间隙元在钻柱瞬态动力学分析中的应用

为了描述钻柱与井壁的随机碰撞接触状态,本文构造了动力间隙元,并推导了动力间隙元的相对压缩量和迭代求解格式。把动力间隙元与梁单元相结合,采用Newmark直接积分法和冲量定理,进行了钻柱碰撞接触非线性瞬态动力学分析。经工程应用表明,构造的动力间隙元能够描述钻柱的碰撞接触状态,所设计的偏心防斜钻具已在大庆油田得到应用,取得了明显的经济和社会效益。

An application of gap element to the transient dynamics analysis of drillstring

In order to describe the random impact and contact between the drillstring and the hole wall, the dynamic gap element is developed and its relative compression and corresponding iterative formulation are derived. Through that the dynamic gap element is connection with the beam element, the nonlinear transient dynamics of impact and contact for the drillstring is analyzed by using the direct integral method of Newmark and the impulsive theorem. From the applications in engineering, it indicates that the gap element presented can describe the impact and contact state of the drillstring, basically. The eccentric BHA designed has been widely used in Daqing oil field, thus the remarkable economic and social benefit are given.