Western Canada Select (WCS), a benchmark for oil from Alberta's oil sands, has plunged in December, falling to just $30 per barrel at the end of this past week. WCS typically trades at a discount to WTI, reflecting the differences in quality from lighter forms of oil, as well as the extra transportation costs to move oil hundreds of miles out of Alberta.
But a discount is usually something like $10 per barrel, not more than $25. A price deterioration of this magnitude has not been seen in years.
There are several reasons why the WCS price has deteriorated.
First, the spill and shutdown of TransCanada's Keystone pipeline in November slowed the flow of oil from Canada to the U.S. as the company was forced to make repairs. That led to a minor spike in WTI as supply tightened a bit in the U.S., but upstream in Canada it put downward pressure on WCS amid a glut of supply. Canadian oil was diverted into storage as the pipeline underwent repairs, and the backup pushed prices down.