Allseas has completed the removal of the fourth and final platform from Shell’s Brent field in the UK’s North Sea as part of a decommissioning project that took over a decade to conclude.
The Brent oil and gas field, located northeast of the Shetland Islands, was one of the largest fields in the North Sea and was served by four large platforms – Alpha, Bravo, Charlie and Delta. When discovered in 1971, it was one of the most significant oil and gas finds made in the UK sector of the North Sea, Shell said.
Continuous investment and redevelopment in the 1990s by partners Shell and Esso Exploration and Production UK extended the life of the field well beyond original expectations. To date, Brent produced around three billion barrels of oil equivalent. At its peak in 1982, the field was producing more than half a million barrels a day.
However, Brent had reached the stage where almost all the available reserves of oil and gas have been retrieved, Shell noted, so the next step in the lifecycle was to retire or decommission its four platforms and their related infrastructure – a complex, major engineering project that requires over ten years to complete.
Allseas reported that it had removed the 31,000-tonne Brent Charlie platform topsides from the UK sector of the North Sea on July 9, in a single-lift removal carried out by the heavy lift vessel Pioneering Spirit . According to the company, this represents the heaviest offshore lift ever performed and concludes years of engineering and planning.
The facility will be delivered to Able UK’s Seaton Port facility in Hartlepool for disposal, where more than 97% of the materials will be recycled.
Edward Heerema , Allseas Chairman, said: “It started in 2013, with Shell’s decision to award Allseas the contract for the engineering, preparation and removal of its four Brent platforms. The trust shown then in Allseas’ technical expertise served as a milestone in the 20-year development of Pioneering Spirit. At the time, the vessel was still under construction, but Shell’s belief in Allseas gave us the opportunity to showcase our single-lift technology.”
Pioneering Spirit has removed and transported close to 100,000 tonnes of topside weight to Hartlepool for disposal at the Able UK Seaton Port facility. To date, 98% of all materials from Delta (2017) , Bravo (2019) , and Alpha (2020) topsides have been recycled, Allseas said.