Using mixtures of metal oxides nano-particles suspended in water to form an injectable nano-fluid (rather than single nano-fluid) has been investigated. The use of mixtures nano-fluids proved its ability as an EOR agent and its advantages over single nano-fluids. This paper investigates the different parameters that affect the oil recovery when using nano-fluids mixtures to suggest an optimum scenario for applying this technique.

Four sandstone cores were used in the experiments. The first core was used to test effect of the dispersing fluid salinity on the oil recovery. A core was flooded three successive times, each time till oil production stopped completely, with the same mixture of nano-particles but dispersed in different brine concentration. It was concluded that dispersing fluid salinity has negligible effect on ultimate oil recovery.

The usage of nano-fluid injection after water flooding was tested on the second core. The core was water flooded with one pore volume followed by nano-fluid injection. The results of the experiments show the possible successful formation of an oil bank and sustaining oil production when nano-fluid mixture is used after waterflooding.

The third core was used to check the possibility of using a nano-fluid slug instead of continuous injection due to its economical advantage. The experiments proved the viability from recovery point of view and the advantages from an economic point of view of using slugs of nano-fluid mixtures rather than continuous injection of nano-fluids.

Finally, combining between low salinity technique and nano-fluid injection was tested in the fourth core. The experimental results show that combining low salinity and nano-fluid mixtures injection (in different slugs) can add additional reserves.

You can access this article if you purchase or spend a download.