Metal sealing mechanism and experimental study of the subsea wellhead connector

Abstract

The subsea wellhead connector is an essential piece of equipment whose successful metal-to-metal sealing capacity is crucial to produce deep-sea oil and gas safely. This paper analyzed the mechanical behavior of the metal seal ring in the subsea wellhead connector under preload and operating conditions while determining the role of contact stress in the theoretical relationship between the seal ring and the structural parameters, as well as working pressure. Theoretical calculations and the finite element method were used to analyze the effects of preload force, contact width, preload compression, and working pressure on contact stress. The results derived from the finite element approach were consistent with those obtained with the theoretical calculation method. Finally, the contact width and preload compression parameters of the metal seal were tested by constructing a test device to evaluate the metal seal of the subsea wellhead connector. The relationship between the preload force, contact width, and preload compression was analyzed, and the maximum sealing pressure under different preload forces was investigated. The results verified the accuracy of the theoretical and finite element calculations. This paper proposed the theoretical calculation method for designing and analyzing the metal seal of the subsea wellhead connector.