Research on bearing capacity and sealing contact characteristics of the subsea wellhead connector

Abstract

This paper analyzed the bearing capacity of a subsea wellhead connector when exposed to external pressure and the bending moment in different operational modes and load conditions to determine the possible areas prone to failure. The contact between certain parts during the pre-tightening process impacts other areas, affecting the sealing performance. A symmetrical, three-dimensional periodic contact model was established via Finite Element Method (FEM) to simulate and analyze the sealing performance of the subsea wellhead connector. Furthermore, this study examined the variation laws governing contact form, preload, contact width, radial compression, and internal pressure, as well as their influence on the contact stress of the metal sealing ring. The results indicated that effective sealing was achieved at radial compression levels ranging from 0.1045 to 0.2089 mm. The preload contact stress was directly proportional to the preload and radial compression and inversely proportional to the contact width. The operational contact stress initially decreased, then increased at a higher internal pressure.

Analytical calculation method for predicting contact loads and structural strength of metallic gasket of subsea connectors under thermal loads

“…Li et al 8 calculated the contact pressure on the sealing surface in the preload and operating state by finite element model to investigate the sealing characteristics of the subsea wellhead connector with consideration of the thermal stress. In another paper, Li et al 9 developed theoretical models for calculating contact stress of subsea wellhead connectors by taking external pressure, internal pressure and bending loads into consideration, and then utilized FEM to investigate relationships between contact pressure and preloads, contact width, radial compression, as well as internal pressure. In that paper, various loads were equivalently converted into a theoretical model in an innovative way in order to perform mathematical analyses.…”

Mechanical Behavior and Sealing Performance Study of Subsea Connector Core-Sealing Components under the Combined Action of Internal Pressure, Bending Moment, and Axial Load

“…Duan et al [19] proposed a stress analysis method (SAM) to solve the theoretical design problem of the main parameters of the hub structure of the subsea connector by establishing a deformation continuum relationship between a thick-walled cylinder and a hollow ring plate. Li et al [20] theoretically analyzed the load-carrying capacity of subsea wellhead connectors when subjected to external pressure and the bending moment under different operating modes and loading conditions. Yun et al [21] developed a heat transfer model to investigate the sealing capability of lens-type sealing structures of subsea clamp connectors under the influence of external seawater and internal oil and gas temperature loads.…”