The State-of-the-Art Review of Risers’ VIV Fatigue

Abstract

As one of the most prominent one, Vortex Induced Vibration (VIV) can create serious fatigue damage in risers used by the offshore industry. In deep waters, where oil and gas exploration and production continue apace, VIV may make the largest contribution to overall riser fatigue damage. Extensive researches have been done to investigate VIV response of risers, and several methods have been proposed for the fatigue life estimation of these structures. This paper addresses some of the methods available in literature for VIV fatigue life estimation of risers, focusing on their main underlying assumptions. The main focus of the study is on the influence of direct action of current on the riser structure. It is observed that riser fatigue life is greatly dependent on different parameters, and any minor change in these parameters would significantly influence the predicted fatigue life. It is illustrated that the available approaches for analyzing VIV fatigue of risers mainly focus on the VIV portion of the task, and indeed less attention is paid to the actual fatigue life analysis using various models. The importance of reconsidering the fatigue damage as a priority when designing risers has been discussed in detail, and recommendations for the future direction of researches on VIV induced fatigue of risers have been proposed.