高频振动钻具冲击下岩石响应机理及破岩试验分析

为了研究深井、超深井硬地层中高频振动冲击钻井的破岩机理及破岩效果，基于机械振动原理，建立了高频振动激励下有限深度范围内岩石稳态振动响应的幅频特性模型，分析了井底岩石的响应特点。通过PDC钻头的旋转、高频振动冲击的联合破岩试验，分析了转速、频率等参数对振动冲击钻井机械钻速的影响。结果表明:随着振动冲击激励频率增大，机械钻速逐渐增大；振动冲击激励频率为1 400~1 500 Hz时，机械钻速达到最大，与无振动冲击激励相比增幅为93.5%~106.3%。理论研究和试验结果都证明，高频振动冲击能够降低岩石抗钻能力，提高破岩效率。 

Rock Response Mechanism and Rock Breaking Test Analysis for Impact of High Frequency Vibration Drilling Tool

In order to study the rock breaking mechanism and effect of high frequency vibration impact drilling in hard formations of deep and ultra deep wells,based on the principle of mechanical vibration,the amplitude frequency characteristics model of rock steady vibration response was established under the limited depth under high frequency vibration excitation,and the bottom hole rock response characteristics were analyzed.On this basis,through joint rock breaking test with PDC bit rotation and high frequency vibration impact,the effects of parameters such as speed of rotation and frequency on the rate of penetration of vibration drilling were analyzed.Experimental results showed that with the vibration impact excitation frequency increased,the rate of penetration increased gradually;between the frequency of 1 400-1 500 hz,rate of penetration reached the maximum,at this point,the increase in the rate of penetration was between 93.5% and 106.3%.Theoretical research and experimental results had proved that the high frequency vibration shock could lower rock resistance,and increase rock breaking efficiency.