Corrosion risk assessment and planned maintenance for corrosion control of onshore and offshore field in Adriatic sea

摘要

This paper describes the study carried out toidentify and evaluate the risk of both internal and externalcorrosion for the facilities of gas fields in Adriatic sea, and theconsequences that a corrosion related failure can have, withregards to plant operability, production economics andpersonnel/environmental safety. The assessment study is basedon a model that quantifies the criticality of each facility buildinga risk matrix (i.e. Corrosion Risk Factor vs. ConsequenceFactor). Dependent upon the region of the matrix in which acomponent appears, various corrosion prevention, mitigation,monitoring, inspection, maintenance or replacement options,programmes and schedules may be selected to make most costeffective use of resources and to ensure safe and economicoperation over plant life.The ENI - AGIP Division District located in Ravenna comprisesseveral onshore and offshore fields, located on the Adriatic seaside in Italy: 14 fields and 180 km pipelines onshore, 25 fields(67 platforms) and 780 km sealine offshore. The first wells wereperforated in 1950, and in several cases the life of the structuresis close to the design life (Fig.1) (1). This means that the olderthe component, the higher the risk of failure because of thedegradation of coatings, and of the thickness wastage ifcorrosion occurred. The study has been carried out for theonshore and offshore pipelines and for the jackets.