The longer the single drill pipe, the lesser the critical compressive force of drill stem.
钻杆的单根长度越长，钻柱所能承受的临界载荷越小。
Drill stem tests are taken from some Wells almost immediately after drilling and completion operations.
有些井刚钻完并进行完井作业后，就立即采取钻杆测试。
Therefore the nonlinear lateral free vibration of drill stem is investigated by the perturbation method.
分析公式表明，钻柱横向线性振动仅是钻柱横向非线性振动的一种特殊情况；
The influence of the initial deflection on the nonlinear lateral free vibration of drill stem is discussed.
讨论了初弯曲对钻柱横向非线性振动的影响。
On the basis of energy method, the possibility of drill stem buckling in inclined straight hole is studied.
本文应用虚位移原理，在充分考虑钻柱所处的特殊环境的基础上，考察了斜直井眼中钻柱屈曲的可能性。
The rotary drill stem will engender direction drift in rotary drilling of directional well and cluster well.
在定向井及丛式井的转盘钻进中，旋转钻柱会产生方位漂移。
A new method for calculating drill stem strength can be applied to designing and checking strength of drill stem.
提出了一种钻柱强度计算新方法，可用于钻柱的强度设计和强度校核。
In this paper, the problem about stability of the drill stem in the borehole with iso-curvature is studied by use of energy method.
文中利用能量法，研究了等曲率井眼中钻柱的稳定性问题。
This paper discusses the prediction of the drill stem torque and bit forward direction in an offshore horizontal well by nonlinear FEM.
探讨了非线性有限元在预测水平井钻进中的钻柱扭矩及钻头前进方向的应用。
In order to enhance the service hfe of hollow steel for rock drill stem, the odd number side section shape hollow steel has been designed.
为了提高凿岩钎杆用中空钢的使用寿命，设计了奇数边截面形状的中空钢。
The Numbers of half wave are related with the length of drill stem, the nature of geometry and material of drill stem and the rock coefficient.
而半波数则与钻柱长度、几何参数，材料性质及地层弹性系数有关。
It is very important for improving drilling rate, reducing drilling cost and safety drilling to carry out drill stem failure analysis and prevention.
开展油田钻柱失效分析与预防对提高钻井速度、降低钻井成本及井下安全钻进具有重要意义。
Drill stem test plays an important role in drilling operation. It is easy to fail or to cause complicated down hole situations if conducted improperly.
中途测试在钻井施工中具有重要的作用，如果测试措施不到位，容易导致测试失败或发生钻井复杂情况。
The research indicated that the critical compressive force of drill stem in horizontal well is closely related with the length of single drill pipe in use.
研究表明，水平井眼中钻柱所能承受的临界载荷和所使用钻杆的单根长度有密切关系。
The effect of initial deflection on the first frequency increased with either the length of drill stem or the axial compressive force on the drill stem increases.
钻柱横向非线性振动的基频随着初弯曲最大挠度的增大而减小，初弯曲对钻柱横向非线性振动基频的影响随钻柱长度的增大而增大，随轴向压力的影响而增加。
This paper describes how the rotary drilling stem lost its stability in detail, and presents the main factors influencing drill stem stability in rotary condition.
系统地进行了斜直井中旋转状态下钻柱稳定性的试验研究，描述了旋转钻柱失稳的过程，分析了旋转状态下影响钻柱稳定性的主要因素。
The utility model relates to a combined flaw detection transporting device for a drill stem or a pipe joint, particularly a curved combined flaw detection transporting device.
本实用新型涉及钻杆或导管接头的探伤检验组合输送装置，尤其涉及曲线式探伤检验组合输送装置。
The drilling circles generally considers that for the drill stem in crooked hole, the phenomenon of losing stability will not happen, but a detail theoretical proof is not seen.
钻井界普遍认为，在弯曲的井眼中钻柱不会发生失稳现象，但未见到详细的理论论证。
Considering the complex influence factors for the failure of drill stem, an analytic model for failure of drill stem based on support vector machine and cluster analysis theory was established.
针对钻具失效影响因素比较复杂的问题，建立了基于支持向量机和聚类分析理论的钻具失效原因分析模型。
Considering the complex influence factors for the failure of drill stem, an analytic model for failure of drill stem based on support vector machine and cluster analysis theory was established.
针对钻具失效影响因素比较复杂的问题，建立了基于支持向量机和聚类分析理论的钻具失效原因分析模型。
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