Serialization Design And Research Of Seal Assembly Of Subsea Wellhead System

Subsea wellhead system as the basis of subsea oil and gas exploitation, is the essential equipment for well drilling, completion and production. Seal assembly as pressure control device of subsea wellhead system, is one of the key components of the wellhead system, the sealing performance and reliability of the seal assembly is to provide security for the whole subsea oil and gas. The purpose of this paper is to study the key factors of seal assembly that influence sealing performance and pressure rating, get a seal assembly seriation design method, realization of subsea wellhead seal assembly series.Firstly, Analysis of all kinds of composite seal method, sealing structure and the principle of high pressure metal seal, got the metal seal assembly sealing performance criterion, which determine the material of seal assembly. Through the serialization design method and the metal sealing mechanism research, determine the seal assembly serialization design principles and evaluation standard, divided 5000 psi to 20000 psi pressure level into four pars: 5000, 10000, 15000 and 20000 psi.Secondly, this paper selected 18-3/4-15000 psi wellhead sealing system as the base type of series design, and completed the design of the base type seal assembly, used ANSYS workbench to analyze base type sealing performance of seal assembly. Analysis of key structural parameters to affect the sealing performance of seal assembly, the sealing contact surface of compressibility and flange radius is a key factor affecting the sealing contact pressure, and through the response surface obtain that the compression is the most important factors that affect the sealing performance, as a seal assembly serialization design parameter. Combined with the traditional theory of elastic-plastic deformation and the seal body geometry analysis the relationship between the sealing pressure and drive body cone width, to obtain the similar ratio of serialization design and complete the structure design of the 5000 psi, 10000 psi and 20000 psi three levels of seal assembly.Finally, used ANSYS to analysis the sealing performance and the mechanical properties, verified the feasibility and effectiveness of the seal assembly serialization design. used ANYSY Workbench of Design Explore module to complete the optimization Design of assembly driver cone width and five sealing flange radius,the optimized three classes of seal assembly have a very good improvement in terms of safety coefficient and driven load.