Cathelco to counter marine growth on Diamond semisub

Cathelco will supply marine growth prevention systems to Diamond Offshore’s semisubmersible Ocean Valiant, currently operating at the Janice field in the UK central North Sea.

Diamond Offshore’s semisubmersible drilling rig Ocean Valiant
Diamond Offshore’s semisubmersible drilling rig Ocean Valiant

Offshore staff

CHESTERFIELD, UKCathelco will supply marine growth prevention systems (MGPS) to Diamond Offshore’s semisubmersible Ocean Valiant, currently operating at the Janice field in the UK central North Sea.

The systems will protect the pipework connected to port and starboard seachests against blockages caused by build-up of barnacles and mussels, which can impact the efficiency of associated equipment.

Cathelco will install copper and aluminum anodes in two electrolysis tanks with pipework connected to the seachests in order to dose the water flowing through the system.

The anodes are fed with a low impressed electrical current from a control panel which results in the production of copper and aluminum ions. Copper ions flow through the seawater pipework system, creating an environment where the larvae of barnacles and mussels do not settle or grow.

At the same time, the aluminum ions form an anti-corrosive layer on the internal surfaces of pipes.

The concentration of copper is only around six parts per billion, but sufficient to prevent marine growth, without harming the wider marine environment, Cathelco said.

The company is also supplying MGPSs for four jackup barges owned by Gulf Marine Services, again to provide protection against blockages in pipework caused by marine growth.

Cathelco will install the systems over the next few months when theKikuyu, Kawawa, Kudeta, and Keloa barges return to the GMS yard in Abu Dhabi for scheduled maintenance work.

It will supply two types of MGPS systems for each of the vessels, one to provide protection when they are in transit with their hulls floating on the water, and the other for when the platforms are in the elevated position.

The seachest installations, protecting the vessel in transit, will consist of two pairs of copper and aluminium anodes connected to a control panel, while in the elevated position copper anodes will be used protect the submersible pumps.

04/19/2018

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