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.