Cathelco ICCP systems protect offshore structures and vessels
One of the largest offshore accommodation units in the world will be installed with a Cathelco impressed current cathodic protection system to protect its underwater surfaces against corrosion, the company reports.
The Prosafe GVA3000E, currently under construction at the Jurong Shipyard in Singapore, will eventually be positioned on the North Sea Norwegian continental shelf where it will provide accommodation for up to 450 people. The semi-submersible will be equipped with DP3 dynamic positioning as well as a 12 point mooring system to operate efficiently in the harshest environmental conditions.
Cathelco will protect the pontoons, columns and bracings of the structure using an arrangement of reference electrodes and anodes which are wired to thyristor control panels.
The system will utilise the latest C-Max disc anodes which are diver changeable, an important factor on semi-submersibles which remain on station for up to 30 years. The thyristor control panel is equipped with a C-Nexus controller which has numerous features to ensure that the level of corrosion protection is precisely controlled and monitored. These include comprehensive data logging and information systems which provide a complete record of the performance of the ICCP equipment.
“The C-Nexus controller is particularly important in multiple anode installations because it enables engineers to see individual anode outputs to ascertain the system is operating correctly. The remote control monitoring unit means that the information can be viewed in any convenient location on the semi-submersible”, said Aneel Mumtaz, a senior corrosion engineer at Cathelco.
Cathelco has also won an order to supply an ICCP system for the Lewek Arunothai, an FPSO which is being modified at the Keppel yard in Singapore. Following conversion, the vessel will be moored in the Kamelia field located in the North Malay basin where it will provide an early flow of gas prior to the full field integrated gas development.
Cathelco are supplying forward and aft ICCP systems for the vessel to protect the hull against corrosion. The forward system will consist of two 100 amp C-Max disc anodes and reference cells, mounted port and starboard, connected to a thyristor control panel. The more powerful aft system will comprise two 200 amp C-Max disc anodes and reference electrodes. All of the anodes are diver changeable to simplify replacement over a design life of 15 years.
Another order has come from Sembcorp Marine, who are building the NS Guarapari drillship at their wholly owned Brazilian shipyard, Estaleiro Jurong Aracruz.
The vessel represents the next generation of high specification drillships. It is capable of operating at 10,000 feet water depth and drilling to depths of 40,000 feet with accommodation facilities to house a crew of 180 personnel.
Cathelco are supplying forward and aft ICCP systems using an arrangement diver changeable anodes and reference electrodes to protect the hull against corrosion.
“Drillships are specialised vessels and require precise positioning of the ICCP electrodes to avoid interference with other systems such as sacrificial anodes and drilling equipment. Cathelco have considerable experience of these vessels and fully understand the requirements”, Mr Mumtaz concluded.
The orders for the systems have been won by Cathelco S.E.A based in Singapore who provide technical support and strategic stocks of equipment for projects in Malaysia, Indonesia, Vietnam, Philippines and Thailand.
