吉木萨尔页岩油超长水平段水平井安全高效下套管技术

SAFE AND EFFICIENT CASING RUNNING TECHNOLOGY OF THE ULTRA-LONG SECTION HORIZONTAL WELL IN JIMSAR SHALE-OIL OILFIELD

吉木萨尔油田属于典型的页岩油油藏,采用"水平井+体积压裂"开发方式。为了探索页岩油产能建设新模式,2019年在该油田开展了超长水平段水平井试验。其中,JHW00421井水平段长3 100.0 m,刷新了多项非常规油气水平井钻井纪录。为了降低超长水平段下套管难度和风险,对下套管技术方案做了诸多优化,主要包括套管柱下入能力预测分析、通井钻具组合设计、井筒清洁参数优选、套管扶正器选型与使用等。研究与实践表明,采用多扶正器通井钻具组合、较高的钻井液排量和钻柱转速能够提高通井和井筒清洁效果,为安全高效下套管创造条件;采用滚轮扶正器、整体式弹性扶正器并优化安装位置,能够有效降低长水平段下套管阻力。此外,若常规下套管技术难以满足要求时,建议采用漂浮下套管技术,慎用或不用"上提下冲操作"。该研究成果能够为超长水平段水平井钻完井设计与施工提供参考。

The Jimusar Oilfield is a typical shale-oil oilfield,developed by horizontal wells with the volume frac⁃turing technique.To explore the new productivity construction mode of shale oil,the ultra-long section horizontal well experiments have been implemented in 2019.Among the trial,JHW00421 Well with the horizontal section length 3081.1m has just been completed,and broken several horizontal drilling records of unconventional oil&gas horizontal well.To decrease the running casing difficulties and risks,more optimizations of running casing technology were made,which mainly included the prediction analysis of running casing;the drill string assembly design of wiper trip;the technological parameters optimizations of wellbore cleaning operation,and the model and position selections of casing centralizers.Research and practice show that,multi-centralizers drillstring assem⁃bly with higher circulating rate and higher drillstring rotary speeds,can lay a foundation to safety and efficient running casing operation;adopting the roller centralizer and integral elastic centralizer and optimizing their posi⁃tions can decrease the running casing frictional force of ultra-long horizontal section.In addition,if the conven⁃tional running casing technique cannot meet the requirements,the floating running casing technique is recom⁃mend;the lifting and releasing operation should be used with caution or abandoned.Research results can support the drilling engineering design and construction to the similar ultra-long section horizontal wells in the future.