Experimental Study on Stick–Slip Vibration Characteristics of Drillstring-Bit-Rock Coupling System in Horizontal Well

Experimentation is a common method to reveal the stick–slip vibration characteristics of horizontal well drill string system. Three different diameters of mini bits and an experimental bench of horizontal well drillstring system are innovatively designed to simulate the interaction between the bit and rock and the interaction between the drill pipe and well wall, which are the two boundary conditions that generate stick–slip vibration. The effects of bit type, drill pipe stiffness, rotational speed, and (ROP) Rate of Penetration on stick–slip vibration are investigated using rock-breaking experiments. The experimental results show that as the rotational speed increases from 9 to 45 r/min, (SSVI) stick–slip vibration intensity decreases. When the rotational speed is 9 r/min, the SSVI of the bit with higher cutter density drilling rock is lower than that of the bit with lower cutter density drilling rock. When the rotation speed is 45 r/min, the SSVI of the three bits is equal. The SSVI of drill pipe with smaller stiffness is greater than that of drill pipe with larger stiffness. The SSVI increases as the ROP increase from 0.36 to 1.26 m/h. The experimental findings aid in our understanding of the causes of stick–slip vibration. It lays the groundwork for the next step in reducing the harm caused by stick–slip vibration.