Ocean services provider DeepOcean is nearing completion of a contract awarded by TotalEnergies for the disconnection and tow of the Gryphon Alpha floating production, storage and offloading (FPSO) unit, as well as the removal of associated subsea infrastructure.
This marks a first, with proprietary tooling designed and developed in-house enabling the entire scope to be executed fully driverless.
The scope of work included the flushing of subsea pipelines and manifolds, disconnecting flowlines and umbilicals from trees, removing risers and midwater arches and recovering FPSO moorings.
Once disconnected, DeepOcean also managed the towing of the FPSO.
The spool disconnection and blind flange installation represent pioneering achievements in diverless operations.
“The bespoke tooling created for this scope of work allowed us to perform the entirety of the scope using diverless methodologies that produced exemplary outcomes. Everyone involved in the design, build and offshore operations should be extremely proud of what they have achieved”, said Robin Mawhinney, Managing Director, DeepOcean UK.
The project has been delivered by DeepOcean’s team in Aberdeen, UK, with support from the company’s office in Haugesund, Norway, as required.
The project is nearing completion with the recovery of mooring chains and removal of the risers and mid water arches to be completed prior to year end.
Gryphon Alpha was the North Sea’s first purpose built, permanently moored FPSO, and was originally commissioned by operator Kerr McGee. The asset was later acquired by Maersk Oil and then by TotalEnergies through its 2018 merger.
Although the field was initially expected to have a lifespan of just ten years, it has exceeded expectations, producing more than 250 million barrels of oil equivalent over three decades of operation.