Way Ahead In Corrosion Control

Deepwater installs RetroPod XL in the Gulf of Mexico


Deepwater Corrosion Services, Inc. provided a cathodic protection (CP) system for the Olympus TLP’s wellheads and permanent guide bases (PGBs) installed in the Mississippi Canyon in the Gulf of Mexico (24 total PGBs). The RetroPod XL is an anode sled that was deployed from Oceaneering’s ROV support vessel, the Ocean Alliance, and installed on the seabed in approximately 3,000 feet of water. This cathodic protection system, in conjunction with the existing PGB anodes, is designed to provide protection for 45 years.



Four RetroPod XL units were deployed around the perimeter of the well bay. To reduce the number of subsea lifts, each anode array was designed to accommodate 6 wells by use of the RetroClamp electro-mechanical grounding clamp. Each RetroPod-XL supports approximately 12,000 lbs. of aluminum anodes, arrayed to provide 32 Amperes of CP current for the 45-year service life. In addition, SunStation CP monitoring systems are contained on each RetroPod-XL to allow instant confirmation of CP readings during installation and for future integrity surveys. These solar-powered CP monitoring systems allow an ROV to take CP readings without the need to mobilize a CP probe and without the ROV flying within the tightly clustered subsea equipment. 

The installation of these 4 RetroPod-XLs and 24 RetroClamps as well as the SunStation CP survey occurred in less than 30 hours.