Synthesis and Properties of Branched Polymer Based on Modified Chitosan for Enhanced Oil Recovery

Abstract

In this study, chitosan and polyamide-amine(PAMAM) were utilized to prepare a branched polymer based on modified chitosan (HPDCS) for enhanced oil recovery(EOR). The structure of the product was confirmed by FT-IR, 1HNMR and SEM. Compared with hydrolyzed polyacrylamide (HPAM), HPDCS exhibited better thickening properties and shear resistance due to its special branched structure and the flexible molecular chains can be deformed through the pore throat of the porous medium, which can avoid serious damage to the molecular chains. After a 45-hour reaction period with biological enzyme, the apparent viscosity of the HPDCS solution decreased significantly, and the viscosity retention rate was only 67.7%, indicating that the introduction of chitosan in the polymer could improve the biodegradability of polymers to a certain extent. Based on sandpacked tube displacement experiments, the HPDCS could build high resistance factor and residual resistance factor in the corresponding porous medium which indicated that the HPDCS performed excellent mobility control ability. Besides, compared with HPAM, the HPDCS solution of 2000 mg/L showed better oil recovery of 24.12% in the corresponding porous medium, which demonstrated that the branched polymer has a more outstanding EOR ability.