Enhanced waterflooding with NiO/SiO2 0-D Janus nanoparticles at low concentration

The nanofluid (nanoparticles dispersed in determined carrier fluid) flooding has been studied for reducing the interfacial tension (IFT), increasing the viscosity of the displacement phase and to alter the rock wettability, which impact the capillary number and hence increase the crude oil recovery. However, this technique requires commonly large concentration of nanoparticles for being efficient in enhanced oil recovery (EOR) processes. Hence, the primary objective of this manuscript is to develop NiO-containing Janus nanoparticles based on zero-dimension (0-D) SiO2 nanoparticles which can be effective at low concentrations. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), surface area (S-BET), zeta potential, interfacial tension (IFT), rheology, contact angle measurements and coreflooding tests. The results showed a sharply increase of the capillary number (Nc) at a very low concentration of 100 mg/L of Janus nanoparticles, mainly attributed to the decrease in the interfacial tension, which can lead to the increase of the oil recovery. Displacement tests using a SiO2 nanoparticles-based nanofluid at a concentration of 100 mg/L did not show an increase in oil recovery regarding the one obtained in the waterflooding step. Meanwhile, the nanofluid based on NiO/SiO2 Janus nanoparticles at the same concentration of 100 mg/L showed an increase in oil recovery up to 50%.