Silica Janus nanosheets anchored with Ni nanoparticles for in-situ upgrading and stimulus-responsive demulsification to enhance heavy oil recovery

The enhancement of heavy oil recovery and the promotion of oil-water separation are crucial aspects of fossil fuel resource development. In this study, silica Janus nanosheets were prepared and anchored with Ni nanoparticles for in-situ upgrading and stimulus-responsive demulsification of heavy oil. The results of aquathermolysis reactions revealed that Ni/Ph-SiO2-Ni/P4VP Janus nanosheets exhibited excellent characteristics in reducing heavy oil viscosity by 98.49 %, and 99.52 % with the addition of a hydrogen donor. FT-IR, 1H NMR and GC, etc. analysis of the oil samples indicated that Ni/Ph-SiO2-Ni/P4VP breaks the C-S bond and reduces the content of the resin, asphaltene, polycyclic aromatics, and long chain alkanes in the oil. Moreover, it can stabilize heavy oil emulsions in an acidic medium (pH = 2) and separate oil and water in a neutral medium (pH = 7) due to its stimulus-responsive performance. This work highlights the potential application of Ni/Ph-SiO2-Ni/P4VP Janus nanosheets for the in situ upgrading and stimulus-responsive demulsification of heavy oil.