Oil prices moved higher in trading dominated by technical factors. The December contract for West Texas Intermediate, the benchmark grade of U.S. crude oil, rose 36 cents to close at $18.93 per 42-gallon barrel on the New York Mercantile Exchange. Volume was moderate in volatile trading that saw the crude oil contract move between a low of $18.51 and a high of $19.18. Refined oil products also rose. Wholesale unleaded gasoline was up 0.27 cent at 49.46 cents a gallon, and wholesale heating oil advanced 0.53 cent to 55.47 cents a gallon.