材料及循环内压对VX钢圈密封性能的影响

Influence of material and cyclic internal pressure on sealing performance of VX gasket

水下井口连接器是海洋油气勘探开发的重要设备,其中VX钢圈密封性能直接影响到整个水下生产系统的安全。为解决目前水下井口连接器分析中采用二维轴对称模型,存在建模不准确的问题,基于ABAQUS软件建立了水下井口连接器有限元三维模型,分析了预紧和生产工况下的VX钢圈密封性能,探讨了材料属性以及循环内压对密封性能的影响。分析结果表明:在预紧和生产工况下,VX钢圈密封性能良好,表面接触应力在环向分布上有一定的波动;材料对密封性能的影响主要体现在屈服强度上,接触应力随屈服强度的增加而提高;在0~155.25 MPa循环内压作用下,连接器的密封性能逐渐降低,因此不能多次使用。研究成果可为VX钢圈的生产和使用提供理论支撑。

Subsea wellhead connector is an important equipment for offshore oil and gas exploration and development. The sealing performance of VX gasket directly affects the safety in the whole subsea production system. In order to solve the problem of inaccurate modeling caused by two-dimensional axismetrical model used in the analysis of subsea wellhead connectors, a three-dimensional finite element model of subsea wellhead connectors was established based on ABAQUS software. The sealing performance of VX steel gasket under preloaded and working conditions was analyzed, and the influence of material properties and cyclic internal pressure on the sealing performance was discussed. The results show that under preloaded and working conditions, the connector has desirable sealing performance, and the surface contact stress of VX gasket fluctuates in the circumferential distribution. The influence of material on sealing performance is mainly reflected in the yield strength, and the contact stress increases with the increase of yield strength. Under the action of 0~155.25 MPa cyclic internal pressure, the sealing performance of the connector decreases gradually. Therefore, the connector cannot be used repeatedly. The research results can provide theoretical support for the production and application of VX gasket.