Óxido de Grafeno funcionalizado com JEFFAMINE® com potencial de aplicação em nanofluidos para recuperação avançada de petróleo.

Abstract

The exploration of mature oil fields to guarantee maximum extraction, reducing the need to open new wells, is an alternative for the efficient use of this energy source, with mitigation of the inherent environmental and social impacts. Within this context, this work presents the synthesis, characterization and stability study of dispersions based on graphene oxide (GO) functionalized with JEFFAMINE® with potential application in nanofluids for advanced oil recovery. The functionalization of graphene oxide was carried out using two types of polyetheramine (JEFFAMINE® M-1000 and M-600) by different synthetic routes - microwave reactor and mechanical mixing - in addition to 3 percentages of JEFFAMINE in relation to the total mass (85%; 92% and 96%). Based on spectroscopic analysis (FTIR), thermal analysis (TG/dTG), morphological analysis (MET) and elemental analysis (CHNO), all the samples were functionalized. The type of synthetic route did not considerably affect the results, and a greater amount of JEFFAMINE® led to greater functionalization when using JEFFAMINE® M-600. Among all the samples, the greatest functionalization occurred with the use of 96% of M-600, which had a nitrogen content of 2.1% by mass. The stability study of the aqueous dispersions was carried out using particle size measurements by dynamic light scattering (DLS) and zeta potential. The best dispersions were of the GO samples aminated with M-1000, and the use of only 85% amine resulted in a functionalization equivalent to the proportion of 96%. Therefore, the dispersions made with GO functionalized with JEFFAMINE® M-1000 at 85% via microwave reactor, which had a Zeta potential of -36 mV and an average hydrodynamic diameter of 662 ± 80 nm, and via mechanical mixing with a Zeta potential of -41 mV and an average hydrodynamic diameter of 348 ± 14 nm, were used for the nanofluid application tests. To produce the nanofluids, nanomaterial concentrations of 0.00, 0.25, 0.50 and 1.00%, and ionic strengths μ = 0.0 and μ = 0.3 were used. The viscosity was calculated using a shear rate of 7.34 s-1 and a temperature of 70 °C, like that of a reservoir. At zero ionic strength all the nanofluids showed gains in viscosity compared to the reference nanofluid (without nanomaterial), while at ionic strength μ = 0.3, only the nanofluids with the highest concentration of aminated GO (1.00%) showed a gain in viscosity, especially the microwave synthesis, which showed a gain of 15% compared to only 2% for the mechanical mixture, thus demonstrating, in addition to a preferable synthetic route, promising applicability.