The giant jacket for the Johan Sverdrup riser platform was installed last week by the Thialf crane vessel owned by Heerema Marine Contractors (HMC) – the first visible sign of one of Norway’s biggest offshore projects finally taking shape.
Weighing some 26,000 tonnes, the jacket is the largest on the Norwegian continental shelf (NCS).
The jacket stretches up 140 meters from the seabed, where it covers an area measuring 94 times 64 meters, and is attached to the seabed by 24 poles weighing more than 9,000 tonnes in total.
After removal of the sea fastening, the massive jacket was launched from the transport barge and upended using the Thialf’s cranes.
“This is a special milestone for us, because it is the first visible sign of the Johan Sverdrup field. I am happy that the installation has been carried out safely and fully in line with the plan. We are now looking forward to the next steps of this industrial adventure and the long line of major operations awaiting us. We have already done a lot of work on and below the seabed, and in the time ahead we will gradually become more visible above the sea surface as well,” says Kjetel Digre, project director for Johan Sverdrup.
Head of transport and installation on Johan Sverdrup Thor Kråkenes has followed the installation of the jacket that was delivered by Kværner Verdal.
“The execution of the work has simply been a feat of engineering. It took a lot of good work and detailed planning to prepare the careful lowering of the jacket onto the seabed without any unforeseen incidents,” says Kråkenes.
The topside is scheduled for installation next year, and production from the field is to start at the end of 2019. Plateau production is estimated at 40% of NCS oil production. Expected field life is 50 years and the ambition is a world class recovery rate of 70%. Recoverable resources are estimated to be between 2 and 3 billion barrels of oil equivalent.