Abstract: In the oil drilling process,the motions of the drill string is very complicated process,which exists longitudinal,horizontal and torsional vibrations and random impacts and rubs between the well wall and drillstring.The non-linear dynamics finite element model of the bottom hole assembly (BHA) system was established with considering random impacts and rubs between the well wall and drillstring,drill bit and the rock.The transient vertical-horizontal-torsional coupling vibrations of the BHA system were studied with finite element method (FEM).The rules of the vibration motions and mechanical properties in the BHA were found out.The calculated results provide the references to oil drill string design and optimization of the system.

Key words: Drillstring , Vertical wells , Bottom hole assembly(BHA) , Finite element method

摘要： 在石油钻井过程中,钻柱的运动过程非常复杂,不仅存在纵向、横向、扭转振动,而且还与井壁发生随机接触碰撞和摩擦。充分考虑钻柱与井壁以及钻头与岩石的随机碰撞作用,建立了竖直井底部钻具系统(BHA)非线性动力学有限元模型,研究了工作过程中的BHA系统的纵向、横向和扭转振动,分析了钻柱在受到井壁约束下的瞬态动力响应特性,探讨了BHA系统在钻井过程中运动规律和力学性能,为石油钻柱系统的设计和优化提供了一定的理论参考。

关键词: 钻柱 , 竖直 , BHA系统 , 有限元法