Series Design of Seal Assembly on Subsea Wellhead System

The seal assembly domestically produced is used only under shallow water and low pressure conditions and fails to meet the needs of usage under different water depths and drilling under different pressures.In view of this, this paper studies the series design method and metal sealing mechanism, and analyzes the key factors that influence sealing performance and pressure rating of seal assembly, so as to define the series design principle and evaluation criteria of seal assembly and identify the series design method.The study confirms that the 103.4 MPa wellhead seal assembly system, as the basic type of series design, can achieve the desired sealing effect and ensure safe recovery, works out the structural parameters of seal assembly under three pressure levels of 34.5, 68.9 and 137.9 MPa, and finishes the series design of seal assembly.ANSYS Workbench is used to complete a detailed mechanical analysis of the sealing performance of the basic type seal assembly.The proposed method could provide the theoretical basis and guidance for series design of the entire wellhead system.