斜直井眼中钻柱侧向屈曲的研究

LATERAL BUCKLING OF DRILL STRING IN INCLINED HOLE

利用能量法，推导了斜直井眼中钻柱的侧向屈曲临界荷载．在力学模型中，考虑了钻柱自重和井斜的影响，给出了斜直井眼中钻柱侧向屈曲临界荷载的一般形式．对于给定截面尺寸的钻柱，临界荷载是钻柱长度的函数，且随井斜角的变化而变化．在确定实际钻柱的临界荷载时，要充分考虑井眼的具体情况．讨论了发生高阶屈曲的条件，所得结果可供工程计算参考．

The expression for critical load of drill string with lateral buckles in inclined hole is derived with energy method. The mechanical models are established with consideration of dead weight of drill string and inclined angle of well. The general forms of critical load are presented. The conditions for producing the high order critical buckles are discussed. The critical load is the function of length of drill string and changes with deviation angle of borehole for the given section of a drill string. The determination of critical load of drill strill should be based on the hole conditions.