| 摘要: |
| 波致、涡激和浮式钻井装置运动引起的疲劳是深水水下井口失效的主要形式之一,井口动力分析方法的选取直接影响水下井口疲劳评估的效率和准确性。针对采用局部精细模型对井口进行动态响应分析时的耗时和精度低等问题,提出基于局部等效方法的深水水下井口半解耦分析模型,研究隔水管-井口整体分析模型中的井口局部等效方法,考虑管土作用建立水下井口局部有限元模型,建立梁和弹簧组合的井口局部等效数学模型,推导梁单元和弹簧单元参数计算公式。采用该半解耦模型进行南海深水水下井口分析,将静力分析结果与精细有限元模型分析结果进行对比,并将动力分析结果与解耦、全耦合两种方法进行对比。结果表明,提出的井口等效模型计算精度高、效率高,可为开展水下井口系统动态响应分析和疲劳评估提供一种高效算法。 |
| 关键词: 水下井口 局部等效 数学模型 半解耦方法 |
| DOI：10.3969/j.issn.1673-5005.2019.03.015 |
| 分类号::TE 52 |
| 文献标识码:A |
| 基金项目:国家自然科学基金重点项目 (51890914); 国家“973”重点基础研究发展计划项目 (2015CB251203); 国家科技重大专项(2016ZX05057-011) |
|
| A semi decoupled analysis model of subsea wellhead based on local equivalent method |
|
CHANG Yuanjiang1, WANG Jian1, JI Jingqi1, LI Jiayi1, XU Liangbin2, SHENG Leixiang2, QIAO Chang1
|
|
(1.Centre for Offshore Engineering and Safety Technology in China University of Petroleum (East China), Qingdao 266580,China;2.Research Institute of China National Offshore Oil Corporation, Beijing 100027, China)
|
| Abstract: |
| Fatigue caused by wave, VIV and motion of floating drilling platform is one of the main failure modes of the deepwater subsea wellhead, and the method for dynamic analysis of subsea wellhead directly affects the efficiency and accuracy of the subsea wellhead fatigue assessment. Aiming at the problems of time-consuming and low accuracy for dynamic response analysis of the wellhead by using the local fine finite element model, a semi-decoupled analysis model of the subsea wellhead based on the local equivalent method is proposed. The local equivalent method of the wellhead in the global analysis model of the riser-wellhead system is studied, where the equivalent mathematical model of the wellhead consisting of beams and springs is built, and the parameter calculation expressions of beam and spring elements are derived. Then the local equivalent model is used for analysis of the subsea wellhead in the South China Sea. The results of static analysis are compared with those of the local finite element model, and the results of dynamic analysis are compared with those of the full-coupled and uncoupled models. The comparison indicates the correctness and efficiency of the semi decoupled analysis model of the subsea wellhead proposed, thus providing an efficient algorithm for the dynamic response analysis and fatigue assessment of the subsea wellhead system. |
| Key words: subsea wellhead local equivalence mathematical model semi-decoupled model |
