Preparation and property evaluation of a temperature-resistant Zr-crosslinked fracturing fluid

Compared with the traditional water-based fracturing fluid thickener guanidine gum, the price of synthetic polymer is relatively low, and the temperature resistance, shear resistance and viscoelasticity of the formed fracturing fluid are better. Therefore, the fracturing fluid formed by the crosslinking of HPAM and organic metal crosslinker will become one of the hot spots in the research of water-based fracturing fluid. In this paper, zirconium oxychloride, acetic acid and triethanolamine were used as raw materials to prepare organic Zr-crosslinked agent. The polymer gel was formed by crosslinking the organic Zr-crosslinked agent with the acrylamide copolymer KY-5S solution, and the viscosity of the gel with different concentrations was investigated. The performance of the fracturing fluid was evaluated through laboratory experiments. The results showed that the viscosity of the fracturing fluid remained above 100 mPa s at the shear rate of 170 s(-1) and after 2 h of shear at 140 degrees C. When the temperature was 20 degrees C, the shear stress was 0.1 Pa, and the frequency f varied from 0.1 to 10 Hz, the elastic modulus of fracturing fluid was at least 11.6 Pa, and the viscous modulus was at least 8.54 Pa. At the temperature of 90 degrees C, when the addition of glue breaker was 0.01 wt%, the longest breaking time was 3 h, and the maximum viscosity of breaking liquid was 4.05 mPa s. The damage rate of core permeability of glue breaker was about 13%. When the temperature was 25 degrees C and the shear rate was 0-170 s(-1), the viscosity of fracturing fluid remained above 200 mPa s. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.