The Chronicles of Dilbit, Part 1

This post is part of a series. For Part 2, click here

What do we know about dilbit? Since coming on the scene, the mixture of tar sands crude and a lighter substance such as natural gas condensate has been a matter of much speculation. How does it behave in pipelines? Does it float in water or sink?

Now, Canadian oil producers are saying that diluted bitumen (dilbit) has gotten a bad name. They are seeking clean up its image with an industry-funded report claiming that the tar sand mixture is no more dangerous to pipelines than some conventional crude oil.

The report, entitled “Dilbit Corrosivity,” was prepared by UK’s Penspen Group for the Canadian Energy Pipeline Association (CEPA). It seeks to debunk arguments like those made at the hearings on the Enbridge Northern Gateway Pipeline, that dilbit’s high viscosity, acidity, and level of sediments could cause corrosion that would leave the areas around pipelines more vulnerable to spills. It argues that, because dilbit is no more corrosive than other forms of heavy crude, no special plans need to be made to prevent spills.

“Some of the literature is ill-informed and wrong: both Dilbit and Synbit in a crude oil transmission pipeline environment is no more corrosive than comparable heavy sour crudes and in many cases may be less corrosive,” it reads.

“Consequently, there are no significant additional implications for corrosion control in a pipeline carrying Dilbit and Synbit as part of pipeline integrity management over and above what is already standard practice.”

Anthony Swift, an attorney with the National Resource Defense Council (NRDC) disagrees with this characterization. He argues that Penspen’s findings are not new and describes the CEPA report as a “rehash of a number of flawed government and industry studies intended to promote tar sands.”

He points to a 2011 NRDC report that states, “There are many indications that DilBit is significantly more corrosive to pipeline systems than conventional crude. For example, the Alberta pipeline system has had approximately sixteen times as many spills due to internal corrosion as the U.S. system. Yet, the safety and spill response standards used by the United States to regulate pipeline transport of bitumen are designed for conventional oil.”

Speaking over the phone from DC, Swift says the CEPA report’s first mistake is to compare dilbit to heavy crude. He believes it would be far more beneficial to compare dilbit to West Texas Intermediate, a lighter crude that is considered the benchmark for crudes in North America and “represents the types of crudes that have historically moved on the North American pipeline system.”

Swift also takes issue with CEPA’s claim that the typical temperature of a pipeline carrying dilbit is 17 to 40 °C and that the Keystone XL pipeline will operate at 26 to 48 °C. He says that public documents on TransCanada’s application for the Keystone 1 had a top range of 70 °C and those for the Keystone XL pipeline had an average operating temperature of 60 °C.

This is a crucial issue because dilbit tends to be more viscous than conventional crude oil and that viscosity can lead to higher pipeline temperatures. Those higher operating temperatures have been linked to rises in both internal and external pipeline corrosion of the kind the National Transportation Safety Board (NTSB) found after 2010 the Kalamazoo River spill.

It should be noted that CEPA is the group responsible for a 2011 letter to the Harper government outlining some of its preferred changes to environmental regulation, which Greenpeace obtained to last year via an Access to Information request.

Sandra Burns, CEPA’s manager of communications, later authored a blog post in the Huffington Post arguing that their lobbying strategies were well within reason and that bills C38 and C45, which included many of their suggested changes, would reduce the number of studies on “activities that were benign or whose effects were well understood and mitigated through standard practices.”

The new report seems to argue that CEPA considers transportation of dilbit through pipelines one of those benign practices.  It concludes that “corrosion mechanisms in pipelines are well understood and are the subject of continuous investigation both in the field and laboratory to fine tune that understanding.”

Should regulators take their word for it? Swift says absolutely not. He says that the NTSB, “have attributed several major pipeline accidents in the States to federal safety regulators delegating too much of their oversight to the pipeline operators they're supposed to be regulating.”

He believes that too often the trend is to seek an explanation for a spill after it has happened rather than preventing it through careful research.

“It's sort of the difference between a safety net and a coroner,” he explains. “More often than not we're seeing regulators diagnose the cause of death in a pipeline spill rather than engaging to ensure one doesn't happen to begin with.”

Image Credit: Dilbit spill in Kalamazoo River from Michigan Department of Environmental Quality.

As a freelance writer, Erika Thorkelson is dedicated to showcasing compelling stories that illuminate our world and how we live.…

Tailings dam failures linked to hefty bonuses for mine managers: report

Generous bonuses for mine managers, rewarding them for cutting costs or increasing production, are linked to tailings dam failures, a new research paper has found....

Continue Reading

Recent Posts