Allseas’ installation and decommissioning vessel Pioneering Spirit has removed the 25,000-tonne Brent Bravo topsides from the North Sea.
Located 186 km off the northeast coast of the Shetland Islands, the Brent Bravo platform comprised topsides structures supported by three 12 m diameter steel-reinforced concrete legs, which stand in 140 m of water.
Cuts between the topsides and supporting legs were made ahead of the lift. The structure was held in place temporarily by purpose-built restraints that prevented lateral movement. The supporting legs will remain in situ, capped with concrete covers.
The removal operation, from positioning the vessel around the platform to the moment of the lift, took approximately four hours.
The 125 m-tall, 70 m-wide topsides have since been sea-fastened on board Pioneering Spirit for transport to a nearshore location off the coast of Hartlepool where they will be transferred on to Allseas’ barge Iron Lady.
For the final leg of the journey, the barge will be towed up the Seaton Channel before the structures are loaded out at the Able UK decommissioning yard in Teesside, UK.
Brent Bravo is the second of four platforms (the first being Brent Delta in 2017) to be decommissioned and removed from the Brent oil and gas field. On both occasions, Shell UK called upon Pioneering Spirit’s for the removal of the structures.