Citing figures from Platts, the company said refining margins were lower versus a year ago in every region it has significant operations. Conoco said the utilization rate at its U.S. refineries was in the mid-90 percent range in the second quarter. That's a significant increase from about 80 percent in the first quarter, when many refiners slowed production because of growing gasoline stockpiles and lower prices. ConocoPhillips has a refinery in Ponca City.