Allseas’ Pioneering Spirit, the largest vessel in the world, will travel to the Irish Sea this year to remove two normally unmanned installations in the East Irish Sea. The 11,000-tonne platforms owned by Spirit Energy used to produce gas in Morecambe Bay. 

The infrastructure used to produce gas as part of Spirit Energy’s complex of eight installations in Morecambe Bay. As the field has matured, the reserves the platforms previously tapped into have been produced by the larger, manned Central Morecambe platform nearby.

The twelve wells, which were connected to the DP3 and DP4 platforms, have already been plugged and abandoned – using a slant rig to accommodate the angle at which the wells were drilled in the 1980s to access the gas reservoir below the seabed. Final preparations for the DP3 and DP4 installations to be lifted are underway and the platforms will soon be taken back to shore.

Also read: Pioneering Spirit removes 14,200-t Ninian offshore platform in single lift

Pioneering Spirit’s first lift assignment outside the North Sea

Allseas’ 382-metre Pioneering Spirit will lift both the DP3 and DP4 platforms, which is well within its limits of lifting 48,000-tonne topsides. This is Pioneering Spirit’s first lift assignment outside the North Sea. Working just 40 km off the coast of Blackpool, northwest England, the strong currents and shallow depths of 22 metres will provide a very different challenge for the vessel’s single-lift capability, states Allseas.

Ongoing preparations include the cutting and removal of risers, caissons and conductors, cutting the platforms’ steel legs, strengthening the topsides and installing made-to-measure lift points. The job includes extensive subsea activities, such as the removal of mattresses, spools, cables and umbilicals, requiring more than 180 separate lifts by Allseas’ construction support vessel Oceanic

‘After two years of preparing the DP3 and DP4 installations for removal, we’re now looking forward to one of the most significant milestones in the project with the removal of both platforms,’ says Donald Martin, Project Manager at Spirit Energy. ‘Seeing the Pioneering Spirit in the East Irish Sea will be an impressive sight – its capacity and single-lift methodology made it a good fit to safely execute this project.’

South Morecambe field

The DP3 and DP4 installations first produced gas in 1985 when the South Morecambe field came online. The area continues to produce enough gas to heat one million UK homes every day thanks to production from the Central Morecambe, North Morecambe, DP6 and DP8 platforms.

Also read: Allseas removes 27,000 tonnes of platform facilities from North Sea / Plans for new Allseas vessel larger than Pioneering Spirit shelved

Picture: Pioneering Spirit removing the Tyra TWA topsides.