β-Cyclodextrin modified anionic and cationic acrylamide polymers for enhancing oil recovery

Both of acrylamicle and allyl-beta-cyclodextrin are utilized to react with acrylic acid and dimethyl diallyl ammonium chloride respectively to synthesize the novel anionic acrylamide polymer and cationic acrylamide polymer by redox free-radical copolymerization. The structures of copolymers are characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Subsequently, the copolymers are evaluated on several aspects such as optimum polymerization conditions, intrinsic viscosity, interfacial tension and stability experiments. It is found that the anionic and cationic acrylamide polymers containing cyclodextrin moieties show better performances on interfacial tension, salt resistance, temperature tolerance, viscosification property and shear resistance than that of polyacrylamide. By the comprehensive comparison and analysis, the anionic polymer is more conductive to decrease the interfacial tension for the tertiary oil recovery process, while the cationic polymer is more suitable for enhancing oil recovery in high-temperature and high-mineralization oilfield. (C) 2011 Elsevier Ltd. All rights reserved.