Bitumen is a solid or semi-solid high-viscosity liquid petroleum product at room temperature. The hot bitumen line discussed in this paper was uniquely designed to transport product at temperatures typically ranging from 140 to 149 degrees Celsius (284-300°F), preventing the application of an anti-corrosion external coating, which is ineffective at such temperatures. In this case, polyurethane foam insulation was used and an integrated moisture detection surveillance system for external moisture infiltration was installed for the long-term integrity of the bitumen line.
Inline inspections are used to identify external corrosion where insulation degradation may occur. Due to the unique properties of the pipeline in the study, the conventional method to assess the risk of external corrosion required further consideration. This paper will provide an example of how the conventional method of assessing external corrosion risk was modified to better suit a buried insulated pipeline through a series of additional environmental data inputs, validated with ILI results, to improve the predictive capability of the inferential external corrosion threat model.
Suncor is an integrated oil, gas exploration, and production company that operates over 1000 km (622 miles) of pipeline in Canada and approximately 386 miles (621 km) of pipeline in US. Suncor also operates refineries in Alberta, Ontario, Quebec (Canada) and in Colorado (USA). Additionally, the company owns a network of more than 1,800 Petro-CanadaTM retail and wholesale locations across Canada.
Bitumen is the basic product that is extracted from Suncor oil sands by mining or in situ (Steam-Assisted Gravity Drainage process, SAGD). Once the bitumen has been extracted, Suncor upgrade it into higher-value synthetic crude oil, diesel fuel and other products. The finished products are delivered to the designated location through the company's own pipelines per market demand.
The product (bitumen) becomes a solid or semi-solid high viscosity liquid phase when the temperature drops to 25 degrees Celsius (77°F). It must be heated or diluted to lower the viscosity to be easily pumped. Suncor's hot bitumen pipeline operates between 140 to 149 degrees Celsius (284 – 300°F). Currently, Suncor operates three (3) hot bitumen pipelines with a combined length of approximately 180km (112 miles). Due to the high operating temperature, traditional buried anti-corrosion coatings are ineffective. The insulation, together with the integrated detection surveillance system for external moisture infiltration, are the alternative technologies that were used for the long-term integrity of this type of high temperature line. This paper discusses one Suncor hot bitumen pipeline.
