Two University of Saskatchewan geologists are calling for better monitoring after a recent report by Husky Energy on the oil spill in July.
The company’s report concluded the cause of the July 21 pipeline oil spill was “a sudden, one-time event in a section of the pipe that had buckled due to the force of ground movement.”
Dr. Grant Ferguson is an associate professor with the department of civil, geological and environmental engineering. He said riverbank slopes are almost never stable.
“I don’t think it’s unexpected that we would have slope stability issues on the riverbanks,” Ferguson told reporters Friday.
According to Ferguson, wetter weather in Saskatchewan over recent years caused the water table to rise, leading to more geotechnical instability. Blaming the instability on heavy industry or fracking, he said, was a “bit of a stretch.”
“There’s all kinds of things that we can pin to fracking,” Ferguson said. “I don’t know if we need to pile on with this issue. Those slopes are sensitive to failure.”
Ferguson said a lot has changed since the pipeline was installed in 1997, and the geotechnical analytic methods used may not be viable today.
“Going forward, maybe this is a good excuse to get more instrumentation and think about how we study these things,” he said.
According to Ferguson, there is no single answer to prevent all future pipeline failures.
“There’s nothing without risk,” he said. “I guess it’s up to our governments, us as a society and these companies to decide what levels of risk we’re comfortable with.”
Dr. Brian Pratt, faculty member of geological sciences since 1989, said Husky can learn valuable lessons from the reports.
“I don’t think this could have been predicted, actually,” Pratt said. “But I think the lesson is to have a more active monitoring program.”
Pratt said strain monitors and inclinometers can be installed on pipelines to provide better feedback on geotechnical stresses, and suggested using thicker pipe in areas susceptible to shifting.
In addition, Pratt said Husky could consider its own meteorological monitoring program to warn of changes in the water table.
According to Husky’s report, planned shutdown activities were taking place on the pipeline network during the failure.
“Under such circumstances it is common for the leak detection system to register anomalies,” the report stated.
Pratt emphasized the importance of following up on all detected anomalies, as any drop in pressure could indicate a potential leak.
Husky said they will review and consolidate their leak detection procedures, and add a “defined time period for diagnostic analysis before proceeding to a mandatory shutdown.”
Pratt said despite the spill, he believes pipelines are “absolutely” the safest method of transporting oil.
“Most of the people I know who are against them have never actually seen one being laid,” he said.
In a written statement to paNOW, Husky spokesperson Mel Duvall said the energy producer will reassess geotechnical risks at all its pipelines, but how often reassessment is performed will depend on the specific location.
Duvall said Husky administrators will be discussing plans to repair the broken pipeline with regulators, and will incorporate the lessons learned from the spill to improve system integrity.
Although the reports seem to absolve the company of blame, Duvall said Husky continues to take full responsibility for the incident.
“We have worked closely with all communities and First Nations to make this right,” Duvall said. “Our commitment to that principle remains unchanged.”