钻柱涡动力学特性模拟与分析

Simulation and Analysis of Whirling Dynamics Characteristics of Drill Strings

摘要: 本研究聚焦于深井钻柱在复杂井眼环境中的涡动力学特性，系统探讨了钻柱在深井条件下横向振动作用下的动态行为。随着钻井深度的增加，钻柱所承受的载荷、钻压及井眼环境的复杂性显著增强，涡动现象尤易加剧钻柱的应力集中、磨损及结构不稳定性。为深入分析这些问题，本文基于有限元法和Euler-Bernoulli梁单元构建了三维有限元模型，并引入Newmark数值积分方法对钻柱的涡动特性进行了动态模拟。研究详细分析了钻柱在不同转速和钻压条件下的运动模式及其稳定性特征，结果表明，钻柱在高转速下明显表现出反向涡动，揭示了高转速与钻柱不稳定状态之间的密切关联。研究成果为钻柱结构的优化设计及涡动控制策略提供了理论依据，有助于提升复杂井下作业条件下的钻井稳定性和效率。

Abstract: This study focuses on the whirling dynamics characteristics of drill strings in complex wellbore environments during deep well drilling, systematically exploring the dynamic behavior of drill strings under lateral vibration. With increasing drilling depth, the loads on drill strings, weight-on-bit, and the complexity of the wellbore environment escalate, making whirling phenomena more likely to exacerbate stress concentration, wear, and structural instability in drill strings. To thoroughly analyze these issues, a three-dimensional finite element model was developed based on the finite element method and Euler-Bernoulli beam elements, incorporating the Newmark numerical integration method to simulate the whirling dynamics characteristics. This study offers an in-depth analysis of the motion patterns and stability features of drill strings under varying rotational speeds and weight-on-bit conditions. The results indicate a pronounced backward whirling in drill strings at high rotational speeds, revealing a strong correlation between high speeds and instability. These findings provide a theoretical basis for optimizing drill string design and developing whirl control strategies, which contribute to improving drilling stability and efficiency under complex downhole conditions.