On the Surfactant Flooding to Heavy Oil Reservoirs Influenced by Flow Barriers - An Experimental Study Using 2D Micromode

Here, an experimental study was conducted to examine the effect of discontinuous shales on performance of surfactant flooding by introducing heterogeneities to represent streaks of shale in five-spot glass micromodels. Results show that, oil recovery in presence of shale streak is lower than in its absence. Presence of flow barriers cause premature breakthrough of injected fluids and unstable displacement front. As well, displacement efficiency of surfactant flooding is dependent strongly on the shale distribution configuration. Increasing shale content causes reduction of ultimate oil recovery and also severe fingering during water flooding while it compensates during surfactant flooding considerably. In shaly patterns, in the case of surfactant flooding, the oil recovery after breakthrough increases significantly, while it changes much less for the case of water flooding as well as flooding in homogeneous model. Oil recovery efficiency and breakthrough time improved with increasing surfactant concentration. However, beyond a specific limit of Sodium Dodecyl Sulfate concentration, around 2000 ppm, incremental oil recovery becomes insignificant. Presence of connate water in surfactant flooding scheme can improve recovery efficiency in shaly patterns. Results of this work can be helpful to investigate the optimal location of injection/production wells during EOR schemes in shaly reservoirs using five-spot micromodels.