WATCHING GOVERNMENT: Assessing oil pipeline risks

Aug. 21, 2006
It quickly grew obvious that US regulators would expand their crude oil pipeline oversight after BP PLC announced 2 weeks ago that it had to shut down part of its Alaska North Slope system because of internal corrosion.

It quickly grew obvious that US regulators would expand their crude oil pipeline oversight after BP PLC announced 2 weeks ago that it had to shut down part of its Alaska North Slope system because of internal corrosion. Much less apparent was the debate that had raged for several weeks already over a US Pipeline and Hazardous Materials Safety Administration proposed rulemaking.

At issue is the extent to which the Department of Transportation agency should regulate currently exempt low-volume, low-pressure oil lines. PHMSA began to consider this soon after another part of BP’s ANS pipeline network sprung a leak in early March. It held a meeting with stakeholders in Washington, DC, in June.

“I think the situation [at Prudhoe Bay] has changed the ballgame,” said Carl Weimer, executive director of the Pipeline Safety Trust in Bellingham, Wash. “My understanding is that PHMSA wants to close part of the loophole. We want to close all of it.” He told me that his group would like to see the exemption removed and all US oil pipelines federally regulated, with stricter rules for areas where a spill would have a high impact.

Industry approach

Industry groups advocate a more careful approach. The American Petroleum Institute and the Association of Oil Pipe Lines have recommended that a new regulation be limited to sites with 0.25 mile of unusually sensitive areas and to smaller-diameter and lower-pressure lines.

API and AOPL also would like to see leak-detection measures appropriate to each pipeline, employee training for abnormal operating events, well-marked routes, more programs to reduce the chance of excavation damage, and prompt reporting of incidents. “We’re trying to preserve the notion that regulation should be risk-based,” AOPL Executive Director Benjamin S. Cooper told me. He expects PHMSA’s proposed rulemaking to be “a proposal to maintain these lines on an integrity management basis because their failures are usually caused by corrosion.”

Seeking alternatives

Corrosion engineers seek other ways to stop pipeline problems, according to Drew Hevle, a senior corrosion engineer with Enbridge Energy Co. Inc., Houston.

“We’re continually developing new standards. One of them is another method of integrity assessment for liquid pipelines, which would be effective where pigging or pressure-testing is not practical. On a low-pressure line, for instance, there’s often not enough force to push a pig through,” he said.

One alternative might be direct assessment, which would identify areas where corrosion is most likely and examine them by cutting the pipeline open or using ultrasonic inspection or x-rays. If there is no corrosion, pipeline operators might be reasonably confident that there is none in lower-risk areas, Hevle said. “Integrity management regulation uses cost-benefit analysis. The compromise in 2000 was to base it on potential impacts on population. The incidents at Prudhoe Bay apparently were a case where the risk was high from a business point of view,” he said.