Abstract: The tubing string is forced by various loads during the production period of the well.An axially loaded tubing string buckles helicaliy and produces wall contact force when constrained within the casing or well wall.The tubing string can be damaged in severe case.In this paper,typical expression of contact force of some savant is summarized.It is very different to calculate results for them.According to needs of engineering application,wall contact force on helical buckled tubing is studied by means of theory and detected by means of the first experiment about the contact force.The experiment method and device were put forward.The experiment results produced form 3-dimensional photoelastical tests of the freezed stress have been given.The distribution of wall contact forces in three sections is presented.The more reasonable expressions are given for engineering application.The different expressions of wall contact force in some papers presented are analyzed according to the works.These works provide scientific basis for analyzing the applied load and engineering application of helical buckled tubing string in wells.

Key words: pipe string, helical buckled, photo elastic analysis, contact force

摘要： 在油井生产过程中管柱会受到各种载荷.管柱在轴向力作用时,在有外管壁或井壁约束的情况下,内管柱与外管壁或井壁间会产生接触压力,并可能发生螺旋屈曲,严重时会导致管柱失效.文中综述了一些学者的典型接触压力计算式,发现不同计算式间的计算结果差异很大.根据工程应用中的需要,进行了理论推导并首次对该问题作了实验检测,给出了三维光弹性应力冻结法的实验结果,探讨了管柱在屈曲时接触压力分布规律的三个阶段和工程应用的更接近实际的计算公式.在此基础上对前人所发表的不同接触压力表达式进行分析和探讨.为研究管柱屈曲时的受力情况和工程应用提供了理论与实验依据.

关键词: 管柱, 螺旋屈曲, 光弹分析, 接触压力