One of the most distinctive vessels operating in the North Sea has undergone a multi-million pound refit and upgrade in Holland to ensure it remains at the forefront of the oil and gas industry for many years to come.
The light well intervention and dive support vessel MSV Seawell has returned to service after a £60 million investment by its owners, Aberdeen-based Helix Well Ops UK
When launched at the Pallion yard in Sunderland by North East Shipbuilders, MSV Seawell was described as the world’s most sophisticated offshore support vessel when it entered service in 1987.
The 374ft. long vessel was the first in a series of vessels to feature electrical propulsion and set a benchmark for multifunctional offshore support vessels, certified as a stand-by and rescue ship, and equipped as an anchor-handler.
It has been at the forefront of the light well intervention market since it undertook its first such project in the Magnus field, north-east of Shetland, in July 1987.
In November 1995, it carried out the first subsea tree replacement from a monohull vessel anywhere in the world. The North Sea’s Arkwright Field was the location of another historic first for the vessel in October 1998, when the world’s first wireline intervention on a horizontal subsea tree was completed.
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 station keeping 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 MSV 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.
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 SIL (subsea intervention lubricator) in addition to its 51/8in SIL. It can also stack the complete SIL and deploy it to the seabed in a single run.
Steve Nairn, Helix Well Ops vice-president, commented: “MSV Seawell has provided an important and invaluable contribution to the North Sea oil and gas industry over the past three decades and has demonstrated the cost-effectiveness of utilising a vessel to deliver light well intervention services compared to a rig.“