BP starts Alaskan oil spill cleanup, may take weeks

NEW YORK/ANCHORAGE, Alaska (Reuters) - BP Plc on Tuesday began cleaning up an oil spill from a leaky Alaskan pipeline, but said it has not determined what caused the leak or how much material spilled onto the snow-covered tundra.

The leak is the latest setback for the British oil giant. A major Alaskan spill in early 2006 revealed pipeline corrosion issues at BP-controlled Prudhoe Bay, the largest U.S. oilfield complex, which the company has sought to fix.

“We are implementing the spill cleanup plan,” said BP spokesman Daren Beaudo in Anchorage.

BP started removing oil mist from a road adjacent to the 18-inch (45-cm) diameter leaky pipeline, but response crews have not been able to reach the main spill area yet, Beaudo said.

The line, which was idle when a leak was discovered by workers on Sunday, serves the 31,000 barrel per day Lisburne field at Prudhoe Bay, whose total production tops 400,000 bpd. Impact on production was “minimal,” BP said.

It may take days or weeks to remove the oil and determine whether BP’s leak caused environmental damage, an Alaskan official said.

“It’s going to take a while, but they will clean it down to the tundra when they’re done. That’ll be a few days to a couple of weeks,” said Dale Gardner, an Alaska Department of Environmental Conservation official.

“They won’t know until they clear everything away how far it penetrated and whether the tundra is affected or not.”

BP has not determined what caused the pipeline leak or how much material leaked, Beaudo said. A situation report said the affected area covered 8,400 square feet (780 square meters).

An ice plug was recently found in the pipeline, which prompted BP to shut the line a few weeks ago, Gardner told Reuters. It wasn’t clear whether the ice plug contributed to the spill, Gardner added.

BP still faces legal problems due to Alaskan pipeline spills in 2006 and subsequent partial shutdown of Prudhoe Bay production. The company remains under a three-year probationary period under terms of a federal criminal settlement reached in late 2007.

The current leak affected a so-called three-phase flow line, which carries oil, natural gas, and water produced along with hydrocarbons. Water-bearing lines can be susceptible to corrosion or freezing, one pipeline expert said.

The spilled material is about 70 percent water, and has probably melted through the snow layer to the tundra, Gardner said. The ground is frozen, “so penetration is not likely,” he said.

Seepage into waterways or the Beaufort Sea nearby is unlikely since a road acts as a barrier between the spill site and waterways, Gardner said.

Cleanup is difficult because of extreme cold, sparse daylight and pipeline safety precautions. Since the line remains partially pressurized, a 10-foot (3-meter) safety barrier has been placed near the pipeline, preventing cleanup workers from getting too close, Gardner said.

BP shares advanced 2.1 percent Tuesday on the London Stock Exchange.

Editing by David Gregorio