直井中钻柱非线性螺旋屈曲准静态加载模型研究  

STUDY ON SEMI-STATIC LOADING MODEL FOR NONLINEAR HELICAL BUCKLING OF DRILL STRING IN STRAIGHT WELLS

作　　者：刘峰[1] 王鑫伟[2] 

机构地区：[1]中国民航飞行学院航空工程学院 [2]南京航空航天大学航空宇航学院

出　　处：《天然气工业》2007年第1期64-67,共4页Natural Gas Industry

基　　金：到中国博士点基金(编号:20020287003);美国SmithTool International公司的资助

摘　　要：采用有限元法对直井中钻柱非线性螺旋屈曲准静态加载模型的控制微分方程进行了求解,对钻柱螺旋屈曲准静态加载模型的合理性进行了理论验证,证明了钻柱螺旋屈曲准静态加载问题和特征值问题,力学模型中考虑了钻柱的重力,摒弃了传统分析中的小位移假设。研究表明,钻柱的螺旋屈曲过程是一个稳定的加载过程;钻柱屈曲位移的幅值随轴向载荷的增大而增大;钻柱的屈曲位移、弯矩和井壁约束力线密度都呈周期性变化;将钻柱的螺旋屈曲问题作为一个准静态加载问题来分析是合理的;采用准静态加载模型计算得到的钻柱初始失稳载荷与钻柱正弦屈曲线性特征值问题的分析结果吻合。The governing differential equilibrium equations of semi-static loading model for nonlinear helical buckling of drill string in straight wells are solved by the finite element method. The rationality of semi-static loading model for helical buckling of drill string is theoretically verified. The semi-static loading problem and eigenvalue problem of drill string helical buckling are proved, the effects of drilling string gravity are included, and the assumption of small displacement is abandoned. The study shows that the helical buckling process of drill string is a stable loading process, the range of buckling displacement increases with the increase of axial load, the buckling displacement, bending moment and restrain force per unit length of the drilling vary periodically, and it is appropriate that the helical buckling problem of drilling string is analyzed as a semi-static loading problem, the initial buckling critical load of the semi-static loading model fits well with the analysis results of linear eigenvalue problem of drill-string sinusoidal buckling.

关 键 词：钻井 钻柱 非线性 螺旋屈曲 准静态加载 力学模型 

分 类 号：TE21[石油与天然气工程—油气井工程]