“…Therefore, it is a critical problem to realize reversible gel breaking with controllable time, complete gel breaking, and low cost for constructing a clean fracturing fluid system. To solve this problem, this article aims to realize the reversible gel breaking of clean fracturing fluid by introducing intelligent control switch, compared with intelligent control switch such as light, oxidation, CO 2 , and temperature; pH switches are time-controlled, thoroughly regulated and cost-effective, with good biocompatibility and high surface activity, so pH-sensitive surfactant is suitable as thickeners for clean fracturing fluids ( Liu et al, 2021a ; Yu et al, 2021 ; Mu et al, 2022 ).…”