Technological improvements could help avert the severe corrosion and leaks that forced the partial shutdown of the US' largest oil field, experts say, but the best way to prevent such problems in pipelines is to simply take better care of them.
BP PLC, which operates the Prudhoe Bay oil field, has said it made a mistake by not more closely inspecting the interior of the 29-year-old pipeline. Before its inspections last month, the company had last run a high-tech tool called a "smart pig" on the western side of the field in 1998. Spokesman Ronnie Chappell on Saturday said it had never previously done so on the eastern side where a leak was discovered a week ago.
"They didn't do a good job of corrosion prevention. That's a big, big embarrassing problem with enormous implications not only for them but also for customers and other oil companies that use the line," said Lois Epstein, senior engineer with Cook Inletkeeper, a conservation advocacy group.
One side of the Prudhoe Bay oil field will be shut down while BP replaces 26km of the pipeline because of the leaks and corrosion, officials said. The pipelines normally carry 400,000 barrels of oil daily, or about 8 percent of US domestic output. With the partial shutdown, the field is currently producing about 150,000 barrels of oil daily.
An oil spill discovered at the same time as the corrosion is three times as large as originally estimated, BP said on Saturday. About 2,840 liters of oil have been recovered, and the cleanup was nearing completion, Chappell said.
Experts say some technological advances could make it easier to maintain existing pipelines and ensure that new pipelines, such as a proposed US$25 billion natural gas pipeline that would run from Alaska into Canada, last longer.
For example, technology for smart pigs and maintenance machines called cleaning pigs -- both of which are pushed through pipelines by the pressure of the oil or gas they carry -- has improved significantly in the decades since the pipeline was built, said Rick Kuprewicz, a pipeline expert with Accufacts Inc.
The ability of steel mills to produce higher quality pipe has also improved.
But those improvements will only help if companies inspect and clean the pipes, and are vigilant about checking for corrosion. Not doing that, Kuprewicz said, is like buying a new car and never changing the oil.
"Pipe can wear out too if you don't pay attention to it, but in most cases its age is many hundreds of years. But, again, you gotta respect it," he said.
He finds it extremely unusual that BP thought it would be OK to go without regular smart pig checks.
Epstein blames government regulators for not forcing the industry to do better. To avoid future problems, she said, federal and state regulators need to adopt stricter oversight.
"The industry will often say a well-designed and maintained and operated pipeline can last a very long time, and to a large extent I agree with that. But, of course, it needs to be well-maintained and operated," she said.
Chappell said the company has a substantial corrosion detection program at Prudhoe Bay. He noted it had regularly used other methods including ultrasound to test the condition of the pipelines, and at the time thought such inspections were sufficient.
"I think it's clear in retrospect that the program as it related to these transit lines wasn't sufficient, wasn't adequate" he said.