Anomalous Behavior of Crude Oil during Visbreaking

摘要

The common technical solution to the transportation of heavy oils through pipelines is dilution with natural gas condensate or a similar light hydrocarbon stream. Diluents are not always available so other technologies must be employed to meet pipeline specifications. The National Centre for Upgrading Technology (NCUT) has found that visbreaking technology can reduce the viscosity of Canadian heavy oils and bitumen (>100,000cP) to pipeline specifications (350cP). Conditions have to be controlled, however, to avoid the formation of coke caused by excessive process severity (a function of temperature and residence time). NCUT was asked to assess procedures and processes, which would allow for the transportation of Rubiales crude via pipeline. Following a preliminary study, NCUT suggested that visbreaking of the whole crude or the vacuum resid would be one option worth pursuing in a pilot plant investigation. Subsequently, a pilot plant study was completed on the crude oil. Results of this work will be compared here, with those for Athabasca bitumen under similar process conditions. The study confirms the need to perform experimental work prior to process selection.