定向井套管柱弯曲挠度的计算及研究

Study on and Calculation of Deflection of Directional Drilling Casing String

本文针对目前国内普遍推荐采用的套管在弯曲井眼里的挠度计算式,从定向井钻进过程的实际情况出发,建立了套管柱在井下的受力模型,进而建立了在横向均布荷载和轴向力同时作用下套管柱的挠曲变形方程及其求解方法。最后通过实例计算分析了纵横弯曲和平面弯曲概念上的差别及其在工程计算上的误差。为描述定向井套管柱的变形状态及指导现场下套管作业,提供了更为准确的计算依据。

This paper is aimed at the deflection formula of casing in bending well recommended to be used popularly at home, sets up the stressed model of the casing string down hole on the basis of the directional drilling process, and establishes further the deflection deform equation of the casing string and its solution activated by both the horizontal uniform load force and the axil force. The calculation and analysis is made finally, with examples, of the conceptual difference of cross and plane bending and its error in the engineering calculation, which provides more accurate computational factors for the description of the casing string deform and for the guidance of site casing running operation.