Investigations of graphene impact on oil mobility and physicochemical interaction with sandstone surface

Abstract

Enhanced oil recovery (EOR) is the recovery of oil trapped in the reservoir after primary and secondary recovery processes through novel techniques. Viscosity is primarily a major cause of the high proportion of hydrocarbon fluid entrapped. Recently, emergence of nanotechnology has gained attention in oil industry. The major factor hindering the efficiency of nanoparticles is poor transport inside the reservoir due to high adsorption energy to grains surfaces, leading to their retention. Some studies have reported the effectiveness of nanoparticles on oil viscosity. However, report on the use of pristine graphene has been missing along with requisite transportation behaviour on sandstone surface. This work investigates the applicability of graphene in EOR. The effects of graphene concentrations (0.01, 0.05 & 0.1 wt%) on flowability of oil (50 cP and 0.85 cP), and its adsorption energy are reported. Experimentally, viscosity of the more viscous crude oil was reduced by 43–65%. Using molecular simulation, diffusion coefficient estimation indicate improvement in diffusivity of light decane by 112%. Furthermore, the adsorption energy of graphene is surprisingly found to be low (−9.11 kcal/mol). This study concluded that graphene is applicable, the oil sample is Newtonian and viscosity well reduced.