Perpustakaan Digital ITB

Waterflooding has always been implemented as a secondary recovery method after primary depletion since 1865 and until now, it is still widely adopted all over the world due to its simplicity, reliability, and economical efficiency. Waterflooding helps increase oil production rate and oil recovery by increasing the reservoir pressure and maintain it to its initial level. Recent studies in the last ten years have found that water chemistry plays an important role in improving oil recovery with waterflood due to the interaction between brine, oil, and reservoir rock. Low salinity water injection is an emerging Enhanced Oil Recovery (EOR) method that has been proven to yield substantial improvement in oil recovery compared to conventional waterflooding, particularly in oil-wet reservoirs. Previous studies have found that implementing low salinity water injection could improve oil recovery by 8-12% (Lager et al., 2008). Therefore, low salinity water could be a promising EOR method especially in recovering oil from brown oil fields or as a secondary recovery method as it is simple to be implemented. In this study, optimum combination of salt concentration and injection rate of the low salinity injection water will be determined. The salinity of the injection water that will be used in the sensitivity analysis are 1,800 ppm and 3,600 ppm. After the most optimum combination of salt concentration and injection rate is acquired, the combination will be used for the optimization process. The optimization process is performed by utilizing existing wells in the field and also by drilling additional injection wells if needed. This analysis is conducted in ?T? Structure at ?S? Field model by using numerical simulator tNavigatorTM simulator. The field initially has two producers and one injector, but later other producer and injectors will be introduced. The production will be forecasted from November 2019, but the injection will be implemented from January 2020 to January 2030. The result of this study verifies preceding researches about LSWI, where oil recovery tends to increase when the salinity of injected water is lowered. To optimize the current implementation of LSWI with T-4 injection well by using the combination of salinity and injection rate determined from sensitivity analysis, a new injection and production scheme is proposed. The simulation result shows that converting a previously plugged-and-abandoned well T-2 and shut-in producer T-3 into injection wells along with the addition of production well T-5 gives the best result with recovery factor of 73.29%. This optimization scheme is deemed to be the most optimum scenario as it could achieve similar result as drilling a new injection well.