Abstract
Cathodic Protection (CP) system retrofits (upgrade or replacement) are typically required to prevent subsea corrosion beyond the initial design life of offshore assets. This paper describes the equipment and installation methodologies used to provide a total of 21,000 A of current output capacity for a 25-year life extension to the three structures platforms Heritage (HE), Harmony (HA), and Hondo (HO), installed between 1979 and 1989, approximately 19 km west of Goleta, California in water depths between 259 m to 365 m. Cost and environmental impact were reduced by re-utilizing existing equipment, minimizing ROV vessel time, and avoiding extensive structural modifications.
21 remote anode sleds mounted onto cassettes with their cable pre-spooled onshore, rated at 1000 A each, were deployed and inspected in 17 days. The fast installation was achieved by applying the hardware required to protect the cable either in the factory or staged onshore. The components were engineered to limit the installation complexity and the potential for damage.
The system was successfully commissioned, operationally tested, and energized to full output. The overall installation was completed safely with no injury to personnel.
