Perpustakaan Digital ITB

With the increase of Indonesia’s mature oil and gas fields and no significant oil and gas reserves found, efforts to maintain the declining rate in production will be challenging. Nevertheless, by 2030 the goal of 1 MMBOPD and 12 BSCFD oil and gas production need to be accomplished, not to mention the net-zero emission target in 2060 should also be attained. Therefore, CO2 EOR is the most appropriate EOR method to improve oil recovery and simultaneously mitigate CO2 emissions into the atmosphere. However, the CO2 gas injection has a weakness where the sweep efficiency is low in a consequence of gravity segregation, viscous fingering, and channeling phenomena. The injection method of CO2 Water Alternating Gas (WAG) could be applied to overcome this. The CO2 WAG injection could reduce gas mobility and improve sweeping efficiency. A comprehensive study should be carried out before implementing CO2 EOR, including the reservoir simulation. This paper presents a reservoir simulation of CO2 WAG injection in X field using a compositional simulation model, the ECLIPSE 300 simulator. Based on the Minimum Miscibility Pressure (MMP) value, the CO2 injection occurs in immiscible conditions. CO2 WAG injection could enhance oil recovery with the incremental oil production of 4.7 MMSTB and store 537,131 MT CO2. The optimum cycle time and rate ratio of CO2 WAG injection are one year and 1:2, respectively.