Preparation and displacement performance of HAPC copolymer suitable for ultra-high saline reservoirs

The modified polyacrylamide (HAPC) based on a benzene ring and an ethoxy chain that can bind metal ions was successfully prepared by micellar polymerization. The structure of HAPC was characterized by Fourier infrared spectroscopy and hydrogen nuclear magnetic spectroscopy. Some properties of the polymer were evaluated, and the temperature resistance, salt resistance, rheological properties, aging resistance and oil displacement physical simulation experiments of HAPC were studied. The experimental results show that the introduction of benzene ring and ethoxy chain greatly improved the salt resistance of the polymer. Among them, the maximum viscosity can be increased by about 5 times in the calcium chloride and magnesium chloride divalent ion solution. When the concentration was 12000 mg/L and the concentration of magnesium chloride was 16000 mg/L, the viscosity retention rate was 63.5% and 90% respectively; The physical simulation experiment of oil displacement shows that HAPC can increase the oil recovery rate by 19.85% at 80 °C and high salt concentration (1.0 × 10 5  mg/L simulated brine).