塔河油田深层侧钻水平井膨胀套管钻井完井技术

塔河油田奥陶系储层侧钻水平井受老井井身结构、地层及地质避水要求等的限制,需要提高造斜点至上部石炭系泥岩段地层,而该地层与奥陶系储层为2套不同的压力系统,因此如何有效封堵石炭系易塌地层,是高效开发该地区奥陶系剩余油的关键。采用膨胀套管充当技术套管封堵钻井复杂地层,通过优化井身结构及后续的钻井工艺,为解决塔河油田深层侧钻水平井钻井、完井难点提供了一套全新的方案。针对塔河油田φ177.8 mm套管深层开窗侧钻井的钻井、完井难点,通过深入分析研究膨胀套管管材和膨胀螺纹等关键问题,完善了深井膨胀套管的施工工艺和实施程序,探索出一套塔河油田深层侧钻水平井膨胀套管钻井完井技术。该技术在塔河油田现场试验3口井,开窗层位均位于石炭系地层,开窗点深于5 100 m,侧钻后在斜井段成功封堵裸眼复杂地层,实现了国产膨胀套管首次在裸眼定向井段的封堵应用,为钻井、完井中封堵复杂地层提供了新的技术手段。 

Expandable Casing Drilling and Completion Technology in Deep Sidetracked Horizontal Wells of Tahe Oilfield

Restricted by the existent casing program,formation and the requirement to avoid acquifer,when sidetracking horizontal wells into Ordovician reservoir in Tahe Oilfield,the kickoff point must be moved up to upper Carboniferous mudstone formation.The two formations belong to different pressure systems,so how to effectively seal the Carboniferous unstable formation is the key for developing the Ordovician remaining oil efficiently.Using expandable casing as intermediate casing to seal complex formations during drilling,provides a new way to solve the problems encountered in sidetracking horizontal wells in Tahe Oilfield by optimizing the casing program and follow-up drilling process.According to the difficulties encountered in deep sidetracking from φ177.8 mm casing in Tahe Oilfield,through dissecting the key technologies of expandable casing,such as expandable pipes and expansion thread,the operation process and procedure of running expandable casing in deep wells were improved,finding out a set of drilling technology with expandable casing.The technology has been tested in 3 wells in Tahe Oilfield,in which the window were all at the Carboniferous layer below 5 100 m,the inclined segments after sidetracking sealed the complex formation successfully,realizing the first sealing with domestic expandable casing in open hole,providing a new technical means to seal complex formations during drilling.