Total has played down fears other wells on the Elgin platform could suffer the same fate as the one spraying gas over the North Sea.
The managing director of the company’s UK upstream business said all other wells from the platform had been closed during Sunday’s emergency shutdown.
Philippe Guys said no issues had been detected in any of the installation’s other wells, despite concerns raised earlier this week about pressure issues.
He said: “When the platform was evacuated, all of the wells were left in a safe condition. Onboard safety systems were activated and we know the operation was successful from the platform control room.
“Following the incident on G4 – the well at the centre of the crisis – our experts have been working hard to identify the cause.
“As part of that process we have reviewed the design and history of all the other wells on Elgin.
“We observed abnormal pressure on G4, no such abnormal behaviour was observed on any of the other wells on Elgin.”
However, Mr Guys was unable to confirm that the company was able to monitor live what was happening in any of the other wells. He also said that because the leak was in a part of the high pressure, high temperature well not designed to have the gas flowing through it, there had not been anything in its design to allow it to be sealed. According to a technical paper published last year, a high pressure, high temperature well specialist at Total said the reservoirs around Elgin were prone, over time, to compacting.
This could affect parts of the well structure – including shearing the liner, the casing around it. Energy Minister Charles Hendry said any lessons learned from the Elgin leak would be applied across the industry.
Responding to calls for the firm to remove staff from the normally-unmanned Franklin platform, Mr Guys said: “We are keeping a few people on the Franklin platform because they can offer valuable assistance with monitoring the situation and at a distance more than five kilometres (three miles) from the Elgin platform we consider them to be in no danger.”