Offshore installation and decommissioning contractor Allseas has removed the Ninian Northern jacket in the North Sea in a single lift, showcasing its new jacket lifting system installed aboard its giant Pioneering Spirit vessel.
In what was the first deployment of the new jacket lifting technology, Pioneering Spirit removed CNR International’s Ninian Northern jacket from the northern North Sea and transported it intact to shore for recycling.
Weighing in at 8100 tonnes, the first commercial lift with Pioneering Spirit’s Jacket lift system (JLS) is one of the heaviest offshore jackets lifts ever, but remains well within the system’s 20,000-tonne single-lift capacity, Allseas said.
The 382 meters long Pioneering Spirit arrived in the Ninian field, 160 km northeast of the Shetland Islands, on April 15. A week later, after final preparations and leg cutting, the eight-legged jacket was lifted out of the water and lowered onto the deck for transit. The jacket will be delivered to the Veolia-Peterson yard in Dales Voe, Shetlands. The facility targets 98% steel reuse.
"Yesterday’s lift successfully concludes two years of planning and design, which started with the safe and successful single-lift removal of the 14,200 t Ninian Northern platform topsides by Pioneering Spirit in 2020," Allseas said.
“CNR International’s decision to select Pioneering Spirit for the Ninian Northern jacket removal demonstrates the industry’s confidence in Allseas’ innovative engineering solutions and further reinforces our reputation as a frontrunner in the global offshore energy market,” says Allseas President Edward Heerema.
'Fundamentally different'
Credit: Allseas
Fundamentally different from conventional crane-lifting vessels, the aft-mounted system comprises two connected 170-meter long beams that lift and support jackets of all sizes during removal and installation operations, Allseas explained.
According to Allseas, the system also enables the transport of jackets in a near-vertical position to safeguard structure integrity. The technology enables direct transfer of structures to and from the quayside and eliminates the need for support barges.
"There is no need to seafasten the jacket to the beams during transit due to the vessel’s high level of stability, significantly reducing time in the field and lowering the emissions footprint," Allseas said.
"With the successful removal of the Ninian Northern jacket, Allseas has realized its long-term vision of a vessel that provides the offshore industry with a total solution for offshore work,” adds Heerema.
According to Allseas, Ninian Northern is the first of several major jacket removal and installation commitments for Pioneering Spirit in 2022. The vessel will lift and transport more than 123,000 tonnes of structures for the offshore energy industry this year utilizing both its jacket lift and motion-compensated topsides lift systems.
The Pioneering Spirit was recently in The Netherlands where it installed the HKZ Beta topside for TenneT in support of Vattenfall's Hollandse Kust Zuid offshore wind farm. Offshore Engineer paid a visit to the HKZ site last month, just as the Pioneering Spirit was getting ready to leave. Read more here.
Also, Offshore Engineer's Elaine Maslin recently interviewed Allseas CEO Edward Heerema to learn more about the jacket lifting system, as well as about Allseas' entry into the deepsea mining sector. Read more here.
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