HummingBird Vessel FFS - Project

Description

The Open vent drain tank on Hummingbird FPSO has been inspected in 2016 and pitting as well as general metal loss due to corrosion has been reported. The main corroded area was the right ellipsoidal head with spattered pitting and two deep pits to maximum depth of 7mm. The nominal thickness of the head is 13.5mm. As part of this job an API 579 (par 6 pitting) fitness for service assessment along with PD5500 (using Fingow software package) code calculated, and the results were found satisfactory based on level 1 assessment. The RSF(Remaining Strength Factor) of the corroded area was found greater than RSF allowable for a vessel deigned to PD5500 (RSFa=0.9) which cakes the anomaly acceptable. A technical report was issued and recommendation was made to arrest the pits in order to prevent further exposure to corrosive content. The vessel is scheduled fsor shut down and weld repair in 2019.