Offshore contractor Allseas has deployed its giant Pioneering vessel and its new jacket lifting technology for the first time to remove CNR International’s Ninian Northern jacket from the northern North Sea and transport 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 jacket lifts ever but remains well within the system’s 20,000-tonne single-lift capacity, Allseas explained in a statement on Friday.

Pioneering Spirit arrived in the Ninian field, 160 km northeast of the Shetland Islands, on 14 April. 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 eight-legged platform, a drilling and production facility, was installed in 1978 and started production in 1980. The production at the platform ceased in 2017.

The jacket has now been delivered to the Veolia-Peterson yard in Dales Voe, Shetlands. The facility targets 98 per cent steel reuse.

The lift concludes two years of planning and design, which started with the single-lift removal of the 14,200 t Ninian Northern platform topsides by Pioneering Spirit in 2020.

“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,” said Allseas President, Edward Heerema.

As explained by Allseas, fundamentally different to conventional crane-lifting vessels, the aft-mounted system comprises two connected 170-metre long beams that lift and support jackets of all sizes during removal and installation operations. The system also enables the transport of jackets in a near-vertical position to safeguard structure integrity.

Pioneering Spirit removes the Ninian Northern jacket with its new Jacket lift system - Allseas
Pioneering Spirit removes the Ninian Northern jacket with its new Jacket lift system

According to Allseas, this advanced 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.

“With the successful removal of the Ninian Northern jacket, Allseas has realised its long-term vision of a vessel that provides the offshore industry with a total solution for offshore work,” added Heerema.

In a separate update on Friday, Scotland’s Lerwick Harbour said that the Ninian Northern production jacket has arrived at the deep-water Shetland port, delivered by Pioneering Spirit. This was the first time the world’s biggest offshore construction vessel has operated at a quayside in a UK port.

According to Lerwick, Pioneering Spirit will initially lift steel support structures onto a barge for removal and re-use, clearing the way for the load-in of the jacket. The vessel will then move to mid-voe to transfer the jacket via a barge, Allseas’ Iron Lady, to the Base in a complex operation over a number of days. The structure will be loaded-in onto a heavy-duty pad.

The jacket will be dismantled and recycled over approximately eight months by Veolia/Peterson.

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 utilising both its Jacket lift and motion-compensated Topsides lift systems.

Earlier this year, the Pioneering Spirit installed the fifth and final platform at the Johan Sverdrup field in the North Sea for Norway’s Equinor.

Source: Offshore Energy