Effect of spacer hydroxyl number on the performance of Gemini cationic viscoelastic surfactant for fracturing fluids

• Published in: Journal of molecular liquids Vol. 346; p. 117889
• Main Authors: Mao, Jincheng, Huang, Zigao, Cun, Meng, Yang, Xiaojiang, Lin, Chong, Zhang, Yang, Xu, Tao, Zhang, Heng, Du, Anqi, Wang, Quanhang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2022
• Subjects: Clean fracturing fluids; Gemini cationic viscoelastic surfactant; Hydroxyl groups; Spacer group; Spacer group; Hydroxyl groups; Clean fracturing fluids; Gemini cationic viscoelastic surfactant
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2021.117889

•Hydroxyl in the spacer intends to promote molecule aggregation and improve the surface activity of the Gemini surfactant.•The tighter double hydration layer helps to improve the salt resistance when wormlike micelles is formed.•More hydroxyl in the spacer leads to better elastic performance. The performance of Gemini cationic viscoelastic surfactant (VES) is affected by the spacer group, which is also the focus for developing the molecular structure design of high -performance clean fracturing fluid. In this study, we synthesized Gemini cationic VESs (VES-O, VES-DO, VES-TO) by introducing different number of hydroxyl groups in the spacer. The effect of the number of hydroxyl groups in the spacer on the performance of Gemini cationic VES was investigated using surface tension measurement, apparent viscosity and viscoelasticity tests in the presence of KCl. Further, the performance of clean fracturing fluids containing VES-O, VES-DO, and VES-TO were evaluated. We discovered that increasing numbers of hydroxyl groups in the spacer improves surfactant performance in fracturing fluid and high-elasticity fracturing fluids with low viscosity. This gives us ideas for future designs of high-performance clean fracturing fluids.