It isn't clear what caused the leak in the oil and natural-gas production well, about five miles from the airport for Deadhorse, a town devoted to servicing the giant Prudhoe Bay oil fields, which began producing 40 years ago.
The BP leak comes as the remote North Slope, once home to the biggest US oilfields, enjoys a resurgence as companies work to improve production from aging wells and extend their reach to new supplies; North Slope production rose to 565K bbl/day in March, its highest level since December 2013.
"Based on an overflight with infrared cameras, the release appears to be contained to the gravel pad surrounding the wellhead and has not reached the tundra", BP spokesman Brett Clanton said Saturday. A second leak had been reduced but was still emitting gas, the Alaska Department of Environmental Conservation or ADEC said in a statement.
But the platform is still venting gas from a leak associated with a damaged pressure gauge.
This April 2017 photo provided by the U.S. Environmental Protection Agency shows an oil well that was misting natural gas on Alaska's frozen North Slope.
The well is too risky at this time for a response team made up of state and federal energy officials and BP employees to get near the well. According to the Alaska Department of Environmental Conservation, the well is no longer spraying crude oil, but workers have not been able to staunch the flow of natural gas. They still don't know what caused the spill.
In 2010, a BP-operated drilling rig called Deepwater Horizon exploded, killing 11 people and spilling almost five million barrels of oil into the Gulf of Mexico, making it the largest oil spill in USA federal waters.
In 2006, a BP oil pipeline in Prudhoe Bay ruptured and spilled 215,000 gallons of crude oil over the North Slope.
Alaskan and federal officials had identified two leaks spewing methane gas which is linked to climate change.