Huge North Sea Well Gas Leak Could Take Months To Plug

A well operated by the French company Total is leaking natural gas in the British North Sea.  All 238 workers have been evacuated from Total's Elgin platform since it sprang a leak on Sunday. The leak has forced the evacuation of drilling platforms for miles around and plugging the leak could take months because of the danger of triggering a gas explosion.  The well may be spewing greenhouse gases equal in impact to the two biggest U.S. coal-fired power plants.

Natural gas is composed largely of methane, which is 21 times more potent a greenhouse gas than carbon dioxide.  Unlike the oil spilled from BP’s Macondowell in the Gulf ofMexico in 2010, the Total leak is primarily natural gas that dissipates in the air.  But the gas in the well is known as sour gas because it contains toxic, flammable hydrogen sulfide as well as gas liquids that have created small surface sheens.

Drilling a relief well, one possible solution, would be difficult because any rig would have to keep its distance from the gas leak. Total said the leak began Sunday after work was done on an old well linked to a production platform in the Elgin field, 150 miles east of Aberdeen. By Monday morning, the companyhad evacuated all 238 people from the platform.

Drilled in a little over 300 feet ofwater, theTotal well reached far below the ocean floor and the reservoir set records for high pressure conditions and high temperatures — about 190 degrees centigrade — when it was drilled in 2003.  The field was discovered in 1991. Total is being being careful to avoid igniting the gas. The worst accident in the North Sea took place in 1988, when 167 people died in an accident at the Piper Alpha oil platform (Wash Post, 3/28/2012)