Thursday, March 20, 2008 - 9:55 AM
Convention Center, Second Level, R07 (Ernest N. Morial Convention Center)
08274

Cathodic Protection Modeling of Buoy Chain Connector by 3D Software Simulation: Influence of Holes Size and Coating

Jean Vittonato, Total; Marcel G. Roche, Total SA

The long term integrity of offshore buoy moorings chain connectors is mandatory, especially for preventing any risk of fatigue corrosion cracks. The chain connector is basically a few meters long hawse pipe with the ratchet on buoy side and the guide ring on the other side. A few links of chain located inside this pipe must be effectively cathodically protected from sacrificial anodes which can only be located on the external part of the hawse. Space between chain link and the internal part of the pipe is narrow, leading to a significant potential drop. To improve current distribution on the chain, holes are drilled on the pipe so that current can flow through the holes. 3D simulation software, based on boundary elements model, can advantageously be used to determine whether these holes can allow the whole chain inside the pipe to be efficiently protected. Positive influence of coating will be quantitatively demonstrated. In addition, comparison of results with analytical simulation will also be given.