Norwegian Ocean services provider DeepOcean is close to finishing a contract from TotalEnergies involving the disconnection and towing of the Gryphon Alpha floating production storage and offloading (FPSO) unit, along with the removal of related subsea infrastructure.
According to DeepOcean, the operation is the first to use a proprietary technology developed internally that allows the entire scope of work to be completed without diver intervention.
The scope of work included flushing of subsea pipelines and manifolds, disconnection of flowlines and umbilicals from subsea trees, removal of risers and midwater arches, and retrieving the FPSO’s mooring systems.
DeepOcean also oversaw the towing of the FPSO once disconnection was accomplished.
DeepOcean described the spool disconnection and blind flange installation as “pioneering achievements” in diverless execution.
The delivery of the project has been managed by DeepOcean’s team in Aberdeen, UK, with support from the Haugesund office in Norway.
The remaining work, which involves recovering mooring chains and removing risers and midwater arches, is expected to be completed before the end of this year.
DeepOcean UK managing director Robin Mawhinney said: “This project is a standout achievement for DeepOcean. We have a world-leading track record in finding unique ways to execute complex subsea operations using our in-house design, technology and tooling expertise.
“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.”
Gryphon Alpha is said to be the North Sea’s “first purpose-built and permanently moored FPSO”, and was initially commissioned by operator Kerr McGee.
Ownership of the FPSO later passed to Maersk Oil and subsequently to TotalEnergies following its 2018 merger.
Last week, DeepOcean announced receipt of a contract to deliver subsea construction and tie-in services for a field development on the UK Continental Shelf, with the project being developed as a subsea tieback to an existing host facility.