Abstract Foam drainage agents are critical for boosting natural gas extraction efficiency by reducing gas well liquid accumulation, yet traditional ones lack sufficient corrosion inhibition, endangering wellbore infrastructure. This study aims to enhance their corrosion inhibition by adding hydrazine hydrate, developing an integrated system with both foam-generation and corrosion-protection functions. The optimized formulation is 0.1 % sodium alpha-olefin sulfonate (AOS) + 0.3 % dodecyl dimethyl betaine (BS-12) + 0.5 % hydrazine hydrate. It achieves a 92.59 % corrosion inhibition efficiency on Q235 steel, lowering the corrosion rate to 0.0076 mm/a. Electrochemical tests (potentiodynamic polarization, AC impedance) show the composite inhibitor mainly inhibits anodic reactions, with a significant positive shift in corrosion potential. The inhibitor’s adsorption on the metal surface follows the Langmuir isotherm model (strong adsorption capacity), and the process is spontaneous (Gibbs free energy: −24 to −27.5 kJ/mol). Thermodynamic and kinetic analyses clarify the adsorption mechanism and inhibitor stability under different temperatures. This integrated agent has a synergistic effect on foam stabilization and corrosion inhibition, offering a promising solution to improve natural gas well operation efficiency and safety. It also contributes to developing multifunctional corrosion inhibitors for complex wellbore environments (high temperature, high salinity, methanol presence).
Xue et al. (Sun,) studied this question.