Abstract:A hydrophobically associating polymer HAWP-18 was synthesized by using a functional hydrophobic monomer, acrylamide (AM), acrylic acid (AA) and 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) as raw materials. Properties of shearing resistance, viscoelasticity and thixotropy of hydrophobic associating polymer HAWP-18 was investigated by using rheometer. The results show that HAWP-18 solutions were pseudoplastic fluid and exhibited stronger shearing resistance, and the critical associating concentration of HAWP-18 solution was 2.31g/L. According to the viscoelasticity results, HAWP-18 is a typical viscoelastic structure fluid and has a relatively wide linear viscoelastic region. The value of storage modulus (G') is larger than loss modulus (G''). The higher the viscosity was, the stronger the elastic characteristic of HAWP-18 was. The variation of shear stress with shear rate was also discussed by using steady-state shear test of HAWP-18 with different mass concentrations. It was shown that HAWP-18 had thixotropy property. With the increment of the mass concentration, the thixotropy property enhanced. The drag reduction property of HAWP-18 solutions with different mass concentrations was tested by using homemade friction tester. The drag reduction test showed that the drag reduction rate of HAWP-18 increased at first and decreased latter with the increment of the HAWP-18. The shearing resistance, good viscoelasticity, thixotropy, and drag reduction of HAWP-18 provide experimental support for its application in fracturing fluids.