Reutilization of thickener from fracturing flowback fluid based on Gemini cationic surfactant

Due to the high cost and environmental damage characteristics of the viscoelastic surfactant (VES) fracturing, a method for recycling the VES from the flowback fluid was proposed in this study. Herein, such VES could be prepared easily and it can be recovered from the flowback fluid based on phase separation by adding a certain amount of hydrochloride acid. Based on this proposed method, the VES in the flowback fluid can be recycled to the greatest extent and the waste fluid can be effectively handled by the base neutralization process. The recycled VES can form wormlike micelles in the aqueous solution, and the fracturing fluid prepared from the recycled VES showed good elasticity and thermal stability. The molecular structure analysis showed that the recycled VES molecules maintained good integrity, which provided a solid basis for recycling the VES from the VES-M fracturing fluid. This technique not only can largely increase the utilization rate of thickener of VES fracturing fluid but also promote the treatment of the flowback fluid in hydraulic fracturing.