Stubbornly high crude oil inventories continued to stymie bulls through the middle of the week, but the market seized on positive economic data to push prices higher toward the end of the week. The oil spill from a collapsed rig off the US Gulf coast may also have played a role in firming prices. Analysts said that the spill could have a short-term impact on supply if it interfered with oil deliveries to US Gulf coast refineries, and a longer-term impact if it led to new restrictions on offshore drilling.