Initially, oil reservoirs have enough energy to produce o in most fields. As time passes and oil production continues, the production rate is reduced and become mostly un-economical. At this time, it is inevitable to supply energy through some Enhanced Oil Recovery) EOR) methods. These methods include water injection, gas injection, foam injection, etc. The use of gas is one of the most common and cost-effective EOR processes for extracting the remaining oil. The gas injection process with gravity enhancement. ) GAGD) might be more suitable for fractured reservoirs. In this paper, the simulation of the GAGD process in an Iranian oil fractured reservoir was carried out using commercial software. The gas injection rate, well injection & production type, and method of injection were also considered. In this process, well perforation and location were also optimized. Based on this study, the highest recovery was obtained with the implementation of GAGAD in comparison to conventional gas injection.