牙轮钻头及钻柱系统扭转振动仿真模型

利用钻柱动力学有限元模型的数值计算方法 ,在考虑了钻头与岩石互作用力学模型的基础上 ,建立了钻头和钻柱扭转振动动力学仿真模型。通过仿真计算可预测钻头处阻力扭矩、钻柱顶部扭矩和钻头转速的变化情况。对 8 英寸XHP2S钻头做了仿真 ,结果表明 ,钻头处受岩石的阻力扭矩是随机变化的 ,并有负扭矩出现 ,扭矩的变化幅值随静钻压的增加而增加 ;钻柱顶部转盘施加的扭矩变化不如底部剧烈 ;钻头的转速在局部有较小的波动 ,其总体变化较为平缓。

Dynamic simulation models for torsional vibration of cone bit and drillstring

By means of the drillstring's finite element model and the numerical solution method, and based on the mechanical models of bit/rock interaction, the dynamic models for torsional vibration of cone bits and drillstrings are established. By means of the simulation calculation, varying of the torques on the bit and the drillstring top and the rotary speed of the bit can be predicted. The result of simulation of Model 81/2 XHP2S bit shows that, the torque on the bit changes randomly, and the degree of the change increases with the increase of the weight on bit; the change of the torque on the upper part of the drillstring is not so large as that on the string's lower part, and the rotary speed of the bit changes smoothly overall. Abstract