Seawell re-enters service after major upgradeVessel & ROV News // November 29, 2016
The light well intervention and dive support multi-service vessel Seawell has returned to service after a £60 million (US$75 million) investment by its owners, Aberdeen-based Helix Well Ops (UK) Limited, a UK subsidiary of international offshore energy service company Helix Energy Solutions Group.
Launched 30 years ago at the Pallion yard in Sunderland by North East Shipbuilders, Seawell was described as the world’s most sophisticated offshore support vessel when it entered service in 1987.
The vessel’s multi-million pound upgrade was carried out at the Damen yard in Vlissingen in the Netherlands, taking around eight and a half months, and was followed by extensive sea trials.
Improving the efficiency and capability of Seawell were set as key outcomes of the project. Six new Rolls-Royce Bergen C25:33L8ACD generator sets have replaced obsolete Hedemora generators, which had powered the vessel since it was built. The dynamic positioning (DP) thrusters and azimuths have been upgraded to DP3 class. This improves the stationkeeping performance of the popular vessel and the safety of wells being worked on, particularly in challenging weather.
Electrically the vessel is completely new, as all electrical systems and cabling have been replaced and upgraded. Onboard accommodation has been improved, enhancing the work and living spaces for Seawell’s 122 crew members. The vessel’s dive system and bells have been refurbished, while its lifeboats have also been upgraded to comply with new North Sea performance standards.
The modifications have changed the distinctive silhouette of the vessel. A new 50-tonne crane with active heave compensation and a multi-purpose tower have replaced the existing twin 65 tonne cranes aft and separate derrick that provided its characteristic profile.
Designed by Royal IHC, the new tower allows the vessel to deploy Helix Well Ops’ 73/8in subsea intervention lubricator (SIL) in addition to its 51/8in SIL. It can also stack the complete SIL and deploy it to the seabed in a single run. The ability to deploy the 73/8in SIL brings it into line with its sister vessels, Well Enhancer and Skandi Constructor.
Helix Well Ops (UK) vice president Steve Nairn said: “Seawell has provided an important and invaluable contribution to the North Sea oil and gas industry over the past three decades. It was the first vessel of its kind and has delivered many firsts throughout its career. The light well intervention sector has evolved in line with this reliable and popular vessel. Its specification and capabilities have helped the vessel become respected in the North Sea, and more recently further afield. Time and again, Seawell has demonstrated the cost-effectiveness of using a vessel to deliver light well intervention services compared to a rig. Refitting Seawell has been a major undertaking and one that underlines Helix Well Ops’ commitment to the North Sea marketplace, and having a robust and capable fleet of vessels, which includes Well Enhancer and Skandi Constructor, to service it. The investment ensures this iconic vessel will continue to pioneer a market it has helped shape.”