大直径集束式潜孔锤反循环钻进方法先导性试验

依托某煤矿区大直径钻井工程项目展开了大直径集束式潜孔锤反循环钻进方法的先导性试验。在试验过程中,采用Φ710/311 mm扩孔用集束式反循环潜孔锤和Φ127/70 mm双壁钻具，通过优化风量、风压、转速等反循环钻进工艺参数，取得了良好的反循环效果，最高机械钻速达到了4 m/h，平均机械钻速2.1 m/h，与同条件下常规牙轮钻头扩孔钻进方法相比提高了2.6倍以上。试验结果表明：大直径集束式潜孔锤反循环钻进方法是解决大直径钻孔硬岩钻进难题的一种行之有效、值得深入研究与推广应用的高效钻进方法。

A Pilot Test for Large-diameter Cluster DTH Reverse Circulation Drilling Technology

A pilot test for large-diameter cluster DTH reverse circulation drilling technology based on the large diameter drilling project in a coal mine was carried out.During the tests，by adopting the Φ710/311mm Reverse circulation cluster DTH and 127/70mm double wall drill-pipe，a good performance of reverse circulation was achieved by optimizing the parameters of reverse circulation such as air volume，air pressure，and rotary speed etc..The highest ROP was 4m/h，and the average ROP was 2.1m/h，which were increased more than 2.6 times as much as that by the conventional cone bit drilling method under the same condition.The pilot test results showed that large diameter cluster DTH reverse circulation drilling technology was an effective drilling technology to solve the problem of hard rock drilling in large diameter hole，and is worthy to be promoted in application.