A study by an Alberta provincial government agency has concluded that diluted bitumen (also known in the industry as “dilbit”) is little different in its effects on pipelines than conventional or ‘non-oil sands derived’ crude oil.
A review of existing studies was conducted by Jenny Been, P.Eng for the provincial agency, Alberta Innovates – Technology Futures. A news release on the website describes Been as a “corrosion specialist.” The study “concludes that the characteristics of dilbit are not unique and are comparable to conventional crude oils during pipeline flow.”
Link News release and study (pdf)
Comparison of the Corrosivity of Dilbit and Conventional Crude
Been’s study takes on the contention that dilbit has higher acid, sulfur, and chloride salts and higher concentrations of abrasive solids than conventional crude. As well, the study looks at the belief that dilbit transmission pipelines operate at higher operating temperatures compared with crude, which would make the dilbit more corrosive. Environmentalists and other critics say this leads to a higher failure rate than pipelines carrying crude.
The study compared the properties of heavy, medium, and light conventional Alberta crude oils with three dilbit and one dilsynbit (a mixture of conventional gas diluent and synthetic gas) crude.
The review concludes “that the characteristics of dilbit are not unique and are comparable to conventional crude oils.”
While two of the four dilbit crudes displayed a slightly higher naphthenic acid and sulfur concentration than the conventional Alberta heavy crudes, the review notes that there are conventional crudes on the market that have displayed higher values. It says while there have been corrosion problems at refineries where the temperature can exceed 200 C, it says “the much lower pipeline transportation temperatures, the compounds are too stable to be corrosive and some may even decrease the corrosion rate.”
The study also says “sediment levels of the dilbit crudes were comparable to or lower than the conventional crudes, except for a dilsynbit crude, which showed more than double the quantity of solids than most other crudes, but was still well below the limit set by regulatory agencies and industry….Erosion corrosion was found to be improbable and erosion, if present, is expected to be gradual and observed by regular mitigation practices.”
The study’s recommendations note that it is a review and “It has to be understood that this was a high-level review and a focused, peer-reviewed study has not been conducted. The scope of the work did not include interviews with industry, regulators, or colleagues.”
It calls for the industry to create a database that would further study that differences between dilbit oils and conventional crude oils, including further study of sludge formation and deposition in the pipeline and the links, if any, “on sludge chemistry to pipeline sludge formation and sludge corrosivity, including the ability of the sludge to support microbial populations.”
Been says in the study that Enbridge supports an industry working group on pipeline corrosion management that is “addressing these issues by correlating sludge corrosivity with a chemical and microbial geochemical characterization of the sludge. The work is further considering and optimizing monitoring technologies to enable measurement of the effectiveness of mitigation treatments. It is recommended that this effort will continue to be supported.”
While the study is a review of existing knowledge on diluted bitumen and conventional oil in pipelines, Been’s introductory remarks clearly show a bias in favour of the bitumen sands, saying, before the Keystone XL project approval was delayed by the U.S. State Department, “TransCanada Pipeline’s (TCPL’s) $13 billion Keystone pipeline system will provide a secure and growing supply of Canadian crude oil to the largest refining markets in the Unites States.”
Been also notes
Environmental groups opposed to the pipelines continue to find material to fuel their concerns: the more than 800,000 gallons of oil spilled into the Kalamazoo River in Michigan last year came from the Cold Lake oil sands region, and the Exxon Mobil spill of 42,000 barrels of oil in the Yellowstone River may have contained dilbit. Protestors against the Keystone pipeline are gathering in demonstrations across North America leading to mass arrests and drawing widespread attention.
The arguments of these environmental groups don’t go unheard with congressmen and other government officials, who have iterated reported statements and concerns. The United States Department of States (DOS) has spent the last three years in review with the industry, scientific community, and other interest parties (including numerous public meetings), evaluating the purpose and need for the Project (pipeline), alternatives, and the associated potential environmental impacts. The result was issued on August 26, 2011 in a Final Environmental Impact Statement (FEIS), a comprehensive, detailed volume of work that is available to the public. Public hearings were held and online comments were accepted.
Been notes that as part of the Keystone assessment, the US Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) issued 57
Project-specific Special Conditions above and beyond the requirements of the United States pipeline code for Keystone XL. Been says TransCanada agreed to the incorporation of the 57 conditions and said would result in a pipeline with a greater degree of safety than typical domestic pipelines.
Environmental groups said the 57 conditions on Keystone were not sufficient, Been noted and the report goes on to say:
Alberta Energy Minister Ron Liepert considers it a challenge of combating emotion with facts, and assures that the facts could be obtained without too much difficulty. Concerns continue to surface in the media and in the face of few factual studies and a strong confidence in … tracking statistics that dilbit is not more corrosive than conventional oil, corrosivity claims continue to be used as fuel by certain environmental groups.
Yet if Enbridge and other energy companies are still working on pipeline corrosion, as Been notes, then there are still problems to be solved.
Given the pro-Keystone statements in the Been’s paper, it is clear that a definitive, independent study is needed on the effects of diluted bitumen in a pipeline, one that doesn’t come from either a pro-energy industry point of view, nor one conducted by an environmental group that would bring criticism from the energy industry.
Until there is such an independent study, the doubts of the environmental activists must be balanced with assurances coming from the energy industry.