Abstract: Through optimization experiments, the optimal experimental condition for nano zirconium boron crosslinker was obtained: based on the amount of 0.5% zirconia emulsion, the amounts of other reagents are 4% borax, 50% glycerin alcohol, 8% acetylacetoneis and 40% triethanolamine, the reaction time is 5 h, and the reaction temperature is 60 ℃. Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM) and high temperature rheometry were used to characterize the properties and structures of the high temperature resistant zirconium boron crosslinker. The results show that at a cross-linking ratio of 0.5%, the nano zirconium boron crosslinker and 0.6% HPG base liquid are formed. The crosslinked jelly is sheared at a constant speed for 2 h under the test conditions of 160 ℃ and 170 s^-1, the elastic modulus is significantly greater than the storage modulus, and the viscosity of the jelly is finally maintained above 130 mPa·s after shearing, showing good temperature and shear resistance.

Key words: Crosslinker, Fracturing fluid, Temperature and shear resistance