Preference of nanoporous graphene to Single-Walled Carbon Nanotube (SWCNT) for preparing silica nanohybrid Pickering emulsion for potential Chemical Enhanced Oil Recovery (C-EOR)

We prepared nanoporous graphene/silica nanohybrid and demonstrated its better Pickering emulsion properties for Chemical Enhanced Oil Recovery in comparison to the similar silica nanohybrid with a single-walled carbon nanotube. The samples were characterized with X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Thermal Gravimetry Analysis (TGA). Emulsion phase morphology was investigated with optical microscopic image. Evaluation results demonstrated that the best samples are 70% nanoporous graphene/Si02 (both methods) and 70% SWCNT/Si02 nanohybrid (Method 1). Contact angle measurement results showed that 70% nanoporous graphene/Si02 nanohybrid (Method 2) is more effective in the improvement of the stone reservoir wettability alteration from oil-wet to water-wet. Interfacial tension results indicate that the maximum amount is related to the injection of water, and the minimum amount is related to the injection of nanofluid of 70% nanoporous graphene/Si02 nanohybrid (Method 2). This result indicates the preference of 70% nanoporous graphene/Si02 nanohybrid (Method 2) for decreasing the interfacial tension in comparison to the other samples.