Statoil probe concludes North Sea gas leak was serious
Kjetil Malkenes Hovland, Dow Jones Newswires
OSLO -- The Norwegian oil and gas company Statoil ASA said Wednesday that the May 26 gas leak on the Heimdal field in the North Sea was serious, and an investigation showed that the company had to strengthen its safety measures.
No one from the crew of 98 was injured by the leak, but both Norway' s Petroleum Safety Authority and Statoil labeled it as a serious incident and launched investigations. The PSA said the leak had "significant potential."
Statoil said Wednesday the incident "was no threat to the platform' s main safety functions or integrity," and that the emergency response and automatic safety systems worked as intended. The company has submitted its investigation report to the Petroleum Safety Authority.
The Heimdal leak is "a strong reminder of the need for continuous learning and improvement in our operations," said Jannicke Nilsson, Statoil' s head of operations North Sea West.
The leak lasted for four minutes and the volume was calculated at 3,500 kilos of natural gas. It happened during testing of valves on the drilling, production and accommodation facility HMP1.
The leak was caused by errors in the original design, insufficient planning and failure to communicate, the company said.
Ms. Nilsson said Statoil had launched a comprehensive improvement effort following a gas leak on Gullfaks B in December 2010, but that the Heimdal leak "has revealed that we need to strengthen this work further."
Statoil said it had taken four immediate measures after the incident, including improving the technical design and updating system drawings. It had also improved planning and risk assessments.
The Heimdal field is nearly empty, but is expected to produce small amounts of gas until 2014. The field originally held 347 million barrels of oil equivalent, mostly gas. The water depth is 120 meters, and the reservoir is 2100 meters deep.
Today, Heimdal is mainly used as a process centre for tied-in fields such as Huldra, Skirne and Vale. Gas from the giant Oseberg field is also transported via Heimdal.
The Heimdal field is operated by Statoil with a 29.4% stake, while Centrica PLC has a 33.8% stake, the Norwegian state-owned oil company Petoro AS has a 20% stake, and Total SA has a 16.8% stake.