Integrated Surfactant for Foam Drainage, Scale Inhibition, and Liquid‐Lock Removal
Tingting Weng, Yubo Lian, Xingyan Ge, Wanjun Chang, Yongfei Li, Gang ChenABSTRACT
Liquid lock and scale deposition are major obstacles in deep gas wellbores, reducing productivity. A ternary integrated surfactant (FC‑1009, lauramidopropyl betaine [LAB], and citric acid [CA]) is developed for synergistic foam drainage, scale inhibition, and liquid‑lock removal. The fluorocarbon surfactant imparts strong amphiphobicity with water/oil contact angles of 120°/55°, whereas LAB enhances foaming and CA chelates Ca 2+ . The formulation lowers surface tension to 28 mN m −1 and achieves 94.9% CaCO 3 scale inhibition by converting angular calcite into loose vaterite. It tolerates high temperature, brine, methanol, and condensate oil. Core tests confirm liquid‑lock removal: water saturation drops to 24%, and gas permeability recovery reaches 60% at 0.8 PV. This multifunctional agent offers a cost‑effective solution for wellbore cleaning and reservoir protection.