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Weather hits Prudhoe Bay, Alaska pipeline High winds on the North Slope and flooding near the Valdez end of the line pummel system; BP cleaning Prudhoe insulators Dan Joling Associated Press Writer
Both the nation’s largest oil field and the trans-Alaska oil pipeline were shut down Oct. 10 after poor weather at both ends of the 800-mile pipeline caused havoc.
BP said high winds were to blame for a power outage that shut down Prudhoe Bay in northern Alaska. Production fell to about 20,000 barrels Oct. 10; about 350,000 barrels were produced Oct. 9.
Flooding near the terminus of the pipeline, caused by heavy rain in Southcentral Alaska, is suspected of knocking out fiber-optic communication lines along the pipeline, said Mike Heatwole, spokesman for Alyeska Pipeline Service Co.
Operators lost communications to remote valves that can be closed in the event of a spill.
Heatwole said company protocol calls for the pipeline shutdown when valves cannot be closed from long distance. The valves must be staffed by crews that can manually operate the valves, he said.
At Prudhoe Bay, layers of dust and dirt blown by high winds built up on high-voltage insulators on power lines and the field, causing a short just before 3 a.m., said BP spokesman Daren Beaudo. “Several days of high winds followed with rain deposited mud on high-voltage insulators that are part of the Prudhoe Bay electrical power distribution system,” he said.
The mud caused two faults at Prudhoe Bay substations, knocking out power to field about 3 a.m. Oct. 10.
“The whole field came down,” Beaudo said.
The power station continued to operate, he said: “It’s the distribution system that had the problem.”
Winds were blowing about 12 mph at Deadhorse near the time of the outage, said Tom Dang of the National Weather Service. However, they were blowing significantly most of Oct. 9, with peak gusts of about 66 mph midday.
Pipeline communications critical Communications are a critical component for operations of the trans-Alaska pipeline, which carries nearly 17 percent of the nation’s domestic oil supply daily.
“We lost communication with five of our remote gate valves just north of Valdez at about 4 a.m. Alaska time (Oct. 10),” Heatwole said.
The remote valves are important when there is a pipeline leak. They are closed to limit the amount of oil dispatched from sections of the line.
“When we lose communication, we shut the pipeline down,” he said.
Flooding and mudslides along the Richardson Highway, which parallels the pipeline and is the only roadway out of Valdez, disrupted vehicle traffic. The Alaska Department of Transportation closed a 65-mile stretch of the highway, starting near Valdez.
The Weather Service said 6.5 inches of rain fell Oct. 8 and Oct. 9 at Valdez. Flooding in Keystone Canyon near Valdez hit four bridges hard and moved one 5 feet, said DOT spokeswoman Shannon McCarthy.
Instead of driving, Heatwole said, crews would be sent by helicopter to the remote valve sites. By midday Tuesday, crews had reached at least two valves and were in transit to others, he said.
Separate crews will seek the cause of the break in the fiber-optic line, Heatwole said.
The company reported Oct. 10 that the line was restarted at 1:40 p.m. after technicians had reached the valve locations. Alyeska said it would maintain 24-hour coverage at the valve sites until the pipeline is back to normal operations.
Flooding at terminal High water along other roads in Valdez was hampering Alyeska’s ability to staff the Valdez Marine Terminal, where oil is loaded onto tankers. The terminal is across Port Valdez from the city and a road leading to it was affected by flooding.
Alyeska said it would limit the number of personnel required to report to work at the terminal until officials could verify the integrity of a bridge on the road.
Essential employees reported to work at the Valdez harbor and were transported across Port Valdez by boat. Nearly 500 Alyeska employees travel the road to work each day.
Prudhoe out for several days Beaudo told Petroleum News Oct. 11 that BP expects it will be “several days” before production can be gradually returned to normal levels at Prudhoe Bay.
He said substations and high-voltage power lines are being systematically washed to clean the insulators. “Washing insulators on high-voltage systems requires specialized skills and equipment and will be done from the ground and from helicopters,” Beaudo said.
Power loads must be minimized by reducing equipment online until the insulators can be washed, and BP’s priorities for returning power are to support life systems in camps and facilities inhabited by workers, he said.
BP is continuing to produce small volumes of oil, about 40,000 barrels per day, from Prudhoe Bay and “will ramp up production facilities when the equipment is cleaned and the power supply is fully stabilized,” Beaudo said.
—Petroleum News contributed to this story
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