A major North Sea gas leak, on board Total’s offshore Elgin platform, has resulted in a fine of over £1.1 million for the oil and gas company.
Tuesday’s (22nd Dec) fine comes after a court hearing Thursday (17th Dec), in which Total pleaded guilty to charges related to the gas leak.
The sentencing saw, Aberdeen Sherif Court fine, the French based oil and gas major, £1,125,000 (US$1.7 million).
Total North Sea Gas Leak
The gas leak occurred on the Elgin platform, 150 miles (241km) east of Aberdeen, back in March 2012.
At the time the offshore platform was manned, with 238 offshore workers onboard, however most staff were evacuated safely back to shore, leaving a skeleton crew of 19 on board to secure the production platform, before they to were evacuated a day later.
The leak occurred from within a well that was in the process of being plugged and abandoned by the Rowan Viking jackup drilling rig.
An investigation after the incident put the likely cause down to a rupture in the well casing caused by both, ongoing work, and corrosion and fatigue of the casing.
The investigation cited that the rupture was above the then newly installed cement plug and allowed gas, from an untapped gas source above the main reservoir, to flow into the well bore.
This in turn escaped out of the well uncontrollably due to a lack of a sufficient well control plan.
The Gas Leak At The Offshore Elgin Platform
On Thursday (17th Dec), Total pleaded guilty at the Aberdeen Sherif Court, admitting that the gas leak had occurred due the company ‘miscalculating a plan designed to kill an unstable gas well on the platform.’
The leak led to tonnes of gas being spewed into the air and gas condensate into the sea, at a rate of 2 tonnes per hour.
The court head that at one point the Elgin was leaking by as much as 7 million cubic feet of natural gas per day.
Due to the size of the flammable gas plume, production on the nearby Shell operated Shearwater platform was shut down, with an air exclusion zone extending to three miles around the offshore platform and a maritime exclusion zone of two nautical miles.
51 Days Later
The gas leak was only stopped, 51 days later, after a specialist team and their equipment had been flown in from Houston, Texas.
The team from ‘Wild Well Control’, set about killing the well, using a two methods known as ‘Top Kill’ and ‘Bottom Kill’.
The ‘Top Kill’ involved pumping heavy drilling fluids (mud) down the well bore to counterbalance the force of the gas pushing up. The work was carried out by the semisubmersible drilling rig West Phoenix.
The ‘Bottom Kill’ was carried out by the Sedco 714 drilling rig, and involved drilling a relief well into the side of the gas source to extract some of gas in a controlled manner.
The gas leak eventually stopped on the 16th May 2012, 51 days after the initial blowout, with production restarting almost a year later on the 9th March 2013.
According to Total’s financial results, the gas leak cost them over £83 million (123m) in lost production revenue.