The Majnoon field is located in the south-eastern province of Basra, along the Iranian border. It is one of Iraq's largest oil fields with estimated oil-initally-in-place (OIIP) of 38 billion barrels. It holds reserves in multiple reservoirs of predominantly early-to-late Cretaceous age. Around half the volumes are in the carbonate Mishrif reservoir. The secondary reservoir is the Yamama which is deeper, and contains light oil with a higher gas content.