The sun is setting on the Brent Oil Rigs, four North Sea platforms which have contributed massive amounts to the UK economy, in terms of energy supply and jobs. When it comes to number crunching the demolition project, there’s a lot to take in.

10 years is how long it’s taken Shell to make preparations for Brent Fields demise. The 300 studies involved take this planning from careful to painstakingly meticulous. With the costs and logistics involved, it has to be.

£20 billion is the amount in today’s money that the field has contributed towards tax revenues.

7500km of pipeline is planned for decommission in the next eight years, along with the partial removal of 100 platforms from both UK and Norwegian seas, and the plugging of 1800 wells.

1982 was the year that the Brent Fields saw its peak, producing more than half a million barrels a day.

There are 4 rigs which make up the Brent Fields – Alpha, Bravo, Charlie and Delta.

The 40-year task of decommissioning and removing Brent Fields is estimated to cost between£30bn – £50bn. This bill could be less if large segments of the rigs are allowed to remain in the sea.

The topside of the Delta rig weighs 24,000 tonnes. When it is moved in May, it’ll involve the single heaviest lift. Last year, the boat The Pioneering Spirit claimed this accolade for its part in removing a rig in Norway last year.