Total Using Two Strategies to Kill North Sea Gas Leak
The first is to use a floating support for well kill operations, while the second involves drilling two relief wells.
Total E&P UK's top official confirmed two strategies that the company is using in parallel to try to stop a major gas leak from its Elgin platform in Britain’s North Sea. The leak began March 25, but Philippe Guys, managing director of Total E&P UK, said during a March 30 news conference that "irregular pressure" was first detected Feb. 25 in the annuli of the well, which had been plugged for more than a year, and the company "very quickly moved to kill the annuli pressure by pumping it full with high density mud."
Guys confirmed the estimated rate of natural gas leaking from the platform is 200,000 cubic meters per day. He said the leaking gas appears to be coming from a rock formation 4,000 meters below the sea bed, which is above the main producing reservoir tapped by the plugged well (at 5,500 meters' depth).
"Now, the question has been asked if there could be similar problems with other wells on Elgin," Guys said. "What I can tell you is that when the platform was evacuated, all other wells were left in a safe condition. Onboard safety systems, known as the Christmas tree valves and downhole safety valves, were activated and we know the operation was successful from the platform control room."
No abnormal pressure was detected on the other Elgin wells, he added.
Guys, who was joined by Rt Hon Charles Hendry, MP, Minister of State for the Department of Energy and Climate Change, began by apologizing for the incident. "Let me say how much Total regrets the incident at the Elgin complex. Our top priority is the safety of our personnel," he said. "I can confirm that, in addition to the safe evacuation of 238 personnel from the Elgin platform, the on-board safety systems of the whole complex, including the other wells, were successfully activated."
Paris-based Total S.A. announced March 27 that it had evacuated the workers without injury from the offshore platform, which is located about 145 miles east of Aberdeen, Scotland. It tapped a high-pressure/high-temperature gas and condensate field. Total E&P UK Limited owns 46.17 percent and operates the field through a wholly owned subsidiary.
Drilling relief wells might take six months to accomplish. A shipping exclusion zone two miles from the platform is in place, firefighting ships are standing by, and Shell has evacuated workers from a rig four miles away, The Telegraph reported.
The company's 2011 financial results, announced Feb. 10, were strong, with $15.9 billion in net income -- up 17 percent from the year before.
The company earlier said a surveillance aircraft overflew the area and confirmed a small sheen related to drilling mud and/or light condensate on the water near the platform. "Preliminary assessments indicate no significant impact to the environment and dispersants are not considered necessary at this stage," it said, adding that Oil Spill Response Limited (OSRL) has been alerted and is evaluating the situation. Total E&P UK Limited is cooperating fully with relevant authorities, including the Department of Energy and Climate Change, the Health and Safety Executive, and the Scottish Environmental Protection Agency.
For updates, visit Total’s Twitter page.