Fuel oil imports into the U.S. Gulf Coast surged in September to the highest level in a quarter century, reflecting the impact of sanctions constraining Venezuelan and Russian crude exports and forcing refiners to improvise with alternative feedstocks. Ship-tracking data from Kpler cited by Reuters show the Gulf Coast imported about 541,000 barrels per day of fuel oil last month, the strongest inflow since 2000. Refiners configured for heavy sour crudes are increasingly relying on residual fuel oil to keep coking units supplied. At the same time,…