It took just 12 hours for the French major to call time on the leak once the top kill procedure kicked off on Tuesday morning, it revealed on Wednesday.
The G4 well at the Elgin processing, utilities and quarters (PUQ) facility has been spewing natural gas following a blowout which was discovered on 25 March.
On Tuesday the Seadrill semi-submersible drilling rig West Phoenix began pumping mud into the well in an effort to plug the leak. At the time Total said it may be a few days before it was able to confirm whether or not the operation had been successful.
In the end it took only half a day for the leak to stop 240 kilometres off Aberdeen.
There was a note of caution from Total, however, which added: “During the coming days…teams will closely monitor the G4 well in order to confirm the complete success of the intervention.”
The company’s president of exploration and production, Yves-Louis Darricarrere, said: “Today, a major turning point has been achieved. Our absolute priority was to stop the gas leak safely and as quickly as possible.
Since 25 March, we have been working closely with the authorities and we have communicated transparently and will continue to do so.
“We shall now fully complete the ongoing task and take into account the lessons learnt from this incident.”
The top kill job was one of two methods by which Total planned to simultaneously try to stop the leak. It also planned to drill two relief wells.
Only one of these actually spudded, Total using the semisub Sedco 714. It had also contracted the jack-up Rowan Gorilla V but this unit never actually began drilling.
Although Total did not make any reference to the relief wells in Wednesday’s announement, it is highly likely that the Sedco 714 will soon halt drilling, if this has not already happened.
UK Energy Minister Charles Hendry welcomed the development, saying in a stament issued by the Department of Energy & Climate Change: ““The fact Total has managed to stop gas leaking from the Elgin platform is clearly excellent news. We will continue to monitor the success of the operation closely to ensure that the well can now be safely and permanently secured.”
Scottish Secretary of State Michael Moore added: “It is important that the work continues to manage and monitor the well over the coming days to ensure the operation to stop the gas leak has been a complete success.
“The UK government has been in touch with the company throughout this incident and DECC has closely monitored progress throughout. I am certain that key lessons will be learned from this leak which can be applied across the sector.”
Gas was originally spewing from the platform at a rate of some 7 million cubic feet per day following the discovery of the leak in late March, but this has since diminished significantly.
A sheen of gas condensate also developed on the water surface.
Total shut in all production at its Elgin and Franklin fields following the discovery of the leak. The oil major evacuated all 238 workers from the Elgin facility and the adjacent Rowan Viking.
Anglo-Dutch supermajor Shell also pulled all workers from its nearby Shearwater platform.