钻柱在钻井液反馈影响下的横向振动

在假设钻柱为无扶正器的均质等截面弹性管，且两端为铰支的情况下，既考虑钻柱内钻井液流速和轴向力对钻柱振动的影响，又考虑振动的钻柱对钻井液的反馈影响，建立了钻井液在钻柱内流动时钻柱横向振动微分方程，推导出钻井液波动压力计算式，并给出了钻柱横向振动固有频率方程。定性分析时取频率方程前两阶进行近似计算，讨论了钻井液滚动压力对钻柱固有频率的影响。

Influence of drill fluid feedback on lateral vibration of drill stem

By assuming the drill stem being a homogeneous elastic pipe with constant section, articulated at both ends and without stabilizers, and in consideration of the influence of the flow rate of the drill fluid in the stem, the axial force and the drill fluid feedback on the vibration of the stem, the differential equation for the lateral vibration of the stem with flowing fluid is established, the equation for calculating the drill fluid dynamic pressure of the drill fluid is derived, and the equation of the natural frequency of the stem's lateral vibration is given. Furthermore, the influence of the drill fluid dynamic pressure on the natural frequency of the stem is discussed.