螺杆钻具井下磨铣管柱受力分析及改进设计

FORCE ANALYSIS AND IMPROVEMENT DESIGN OF DOWNHOLE MILLING PIPE STRING OF SCREW DRILL TOOL

针对螺杆钻具磨铣钻削井下桥塞、水泥塞及类似钻削工作中管柱在井下所产生的巨大反扭矩的危害，在对磨铣钻削管柱进行受力分析的基础上，提出了改进方案，即“井下防扭装置”和“磨铣钻削管柱的配置”，有效地降低了反扭矩带来的危害，改善了磨铣钻削管柱的受力状况。现场２口井的实际应用说明，改进后的管柱在应用上更为安全可靠，钻削用时比简易管柱缩短 １／４～１／３。

The downhole milling pipe string of screw drill tool will produce great reverse torque while milling and grinding the bridge plug, cement plug and so on, and which is extremely harmful to the screw drill tool. Based on the analysis to the forces exerted on the milling pipe string, the paper presents the improvement design, that is, the downhole antitorsion device is collocated with the downhole milling pipe string. This has effectively reduced the harm resulted from the reverse torque, and improved the force condition of the downhole milling pipe string.