A little history on WCS Western Canadian Select
Western Canadian Select (WCS) is a specific crude oil product used as a benchmark for most Western Canadian crude oil blends. WCS is a heavy sour blend of bitumen blended with synthetic sweet crude and condensate. WCS is mainly produced by Cenovus Energy, Canadian Natural Resources, Suncor Energy, and Repsol. These four companies created the WCS stream in 2004. WCS is primarily traded in the Husky oil terminal in Hardisty, Alberta.
WCS often trades with a sizable discount to WTI. This discount is partly because of the higher cost of refining heavy oil compared to light oil and sour crude compared to sweet crude. But a more significant portion of this discount is because of limited transportation capacity from northern Alberta to oil markets.