ABSTRACT
Clean fracturing fluids based on VES (viscoelastic surfactant) have experienced 20 years of development since first applied in 1997. They are still not widely used because of costs, although they have many advantages and have achieved good results in early applications. To better understand these fluids and promote their application, a comprehensive investigation of the clean fracturing fluids was performed. The mechanisms of the clean fracturing fluids, the methods for performance enhancement, and their limitations in field applications were elaborated. We also analyzed some misunderstandings about clean fracturing fluids and generated new ideas. We are convinced that clean fracturing fluids will dominate future reservoir stimulations. In addition, we considered the future development of clean fracturing fluids, and we offered advice.