Project Review:
Deepwater retrofits the cathodic protection on
five structures in fourteen days

Overview

In the month of December 2007, Deepwater Corrosion Services performed anode retrofits on five structures located in the Gulf of Mexico. The installation took a total of fourteen days. The platforms consisted of:

• 8-pile in 176 fsw (2.5 days)
• 8-pile in 113 fsw (2.75 days)
• 8-pile in 111 fsw (4 days)
• 4-pile in 111 fsw (4 days)
• 1-pile in 115 fsw (.5 days)

The retrofitted CP system consists of:

• Ninety-four (94) RetroPod sacrificial alluminum anode pods
• Ninety-four (94) RetroClamps for attachment

Installation

The work was accomplished utilizing a 210' four point boat, with divers. Divers essentially guide the RetroPod down to the bottom and apply the RetroClamp to the prescribed tubular (usually a diagonal near the sea-floor). The time-differences are due to some structures requiring minor scrapping, and to standby time caused by other operations being performed. There were a total of 94 anode pods positioned strategically around and inside the structures on-bottom.

The ease and simplicity of the system reduces diver's time on bottom (one pod can be installed in as little as one hour), and the diver is not required to interface with any heavy loads in the water (as they are using clamp-on anode replacements). The innovative RetroClamp system, allows the pod to be clamped and electrically connected to the diagonal member, completing the circuit necessary for the cathodic protection system to begin polarizing the structure. The RetroClamp can be installed by diver or ROV (divers in this case).

Image gallery