A Sensitivity Study on Low Salinity Waterflooding

Barham S. Mahmood1, Jagar Ali2, Shirzad B. Nazhat2, and David Devlin2

1. Department of Petroleum Engineering, Koya University, Kurdistan Region, Iraq

2. Department of Petroleum Engineering, Soran University, Kurdistan Region, Iraq

Abstract: It is widely accepted that different salinity brines injection may increase the oil recovery. However, the mechanisms by which low salinity flooding increases oil recovery are not yet fully understood. This work is to run simulation on ECLIPSE 100 simulator to show the effect of injecting low salinity into a reservoir. A three dimensional synthetic model was created to mimic a real reservoir. The effect of low salinity on oil recovery was observed by conducting sensitivity study on; injecting brine salinity, slug injection of low salinity, and endpoint saturations. A difference of 22% in oil recovery observed when the low salinity water is injected compared to the high salinity water only in the threshold range between 0 kg/m3 to 5 kg/m3.

Performing slug injection can reduce the requirement for low salinity water and recovers approximately the same percentage of oil. This can indeed give better cost saving when opting for low salinity injection.

The brine option in ECLIPSE 100 indicated to be very sensitive to the saturation endpoint and relative permeability. Thus, it is important to be aware of this during simulation of such augmented waterflooding, and input from experimental data is needed for accurate simulations.

Key words: improved oil recovery, low salinity waterflooding, Salinity, Slug injection, wettability