Influence of non-covalently functionalized graphene nanoplatelets on viscosity and wettability for improved oil mobility at reservoir conditions

Noncovalent functionalized graphene nanoplatelets (GNPs) were successfully prepared with Gum Arabic as exfoliation solvent via an ultrasonication-assisted process to produce a highly dispersed material under high salinity and high temperature conditions. The implementation of the functionalization groups was validated with Fourier transform infrared spectroscopy and Transmission Electron Microscopy. The functionalized graphene nanoplatelets with Gum Arabic were dispersed in 3 wt.% high salinity brine with various concentrations to prepare Gum Arabic-GNP/brine nanofluids. The dynamic viscosity of the produced nanofluid at different concentrations was higher than that of crude oil at a high temperature (90 degrees C) and a high shear rate (1000 L/s). The functionalized graphene with Gum Arabic altered the wettability of sandstone from oil to water and changed the contact angle from 108 degrees to 21 degrees at 0.1 wt.%. Moreover, the value of contact angle reduced to 87% with presence 0.1 wt.% of GA-GNPs. These results are demonstrating that the GA-GNPs nanofluids could improve the mobility of the residual oil from the porous media to the production well with high efficiency of oil displacement.