By Liz Hampton and Erwin Seba HOUSTON, Aug 30 (Reuters) - Hurricane Ida pummeled U.S. Gulf Coast energy suppliers, knocking out most of the region's offshore wells, nearly half its motor fuel production and closing energy-export ports. Production losses - including at six Gulf Coast refineries - will lift retail gasoline prices by 5 to 10 cents a gallon, tracking firm GasBuddy said. The closures included Louisiana Offshore Oil Port (LOOP), the largest privately-owned crude export and import terminal in the United States.