歧深1井高温深层小间隙尾管固井技术

SMALL-CLEARANCE LINER CEMENTING IN DEEP AND HIGH-TEMPERATURE WELLBORE OF THE WELL QISHEN-1

歧深1井尾管裸眼封固段油气活跃、温度高、环空间隙小,在固井过程中易出现层间互窜、顶部水泥石超缓凝等复杂情况。针对以上难题开展了技术攻关,提出综合采用套管居中、井眼清洁及界面清洗、隔离液、防窜水泥浆及动态压力平衡固井技术。该套技术的运用,确保了该井φ177.8mm和φ127mm尾管固井环空水泥环分布均匀,且现场施工作业安全顺利,有效地解决了歧深1井尾管固井过程中易出现层间互窜、施工泵压过高(易压漏地层)、顶替效率差、水泥环薄且分布不均匀、顶部水泥石易超缓凝等问题。施工结束后候凝24h测井固井质量合格。

Complicated problems were encountered during open-hole liner cementing of the well Qishen-1,such as active oil/gas movement,high temperature,small annulus clearance,oil/gas channeling,and over-retarded upper cement stone,etc.Thus lots of efforts had been made,casing centralization,hole cleaning,interface cleaning,spacer,anti-channeling cement slurry and dynamic pressure balance had been proposed and tried.The application has been proved to be safe and successful in operation with evenly-distributed cement sheath around the annulus by use of φ177.8 mm and φ127.0 mm liner cementing.Those measures had effectively solved the problems of channeling,extremely high pump pressure(leading to formation crackdown),low displacement efficiency,thin and unevenly-distributed cement sheath,and over-retarding of upper cement stone.Through 24-hour waiting on cement after operation,the cementing works have been done successfully.