Double Shoulder Thread Mechanics Study and Life Analysis of Drilling Tools

Under the trend of the continuous in-depth development of global oil and gas exploration and development, the torque in deep drilling is excessively high, and drill string failure accidents occur frequently. The threaded connection part of the drill string is the main weak link of the drill string, and improving its torsional resistance performance is the main way to reduce the risk of drill string fracture and failure. Based on the mechanical analysis of the torque load of the double-shoulder drill string thread in this paper, a double-shoulder drill string thread model was established. By comparing it with the stress collected from experiments, the rationality of the simulation model was verified. The sensitivity analysis of the torsional resistance performance of the double-shoulder joint thread under torque load was studied, and its torsional resistance performance is better than that of the API thread. The sensitivity analysis of the fatigue life of the double-shoulder joint thread under torque load was carried out, and its torsional resistance performance is significantly improved compared with that of the API thread. The research results show that the torsional resistance performance of the double-shoulder joint is increased by 20.8% compared with that of the API joint, and the fatigue life is increased by 147%.