Abstract In view of the poor thermal stability and shear resistance of conventional polyacrylamide under the conditions of high temperature and high salinity class III reservoir, a new type of temperature tolerant and salt resistant polymer was synthesized by using acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as the main monomers and introducing self-made hydrolysis resistant monomers (APS-3). The effects of initiator dosage, pH value and initiation temperature on viscosity-average molecular weight of polymer for oil displacement were studied. The application properties of the synthesized polymer, such as temperature resistance, salt resistance, thermal stability and shear resistance were tested. The results showed that temperature and salt resistant polymer with viscosity-average molecular weight more than 2.0×107 could be synthesized under the condition of initiator 0.40%，pH value 7-9 and temperature 25 ℃. The viscosity retention rate of the polymer was 80.04% after 100 days under the condition of 80 ℃ and salinity of 10×104 mg/L, which meet the demand of polymer flooding in high temperature and high salinity class III reservoir. The product had been applied in six well groups in Zhongyuan oilfield, the comprehensive water cut had been reduced by 2.10% and the recovery had been increased by 2.45%.
