Britain’s BP PLC is closing 12 oil wells on Alaska’s North Slope as a precaution after whistleblowers alleged more than 50 were leaking.
The wells were in the process of being shut down Tuesday, BP spokesman Darren Beaudo said.
The action came after workers told the Financial Times of London about the leaks, according to the newspaper, which first reported the shutdowns on its Web site.
Most of the shuttered wells were in Prudhoe Bay, Beaudo told The Associated Press.
The shutdowns come a month after BP confirmed it had received a subpoena from a U.S. grand jury investigating a massive oil leak in Alaska last year.
BP blamed the March 2005 incident at Prudhoe Bay, the largest-ever spill in Alaska’s North Slope region, on a small hole caused by corrosion in a pipeline. Up to 267,000 gallons were believed to have spilled onto the frozen ground about 250 miles above the Arctic Circle.
The 12 well shutdowns affect about 8,000 barrels a day out of the North Slope’s total daily production of about 800,000 barrels, Beaudo said.
BP plans on running integrity tests on the affected wells.
“If we reconfirm that they met those standards we will put them back on production,” he said.
Beaudo said BP was being cautious in addressing the leaks of a freeze protection material known as arctic ice pack. The material is usually crude oil or diesel fuel. A typical well has about 168 barrels of freeze protection material.
None of the leaked material had reached the Arctic tundra, Beaudo said.
“We decided in an abundance of caution to shut down and reconfigure the integrity of 12 operating North Slope wells,” he said. “We have no reason to believe that continued operation poses a risk to workers or the environment.”
Ten of the wells were in Prudhoe Bay, one was at Milne Point and another was at Northstar.
All but one of the wells was shut down by Tuesday. Beaudo said the remaining gas injector well at Northstar was somewhat more complicated to shut down and could take a couple of days.
Beaudo said BP had become aware recently that concerns were increasing about freeze material making its way into well cellars.
“We were made aware of anonymous concerns about spills to well cellars, as well as nonspecific safety concerns around working these wells,” Beaudo said.
He said the anonymous concerns were attributed to workers and a regulator.
The company will invite regulators from the Alaska Oil and Gas Conservation Commission and the Alaska Department of Conservation to observe the integrity tests, Beaudo said.
The commission is a state regulatory agency.
Messages left Tuesday night for Commissioner Cathy Foerster and DEC spokeswoman Linda Giguere were not immediately returned.
BP also will appoint an independent ombudsman to receive future concerns about BP operations, he said. That person should be in place in the next 60 days.