Dynamic stability evaluation of subsea wellhead based on fully coupled model. (1st August 2022)

• Record Type: Journal Article
• Authors: Qiu, Na; Liu, Xiuquan; Liu, Zhaowei; Li, Yanwei; Chang, Yuanjiang; Chen, Guoming; Xu, Liangbin
• Is Part Of: Ocean engineering. Volume 257(2022)
• Publication Date: 2022-08-01
• Subjects: Subsea wellhead -- Drilling riser -- Fully coupled system -- Dynamic stability; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.111720
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: The subsea wellhead is a key equipment for offshore oil and gas development. Traditional research focuses on static stability of subsea wellhead system in which the dynamic effect is neglected. In this paper, a drilling platform/riser/wellhead/conductor fully coupled dynamic model is established to evaluate the dynamic stability of subsea wellhead system. An algorithm for solving the fully coupled dynamic model is proposed based on finite element method and Newmark integral method. A fully coupled analysis program is also developed in MATLAB to conduct the dynamic stability evaluation of subsea wellhead system based on the proposed fully coupled model and solving algorithm. Simulation results show that the maximum dynamic response of subsea wellhead system is obviously larger than static response. That is, the subsea wellhead system is likely to be unstable with dynamic loads. The depth of wellhead dynamic displacement and bending moment induced by dynamic loads reaches 32 m and 45 m under mudline, respectively. The dynamic response value appears an inflection point at a certain depth under the mud line. The subsea wellhead system vibrates in the opposite direction before and after the inflection point. Highlights: A drilling platform/riser/wellhead/conductor fully coupled dynamic model is established. An algorithm for solving the fully coupled dynamic model is proposed. A fully coupled analysis program is developed in MATLAB. The subsea wellhead system is likely to be unstable with dynamic loads. The subsea wellhead system vibrates in the opposite direction before and after the inflection point.