The Islamic State captured the Ajil and Allas oil fields in northern Iraq during the Mosul campaign in 2014, as well as the Qayyarah oil field, producing 8,000 barrels a day of heavy crude oil. Ajil in north of Tikrit and Himiran were important ISIS-controlled oil fields in Iraq. Oil production was centrally controlled by the top leadership. Until his death in May 2015, Abu Sayyaf had been the "emir" or top official for oil production controlling oil production from 200-plus wells.