川西老区中浅层新型泡排药剂研发与应用

川西老区中浅层气井已总体处于低压低产阶段，井口压力低于1 MPa占比76.13%，产量低于0.2$\times$10$^4$m$^3$/d占比57.14%，80.62%的气井已介入泡排工艺，但泡排工艺效果逐渐变差。针对高含凝析油气井泡排效果差、低压低产气井泡排低效及积液与乳化并存致气井治理难度大等问题，研发了3种新型SCU系列泡排剂。通过建立CHSB—SDS—PFBS三元表面活性剂体系，研发了高抗凝析油泡排药剂SCU—2，可将气液表面张力降低至26.73 mN/m，抗凝析油含量达50%；优选反应体系及催化剂，研发了自生能量型泡排药剂SCU—3，可在井筒发生化学反应生成N$_2$，并释放热量，提高低压低产井泡沫举升效率；优选复合酸与抗油性表面活性剂复配，研发了净化与排液一体化药剂SCU—6，同等浓度下降黏能力优于常规净化剂，起泡能力优于常规泡排剂。SCU系列药剂应用138口井，有效率89.73%，增产天然气774$\times$10$^4$m$^3$。新药剂拓展了泡排工艺技术的应用范围，具有良好推广应用前景。

Development and Application of New Foaming Agent for Gas Drainage in Middle and Shallow Layer of Western Sichuan

The middle shallow gas well in the old part of Sichuan Basin has been in the low pressure and low production stage. The gas wells with wellhead pressure lower than 1 MPa accounted for 76.13%, and the production lower than 0.2$\times$10$^4$ m$^3$/d accounted for 57.14%; 80.62% of the gas wells have been involved in the bubble discharge process, but the effect of bubbling process is gradually getting worse. In view of the poor bubble drainage effect of high condensate oil and gas wells, the low bubble drainage efficiency of low-pressure and low production gas wells, and the difficulty of gas well treatment caused by the coexistence of effusion and emulsification, three new SCU series foam discharge agents have been developed. By establishing CHSB-SDS-PFBS ternary surfactant system, we developed a high anticoagulant oil bubble drainage agent SCU-2, which could reduce the gas-liquid surface tension to 26.73 mN/m and hold 50% content of anticoagulant condensate. Through the optimization of reaction system and catalyst, we developed self generated energy type foam discharge agent SCU-3, which could generate N$_2$ and heat in the wellbore and increase the foam lifting efficiency in low pressure and low production wells. Optimizing the combination of compound acid and oil resistant surfactant, we developed the purification and drainage integrated foaming agent SCU-6, which is better than conventional foaming agent for gas drainage in the properties of reducing viscosity and foaming ability with same concentration. Currently, SCU series foaming agent have been applied in 138 gas wells with 89.73% effective rate and 774$\times$10$^4$ m$^3$ gas production increase. The new foaming agent gas drainage expand the application scope of foam drainage technology and have excellent prospect of popularization and application.