The discount on Canadian heavy crude versus the West Texas Intermediate (WTI) benchmark widened slightly on Wednesday.
Western Canada Select (WCS) heavy blend crude for August delivery in Hardisty, Alberta, settled at $21.65 a barrel below WTI, according to NE2 Group, widening 40 cents from Tuesday.
Heavy crude differentials have widened in recent months due to the release of sour crude from the U.S. Strategic Petroleum Reserve and higher natural gas prices that make refining heavy crude more expensive.
Light synthetic crude from the oil sands for August delivery settled at $14.50 a barrel over WTI, unchanged from the previous session.