Synthesis and properties of hydrophobically associating polymer fracturing fluid

The double tailed hydrophobic monomer PMB-16 was synthesized by the reaction of phenylethylamine,1-bromohexadecane and methacryloyl chloride. The ternary hydrophobic association polymer (PADM) was synthesized by free radical copolymerization of PMB-16 with acrylamide (AM) and methacryloyloxyethyl trimethylammonium chloride (DMC). The optimum synthesis conditions were as follows, the mass ratio of m (AM):m (DMC):m (PMB-16) was 80:19.6:0.4, the total monomer concentration was 35.0 wt%, the amount of initiator (V50) was 0.1 wt% of the total mass of monomer, the reaction temperature was 55 °C, the reaction time was 6.0 h, the system pH was 7, and the amount of metal ion chelating agent (EDTA-4Na) was 0.01 wt% of the total mass of monomer. The results of performance evaluation showed that PADM aqueous solution had excellent temperature and salt resistance. Using zirconium acetylacetonate as crosslinking agent, the mass crosslinking ratio of PADM solution to zirconium acetylacetonate was 100:0.9, the crosslinking temperature was 60 °C, and the pH value was 6.0. The system presented good thickening, temperature resistance, shear stability and low residue content, so it was a low damage fracturing fluid.