内外钻井液作用下的旋转钻柱涡动分析

在理论上研究了内、外钻井液流体作用下的钻柱涡动问题．分析了钻柱内钻井液随钻柱旋转时的流体动压力和钻柱弯曲变形等所产生的扰动压力之和对钻柱运动的影响，推出了在这种情况下保持钻柱规则涡动的动力学条件；进一步分析了钻柱外环空钻井液流体对旋转钻柱所产生的反作用自激现象，通过对其数学模型的建立和求解，得到了钻柱涡动失稳的临界条件．较详细地探讨和论述了内、外钻井液作用下钻柱涡动过程的力学机理和运行规律

Whirling Analysis of the Rotary Drill String by the Action of Drilling Fluid Inside and Outside the Drill String

The paper studied theoretically the whirling of rotary drill string by the action of drilling fluid inside and outside the drill string.It analysed the affection on the drill string motion by the sum of pertubing pressure produced by both hydrodynamic pressure of drilling fluid inside the drill string with the rotating of the drill string and the bending deformation of the drill string,derived the dynamic conditions of keeping the drill string whirling in a regular manner.It also analysed the phenomenon of reactive self exciting on the rotary drill string,which is attributed to the drilling fluid outside the drill string.The critical condition of unstable whirling of the drill string was obtained by building and solving the mathematical model.The paper discussed in detail the mechanical mechanism and operating laws of the drill strings whirling course by the action of drilling fluid inside and outside the drill string.