Crude oil prices topped $91 a barrel Thursday morning, recovering from a drop prompted by a report on U.S. stockpiles issued Wednesday. The U.S. Energy Information Administration said stockpiles rose to a 22-year high in the latest weekly report. That took oil prices below $90 a barrel on the New York Mercantile Exchange. West Texas Intermediate crude for July delivery staged a slight comeback overnight, adding $1.13 to $91.03 per barrel. Natural gas for June delivery lost 3.6 cents to $2.701 per million British thermal units. Home heating oil added 1.36 cents to $2.8291 per gallon. Gasoline futures were up 0.5 cents to $2.8065 per gallon. At the pump, the national average price of unleaded gasoline fell to $3.676 per gallon from Wednesday\'s $3.678, AAA said.