页岩气井泡沫排水复合杀菌起泡剂研究

Study on compound bactericidal foaming agent for foam drainage in shale gas wells

目的针对页岩气井的泡沫排水稳产及细菌腐蚀的控制,研究出150℃井温下兼具泡沫排水及杀菌防腐功能的复合杀菌起泡剂。方法结合对泡沫生成到破灭变化过程的分析,通过对起泡主剂、稳泡助剂及杀菌助剂的优选,复配形成复合杀菌起泡剂并进行现场试验验证。结果在温度为90℃、复合杀菌起泡剂的质量浓度为1.0 g/L时,起始泡高大于185 mm、5 min泡高大于122 mm、携液量大于149 mL/15 min;在压力为5 MPa、温度为150℃、复合杀菌起泡剂的质量浓度为2.0 g/L时,发泡体积大于650 mL、1000 s时泡沫体积降低率小于10%;复合杀菌起泡剂的质量浓度为1.0 g/L时,对SRB的杀菌率达100%;现场试验中,相同用量的常规起泡剂和复合杀菌起泡剂的气产量、水产量相当,未实施泡沫排水的井使用复合杀菌起泡剂后气产量、水产量稳定,杀菌率达98.0%以上。结论研制的复合杀菌起泡剂兼具泡沫排水及杀菌防腐功能,可用于井底温度为150℃页岩气井的泡沫排水稳产及杀菌防腐。

Objective In order to meet the needs of stable production of foam drainage and control of bacterial corrosion in shale gas wells,a compound bactericidal foaming agent with functions of foam drainage,bactericidal and antiseptic at 150℃well temperature was developed.Methods Combined with the analysis of foam formation to burst process,through the optimization of foaming agent,foam stabilizing agent and bactericidal agent,compound bactericidal foaming agent was formed and verified by field test.Results At 90℃and the mass concentration of 1.0 g/L,the initial bubble height was more than 185 mm,the 5 min bubble height was more than 122 mm,and the liquid carrying capacity was greater than 149 mL/15 min.At 5 MPa,150℃and the mass concentration of 2.0 g/L,the foaming volume was more than 650 mL,and the foam volume decreases less than 10%at 1000 s.The bactericidal rate of sulfate reducing bacteria(SRB)was 100%at the the mass concentration of 1.0 g/L.In the field application test,the gas yield and water yields of conventional foamer and compound bactericidal foamer with the same the mass concentration were equal,the gas yield and water yield of the wells without foam drainage were stable after using the compound bactericidal foaming agent,and the bactericidal rate was over 98.0%.Conclusions The compound bactericidal foaming agent has functions of foam drainage,bactericidal and antiseptic.It can be used for stable production and bactericidal antiseptic of foam drainage in 150℃shale gas well.