Sinking oil – The science of diluted bitumen in lake water

Faculty of Science
Biology
Aerial view of the campus and rideau canal
The tendency of oil to float on water has inspired numerous proverbs and philosophical quotes in numerous cultures around the world.

In the case of certain crude oils, its physical property to float on water is not as simple as it sounds. With the looming threat of climate change, and the quest to decarbonize our economy, the world is rapidly trying to find alternatives to aid with the transition of energy sources. However, we still rely on crude oil and petrochemicals, which can pose a threat to aquatic environments when they are transported by ship, rail, or through pipelines. Although oil refineries go to great lengths to mitigate oil spills in the environment, there is always an inherent risk of oil spills. So why would scientists intentionally spill oil into a lake? Sawyer Stoyanovich, a PhD student working with Dr. Jules Blais, conducted a controlled oil spill experiment to determine the fate and behavior of diluted bitumen (dilbit), a formulation of crude oil that is widely transported through Canada, in one of the largest controlled experimental oil spill projects that was ever carried out in Canada or anywhere else. The “Boreal Oil Release Experiment by Additions to Limnocorrals” (BOREAL) team intentionally spilled different volumes of dilbit (the form of crude oil transported from the Alberta Oil Sands), into lake enclosures in Northwestern Ontario to simulate oil spills in lake water. In a recent study published in the Science of the Total Environment, Sawyer reported that dilbit sinks. The study found that some spilled oil can weather while remaining suspended in water, and when the lighter volatile constituents in oil evaporate away, the residual oils, some of which contain the ingredients of asphalt in our roads, can sink like a stone. The topic of sinking dilbit is heavily debated when dealing with dilbit spills, and it had never been demonstrated at this scale before in a controlled experiment. Sawyer and his colleagues highlight the possible challenges and complexities associated with the remediation of sunken dilbit and the short response time required to mitigate major damage to the environment.

PhD student Sawyer Stoyanovich
PhD student Sawyer Stoyanovich

These results are extremely timely and important with the future of oil usage a major topic of political debate. Sawyer and his team hope to get all of their results out as soon as possible to provide decision makers with sound evidence to help inform the future of crude oil transportation in Canada and abroad.

Sawyer hopes to find a role in the oil spill prevention industry, working on predictive models that will change the way we respond to oil spills in Canada. He attributes his success to his supervisor Dr. Jules Blais and the BOREAL project team who afforded him the opportunity to work this project.

Sawyer’s advice to new graduate students is to never think of themselves as being under-qualified or lacking certain skills needed to carry out their research. He believes that being a part of a lab offers an amazing support system and there is always somebody in the lab who can help.

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