Abstract: Accurate calculation of drill string’s hanging load is an important and crucial part in liner cementing process. The article analyse and research the stress about analysis of the drill-pipe，draw lessons from "Soft String Model", the drill string was divided into three parts which was vertical interval, deflecting interval and angle maintaining interval in this paper and formula to calculate hanging load & friction of each part was deduced through analysis of forces. Arc model and infinitesimal calculus were used in deflecting interval calculation. The calculation results tally with field actual weighting result, which verifies the rationality of the formula，that is worthy of popularization.

Key words: Drill string,    , Hanging load,    ,  Soft string model,    ,  Friction,   ,  Arc model,    ,  Infinitesimal calculus

摘要： 尾管固井施工中准确判断钻具悬重是一个关键环节。通过对尾管送入钻具进行受力分析,对送入钻具在套管内的悬重计算进行了研究,借鉴“软钻杆暠模型,将送入钻具分为直井段、造斜段和稳斜段三部分,推导出各部分送入钻具悬重及摩阻计算公式,其中重点对造斜段建立圆弧模型并进行微积分。计算结果与现场实际称重吻合,验证了计算公式的合理性,证明推导的公式在现场实际有推广意义。

关键词: 送入钻具 , 悬重 , 软钻杆模型 , 摩阻 ,  , 圆弧模型 ,  , 微积分