聚醚两性离子泡沫剂的性能及应用

Properties and Application of Polyether Zwitterionic Foaming Agent

针对天然气井排液采气技术中表面活性剂耐温耐盐性不足和稳泡性能弱等问题,研制了聚醚两性离子泡沫剂(LAEB)。实验考察了模拟地层盐水矿化度、温度、pH值和泡沫剂浓度对LAEB泡沫性能的影响,并与常规两性离子泡沫剂甜菜碱(LAB)性能进行了比较。结果表明:与LAB相比,LAEB的聚醚链段具有较大空间位阻,限制了羧基基团的反转,提高了LAEB的泡沫稳定性。在地层盐水的矿化度为0~155 g/L,pH值为3~7,温度为50~80℃,以及泡沫剂浓度为0.050%~0.150%(质量分数)条件下,LAEB起泡高度均达到150 mm。确定了LAEB较佳泡沫剂浓度为0.075%(质量分数),较佳使用地层盐水矿化度为0~141 g/L。普光104-1井水淹后放喷无法恢复生产,采用LAEB泡沫排液措施后,放喷4 h产液19 m^(3),产气由水淹前1.8×10^(5) m^(3)/d提高到2.5×10^(5) m^(3)/d,产液由82.3 m^(3)/d增加到138.8 m^(3)/d,成功复产。表明LAEB在超深井水淹气藏的泡沫排液采气中具有良好的应用前景,为气井长时间的稳产高产提供保障。

In view of the insufficient temperature and salt resistance of surfactants,as well as weak foam stability,the polyether zwitterionic surfactants(LAEB)were prepared for foam deliquification of natural gas wells.The effects of synthetic reservoir brine salinity,temperature,pH value and surfactant concentration on the foam properties of LAEB were investigated experimentally and compared with the performance of the conventional zwitterion surfactant Betaine(LAB).The results showed that the reversal of the carboxyl group in LAEB was limited due to larger steric hindrance of the polyether segment and thus foam stability was enhanced,compared with LAB.Under the conditions that the salinity of synthetic reservoir brine was 0-155 g/L,the pH value was 3-7,the temperature was 50-80℃and the foaming agent concentration was 0.050%-0.150%(mass fraction),the foaming height of LAEB reached all higher than 150 mm.The preferred concentration of LAEB was 0.075%(mass fraction)and the preferred salinity of synthetic reservoir brine was 0-141 g/L.LAEB was tested in a gas well Puguang 104-1,which was unable to loading liquid itself.After foam deliquification,19 m^(3) of liquid was produced in 4 h,the gas production was raised from 1.8×10^(5) m^(3)/d to 2.5×10^(5) m^(3)/d,and the fluid production increased from 82.3 m^(3)/d to 138.8 m^(3)/d.It indicates a good application prospect for LAEB in foam deliquification in ultra deep water flooded gas reservoirs,which provides guarantee for long-term stable and high production of gas wells.