【摘要】 在钻井作业中 ,钻头与岩石的作用产生的振动实际上是随机振动 ,是造成整个钻柱系统振动的根源 ,也使得钻头与井底间的实际钻压产生较大范围的波动。由于钻头的横向振动使钻头中心实际运动轨迹偏离井眼中心 ,当钻头横向振动的振幅较大时 ,钻头将与井壁发生碰撞 ,这是造成钻头损坏的重要原因之一。文章利用较为简单的室内试验初步确定了钻头与井壁发生碰撞时恢复系数及碰撞力的大小。实验结果表明 ,牙轮钻头与J2 s2 砂岩碰撞的恢复系数约为 0 .1;碰撞力与碰撞速度呈近似的线性关系 ,碰撞发生的时间较短。实验结果对于完善钻柱动力学研究 ,以及改善钻头的设计均有着重要的意义。更多还原

【Abstract】 In drilling process,the vibration prod uced from the drill bit colliding with rocks is a random vibration actually,bein g the source of causing drillstring system vibration,and making a great change b e taken place in the practical WOT.Owing to the fact that the lateral vibration of drill bit causes its practical moving locus to be departed from the center of borehole,the bit will collide against borehole wall as a larger amplitude of th e lateral vibration of the bit occurs,which is one of the important reasons maki ng the bit be damaged.When the bit was colliding with the borehole wall,the rest oration coefficient and collision force were primarily determined by use of a si mple laboratorial test.The test result indicates that the restoration coefficien t of roller bit colliding with Member Sha 2 sandstone is about 0.1,an approxima te linear relation between the collision force and the collision speed is found and the collding time is relatively short.This result possesses important signif icance for perfecting drillstring dynamic research and improving drill bit desig n.更多还原