Tar Sands Oil May Increase Risk of Pipeline Spills

84,000 gallons of crude oil are glugging their way across an Arkansas community right now, putting the spotlight on the transport of tar sands oil across the United States. While Exxon is claiming it’s just “heavy” oil, the naming is a matter of semantics, because the oil comes straight from Canada’s infamous tar sands. It’s not the only recent spill involving oil from this region; in 2010, 877,000 gallons of oil were released in Michigan, for example. With more tar sands oil being transported, the frequency of such spills is only going to increase, and worse, there are signs that tar sands oil is more prone to spills than its conventional counterpart.

To understand why this is, it helps to understand a little bit of the chemistry behind tar sands oil. It’s made by extracting bitumen, an extremely thick petroleum product that’s about the consistency of peanut butter at room temperature. As you can imagine, forcing peanut butter through an oil pipeline wouldn’t work out very well, so it’s thinned with chemical agents, producing a product called diluted bitumen or dilbit. Even diluted, the oil needs to be transported in a warmed pipeline to ensure it won’t clog, and the pressure of the pipeline needs to be increased to keep it flowing.

Warmer temperatures can increase corrosion rates and stress on joints, while the increased pressure can make a spill more likely in a pipe that’s under stress. This means that the very conditions needed to move dilbit around can increase the risk of a spill. Internal corrosion with dilbit appears to be worse because of its chemical composition, which compounds the problems with moving it around.

Furthermore, pressure changes inside a pipeline carrying dilbit can cause a phenomenon known as column separation, where tiny bubbles of natural gas liquids develop in the fluid. These can mimic a leak on detection systems, and pipeline monitors have trouble telling the difference between true leaks and column separations. Consequently, oil may continue to flow for hours before a leak is detected. The infamous Enbridge spill in Michigan started with a misdiagnosed column separation.

As if all this wasn’t bad enough, dilbit is also harder to clean up once it gets into the environment. It tends to separate into its components,  and conventional oil spill response techniques are typically not adequate for controlling it. Consequently, it leads to much greater damage, and it’s more expensive to clean up. Meanwhile, manufacturers, transporters, contractors and governments wrangle over the economic liability for handling spills.

Already, the United States is working with aging oil pipeline infrastructure that’s vulnerable to leaks even with the prized light sweet crude oil companies prefer. With the push to transport more tar sands oil, the risk of spills is likely to increase, and that poses a serious risk to the environment. It also presents a significant argument to move away from petroleum products and on to renewable resources, and to address the seriously outdated oil infrastructure in the United States to make it safer to move oil around when it does need to be moved.

That includes updating infrastructure to cope with the unique conditions posed by tar sands oil, including developing more sensitive and effective equipment for identifying column separation versus leaks, as well as better inspection equipment that can catch corrosion and internal pipeline damage before pipelines rupture, rather than after. The high environmental costs associated with tar sands oil also need to be weighed in discussions about corporate liability and establishing plans to ensure that governments aren’t left holding the bag when it comes to costly oil cleanups.

This has especially important ramifications for the forthcoming decision on the Keystone XL pipeline; could the dangers of dilbit be the nail in the coffin when it comes to authorizing the highly controversial project?

Related posts:

Oil Spill Will Spell Trouble for Wildlife Long After It’s Repaired

As Administration Decides on Keystone, U.S. Experiences Two Tar Sands Spills

The Foul Legacy of the Tar Sands: Lakes Turned Into Cancer Sites

Photo credit: chesapeakeclimate


Carrie-Anne Brown

interesting article, thanks for sharing

Debbie Crowe
Debbie Crowe5 years ago

Pipelines scare the dickens out of me!

Katherine Wright
Katherine Wright5 years ago

Well duh.............................

Neil A.
Neil A5 years ago

Total lunancy for the average taxpayer & disasterous for the environement! if Obama does not stop it he is just gutless.

Nancy S.
Nancy S.5 years ago

Do you realize that paper towels such as Brawny and others are made by companies owned by the Koch Brothers. Who also own acouple of refineries in Texas and lets not forget their pastic pipe company. Guess who is going to make the money off of tar sands??? Guess who is paying for it???

Linda McKellar
Past Member 5 years ago

The wonderful and caring Harper government is now going to let some people write letters to the government expressing their views on the east/west pipeline. How magnanamous! First, one must apply for a permit to write, which also explains how the procedure will work. The application makes it clear that not all letters of comment will be accepted. A board will review your application to participate and notify you if you are allowed to file a "letter of comment". The pipeline must DIRECTLY affect you as well, whatever that means. How ridiculous...you need to apply for a permit to write to the government. Democracy is alive and well. Thanks Stevie Baby!

Kimberlee W.
Kimberlee W5 years ago

I hate to say this but I think we're going to lose big time on this one.
I think the prudent thing to do now is to fight them on their own safety regulations and keep them in court. That will be expensive, but Al Capone wasn't put away on any other crime than the boring tax ones he broke. This will be boring, engineering shit but I believe if we can continue to prove that they're not taking steps to repair and monitor this pipeline, we can keep them from doing business with it until they commence to spend the damned money and make the inspections and repairs that are so badly, badly needed to do this AT ALL!

The Embridge incident occurred on an area of pipe that wasn't even listed as potentially dangerous. There are incident reports that go back to the early 1970's; potential break-points that haven't been inspected SINCE 1973!!
I moved south of that area last month and started doing the research. Spent 4 1/2 hours reading court minutes of the investigation's aftermath.
Like I said, expensive & boring, but our best chance is to play Whac-a-Mole in the courts with this one. Now we need a judge who isn't in Koch Brothers' pocket.

David King
David King5 years ago

part two

President Obama said during his re-election campaign that he would cut over $4 billion of the subsidies going to Big Oil. On Wednesday, he releases the first budget of his new term, so let's work together to remind the president to follow through on his promise.

Sign our petition today to tell President Obama to end the Big Oil Billion Dollar Bonanza.
(please cut and paste the link to sign the petition)


David King
David King5 years ago

Congress has drafted a budget — three of them in fact. And tomorrow President Obama will release his budget to spend more than 1 trillion of our dollars. We need to ensure he makes good on his campaign promise to cut billions in subsidies to Big Oil.

Not only are these subsidies a drain on our budget, they are helping wreck the planet by ensuring we rely on fossil fuels for our energy needs — when clean, green alternatives are more than capable of powering our lives.

Please sign our petition today asking President Obama to end the Big Oil Billion Dollar Bonanza by cutting these taxpayer-funded subsidies from his budget proposal. Your signature will be delivered directly to the president.

Big Oil doesn't need the money, and we don't have the money to give. The five biggest oil companies on the planet made more than $110 billion in profits last year, while the President and Congress have been forced to make major budget cuts to important programs that protect our people and the planet.

Even worse, these subsidies make all of us investors in the biggest polluters on the planet. Each year the planet is warming faster than the year before, causing more extreme weather events, record heat waves, wildfires, droughts and floods across the planet. Burning more oil will only make the planet get warmer faster, and lead to even worse disasters than Superstorm Sandy.

President Obama said during his re-election campaign that he would cut over $4 billion of the s

Eternal Gardener
Eternal G5 years ago