水平井倒装钻具抗扭强度的研究及其计算方法

Research and Calculation Method on Twisting Strength of Upside -Down Drilling Tool for Horizontal Well

本文针对钻水平并常采用的倒装钻具结构,采用莫尔应力圆的分析和计算方法,指出目前在设计水平井钻具结构中,除了考虑轴向力及刚度以外,还应考虑在轴向荷载情况下,钻柱本身的抗扭强度问题,这是关系到水平井钻具结构及井下安全的重要问题。同时文中对现行API规范进行了分析,指出了在使用中应考虑的因素及其正确的使用方法。

This paper aimed at the upside -down drilling tool generally employed in horizontal well drilling and adopted with the Mohr's stress circle analysis and calculation method indicates that at present the drilling tool structure design for horizontal well shall consider the twisting strength of the drilling stem under axial loading condition with the exception of the consideration of axial force and stiffness, this is an important problem related with the drilling tool structure of horizontal well and well safety. Moreover, the paper analyzes current API specification and indicates some factors to be consider in use and its correct application method.