甜菜碱/AOS/Gemini季铵盐三元复合型泡排剂的研制与性能评价OACSTPCD

Foam-based deliquification is important to ensure the production of gas wells,therefore,there is no doubt that the development of high-performance foaming agents is extremely critical for the gas wells with high salinity,high condensate oil content and high temperature.For this reason,a highly efficient and environmentally friendly ternary foaming mixture was prepared by coconut oil amide propyl hydroxy sulfobetaine(CHSB),sodium α-olefin sulfonate(AOS)and synthetic Gemini cationic surfactant(CAGB)in this study.The results showed that the AOS/CAGB/CHSB mixture had the best performance when the molar ratio was 12∶3∶35 at the total amount of 20 mmol/L.The foam volume and half-life reached 360 mL and 30.27 min,respectively.In the foaming agent solution containing 30%methanol,the measured liquid unloading efficiency was 31%,and the foaming efficiency was 95%.With 0%-50%condensate oil,the ternary foaming mixture showed good performance.With 20%condensate oil,the liquid unloading efficiency was up to 38%and the foaming efficiency was 95%.The optimized AOS/CAGB/CHSB exhibited poor tolerance to salt ions.However,with trisodium aminotriacetate(NTA),the ternary complex system was still effective at a salinity of 150 g/L.At temperatures higher than 50℃,the liquid unloading efficiency of the foam also gradually increased,and the liquid unloading efficiency was above 95%at 90℃.In addition,the surface tension test and foam microstructure observation also confirmed the presence of synergy in foaming,foam stabilization and foam liquid unloading.