Finite element modeling of a metal tubing hanger seal

The process of underwater oil and gas production is accompanied by high values of well pressure, which can reach thousands of atmospheres, while the service life of this equipment, laid down in the technical specifications, can reach 20 years or more. To ensure the safety of the subsea production process throughout the life of the equipment, it is important to pay special attention to the tightness and strength characteristics of metal seals as part of the design. In this regard, this article is aimed at identifying the degree of influence of such a geometric parameter as the depth of the recess on the characteristics of the tightness and strength of metal seals. The finite element method was modelled, using the Ansys calculation complex, of the stress-strain state of the metal seal of a tubing hanger of a standard design during installation and under the influence of well and test pressure. Finite element modeling was carried out using elastoplastic models of material deformations. To analyze the performance of a metal seal design, criteria for assessing strength and tightness are given. During the modeling, parameters characterizing the tightness and strength of the structure were determined. In order to study the degree of influence of the recess depth of the metal seal on the characteristics of tightness and strength, modeling was performed with an increase in this parameter to 80 %. The results of calculations of tightness and strength parameters with different recess depths are presented. The materials of the article are of practical value for design engineers and scientists dealing with the problems of ensuring a hermetic underwater connection using metal seals.

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