Abstract: The frictional drag and torque of the whole drill string in a horizontal well or other kind of well is analysed deeply with the consideration of the stiffness of its main part.A systematic calculation model and its applications for the drag and torque are presented.Calculations and discussions for hook load and friction in moving the pipe along well bore and in rotating the pipe,as well as length design of horizontal section,and so on,are carried out in this paper.

Key words: frictional drag, torque, drill string, bottom-hole assembly

摘要： 考虑钻柱主要部分的刚度,对水平井乃至其它井中的整个钻柱的拖扭阻力,进行深入分析,提出了系统的计算模型、方法及其功能与适用范围,并对起下钻及钻进时的大钩载荷、摩阻、水平段长度设计、井身优化等问题,进行了计算分析.

关键词: 摩擦阻力, 扭矩, 钻柱, 钻具组合