This report evaluated the claim made that dilbit is more corrosive than other crudes. This evaluation was benchmarked against conventional and/or sour crude, and was based on the existing literature on crude and dilbit properties and characteristics, data on pipeline integrity and results of engineering assays of pipe that has been transporting dilbit, with such outcomes supplemented by interviews of industry engineering experts from operators with pipelines transporting dilbit.
It was found that the literature on this topic concludes that “the characteristics of dilbit are not unique and are comparable to conventional crude oils.” The relative measure of similarity developed in this project did not indicate that crude oil derived from diluted bitumen is significantly more corrosive than any other oil, and that the dilbit oils likely have corrosivities close to the heavy sour conventional oils. In addition to this relative outcome, the experience of operators transporting dilbit does not indicate it behaves differently from typical crudes. That view can be supported with images of the inside of such pipelines, which appear no different after many years of service than those shipping conventional crude and data reported to PHMSA that no releases from pipelines transporting Canadian crudes and caused by internal corrosion occurred from 2002 to early 2011.