Development and Evaluation of a Novel Zwitterionic Surfactant-Based Foaming Formulation for Gas Well Deliquification

A novel zwitterionic surfactant (HAPB) was synthesized and combined with lauramidopropyl trimethylammonium chloride (LATC) and alpha olefin sulfonate (AOS) to form a high-performance foaming formulation for gas well deliquification. The optimized LATC/AOS/HAPB formulation (15 mmol/L, molar ratio of 16/4/5) achieved a foaming volume and half-life of 400 mL and 9.46 min, respectively. Adding 0.2% sodium alginate (SA), a green polymer, the LATC/AOS/HAPB/SA foam's volume dropped to 350 mL; however, its half-life ramped to 55.47 min. With 0.1 SA and 0.01% calcium lactate (CL), the LATC/AOS/HAPB/SA/CL system exhibited excellent foaming and liquid-carrying performance. At 50% methanol, its liquid-carrying rate reached its maximum (57.44%), while the foaming rate remained 100%. Condensate oil slightly reduced the LATC/AOS/HAPB/SA/CL mixture's liquid-carrying performance, but did not affect its foaming ability, which was maintained at 100% below 50% condensate oil content. The foaming formulation demonstrated outstanding salt resistance, producing a liquid-carrying rate of 26.40% and a foaming rate of 90% at an extremely high salinity of 410 g/L, which was the highest level reported in the literature to date. Furthermore, surface tension tests and the foam's morphological analysis verified the presence of synergy among the LATC/AOS/HAPB/SA/CL system, which effectively enhanced its foaming capability, foam stability, and liquid-carrying ability.