| As one of the most important method for enhanced oil recovery, polymer flooding could displace the residual oil after water flooding, which is beneficial to stable production of reservoirs. While, the partially hydrolyzed polyacrylamide (HPAM), commonly used for EOR, is apt to hydrolyze or crimp in high temperature and high salinity circumstance, which would bring remarkable viscosity reducing and low oil displacement efficiency.A series of rigidity picolinamide monomer as N,N-diallylisonicotinamide (DAIA), N, N-diallylpicolinamide (DAPA), N-allylisonicotinamide (CAIA), N-allylnicotinamide (CANA) and N-allylpicolinamide (CAPA) were synthesized in this paper. And then these monomers were polymerized with acrylamide (AM) and acrylic acid (AA) to obtain a series of polymers such as AM/AA/CAPA、AM/AA/CANA、AM/AA/CAIA、AM/AA/DAPA and AM/AA/DAIA, which contained different picolinamide structural units, respectively.The optimum synthesis conditions had been determined by single factor experiments. After that, all of the polymers were characterized by IR,1HNMR, intrinsic viscosity and scanning electron microscope (SEM). The microstructures of polymers solution showed that the synthesized polymers present denser microscopic nets compared to HPAM, which is beneficial to stabilized polymers solution performance. The performance evaluation indicated that the synthesized polymers, which contained picolinamide structural units, represent better temperature-, salt- and shearing-resistance than HPAM. Furthermore, copolymer (AM/AA/CAIA) that presents much better performance (the retention rate of the apparent viscosity could be reached up to 52.54% at 120 ℃ and 11.53% at 1000 s-1,27.29%,20.83% and 16.21% under 12000 ppm NaCl,1500 ppm MgCl2 and 1500 ppm CaCl2, respectively) than other synthesized polymers.The optimal performance copolymer AM/AA/CAIA was used to conduct indoor simulation flooding experiments after performance evaluation experiments. More than 17.58% and 15.01% oil recovery could be enhanced in a permeability of 1019 mD and 382 mD in 5000 ppm NaCl at 60 ℃ by 2000 mg/L AM/AA/CAIA. |
