Tri-cationic viscoelastic surfactant, preparation method and application thereof and clean fracturing fluid

Abstract

A three-poly cationic viscoelastic and a clean fracturing fluid containing the three-poly cationic viscoelastic surfactant are provided. N, N′-dimethyl-1,3-propanediamine and epichlorohydrin are used to prepare an intermediate A, and then the intermediate A and a fatty acid amidopropyl dimethylamine is used to prepare the three-poly cationic viscoelastic surfactant. The preparation process is simple. The clean fracturing fluid including the three-poly cationic viscoelastic surfactant has excellent temperature and shear resistance, strong suspended sand performance, simple on-site preparation, automatic gel breaking, small damage to formation, low cost and simple preparation process. The clean fracturing fluid including the surfactant also has strong temperature resistance, and the viscosity of the product can be maintained at 42 mPa·s after 80 minutes at 180° C. and 170 s−1, which is higher than the viscosity requirement (>25 mPa·s) of the clean fracturing fluid in on-site construction.

Dependencies are inferred from the claim text.