Research on Drillpipe Stick-slip Vibration and Its Suppression Mechanism in Deep Well Drilling

Abstract During drilling deep wells, stick-slip vibration(SSV) is a reciprocating vibration form of drill bit adhesion, sliding, re-adhesion, and re-sliding. If not suppressed, it can cause serious drilling accidents, such as accelerated wear of drilling equipment, which lead to decreased drilling safety, reduced drilling efficiency, and prolonged drilling cycle. This article establishes a SSV model of the drill string system, considering the three degrees of freedom of the rotary table/top drive, hammer, and drill bit, and analyzes the SSV characteristics of the drill bit during deep well drilling. The SSV analysis of the drill string system was carried out for well XX-X-4, and the sensitivity of rotational speed, viscous damping, drilling pressure, drill bit length, and friction torque coefficient was analyzed. The results showed that the friction torque coefficient and rotational speed are the main factors affecting stick reduction efficiency, while the length of the drill collar is a secondary factor. The WOB and viscous damping have the least impact on stick reduction efficiency. The parameters were optimized to reduce SSV as the target. This article has certain guiding significance for deep well drilling operations.