直井眼钟摆钻具纵向振动特性的实验研究

Experimental study on longitudinal vibration characteristics of pendulum assembly in straight hole

为了了解直井眼中底部钻柱的纵向振动特性,利用根据相似理论设计出的钻柱动力学模拟试验装置,对不同参数组合下的钟摆钻具组合纵向振动特性进行了模拟实验研究。实验结果表明,钻柱的纵向振动主要与转速和钻压有关。转速一定时,提高钻压有利于减轻钻柱纵向振动;钻压一定时,降低转速有利于减轻钻柱的纵向振动;当对钻具施加的名义钻压一定时,随着转速的增加,平均钻压有减小的趋势。另外,在减小直井底部钻柱纵向振动的问题上存在钻压与转速的优化组合。

According to the experimental device designed on the basis of the principle of similitude, the longitudinal vibration characteristics of bottom string in straight hole were investigated. The longitudinal vibration characteristics of pendulum stem with different assembled parameters were simulated and the dynamic rules of bottom hole assembly were analyzed, The results show that longitudinal vibration of drill string is relative to rotary speed and weight on bit （WOB）. The increasing of WOB is advantageous to reduce the longitudinal vibration of drill string when rotary speed is certain, and the reduction of the rotational speed is advantageous to reduce the vibration when WOB is certain. When nominal WOB is certain, the average value of WOB has the tendency of reduction with the rotational speed increasing. Moreover, regarding to reducing the longitudinal vibration of bottom string in straight hole, there is the problem of optimization grouping between WOB and rotary speed.