Advanced systems engineering firm 2H has launched the second phase of its Measurement-Based Wellhead Fatigue joint industry project (JIP), which aims to improve riser, wellhead, and conductor fatigue estimates and make drilling operations more reliable and efficient.
In Phase 1 of the project, 2H collaborated with nine major operators to gather and analyze field measurements from 10 drilling campaigns in the Gulf of Mexico and the North Sea. The data covered a range of environments, water depths, soil characteristics, riser and wellhead configurations, and vessel types. Findings from the analysis verified that industry assumptions for wave and vortex-induced vibration (VIV) fatigue assessments are conservative and remaining fatigue life tends to be higher than that determined by typical design methods. A more accurate prediction of remaining fatigue life can eliminate the need for costly mitigation methods or unnecessary upgrades and downtime during severe events.
In the second phase, the field data analyzed in Phase 1 will be used to explain uncertainties identified in the riser, wellhead, and conductor fatigue analysis. The findings will further improve the accuracy of future wellhead fatigue assessments and provide an industry consensus on design methodology.
“Wellhead and conductor fatigue challenges have become more prevalent in recent years due to the use of newer generation vessels with larger blowout preventers (BOPs) and longer drilling operations being conducted in more harsh environments,” said Bulent Mercan, 2H project manager. “The first phase of the Measurement-Based Wellhead Fatigue JIP proved to be a great industry collaboration to solve this problem through sharing resources. A reliable set of analytical parameters leveraging diverse field measurements will lead to improved accuracy and more efficient drilling operations.
“There are a lot of learnings from the field measurements. We plan to further utilize the data sets to address some uncertainties in the analysis. The findings will be used in the near term to increase the accuracy of wave and VIV fatigue assessments and will eventually inform a revision of industry riser design codes.”
Currently, seven major oil and gas operators have agreed to join the second phase of the JIP.
Details of the work carried out in Phase 1 is summarized in this paper, which was presented at the 2020 Offshore Technology Conference.