Allseas' giant Pioneering Spirit offshore installation and decommissioning vessel has earlier this month removed 2500-t Valhall Quarters Platform (QP) lower jacket out of the water in the North Sea, off Norway.
"The jacket on Valhall QP has now been removed and is on its way to Stord for recycling. As much as 100 percent of the steel is recycled," Aker BP, the operator of the North Sea field said via social media.
The removal work is part of developing the Valhall field center to produce up to 2 billion oil equivalents. The removal work was carried out together with Allseas Pioneering Spirit and Aker Solutions in Stord.
Allseas said it had carried out the operation using in-house designed, fabricated, and installed lifting tools.
"Machinefabriek Schaap cut, machined, and assembled the hooks from 690-grade steel leftover from the JLS beams, while Allseas Fabrication delivered the spreader bars and hook integration with lifting/operating frames and hydraulics. Design and procedures were drawn up by a team from Allseas’ Heavy Lift and Innovations Departments," Allseas said.
Cuts to the jacket legs and holes for the hooks were performed from the vessel Oceanic, with the vessel providing ROV support. The 800-t upper jacket section was removed previously.
Allseas won a contract for multiple topsides and jackets removal from the Valhall area in the Norwegian North Sea back in April 2020.
Work comprises removal and disposal of the Drilling Platform (DP) 5,950 t topsides and 4,350 t jacket, and Production and Compression Platform (PCP) 10,900 t topsides and 9,500 t jacket from the Valhall complex, plus the 1,100 t Hod topsides and 3,500 t jacket from the connected Hod field, 13 km to the south.
In addition, Aker BP at the time also invoked the option for the removal and disposal of the Valhall Quarters Platform (QP) jacket - removed earlier this month - and the 2/4-G jacket on the Ekofisk field, 24 km north of the Valhall complex.
This option was associated with the 2017 award for the removal and disposal of the QP topsides, removed by the Pioneering Spirit in June 2019.
See the video of that operation below.
The QP topsides was the first of the three original structures (QP, DP, PCP) at Valhall to be removed as part of the modernization of the Valhall field center by Aker BP.