Nigeria has a maximum production capacity of 3 million barrels per day. In 2006, Nigeria averaged approximately 2.45 million barrels per day of production.
2008 Statistics from EIA show America producing somewhere around 5,100,000 barrels a day.
http://tonto.eia.doe.gov/dnav/pet/pet_crd_crpdn_adc_mbblpd_m.htm