The inclusion of supplementary assemblies of sacrificial anodes placed on the sea bed can be an effective method for upgrading the existing cathodic protection of platform legs, where the old sacrificial anodes provide insufficient current for polarizing the structure to reach the protective potential. The use of this approach made it possible to obtain a satisfactory effect on the cathodic polarization on platform legs with a length of 80 m that were immersed in the sea. After the installation of anodic systems, the level of full cathodic protection of one leg was reached in just a week, and the potentials of the upper portions of the two remaining legs deviated from the protective potential value by only 20 mV. However, these were not final operational potential values, as after startup of the cathodic protection installation; the degree of cathodic polarization always increases. This process may last several weeks, or even months, due to the large surface area of the protected structure and a relatively bad condition of the protective layers. Moreover, the process of the formation of non-conductive calcareous deposits that are formed on cathodically protected steel in the seawater environment will favour the increase of the polarization.
Studying the effectiveness of a modernized cathodic protection system for an offshore platform
Effektivität eines modernisierten kathodischen Korrosionsschutzsystems einer Offshore-Plattform
Anti-Corrosion. Methods and Materials ; 58 , 4 ; 167-172
2011
6 Seiten, 6 Bilder, 11 Quellen
Aufsatz (Zeitschrift)
Englisch
Offshore platform cathodic protection retrofits
Tema Archiv | 1996
|Cathodic protection of offshore structures
Tema Archiv | 1977
|Effectiveness of cathodic protection
Tema Archiv | 1983
|Cathodic protection of offshore well casing
Tema Archiv | 1988
|