CO2 foam flooding is a type of immiscible process which aided by foam to overcome the weaknesses of wateralternate gas (WAG) flooding. Foam favourable for injectivity and mobility control to prevent viscous fingering and gravity segregation experienced by CO2, thus increasing the sweep efficiency. The purpose of this study is to determine the comparison incremental oil recovery between CO2-foam flooding and WAG by using simulator t-Navigator. A sensitivity analysis of key parameters such as biosurfactant concentration and level of injection interval was performed to optimize a flooding design for a sandstone reservoir in the Alpha field. The base case design which comprised of primary recovery, waterflood as secondary recovery and the tertiary recovery which consists of WAG and CO2-foam flooding was developed based on actual field data. The simulation results indicate that CO2-foam flooding is a potential enhanced oil recovery (EOR) method to be implemented in this field as it capable to give an incremental oil recovery about 71 compared to 62 by WAG. The result of the study on parameters selected indicates that the optimum biosurfactant concentration is 0.3 wt as it delivers the highest oil recovery with the best injection interval occurs at middle region of the reservoir. © 2023 Author(s).