Efficiency of nano-water/gas alternating injection technique to enhance oil recovery in an oil field

The effects of the nanoparticles on the wettability, relative permeability curves, and IFT during nanoparticle-treated water or nano-water alternating gas approach (NWAG) were investigated through modelling the fluid/rock interactions in coreflooding experiments. Moreover, the performance of the proposed approach as an EOR method in field scale was evaluated. In this novel approach, nanoparticles sit on the surface of the reservoir rock and improve the wettability. Additionally, those nanoparticles located at the oil/water interface reduce the interfacial tension. Our results showed that applying nano-water instead of water during WAG process shifts the wettability of the system toward more water-wet conditions which enhances the oil recovery. It is found that a six-month long NWAG cycle with five months of nano-water and one month CO₂ injection in 2:1 NWAG ratio with dual five-spot well pattern improves the oil recovery by 13% compared to the conventional WAG method. [Received: January 22, 2016; Accepted: August 13, 2016]