Allseas is celebrating another major offshore milestone, the safe removal and transport to shore of Repsol Norge’s massive 30,000-tonne Gyda platform in a matter of days.
Pioneering Spirit delivered the platform’s 11,000-tonne jacket to Aker Solutions’ disposal yard in Stord, Norway, less than 48 hours after removing it from the southern Norwegian Sea. The latest job for the vessel’s new jacket lift technology is one of the heaviest ever, but well within the system’s 20,000-tonne lift capacity.
The jacket was set down directly onto the quayside and reunited with its decommissioned drilling and production topsides, delivered by Pioneering Spirit in May this year. Aker Solutions expects to recycle around 98% of the facilities.
Split across two campaigns to allow for the vessel’s busy schedule, Pioneering Spirit completed the removal, transport and load-in to the disposal yard of the entire Gyda platform, its 32 conductors and template in 12 days.
To facilitate removal of the jacket, the structure’s 24 foundation piles were cut below seabed level. Main hoist blocks suspended from the Jacket lift system (JLS) beams were connected to pre-installed rigging and the entire structure lifted and aligned with the lifting beams.
As the jacket was vertically fabricated and installed, the structure could not sustain loading in the horizontal position during transport. The solution of transporting the jacket in a near-vertical (60%) position, with interface supports and grillage made delivery of the complete jacket to the yard possible.
Unlike conventional lift vessels, Pioneering Spirit only requires days in the field to remove entire platforms and subsea facilities, eliminating the need for multiple trips and a support fleet. Saving time and reducing vessel operations to a minimum significantly reduces the vessel’s emissions footprint.