Experimental study ofin-situW/O emulsification during the injection of MgSO4and Na2CO3solutions in a glass micromodel

In-situ emulsification of injected brines of various types is gaining increased attention for the purpose of enhanced oil recovery. The present experimental study aims at evaluating the impact of injecting various solutions of Na 2 CO 3 and MgSO 4 at different flow rates resembling those in the reservoir and near wellbore using a glass micromodel with different permeability regions. Emulsification process was visualized through the injection of deionized water and different brines at different flow rates. The experimental results showed that the extent of emulsions produced in the vicinity of the micromodel exit was profoundly higher than those at the entrance of the micromodel. The injection of Na 2 CO 3 brine after deionized water caused the impact of emulsification process more efficiently for attaining higher oil recovery than that for the MgSO 4 brine. For instance, the injection of MgSO 4 solution after water flooding increased oil recovery only up to 1%, while the equivalent figure for Na 2 CO 3 was 28%. It was also found that lower flow rate of injection would cause the displacement front to be broadened since the injected fluid had more time to interact with the oil phase. Finally, lower injection flow rate reduced the viscous force of the displacing fluid which led to lesser occurrence of viscous fingering phenomenon.