South China Sea - ExxonMobil RetroPods^™

Two ExxonMobil platforms in South China Sea retrofit with RetroPods™

Deepwater Australasia Pty Ltd (DCA) was contracted by Wasco to provide installation support for the cathodic protection life extension of ExxonMobil’s assets Guntong-F (GuF) Platform and Irong Barat-C (IbC), which are both located in the South China Sea. Subsea operations were performed using a work class remotely operated vehicle (ROV) Triton XL43, and deployed from the MVSV DPII dynamic positioning vessel Bahtera Azalea.

DCA, in conjunction with WASCO, supplied a total of 36 RetroPod™ anode retrofit systems. The installation was performed from the work vessel utilizing an ROV in 63 meters of water. Two platforms were being retrofit, and each platform required 18 RetroPods™ to revitalize its cathodic protection system.

The RetroPods™ were manufactured and assembled locally in Malaysia by WASCO using Deepwater’s design and the RetroClamps™ and dual tie-back cables were manufactured by Deepwater in Houston and shipped to Malaysia.

Platform Irong Barat C (IbC) was retrofit between August 14-19, 2019. All 18 RetroPods and associated RetroClamps were successfully installed. Platform Guntong F (GuF) was retrofit between August 26-Sept. 5, 2019. All 18 RetroPods™ were successfully installed; however, the RetroClamp™ associated with RetroPod™ GuF14 was abandoned and is not connected to the platform. The remaining RetroClamps™ were successfully installed.

Once lowered to its final installation location, the ROV disconnected the lifting sling from the vessel crane and the lifting sling was left attached to the RetroPod™. The RetroClamp™ was then retrieved and installed onto the designated location on the structure. Once installed, CP readings were taken on the RetroClamp™ and the member to ensure that the RetroClamp™ was electrically continuous.

The average potential shift along the leg of platform IbC was 38mV to a new platform average potential of -1007mV.The average potential shift along the leg of platform GuF was 31mV to a new platform average potential of -1015mV.

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