Workers attempted to bring the well under control, but the Alaskan North Slope is host to temperatures lower than 20 degrees Fahrenheit and 38 mph wind gusts. The damage to the well is extensive: it has risen three or four feet out of the ground and its pressure gauge has been severely damaged, according to the Alaska Department of Environmental Conservation (ADEC) on Saturday.
On Saturday night, workers were able to enter the wellhouse and slowly reduce the pressure. It wasn't until Monday, however, that BP announced that the well had been killed and the oil had stopped flowing.
BP did not have an estimate available for the volume of oil and natural gas spilled. They claim that two leaks had sprung, one at the well's top and one at the well's bottom. Both BP and ADEC, which used an airborne infrared camera to examine the scene, say that the vast majority of the spray landed on the drilling pad.
"The top leak was misting oil in conjunction with releasing natural gas," said ADEC in a statement, but "the activation of the surface safety valve has stopped the release from that point. The bottom leak has been reduced, but is currently leaking gas as well as some minor amount of crude oil."
No people were at the well when it burst, and no injuries have been reported. The cause of the well bursting remains unknown.
"Whenever you have an out-of-control well like this, that means something very serious went wrong," Lois Epstein, Arctic Program Director for environmentalist group The Wilderness Society, told Bloomberg. "This really needs to be thoroughly investigated to find out what went wrong and whether there's a danger of it happening again."
The well that burst is in the Prudhoe Bay Oil Field, the largest oil field in North America. The field is estimated to have contained over one trillion gallons of oil before exploration began in the 1970s. Between then and 2005, around 460 billion gallons have been extracted, mostly by BP.
In 2006, a BP oil pipeline in Prudhoe Bay ruptured and spilled 215,000 gallons of crude oil over the North Slope. BP was fined $255 million by the state of Alaska for negligence in their maintenance of Prudhoe Bay pipelines. The infamous Exxon Valdez, which in 1989 spilled tens of millions of gallons of oil into the Gulf of Alaska, was carrying oil extracted from Prudhoe Bay.
