Oil pipelines transport crude oil from producing fields to refineries, where it is turned into a range of petroleum products. These pipelines, referred to in the industry as ‘liquids’ pipelines, are also used to transport petroleum products from refineries to terminals and distribution centres before they are routed to consumers.
Liquids transmission lines may carry different types of crude oil, natural gas liquids and refined products. These different commodities travel through the pipe in batches that can be many kilometres long. Because every batch in a pipeline is traveling at the same speed, it is not necessary to separate them. Simple hydraulics prevent batches from mixing. If batches come in contact with each other, these small volumes are reprocessed.
Powerful electric motors drive the centrifugal pumps on most Canadian crude oil pipelines, although diesel engines are used in a few remote locations. Oil travels through the pipes at four to eight kilometres per hour.