Preparation and Evaluation of Salt‐Resistant Hydrophobic Association Polyacrylamide for Fracturing

Abstract Developing a polymer thickener suitable for high temperature and high salt formation environments, which are often faced during the fracturing process, is of considerable importance. In this study, a hydrophobic association P(AM‐AA‐SSS‐DMAAC 16 ) copolymer thickener was synthesized through aqueous polymerization using acrylic acid, acrylamide, sodium p‐styrene sulfonate, and 2,2′‐azobis[2‐methylpropionamidine] Dihydrochloride as monomers. The P(AM‐AA‐SSS‐DMAAC 16 ) copolymer exhibited an intrinsic viscosity of 1244.0 mL g −1 and a critical association concentration of 0.32 wt%. The salt resistance test demonstrated that the P(AM‐AA‐SSS‐DMAAC 16 ) copolymer could maintain a favorable apparent viscosity in NaCl and CaCl 2 solution and exhibited exceptional resistance to salt. Furthermore, gel fracturing fluid with a mass fraction of 0.4 wt% P(AM‐AA‐SSS‐DMAAC 16 ) polymer was prepared. At 170 s −1 and 120 °C, the viscosity of fracturing fluid remained above 60 mPa·s. Additionally, after alternating shear rates (170 and 1024 s −1 ) for 12 min, the shear recovery rate of the fracturing fluid reached as high as 94.7%. The residual viscosity after gel breaking is less than 5 mPa·s. According to our research, this fracturing fluid has good application prospects in high‐salt conditions.