BANGKOK, Thailand _ Oil fell back Thursday in Asia ahead of a report expected to show U.S. inventories of crude and petroleum products grew last week.Prices remained volatile, though, buffeted about by threats against Nigerian oil facilities, worries about falling gasoline demand in the U.S. and volatility in the dollar.Late afternoon in Singapore, the light, sweet crude contract for July delivery was down 63 cents at US$130.40 a barrel in electronic trade on the New York Mercantile Exchange.The