3 Feb 2015

Biggest ever oil platform break-up: in numbers

Shell announces decommissioning plans for its North Sea Brent Delta platform – a colossal project involving more than 1,000 people and the world’s biggest platform vessel.

115 miles off shore

The Brent oil field is located 115 miles north east of the Shetland Islands in the North Sea. It was discovered in 1971 and has produced around 4 billion barrels of oil, but is now close to the end of its life.

The Brent Delta platform, one of four platforms in the field, will be the first to be decommissioned.

300m above the sea bed

The Brent Delta platform stands at more than 300m tall from the sea bed. The “topside” of the platform rests on three giant concrete legs, each 170m tall. At the base of the legs are 16 storage tanks standing at almost 60m tall, and each with the capacity of four Olympic-size swimming pools.

382m long ship will lift 23,500 tonne platform

The operation will involve the world’s heaviest vessel ever constructed – the Pieter Schelte – which is 382m long and weighs more than 400,000 GT.

The 23,500 tonne “topside” of the Brent Delta platform will be lifted by huge hydraulic arms on the Pieter Schelte, which Shell says will be one of the heaviest lifts the North Sea has ever seen. The platform will then be carried for 380 miles to Hartlepool.

£40bn decommissioning cost

The Brent field is just one of 470 fields that will require decommissioning over the next 30 to 40 years. Estimates by Oil & Gas UK suggest the process will cost £35-£40bn.

Around 1,000 people will work on the offshore Brent field operation. Once the “topside” of the Delta platform arrives in Hartlepool more than 97 per cent of the material will be reused or recycled, much of it turned into washing machine parts.

30 days’ consultation

Starting on 16 February, Shell will launch a 30-day public consultation on its decommissioning plans.

In 1995 the company drew strong criticism from environmental campaigners over its plans to bury a Brent Spar oil storage module in deep north Atlantic waters. Greenpeace protesters occupied the accommodation for several days, forcing Shell to reverse its decision.

“We hope many people will play an active part in the consultation,” said Alistair Hope, Brent decommissioning project director.