井下柔性复合管注水技术及应用

Water injection technology based on downhole flexible composite pipe and its application

目前长庆油田采出水腐蚀结垢严重,导致钢制防腐油管使用寿命较短。通过力学计算及结构材料优选,研发了不同管径的井下柔性复合管并进行了相关的管柱强度校核、有限元分析及室内性能评价,形成了适用于采出水回注井的井下柔性复合管注水工艺管柱系列。现场试验32口井,试验成功率100%,截至2016年5月试验井的最长注水时间已达4年。开展了12井次的取样性能检测,表明井下柔性复合管具有良好的防腐性能,可有效提高注水管柱使用寿命,预计使用寿命达10年以上,是钢制防腐油管使用寿命的2倍以上,同时该工艺可有效降低作业强度和生产成本,具有广阔的推广应用前景。

In Changqing Oilfield,the produced water currently presents serious corrosion and scaling behavior,shortening theservice life of anti-corrosion steel tubing.In this paper,flexible composite pipes were developed for wells with different pipe diametersby carrying out mechanical calculation and structured material optimization.Then,string strength verification,finite element analysisand indoors performance evaluation were performed on the pipes,and a series of water injection strings were developed,which based ondownhole flexible composite pipe and suitable for reinjection wells of produced water.They were tested on site in32wells,and the successratio is100%.So far,the longest water injection period is4years.Performance test was carried out by12well times.It is indicatedthat downhole flexible composite pipes have good anti-corrosion property,and they can increase the service life of water injection stringssignificantly.It is expected that the service life can be up to10years,which is2folds that of anti-corrosion steel tubing.And besides,the operation intensity and production cost can be decreased effectively.Therefore,this technology is promising in popularization andapplication.