A Practical Drilling Riser and Wellhead Vortex Induced Vibration Fatigue Comparison Between Analysis and Field Measured Data

In order to design a drilling riser system that meets the operational requirements, it is industry practice to use analytical tools to predict the riser and wellhead fatigue damage. This paper focuses on the comparison between the analysis and field measurements for both the drilling riser and wellhead vortex induced vibration (VIV) fatigue damage, during a recent loop current event in the Gulf of Mexico. The field data, which includes the drilling riser configuration, riser tensioner setting, and loop current data, were considered in this comparison. As one of the key contributors to VIV fatigue, the loop current, was measured from a survey vessel in the field during the blowout preventer (BOP) latched and retrieval period. The analysis utilized the VIV program SHEAR7 V4.6 to calculate the fatigue damage for both the drilling riser and wellhead system. The field measured acceleration data from the installed monitoring system was converted to the fatigue damage by transfer function methods. Key findings and conclusions are summarized to improve future analysis predictions of drilling riser and wellhead fatigue damage.