Canadian heavy oil is the weakest in almost five years, leading Canada’s largest producer to focus on drilling for lighter crude. Western Canadian Select’s discount to benchmark West Texas Intermediate widened 20 cents to $31 a barrel Friday, the biggest gap since December 2013, data compiled by Bloomberg show. Prices have tumbled amid constraints on pipeline and rail capacity out of Western Canada and as the U.S. Midwest’s biggest refinery prepares for maintenance later this month on its largest crude distillation unit. Canadian Natural Resources Ltd. announced Thursday it was curtailing heavy oil drilling and shifting capital to the production of lighter oil. The company drilled 39 primary heavy wells in the second quarter versus 63 originally planned, executives said in its second-quarter earnings call. While it plans to cut back heavy oil exploration further in the second […]