This report is currently available at http://crrc.unh.edu/sites/crrc.unh.ed/file/1633_dilbit_technical_report_e_v2_final-s.pdf
Federal Government Technical Report
Properties, Composition and Marine Spill Behaviour, Fate and
Transport of Two Diluted Bitumen Products from the Canadian
Oil Sands
Environment Canada
Emergencies Science and Technology
Fisheries and Oceans Canada
Centre for Offshore Oil, G
as and Energy Research
Natural Resources Canada
Canmet ENERGY
November 30, 2013
Executive Summary
Effective spill response depends on good scientific understanding of petroleum product behaviour in the environment (e.g., movement and changes in physical properties and chemical composition of the oil). This study reports the early research simulating diluted bitumen products spilled at sea. This work was undertaken by the Government of Canada as part of the first phase of a strategy to implement a world class prevention, preparedness and response regime for oil spills from ships.
The behaviour of the diluted bitumen products was studied under laboratory conditions in three phases. First, the properties and composition of two samples representative of products currently being shipped in Canada were measured before (fresh) and after (weathered) exposure to environmental conditions. Secondly, the potential for evaporation, exposure to light, mixing with saltwater, and sediments in the salt water to affect whether diluted bitumen products float or sink
in saltwater was examined. Finally, the effectiveness of two existing spill treating agents meant to disperse spilled oil products was evaluated.
This work is a collaborative effort between the Emergencies Science and Technology
Section, Environment Canada; the Centre for Offshore Oil, Gas and Energy Research, Fisheries and Oceans Canada ; and Canmet ENERGY, Natural Resources Canada. As well as the laboratory and wave-tank experiments, a literature review was conducted to identify knowledge gaps on the physical and chemical properties of conventional and non-conventional heavy oils, and their fate and behaviour in marine environments. The use and effectiveness of oil spill treating agents is
also reviewed for heavy oils. Two diluted bitumen products, Access Western Blend (AWB) and Cold Lake Blend (CLB), were selected for study as the highest-volume products transported by pipeline in Canada for 2012–2013. The physical characteristics and chemical composition of each product were m easured to aid in potential spill preparation and response.
The major results of the studies were:
- Like conventional crude oil, both diluted bitumen products floated on saltwater (free of sediment), even after evaporation and exposure to light and mixing with water
- When fine sediments were suspended in the saltwater, high-energy wave action mixed the sediments with the diluted bitumen, causing the mixture to sink or be dispersed as floating tarballs; The use of the term “tarball” in this report follows convention in the literature and refers to the consistency of floating, heavily-weathered oil. It does not describe the chemical composition of the product.
Internal copy of this report:1633_dilbit_technical_report_e_v2_final-s