The Globe and Mail reports in its Thursday, Sept. 20, edition that a maintenance shutdown at the refinery that is the largest buyer of Canadian heavy oil in the United States is expected to extend and possibly worsen the price discounts on crude from north of the border. A Canadian Press dispatch to The Globe reports that AltaCorp Capital analysts say the planned turnaround at the 430,000-barrel-a-day BP Whiting refinery in Indiana will reduce demand over the next 45 days. They say the shutdown adds to a heavy schedule of refinery maintenance in the U.S. Midwest, with about 829,000 b/d of capacity expected to be unavailable through October, higher than 560,000 b/d in the same period of 2017 and 300,000 b/d the year before. The difference between benchmark oil sands blend Western Canadian select and New York-traded West Texas intermediate (WTI) has widened to five-year highs of more than $30 (U.S.) a barrel in the past week, closing on Tuesday at $31.50 (U.S.) a barrel. That is more than double the typical discount and also reflects continuing export pipeline constraints. Separately, Haywood Securities points out that Canadian light oil is also facing higher-than-usual discounts to WTI.