Offshore cathodic protection design, inspection, and computer modeling: Innovations from the 1980s
- CorrOcean as, Trondheim (Norway)
Throughout the 1980s, equipment was used increasingly to monitor electric fields (EF) strength/current density in CP surveys of North Sea structures. Probes for remote-operated vehicle (ROV) and diver operations are used to measure simultaneously the potential and the EF strength at exposed steel, at typical stand-off anodes, at sacrificial bracelet anodes on pipelines, and so on. A sensitive system for such purposes is based on a pair of electrodes at the tips of a T-shaped spindle rotating at a known frequency. The 1980s saw several innovations in the field of offshore cathodic protection (CP). The increasing use of organic coatings on offshore structures is more or less a result of the need to reduce the number of anodes. In a design incorporating coatings, coating breakdown plays a key role. In later years, aluminum-coated structures have been introduced for submerged conditions. It seems that in the future, aluminum coatings will be used merely as barrier coatings. The bare aluminum coating has a very low current demand on the order or 10 mA/m[sup 2] or less. Emphasis is now on CP design by computer modeling and on data retrieved during inspections using sophisticated equipment and procedures. The effect of the innovations on traditional design, on design verification, and on retrofitting is discussed in relation to relevant cases and field work. Future applications that may give better insight into CP system performance at reduced cost are also suggested.
- OSTI ID:
- 5074865
- Journal Information:
- Materials Performance; (United States), Vol. 32:12; ISSN 0094-1492
- Country of Publication:
- United States
- Language:
- English
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