长庆气田水平井优快钻井配套技术

长庆气田水平井钻进具有地层条件复杂,岩石可钻性差的特点。为探索适合长庆气田水平井提速的配套技术,从复合钻井工艺、钻井液体系性能、防托压和事故复杂预防4个方面进行了生产应用。实践表明,高效PDC钻头配合螺杆复合钻井可显著提高机械钻速,缩短建井周期;膨润土、聚合物和聚磺钻井液体系可通过控制钻井液性能参数防止不同井段的地层漏失、坍塌,并满足钻具润滑要求;采用倒装钻具组合和应用水力加压器可减小钻具摩阻,减缓托压现象,从而提高滑动钻进速度;此外,应做好井下复杂事故的防治方案并在施工中严格执行。该配套工艺可为长庆地区同类结构水平井钻进提供参考,对提高勘探开发效益具有重要意义。

Matching technology for optimized fast drilling of horizontal wells in Changqing Gasifeld

Drilling of horizontal wells in Changqing Gasfield is characterized by complex formation conditions and poor rock drillability. To explore the matching technology for speeding up the horizontal well drilling in this area, the compound drilling technology, mud properties, prevention of backing pressure and preventing of complex conditions and accidents were applied in field drilling practices. The practices indicated that high efficiency polycrystalline diamond compact (PDC) bit and screw compound drilling can improve rate of penetration significantly and reduce well construction period. By controlling mud properties, the bentonite, polymer and sulphonated polymer drilling fluid systems can prevent the formation leakage and collapse at different intervals and can satisfy the lubrication requirement of drill string. Method of inverted drill string and application of hydraulic thruster can decrease frictional resistance of the drill string so as to mitigate backing pressure and improve ROP of slide drilling. Besides, plans to prevent complex conditions and accidents should be developed and executed strictly during drilling. This matching technology provides a reference for the horizontal well drilling with similar well structures in Changqing area, which is of great significance to improvement of exploration and development benefit.