LAUSR

Abstract Polymer flooding technology has become a common flooding technology in medium-high permeability reservoirs. With the gradual development of high salinity reservoirs, higher requirements for the salt resistance of polymers have been put forward. Herein, a novel binary copolymer amphiphilic polymer (PAMA) with salt thickening property was synthesized by free radical polymerization without soap. The synthetic parameters of polymer were optimized by using apparent viscosity as evaluation index which were as follows: the monomer molar ratio of AM:MALPS was 97:3, and the concentration of initiator and total monomer was 0.02% and 25% respectively, polymerization temperature of 45 °C, and the reaction time of 4.5 h. The PAMA was characterized by FT-IR and 1HNMR. Meanwhile, the salt thickening mechanism was analyzed combining with the apparent viscosity and microscopic structure. Finally, the injection performance of PAMA was explored with the core flooding experiment, and the feasibility of PAMA in high salinity reservoir was evaluated. The results showed that the increase of hydrodynamic radius and enhancement of hydrophobic association made PAMA had the property of salt thickening. The core flooding test also showed that PAMA had salt thickening behavior and anti-scouring capacity in porous medium in high salt reservoirs. The microscopic displacement experiments showed that PAMA could enhanced the oil recovery by displacing the “blind end” residual oil and the residual oil in pore intersection.