CO2注入井封隔器胶筒研究

Study on packing element of packer for CO2 injection wells

为了解决CO2注入井存在注入压力,封隔器胶筒由于CO2溶胀老化,以及密封有效周期短的问题,进行了CO2封隔器胶筒研究。通过对丁腈橡胶、氢化丁腈橡胶、全氟醚橡胶、三元乙丙橡胶、四丙氟橡胶5种橡胶力学性能和耐热性评价测试,优选出各项参数达标的氢化丁腈橡胶作为胶筒材料,采用合理的胶筒结构加工成型,进行油浸试验检测,性能指标为耐温120℃、承压35MPa,取出后胶筒完好。现场验证采用优选后橡胶制作的胶筒, 4年后仍然密封有效,较同区块其他分注井套压低5MPa以上,具有较好的社会效益。

In order to solve the problems of high injection pressure,short effective sealing validity of packing element due to CO2 swelling and aging,etc.in CO2 injection wells,the packing element of packer for CO2 injection wells has been studied.By evaluating and testing the mechanical properties and heat resistance of five kinds of rubbers,including nitrile-butadiene rubber,hydrogenated nitrile-butadiene rubber(HNBR),perfluoroether rubber,ethylene propylene terpolymer rubber and tetrapropyl fluoro rubber,the HNBR has been selected as the packing element material whose parameters reach each standard.The reasonable structure of packing element has been made to manufacture.Oil immersion test showed that the temperature endurance was 120℃and pressure-bearing was35 MPa,and the packing element was in good condition after taking it from the oil immersion test.The packing element with selected rubber has been applied in field application test,which still has effective sealing ability after four years,and the casing pressure of the well is 5 MPa lower than that of other separate layer injection wells in the same block,with good social benefit.