海洋水下井口装置密封技术研究

Research on Sealing Technology of Subsea Wellhead

密封技术是水下井口装置的关键技术之一,密封性能的优劣直接影响并决定整个海洋石油开采系统的安全性和可靠性。介绍了国内海洋水下井口装置密封技术现状,尤其对美国VetcoGray公司的VX、VX-2、VGX、VGX-2、VT、VT-2等垫环密封和SG-LTR环空密封、DrilQuip公司的环空密封以及Aker公司的环空密封的结构技术参数和性能特点进行了重点分析研究。同时阐述了海洋水下井口装置密封的设计与制造关键技术。指出井口头密封的双密封面结构和球面密封面结构技术先进;环空密封的全金属密封、压入安装方式具有承压高、工作可靠、寿命长的优点。最后建议借鉴国外海洋水下井口装置密封的结构特点,加大科研力度,做好试验设施建设,以推进海洋水下井口装置国产化进程。

Sealing is one of the key technologies of the subsea wellhead. The sealing performance directly af- fects and determines the safety and reliability of the whole system of offshore oil exploitation. The current subsea wellhead sealing technologies in China are introduced. Moreover, analytical investigations are focused on the struc- tural parameters and performance characteristics of some foreign technologies, including VetcoGray＇ s gasket like VX, VX - 2, VGX, VGX -2, VT, VT - 2 and SG - LTR casing annulus seal, Dril-Quip＇ s and Aker＇ s casing annulus seal. The key technologies of subsea wellhead seal design and manufacture are also introduced. Conclusions are made that the dual sealing surface structure and the spherical sealing surface structure for wellhead seal are ad- vanced; the all-metal seal and pressed-in installation way of casing annulus seal has the feature of high pressure- bearing capacity, reliability and long service life. Recommendations are finally proposed that, to promote the do- mestication of subsea wellhead device, the structural characteristics of foreign subsea wellhead seal should be refer- enced; research should be strengthened and test facilities should be well established.