Ali Mohsenatabar Firozjaii - Master Student of Petroleum Engineering, Department of Petroleum Engineering, Petroleum University of Technology(PUT), Abadan, Iran.
Siyamak Moradi - Assistance Professor of Petroleum Engineering, Department of Petroleum Engineering, Petroleum University of Technology(PUT), Abadan, Iran

Enhanced oil recovery (EOR) methods are employed for increasing oil recovery after natural production of the reservoir. Each EOR process has limitation for applying in reservoirs due to rock and fluid condition. In water alternating gas (WAG) flooding, many parameters such as reservoir thickness, horizontal permeability, connate water saturation effect on oil recovery factor. In this study, main parameters that effect on WAG oil recovery are discussed. The CMG-GEM simulator is used for simulation study and Minitab statistical experimental design software is used for stochastic analysis. The results show reservoir thickness and connate water saturation have great effect on recovery where the value of these parameters are at minimum level; recovery factor has maximum value. On the other hand, the interaction of two parameters reservoir dip angle and horizontal permeability has main effect on oil recovery factor.

EOR, Water Alternative Gas, WAG, CMG, GEM, Optimization