Experimental investigation of nanofluid injection assisted microwave radiation for enhanced heavy oil recovery in a micromodel system

Microwave (MW) absorption ability of Fe 3 O 4 nanoparticles was increased by attaching NiO nanomaterials to them through a co-precipitation approach. The surface of the synthesized nanohybrids was hydrophilized using three different natural agents to disperse in water. The synthesized nanohybrids were characterized by several analyses. The colloidal stability, magnetic behavior and the effect of surface modification agent on the MW absorption ability of the synthesized nanohybrids were investigated. The ability of surface-modified nanohybrids to increase the oil recovery factor was studied by injecting them into a 2D glass micromodel as the porous medium. The results showed that CA is the best modification agent with high colloidal stability strong MW absorption and the lowest effect on the reduction of magnetic saturation of uncoated nanohybrids. Citric acid decreased the saturation magnetization from 55.43 emu/gr at the uncoated state to 52.82 emu/gr at the modified state. The oil sample with more polar compounds such as asphaltene could be further heated and its viscosity further reduced in an EM heating process. By adding 0.1 wt% of the Fe 3 O 4 -NiO nanohybrids, the viscosity of sample (S1) was reduced by 266 mPa·s more than the MW radiation state alone. The findings indicate that MW radiation can significantly increase the heavy oil recovery factor. Water injection had only 16.6% oil recovery; however, this value increased to 41.5% by radiating 400 watts MW This increase will be further enhanced by adding modified Fe 3 O 4 -NiO nanohybrids to water. The Fe 3 O 4 -NiO @ CA, Fe 3 O 4 -NiO @ APTES, and Fe 3 O 4 -NiO @ PEG had 69%, 63.5%, and 58.3% oil recovery, respectively. Finally, it was found that the surface modified nanohybrids could change the wettability of the porous medium from oil-wet to water-wet. After coating the glass with the Fe 3 O 4 -NiO @ CA nanofluid, the oil contact angle decreased from 140° to 17°.