Abstract
The VX gasket is an important part of the wellhead connector for a subsea Christmas tree. Optimization of the gasket’s structure can improve the connector’s sealing performance. In this paper, we develop an optimization approach for the VX gasket structure, taking into consideration working load randomness, based on the Kriging surrogate model-NSGA-II algorithm. To guarantee the simulation accuracy, a random finite element (R-FE) model of the connector’s sealing structure was constructed to calculate the gasket’s sealing performance under random working load conditions. The working load’s randomness was simulated using the Gaussian distribution function. To improve the calculation efficiency of the sealing performance for individuals within the initial populations, Kriging surrogate models were constructed. These models accelerated the optimization speed, where the training sample was obtained using an experimental method design and the constructed R-FE model. The effectiveness of the presented approach was verified in the context of a subsea Christmas tree wellhead connector, which matched the 20'' casing head. The results indicated that the proposed method is effective for VX gasket structure optimization in subsea connectors, and that efficiency was significantly enhanced compared to the traditional FE method.
Highlights
A horizontal Christmas tree wellhead connector links the Christmas tree body to the subsea wellhead
The results indicated that the proposed method is effective for VX gasket structure optimization in subsea connectors, and that efficiency was significantly enhanced compared to the traditional finite element (FE) method
We considered the randomness of the working load, in which the Kriging surrogate models of the sealing performance are constructed to accelerate the optimization efficiency
Summary
A horizontal Christmas tree wellhead connector links the Christmas tree body to the subsea wellhead. Its working performance directly affects the stability and reliability of a subsea production system [1]. Sealing performance is the most important index for evaluating a connector’s working capability, and attempts to improve the connector’s sealing performance are underway. Research is currently focused primarily on improving the seal’s form and optimizing its structural parameters. To address seal form improvement, Peng et al [2] designed a double sealing structure comprised of a lens gasket and an O seal ring. When applied in deepwater pipelines, the sealing structure had a certain temperature compensation capability, and the axial pretension force on the collar’s flange was reduced, indicating an improvement in the sealing performance of the subsea connector. Wang et al [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
