNG, Gimi, had arrived at the Greater Tortue Ahmeyim project site offshore Mauritania and Senegal.

The company said it was "fully focused on the safe completion of the project", but provided no information about commissioning activities and the commercial launch of the delayed project.

Last month, Golar reported that the FLNG, which was converted from a Moss LNG carrier built in 1975 with a storage capacity of 125,000 cbm, had arrived at the site.

However, Golar and BP have agreed that the FLNG "will proceed with mooring offshore Tenerife pending completion of the necessary preparatory activities", Golar said at the time.

The FLNG left the Seatrium yard in Singapore on November 19. The FLNG vessel is at the heart of the GTA Phase 1 development, operated by BP with partners Kosmos Energy, PETROSEN and SMH. The project is expected to produce around 2.3 million tonnes of LNG per year.

The GTA Phase 1 project will produce gas from deepwater reservoirs around 120 km offshore, via a subsea system to a floating production storage and offloading (FPSO) vessel, which will initially process the gas, removing the heavier hydrocarbon components.

The gas will then be transported by pipeline to the FLNG vessel at the GTA hub, where it will be cryogenically cooled in the vessel's four liquefaction trains and stored before being transferred to the LNG carriers.

FPSO in Tenerife

According to the project's FPSO unit, it left Cosco Shipping Heavy Industry's yard in Qidong, China, in January last year. Equipped with eight processing and production modules, the FPSO will process around 500 million standard cubic feet of gas per day. Kosmos had previously stated that the FPSO should arrive on site in the first quarter of 2024. Its AIS data showed on Wednesday that it was in Tenerife.

Golar stated in its third-quarter report that commissioning of the FLNG project is expected to take around six months from the commissioning start date, with commercial operations (COD) expected thereafter.

This means that the commercial launch of the project could take place in the third quarter of 2024.