Investigation of a highly efficient foaming mixture compromising cationic Gemini-zwitterionic-anionic surfactants for gas well deliquification

Foamers with high resistance to condensate, salinity and high temperature play a crucial role in gas well deliquification. In this study, we developed an efficient foaming mixture containing a Gemini surfactant (CAGB), a betaine surfactant (CAPB) and sodium lauroyl glutamate (SLG), which exhibited excellent foaming performance (at a molar ratio of 3:3:4 and a dosage of 20 mmol L-1) with a foam volume of 440 mL and a half-life of 11 min. The optimized CAGB/CAPB/SLG mixture showed exceptional liquid unloading and foaming ability under high methanol (up to 40 vol.%) and condensate (up to 50 vol.%) content conditions. Trisodium aminotriacetate (NTA) facilitated the liquid unloading performance at a salinity of 90 g L-1. With 10 vol.% methanol, the liquid unloading rate of CAGB/CAPB/SLG foam at 90 degrees C could be increased to 90 %. Furthermore, surface tension and morphology analysis confirmed the presence of synergy within the CAGB/CAPB/SLG mixture in foaming, foam stabilizing and liquid unloading ability.