ANCHORAGE, Alaska – An oil well leaking natural gas on Alaska’s North Slope was successfully plugged by pumping saltwater into the well, according to private and government responders.
The state Department on Environmental Conservation on Monday said the well operated by BP Exploration Alaska Inc., a subsidiary of BP, was “killed” at 3:35 a.m.
The well is five miles from the airport at Deadhorse. Employees on Friday morning discovered uncontrolled natural gas flowing from the top of a well house, a metal structure that looks like a large box over a well.
About 45 minutes later, they determined that the well was spraying a mist of crude oil into the air.
BP reported the leak and set up a joint response team with state, federal and municipal responders.
A weekend statement from the “unified command” said two leaks were detected. Oil was spraying from a leak near the top of the well. Workers contained that leak by activating a safety valve.
Oil droplets likely were contained to 1.5 acres (0.61 hectares) of the drill pad, responders said. They were waiting for the well to be plugged to determine if oil reached nearby snow-covered tundra.
Responders determined the well had risen up to 4 feet (1.22 metres) causing a pressure gauge to break off and preventing responders from pumping material into the well to kill it.
Responders on Saturday night were able to enter the well house and connect hoses to valves. That allowed the bleeding off of gas from space around the well’s below-ground piping and a reduction in gas pressure.
Responders from Boot and Coots Services, a well-control contractor, entered the well house and placed a plug in the above-ground piping. That allowed responders to pump in a solution of methanol and saltwater, killing the well.
The temperature at the site Monday was 21 degrees F (-6.11 Celsius).
The nearest village, Nuiqsut (noo-IK-sit), is 50 miles (80.46 kilometres) away.
An earlier version of this story listed an incorrect name for the Alaska Department of Environmental Conservation. The story also incorrectly said federal and state workers, not oil field workers, reduced pressure in the oil well.