Relief well to stem gas leak at evacuated offshore rig could take six months to drill

 

It could take another six months for oil engineers to drill a relief well to the leaking gas field beneath the offshore platform in the North Sea that was evacuated over the weekend when highly inflammable and toxic gas reached dangerous levels.

A two-mile exclusion zone for shipping, and a three-mile exclusion zone for aircraft, have been imposed around the Elgin Well Head Platform and Rowan Viking Drilling Rig situated 150 miles off the coast of Aberdeen on the east coast of Scotland.

The incident occurred on Sunday during work to plug and abandon the gas well which was no longer in production. Although all nearby wells have been shut down, gas continues to seep to the surface where a six-mile “light sheen” of condensed gas has been spotted on the water nearby.

Total, the oil company that operates the platform, said it will drill the relief well to the leaking well head, which could then be blocked with a concrete plug similar to the plugging technique used to stem the Deepwater Horizon spill in the Gulf of Mexico.

Another possibility is to try to block the flow of gas by injecting mud back down the existing gas pipeline leading to the well head. However, the company is hoping that the gas leak will begin to peter out over the coming days or weeks, which it said is possible given that the gas field was already depleted when the accident happened.

“The gas is flammable but the platform power was turned off to minimise risk of ignition, but clearly there is a risk,” said David Hainsworth, Total's manager for health, safety and environment.

“We have taken away a series of risks but there is always a possibility, it's low but you never say never. The best-case scenario is that the gas in this area is not very productive and it dies off in the coming days and weeks,” Mr Hainsworth said.

“At the moment there is no real evolution of the sheen on the sea but if that was to change ... then the exclusion zone may be increased,” he added.

Simon Boxall of the National Oceanography Centre in Southampton said that the gas coming to the surface is a “sour” mixture of methane, hydrogen sulphide - which are both flammable - and carbon dioxide.

“If this gas is bubbling from the seabed the hydrogen sulphide will be dissolving in the water column and that could kill any nearby fish. However, it is likely only to be a localised problem and there is little risk for anyone on the mainland,” Dr Boxall said.

“This is a fantastically advanced platform designed to pull sour gas from five kilometres below the seabed. They've evacuated the workforce safely, but I wouldn't want to be the one who goes in and tries to deal with this. One spark could cause an explosion,” he said.

After the leak was discovered on Sunday, Total ordered the evacuation of 219 workers from the Elgin platform and the nearby Rowan Viking drilling rig. As a precautionary measure, Shell has also reduced staffing levels on its Nobel Hans Deul rig four miles away.

Start your day with The Independent, sign up for daily news emails
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Junior Web Developer

£19000 - £22000 per annum: Recruitment Genius: This exciting, fast growing man...

Recruitment Genius: Web Application Developer

£35000 - £40000 per annum: Recruitment Genius: This exciting, fast growing man...

Recruitment Genius: Vehicle Accessory Fitter

Negotiable: Recruitment Genius: Vehicle Accessory Fitter required. Bristol

Recruitment Genius: Outbound Telesales Advisor - OTE £30,000

£14000 - £30000 per annum: Recruitment Genius: This company is very proud of t...

Day In a Page

Turkey-Kurdish conflict: Obama's deal with Ankara is a betrayal of Syrian Kurds and may not even weaken Isis

US betrayal of old ally brings limited reward

Since the accord, the Turks have only waged war on Kurds while no US bomber has used Incirlik airbase, says Patrick Cockburn
VIPs gather for opening of second Suez Canal - but doubts linger over security

'A gift from Egypt to the rest of the world'

VIPs gather for opening of second Suez Canal - but is it really needed?
Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Fashion editor, Alexander Fury, applauds a man who clearly has more important things on his mind
The male menopause and intimations of mortality

Aches, pains and an inkling of mortality

So the male menopause is real, they say, but what would the Victorians, 'old' at 30, think of that, asks DJ Taylor
Man Booker Prize 2015: Anna Smaill - How can I possibly be on the list with these writers I have idolised?

'How can I possibly be on the list with these writers I have idolised?'

Man Booker Prize nominee Anna Smaill on the rise of Kiwi lit
Bettany Hughes interview: The historian on how Socrates would have solved Greece's problems

Bettany Hughes interview

The historian on how Socrates would have solved Greece's problems
Art of the state: Pyongyang propaganda posters to be exhibited in China

Art of the state

Pyongyang propaganda posters to be exhibited in China
Mildreds and Vanilla Black have given vegetarian food a makeover in new cookbooks

Vegetarian food gets a makeover

Long-time vegetarian Holly Williams tries to recreate some of the inventive recipes in Mildreds and Vanilla Black's new cookbooks
The haunting of Shirley Jackson: Was the gothic author's life really as bleak as her fiction?

The haunting of Shirley Jackson

Was the gothic author's life really as bleak as her fiction?
Bill Granger recipes: Heading off on holiday? Try out our chef's seaside-inspired dishes...

Bill Granger's seaside-inspired recipes

These dishes are so easy to make, our chef is almost embarrassed to call them recipes
Ashes 2015: Tourists are limp, leaderless and distinctly UnAustralian

Tourists are limp, leaderless and distinctly UnAustralian

A woefully out-of-form Michael Clarke embodies his team's fragile Ashes campaign, says Michael Calvin
Blairites be warned, this could be the moment Labour turns into Syriza

Andrew Grice: Inside Westminster

Blairites be warned, this could be the moment Labour turns into Syriza
HMS Victory: The mystery of Britain's worst naval disaster is finally solved - 271 years later

The mystery of Britain's worst naval disaster is finally solved - 271 years later

Exclusive: David Keys reveals the research that finally explains why HMS Victory went down with the loss of 1,100 lives
Survivors of the Nagasaki atomic bomb attack: Japan must not abandon its post-war pacifism

'I saw people so injured you couldn't tell if they were dead or alive'

Nagasaki survivors on why Japan must not abandon its post-war pacifism
Jon Stewart: The voice of Democrats who felt Obama had failed to deliver on his 'Yes We Can' slogan, and the voter he tried hardest to keep onside

The voter Obama tried hardest to keep onside

Outgoing The Daily Show host, Jon Stewart, became the voice of Democrats who felt the President had failed to deliver on his ‘Yes We Can’ slogan. Tim Walker charts the ups and downs of their 10-year relationship on screen