Shell, Murphy evacuating non-essential workers from U.S. Gulf due to storm

HOUSTON (Reuters) - Royal Dutch Shell Plc and Murphy Oil Corp began evacuating non-essential workers from the U.S. Gulf of Mexico on Thursday because of the threat from Tropical Storm Cristobal.Shell said its production and drilling operations in the U.S.-regulated northern Gulf were unaffected despite the evacuations.Gulf Coast spot gasoline prices remained steady, traders said. Gulf CBOB gasoline traded on Thursday at 12.50 cents per gallon below the futures benchmark , little changed from..