| abstract |
The present invention discloses a tri-cationic viscoelastic surfactant, a preparation method and an application thereof, and clean fracturing fluid. According to the present invention, 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 tri-cationic viscoelastic surfactant. The preparation process is simple. And the clean fracturing fluid including the surfactant have excellent temperature and shear resistance, good suspended sand performance, simple on-site preparation, automatic gel breaking, low 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. |