EVALUATING THE IMPACT OF SMART WATER FOR ENHANCED OIL RECOVERY IN A TIGHT RESERVOIR

Tight reservoirs contain a large amount of hydrocarbon resources, but producing oil from them is often difficult because of their very low permeability and complex pore structure. Conventional water flooding is commonly used to maintain reservoir pressure and displace oil; however, in tight formations it usually results in low oil recovery due to restricted fluid flow and strong capillary forces. Because of this limitation, there is growing interest in improved water flooding techniques such as smart water injection. This study evaluates the impact of smart water injection on oil recovery in a tight sandstone reservoir using numerical reservoir simulation. A synthetic reservoir model representing a typical tight sandstone formation in the Niger Delta was developed using the Computer Modelling Group (CMG) GEM simulator. Two injection scenarios were considered under the same reservoir conditions: conventional high-salinity water flooding and low-salinity smart water flooding. The smart water case involved reducing the salinity of the injected brine in order to examine its effect on oil displacement and reservoir performance. The performance of both injection strategies was analyzed by comparing cumulative oil production, oil recovery factor, water cut, and reservoir pressure over a production period of 45 years. The simulation results show that smart water injection produced a slightly higher oil recovery compared to conventional high-salinity flooding and also delayed the increase in water cut. However, the overall improvement in recovery was relatively small because fluid movement and ion transport are limited in tight sandstone formations. The results suggest that although smart water injection can improve oil recovery to some extent in tight reservoirs, its effectiveness may be limited when used alone. Combining smart water flooding with other enhanced oil recovery methods may provide better production performance in tight formations.