隔水管弯曲对钻柱振动影响的计算与分析

海洋油气资源钻探中隔水管的弯曲对钻柱振动以及钻进特性有特别的影响。为得到隔水管弯曲对钻柱振动的影响规律,对南海已钻深水井使用非线性有限元软件建立全井钻井数值计算模型,研究获得了不同垂深时隔水管弯曲对钻柱振动特性的影响规律。研究表明:隔水管弯曲会加剧钻柱的振动,钻柱振动加剧会导致钻井能耗上升、钻头切削能力下降并且会加快钻柱疲劳;当隔水管的弯曲达到某临界值,钻柱与隔水管间的接触力会陡增;井口的钩载越大,隔水管弯曲带来的井口钩载波动量越大;井越深,隔水管弯曲对全井钻柱最大弯矩和钻头切削能力的影响越小。

Effects of the bending of the riser on the vibration of the drill string

In the ocean drilling,the bending of the pipes has special effects on the vibration and motion of the drill string.In order to get the effects of the bending of the riser on the vibration of drill string,the nonlinear finite element software is used for drilling deep Wells in the South China Sea,and the drilling value calculation model of the whole well is established.The influence of the bending of the drill string on the vibration of drill string is studied.Research shows that:the bending of the riser increases the vibration of the drill string.The increase of drill string vibration can result in the increase of drilling energy consumption,the decrease of the cutting ability of the drill bit and the acceleration of drilling column fatigue.The contact force between the drill string and the riser increases rapidly when the riser bending reaches a critical value.The larger the hook load,the larger the hook load variation that is caused by the bending of the riser.The deeper the well,the smaller the impact of the riser bending on the maximum bending moment of the drill string,and the smaller the impact on the drill's cutting ability.