Synthesis and performance evaluation of hydrophobic association polymer by asymmetric double-tail chain hydrophobic associating monomer for fracturing fluids

To address the challenges of conventional polymer fracturing fluids in hydraulic fracturing, including poor temperature-salt resistance, incomplete gel-breaking, and high production costs, this study designed and synthesized a novel hydrophobically associating polymer (AHAP). The molecular structure of the synthesized product was confirmed through FTIR analysis and ¹H-NMR characterization. Systematic investigations were conducted on the water solubility, thickening capacity, and temperature-salt tolerance of AHAP polymers. The self-assembly behavior of polymer chains was studied using the molecular dynamics simulation method, revealing the interaction mechanism between polymer chains at the molecular level. Under high-temperature and high-salinity conditions, AHAP demonstrated markedly superior viscosity retention compared to HPAM. Rheological analysis showed that increasing polymer concentration delayed the crossover point of storage modulus (G') and loss modulus (G'') in stress sweep tests while advancing it in frequency sweep tests, indicating excellent viscoelastic properties and proppant-carrying capacity.