Mehdi Amiri - South Zagross Oil and Gas Production Company / ICOFC / NIOC, Shiraz, Iran
Jamshid Moghadasi - Department of Petroleum Engineering, Petroleum University of Technology, Ahwaz, Iran
Mahmood Nasiri - South Zagross Oil and Gas Production Company / ICOFC / NIOC, Shiraz, Iran

Enhanced oil recovery methods are used to recover the percents of oil which are not naturally recoverable from reservoirs. Water injection as asecondary recovery is used to maintain the pressure in water-drive reservoirs. An important point for having a successful injection is the compatibility ofinjection and formation waters. OLI ScaleChem software predicts mineral scaling potentials of 54 solids for virtually any oil and gaswell and processing facility in the world. There areseveral advantages over other commercially availablescaling software: 1) By including all brines in the calculations, the well and processing facility are modeled more accurately; 2) Scaling potential and scale buildup are reported at each calculation point;3) Automatic correction of pH and charge balance, therefore the chance of unexpected problems from bad water analyses decreases. Also, more effectivetreatment can be made; 4) Accurately predict the behavior of any mixture of chemicals in water and mixed solvent.This paper presents the predicting of Iron carbonatescale tendency of formation water, injection water and mixing of injection water with formation water at different temperatures. The experimentally measured chemical analyses of formation water and injection water were used by OLI ScaleChem software todetermine the tendency of Iron carbonate scale formation.