Effect of polymer-graphene-quantum-dot solution on enhanced oil recovery performance

This study aimed to utilize graphene-quantum-dots in addition to a D118 superpusher polymer to increase oil recovery from mature oil fields. First, nanoparticles (NPs) were synthesized and fully characterized. These were then added to polymer solutions so the prepared fluids could alter the microscopic and macroscopic sweep efficiencies. To identify the best samples, concentrations of the NPs and polymer, as well as two types of salt, were carefully selected as influencing parameters using Design Expert as a time- and cost-saving technique. Interfacial tension (IFT) and contact angle-parameters affecting microscopic efficiency-as well as shear viscosity, which affects macroscopic efficiency, were considered as responses in this method. IFT reduction (of approximately 1.78 mN/m) and an extraordinary change in the wettability to hydrophilic were achieved, particularly in carbonate rocks as opposed to sandstone. In addition, the polymer resulted in improved mobility ratio. From the experiment and analysis of variance, two flooding fluids that increase the recovery factors for carbonate and sandstone core samples by up to 31% and 20%, respectively, are proposed. Furthermore, core flooding experiments confirmed the effectiveness of the proposed fluids for enhanced oil recovery. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study focused on utilizing graphene-quantum-dots and a superpusher polymer to enhance oil recovery from mature oil fields. By synthesizing nanoparticles and combining them with polymer solutions, the sweep efficiency of the fluids was improved. Experimental results showed reduced interfacial tension and altered wettability in carbonate rocks, as well as improved mobility ratio with the polymer. Two flooding fluids were proposed based on the experiment, increasing the recovery factors for carbonate and sandstone core samples.