Decommissioning plans which could see the giant legs of three offshore oil platforms left in the North Sea are to go before a public consultation early next year.

Shell has lodged documents with the UK Government’s Department for Business, Energy and Industrial Strategy (BEIS) to close down four platforms in the Brent field, which started producing oil about 115 miles east of Shetland 40 years ago but is said to be ”no longer economically viable”.

Earlier this year, the oil company said it would seek an exemption to leave platform legs – said to weigh about 300,000 tonnes – on safety grounds.

The latest report from Shell said the “footings” of the Brent Alpha platform would be left under sea level while the steel and concrete legs of the other three larger platforms – Bravo, Charlie and Delta – would remain under current plans.

The report said: “Each structure which supports the topsides above the surface of the sea weighs 300,000 tonnes, roughly the same as the Empire State Building.

“We have analysed a long list of options for the gravity base structures (GBS) such as re-floating, partial removal or leaving them in place.

“Our recommendation is that the safest and most responsible solution is to leave the GBS legs and oil storage cells in place, marked with navigation aids so they are recognisable to shipping, fishermen and other users of the sea.”

A spokeswoman said: “Shell is liaising with the BEIS and expects the public consultation on the Brent decommissioning programme to commence in the new year.”

WWF Scotland believes the legs could pose an environmental risk if left in the North Sea.

Director Lang Banks said: “It’s good to have greater clarity around the timings regarding the public’s opportunity to comment on the potential environmental impacts of Shell’s proposals.

“It’s also good that the formal consultation period will begin after the holidays and not before, hopefully allowing the public more time to respond.

“While removing these structures is not without environmental risk, neither is leaving them lying on the seabed to slowly break down over hundreds of years.

“Given the potential impact on the marine environment, we will be carefully examining the proposal that goes out for consultation.

“The industry pushed the boundaries of science and engineering to access North Sea oil and gas.

“Having made massive profits over the last few decades, it’s only right that it should push those limits once again to clean up their potentially hazardous legacy and protect the marine environment.”

The latest Shell update revealed Nasa has been involved in the decommissioning process with a camera and scanner used to inspect space shuttles sent down to investigate the legs of the Brent Bravo platform.

Nasa engineer Darby Magruder, who dived to the depths of the North Sea with the probe, described it as “just like being an astronaut”.

Source: www.reuters.com