环形金属密封总成密封机制及性能分析

Mechanism and Performance Analysis of Annular Metal Seal Assembly

环形金属密封总成是水下井口头系统重要组成部分,其性能直接影响到水下井口头系统的安全性,甚至整个水下油气系统的可靠性。分析环形金属密封总成的密封机制和工作原理,结合有限元分析结果,从密封环在密封过程中的变形情况来分析其密封性能。结果表明:密封环在弹性变形阶段可以实现密封,但对密封环的表面粗糙度和表面质量有很高的要求,在环形密封总成工况条件下无法保证,应避免在此阶段实现密封;密封环在塑性变形阶段能够填补环表面存在的缺陷,实现良好的密封;在塑性变形阶段,密封环接触面的变形情况成为影响密封性能的唯一因素。

Annular metal seal assembly is an important part of the subsea wellhead system,its quality directly affects the security of subsea wellhead system,and even the reliability of subsea oil and gas system.By discussing the mechanism and working principle of annular metal seal assembly,the sealing performances were analyzed from the deformation of sealing ring in the sealing process and combining with the finite element analysis results.The results show that the seal can be a-chieved at the elastic deformation stage of sealing ring,but there is high demand of surface roughness and quality that the annular seal assembly cannot be guarantee under the working conditions.The sealing ring can achieve good seal because the surface defects of the sealing ring can be filled at the stage of plastic deformation.The deflection of the sealing ring contact surface becomes the only factor affecting sealing performance at plastic deformation stage.