By WESLEY LOY
Anchorage Daily News
May 11, 2006
The shutdown follows the March 2 closure of a major Prudhoe Bay oil field pipeline that sprang a leak and spilled an estimated 201,000 gallons, or 4,790 barrels, of oil onto the tundra. Corrosion was blamed for eating a hole through the inner pipe wall, leading to the largest oil spill ever on the Slope.
The leak, which has drawn scrutiny from federal pipeline regulators, members of Congress and criminal investigators, prompted BP to conduct a flurry of extra inspections in the vast pipeline web across the North Slope oil fields.
However, those inspections were not what led to discovery of corrosion problems in the two additional pipelines BP is shutting down, said Maureen Johnson, a BP senior vice president.
Rather, it was BP's regular, long-term corrosion monitoring along the two pipes, each of which has well-documented corrosion problems and had deteriorated despite aggressive and expensive chemical treatments that add a protective coating to the steel pipe inner walls, Johnson said.
One of the damaged pipelines is in the Lisburne oil field, which BP runs on behalf of itself and other owners including Exxon Mobil and Conoco Phillips. The line is 24 inches in diameter, is nearly five miles long and carries 20,000 barrels of oil per day, said BP spokesman Daren Beaudo.
The other pipe is in BP's Milne Point field and is 14 inches in diameter, nearly 3 1/2 miles long and carries 2,000 barrels of oil a day, he said.
Neither pipe leaked any oil, and that's the goal of the company's corrosion monitoring program, Johnson said.
But corrosion in one segment of the Lisburne line is extensive and was getting worse, despite increased use of chemical treatments costing $2.5 million a year, she said.
"It's highly likely that the ultimate solution will be replacing the line. There's enough damage," Johnson said.
The Lisburne and Milne Point pipelines carry oil from wells toward processing plants that remove water and natural gas that come out of the ground mixed with the crude.
They're likely to be closed down for some weeks, idling wells and interrupting the flow of oil worth $1.5 million a day at Monday's closing West Coast price of $68.17 a barrel.
The oil outage represents a small fraction of total North Slope production of about 825,000 barrels a day.
BP plans to test the lines to see if they can be safely operated pending permanent repair or replacement decisions, Johnson said.
The pipeline leak discovered March 2 in the giant Prudhoe Bay field, which BP also operates, involved a 34-inch pipeline and a production loss of up to 100,000 barrels of oil per day.
That pipeline remains shut down, but BP is using a bypass pipeline to restore 85,000 barrels of the lost production, Johnson said.
Federal pipeline regulators gave BP an order to test and fix the Prudhoe line, as well as two other major North Slope pipes, before restarting it.
The Lisburne and Milne Point
lines BP is closing were not among the lines cited in the federal
order, Johnson said.
Scripps Howard News Service, http://www.shns.com
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