The Role of Chemistry of the Oil-Field Water in the Distribution of Reservoir Pressures: A Case Study of Mishrif Reservoir in the Southern Oil-Fields, Iraq

Mishrif Formation is the main reservoir in oil-fields (North Rumaila, South Majnoon, Zubair and West Qurna) which located at Basrah southern Iraq. The Inductively coupled plasma-Mass spectrometer (ICP-MS) was used for water chemistry analysis Scanning Electron Microprobe (SEM) purpose of mineralogy diagnosis. A weak acidic salinity six-time greater than seawater plays a role generating formation pressure controlling fluid flow. potentiometric subsurface maps were modeled direction super-pressure sites that are great importance oil exploration marked to pay attention during future drilling.