Design and Application of a Rock Breaking Experimental Device With Rotary Percussion

The rotary impact drilling technology is one of the effective speed-up methods in drilling deep well. The dynamics model of the impact process and rock breaking shows that the peak value of the impact load is affected by the spring compression, and the impact time increases with the piston’s mass increasing. The stress wave in rock is proportionate to the impact load. A new rock broken experiment device with rotary impact was designed, and the device can measure and adjust the WOB, rotary rate, impact load and frequency, also has the ability of rock breaking for conventional and rotary percussion drilling. The rock breaking experiments show that the rotary percussion drilling technology can improve the rate of penetration of PDC bit significantly; increasing the value of impact load can improve the ROP significantly. When different rotary percussion drilling tools used in different formations, optimizing the WOB and rotary rate for fast drilling is very necessary. The influence of the rotary impact drilling on the rock broken can be studied by the experiment device, which is helpful for the design and optimization of the percussion tools