Breaking records at Brent Alpha - removing Shell's 10,100 metric ton jacket

Brent Alpha Sleipnir 2020 (1)
Brent Alpha Sleipnir 2020 (1)
Offshore decommissioning

Brent Alpha Jacket Removal

Shell's Brent Alpha jacket removed after 44-years using Heerema's novel method to remove and transport the conductors with the jacket

See our response

At a glance

  • EPRD (Engineering, Procurement, Removal and Disposal) of Brent Alpha Jacket including conductors.
  • Single lift jacket removal with novel conductor removal method
  • Cutting legs at 7.3 meter diameter using a specially designed Diamond Wire cutting tool.
  • 10,100 metric tons jacket lift.
  • Record-breaking lift.

The Heerema promise

Sustainability
Sustainability

As a carbon-neutral contractor you can trust Heerema to create sustainable value on your project.

Team onboard Aegir Greater Changhua project
Safety

We have the highest standards of safety and believe in an incident and injury-free workplace. To achieve this goal we follow our Dare to Care program.

Champion bij Ekofisk 1973
Reliability

With over fifty years of experience in transporting, installing, and removing offshore infrastructure you can rely on Heerema.

Brent Alpha Sleipnir 2020 (2)
Brent Alpha Sleipnir removal decommissioning
Brent Alpha Sleipnir Shell Heerema conductor
Brent Alpha Sleipnir 2020 (3)
Sleipnir at the Brent Field

Ready to begin the removal operations

Sleipnir with Brent Alpha jacket suspended

Sleipnir transported the 10,100 metric ton jacket in its cranes 

Sleipnir with Brent Alpha jacket suspended

The conductor hang-off frame can be seen at the top of the jacket

Sleipnir delivering the Brent Alpha jacket for recycling

The jacket will be recycled up to 97%at the AF Miljøbase decommissioning site in Vats, Norway

Brent Alpha Sleipnir 2020 (2) Brent Alpha Sleipnir removal decommissioning Brent Alpha Sleipnir Shell Heerema conductor Brent Alpha Sleipnir 2020 (3)

Removing the Brent Alpha jacket

In July 2020, Heerema's Sleipnir removed the 10,100 metric ton jacket from the UK sector of the North Sea. It will now be recycled up to 97% at the AF Miljøbase decommissioning site in Vats, Norway. 

Brent Field Alpha Jacket

The Brent Alpha jacket was installed by Heerema in 1976 using 32 piles to anchor it to the seabed. The structure has eight legs and was built in Scotland before being floated out to position. The Alpha jacket was the only one of the four Brent platforms that had a steel jacket. It stood in water depth deep enough to completely submerge the London Eye at a depth of 140 meters below sea level. 

Technical challenges

The Brent Alpha removal presented some novel challenges, which required unique solutions. During the project, Heerema cut jacket legs with a 7.3m diameter using a 288” Diamond Wire Cutting Tool developed alongside CUT UK, especially for the Brent Alpha removal - the largest leg diameter to have been cut this way. Also, the Brent Alpha conductors were removed and transported with the jacket, an entirely new way of decommissioning. The conductors were suspended on a Heerema Fabrication Group built Conductor Hang-off Frame made for this project.

There were quite some technical challenges during this record-breaking lift. However, due to the excellent preparation and perseverance during execution, we successfully delivered this jacket for recycling safely and sustainably.

Jeroen van Oosten, Heerema Decommissioning Director

Safe operations

Sleipnir arrived at the Brent Field located 186 km northeast of Scotland’s Shetland Islands on July 23, 2020, and completed the project by offloading the jacket onto the quayside at the AF Miljøbase decommissioning site in Vats, Norway on August 11, 2020.

Now that the Brent Alpha jacket has been safely and sustainably transported to Vats, it will end its lifecycle by being over 97% recycled.

Key information

Milestones

Contract signed: September 12, 2017

Offshore start date: July 23, 2020
Offshore end date: August 11, 2020

Main technical data

Conductor hang-off frame

288” Diamond Wire Cutting Tool

Need a specific answer? Let us help.

Karen Vennik
Karen Vennik

Commercial Manager Decommissioning

Get in touch
Brent Alpha Sleipnir 2020 (1)

Let’s talk about your challenge.

Want to discuss how our solutions can help your decommissioning project? Get in touch with one of our experts!