Rheological Behaviour of Graphene Nano-sheets in Hydrogenated Oil-based Drilling Fluid

An experimental investigation has been carried out to investigate the rheological effect of hydrogenated oil-based drilling fluid when dispersed with graphene nano-sheets. The rheological aspects that were investigated were viscosity and shear stress of the fluid respectively. The weight concentration of graphene sheets carried out in this experimental investigation were 25 ppm, 50 ppm and 100 ppm respectively. Graphene nano-sheets were dispersed via hydrodynamic cavitation dispersion and ultrasonic bath for three (3) hours each. From the analysis, the graphene-oil based drilling fluid exhibit higher viscosity as compared to the hydrogenated oil-based drilling fluid over the shear rate range of 0 – 140 s-1. Interestingly, the graphene-oil based fluid is a Bingham fluid but behaves similar to a Newtonian fluid as it possesses zero shear stress. Temperature dependence of the studied nanofluid was carried out at 30̊C, 40̊C and 50̊C respectively to observe the relationship between the additions of nanoparticles into the hydrogenated oil-based drilling fluid as compared to the base fluid. Two rheological models (Bingham model and Power Law model) were fitted to predict the behavior of graphene-oil based drilling fluid with respect to temperature and shear rate.