Abstract
The metal sealing performance of subsea X-tree wellhead connectors is crucial for the safety and reliability of subsea X-trees. In order to establish the theoretical relation between metal sealing ring’s contact stress and its structural parameters and working pressure, a mechanical analysis method for double-cone sealing of high pressure vessels is applied in analyzing the metal sealing ring under the condition of preload and operation. As a result, the formula of the unit sealing load for the metal sealing ring under operation with residual preload is shown in this paper, which ensures that the metal sealing ring has an excellent sealing effect and can prevent the metal sealing ring from yielding. Besides, while analyzing the sealing process of the metal sealing ring, the change rule of contact stress and working pressure is concluded here, putting forward that the structural parameters of the metal sealing ring are the major factors affecting the change rule. Finally, the analytical solution through theoretical analysis is compared with the simulation result through finite element analysis in a force feedback experiment, and both are consistent with each other, which fully verifies for the design and calculation theory on metal sealing ring’s contact stress and its structural parameters and working pressure deduced in this paper. The proposed research will be treated as an applicable theory guiding the design of metal seal for subsea X-tree wellhead connectors.
Similar content being viewed by others
References
HUANG **aoguang, HAN Zhongying. Contact analysis of pressure vessel based on ABAQUS[J]. Petro Chemical Equipment, 2011, 40(2): 35–39. (in Chinese)
LARSON E D, KEOSOFF K G. Marginal subsea development with existing subsea trees[C]//Offshore Technology Conference, Houston, Texas, USA, May 3–6, 2004: OTC 16533.
HILBERT L B, BERGSTRÖM J S. Evaluating pressure integrity of polymer ring seals for threaded connections in HP/HT wells and expandable casing[C]//IADC/SPE Drilling Conference, Dallas, Texas, USA, March 2–4, 2004: SPE 87214.
PEI Yanli. Structure design and optimization of seal assembly of subsea wellhead system[D]. Dongying: China University of Petroleum, 2012. (in Chinese)
DORT R V. Metal to metal seals meet downhole hazard demands[J]. Journal of Petroleum Technology, 2009, 39(10): 24–26.
MILBERGER L J, RADI A. Evolution of metal seal principles and their application in subsea drilling and production[C]//Offshore Technology Conference, Houston, Texas, USA, May 4, 1992: OTC 6994.
SWEENEY T, SCHNAKENBURG K. Behavior of 15-ksi subsea wellhead gaskets as determined by analysis and testing[C]//Offshore Technology Conference, Houston, Texas, USA, May 6, 1991: OTC 6708.
SWEENEY T, PARK N, SCHNAKENBURG K. Wellhead housing seal assembly for damaged sealing surfaces: US, 5103915[P]. 1992–01–14.
KELLY T P, THEISS D H. Rationale for sealing systems for subsea production systems[C]//Offshore Technology Conference, Houston, Texas, USA, May 1, 1989: OTC 6083.
ADAM L J, GARIEPY J. HT technology-all-meta sealing answers safety & environmental concerns[C]//Offshore Technology Conference, Houston, Texas, USA, May 1, 1995: OTC 7916.
KUROKOUCHI S, OKABE M, MORITA S. Taper-seal type metal sealing system and available applications[J]. Applied Surface Science, 2001, 169–170: 799–802.
LIU Lei, WEN Weibin, WANG Chen. Analysis research of the bimetal face seal by FEA[J]. Lubrication Engineering, 2001, 11(6): 23–27. (in Chinese)
FEI Guobiao, LIU Zhenglin, HAI Pengzhou, et al. Analysis research of the super high pressure seal by FEA[J]. Journal of Wuhan University of Technology (Transportation Science & Engineering), 2006, 30(6): 1055–1057. (in Chinese)
GONG Xueting, CAI **ing, ZHANG Qiuxiang, et al. Elastoplastic contact of metal W-sealing ring by FEA[J]. Lubrication Engineering, 2010, 35(11): 82–85. (in Chinese)
CUI **aojie. Research on metal sealing technology and sealing theory analysis[J]. China Petroleum Machinery, 2011, 39(z1): 102–105. (in Chinese)
GLIDDEN G L, SINGEETHAM S P. Improved wellhead connector design-preload production and maintenance[C]//Offshore Technology Conference, Houston, Texas, USA, May 7–9, 1984: OTC 4794.
TEODORIU C, BADICIOIU M. Sealing capacity of API connections-theoretical and experimental results[J]. SPE Drilling & Completion, 2009, 24(1): 96–103.
OWENS J H. Seal integrity and connector clam** force at the subsea wellhead[C]//Offshore Technology Conference, Houston, Texas, USA, May 2–5, 1983: OTC 4483.
PRADO L A, SDUARDO E M, OLIJINIKL A. Spool-tree development for 2,500-m water depth[C]//Offshore Technology Conference, Houston, Texas, USA, May 3–6, 1999: OTC 10970.
DELANGE R, GANDIKOTA R, OSBUM S. A major advancement in expandable connection performance, enabling reliable gastight expandable connections[J]. SPE Drilling & Completion, 2011, 26(3): 412–418.
LEWIS S, SUTER J. Requirements for a full drill through subsea wellhead and tree system[C]//IADC/SPE Drilling Conference, Orlando, Florida, USA, March 4–6, 2008: SPE 112723.
LOMBARD M S, TOWNSEND T, RAMIREZ E, et al. Field trials using an all metal ring seal floating packer[C]//SPE Western Regional Meeting, Bakersfield, California, USA, March 21–23, 2012: SPE 153839.
MORITA N, FUH G. Parametric analysis of wellbore-strengthening methods from basic rock mechanics[J]. SPE Drilling & Completion, 2012, 27(2): 315–327.
PICCIANI F, ISMAIL N E, LUCE R, et al. North bardawil development project[C]//North Africa Technical Conference and Exhibition, Cairo, Egypt, February 14–17, 2010: SPE 130281.
BERNARD M J, SINGEETHAM S P. Development of the 18–3/4′–20,000 psi subsea wellhead system for high pressure and high temperature applications[C]//Offshore Technology Conference, Houston, Texas, USA, May 5–8, 2008: OTC 19694.
NELSON S G. AKPO: the subsea production system[C]//Offshore Technology Conference, Houston, Texas, USA, May 3–6, 2010: OTC 20993.
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2012AA09A205)
ZHAO Honglin, born in 1962, is currently a professor and a master tutor at Offshore Oil & Gas Center, China University of Petroleum, Bei**g, China. His research interests include offshore oil and gas equipment.
CHEN Rui, born in 1989, achieved her master of engineering degree from China University of Petroleum, Bei**g, China, in 2013.
LUO ** is currently a senior engineer at Kingdream Public Limited Company, China.
YE Daohui is currently an engineer in Kingdream Public Limited Company, China.
Rights and permissions
About this article
Cite this article
Zhao, H., Chen, R., Luo, X. et al. Metal sealing performance of subsea X-tree wellhead connector sealer. Chin. J. Mech. Eng. 28, 649–656 (2015). https://doi.org/10.3901/CJME.2015.0309.026
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.3901/CJME.2015.0309.026