NCS38气密封钻杆接头应力分析与结构优化研究

摘要

为适应更高的钻井环境要求,在NC38钻杆接头的基础上,设计了一种新型气密封钻杆接头NCS38.该新型接头设置了专门的径向金属密封结构以及辅助扭矩台肩,圆锥形密封面通过过盈配合实现密封,辅助扭矩台肩则可保护密封面.为了确定合适的密封锥度和密封过盈量,建立了NCS38接头的有限元模型,运用有限元方法进行了模拟计算.计算结果表明:不同的密封锥度和过盈量对密封面的密封性能和应力分布有较大影响,合理的锥度及过盈量参数可提高接头的密封性能.研究结果对于气密封钻杆接头的现场应用具有一定的指导作用.%To meet the requirements of tougher drilling environment,a new gas-tight drill pipe joint NCS38 was designed on the basis of NC38 drill pipe joint.The new joint is designed with a special radial metal sealing structure and auxiliary torque shoulder.The cone-shaped sealing surface formed the seal through interference fit.The auxiliary torque shoulder could protect the sealing surface.To determine the appropriate sealing taper and seal interference,the finite element model of NCS38 joint was established to conduct simulation.The calculation results show that the sealing taper and interference had great effects on the sealing performance and stress distribution of the sealing surface.The appropriate taper and interference could improve the joint sealing performance.