Under the UAEs constitution, each emirate controls its own Oil production and resource development. Although Abu Dhabi joined OPEC in 1967, Dubai does not consider itself part of OPEC or bound by its quotas. The UAEs current OPEC production quota (effective July 1, 2005) is 2.44 million barrels per day (bbl/d), and its current Crude Oil production as of May 2006 is 2.50 million bbl/d. The UAEs total production capacity is 2.50 million bbl/d, so it does not have any spare capacity at the current level of production. The Abu Dhabi National Oil Company (ADNOC) selected ExxonMobil in April 2005 as a strategic partner in the development of the Upper Zakum field, with a 28 percent ownership stake, after a competitive bidding process. A binding contract between ExxonMobil and ADNOC was finalized in March 2006. ExxonMobil is set to undertake a program of upgrades to the Upper Zakum field to raise its capacity from the current 550,000 bbl/d to 750,000 bbl/d, and introduce enhanced recovery technologies to extend the productive life of the field. The Japan Oil Development Company (JODCO) already holds a 12 percent stake in the field from a previous investment in 1972, when the field was first developed.