10 Years Experience of North Sea FPSO Moorings Repair, Renewal and Life Extension Work

摘要

This paper summarises 10 years of experience gained during the repair/renewal/life extension of several North Sea FPSO mooring systems. This includes reference to Phases 1 and 2 of GL Noble Denton’s Mooring Integrity Joint Industry Project (JIP) plus recent North Sea mooring system repair and replacement operations. Issues encountered and typical mooring degradation mechanisms are reviewed making reference to the age of the components. The paper discusses how issues have been addressed in practice taking into account the risk of failure, offshore conditions and equipment availability. Brief descriptions are included of the various mooring intervention campaigns including actual offshore schedules, selected vessels, required additional equipment and ROV spreads. Positive and negative lessons learnt during the intervention campaigns are included. The importance of allowing sufficient time for planning and preparation of the intervention campaigns is stressed.