The Open Petroleum Engineering Journal

2016, 9 : 279-287
Published online 2016 December 14. DOI: 10.2174/1874834101609010279
Publisher ID: TOPEJ-9-279

RESEARCH ARTICLE
 Analysis on the Operation Fatigue of Deepwater Drilling Riser System

Xiuquan Liu, * , Guoming Chen , Jingjie Fu , Jingqi Ji , Qiang Song and Yuanjiang Chang

*Address correspondence to this author at the Centre for Offshore Engineering and Safety Technology, China University of Petroleum, No. 66, Changjiang West Road, Huangdao District, Qingdao, China; Tel: 0532-86983393; Fax: 0532-86983393; E-mail: lxqmcae@163.com

ABSTRACT

Fatigue is one of main failure modes of deepwater drilling riser system. Analysis models of wave induced fatigue and vortex induced fatigue of deepwater drilling riser are established according to the riser connection, installation and hang-off operations. Characteristics of wave induced fatigue and vortex induced fatigue of riser system in different operation modes are studied. The influence of each operation fatigue on the combined fatigue is also identified. The results show that wave induced fatigue damage and vortex induced fatigue damage of upper riser are large in installation and hard hang-off modes. The fatigue damage of riser system in soft hang-off mode is less than that in hard hang-off mode. The combined fatigue damage of the upper and lower riser is large. The lower riser is under the influence of wave induced fatigue and vortex induced fatigue, while the upper riser is mainly under the influence of wave induced fatigue, especially that in installation and hang-off modes. The fatigue damages of riser in installation and hang-off modes have a great influence on the combined fatigue of riser and cannot be neglected in riser fatigue analysis.

Keywords:

Deepwater, Drilling riser, Operation fatigue, Vortex induced fatigue, Wave induced fatigue.