Four RetroSleds^™ installed on two pipelines

Four RetroSleds™ installed on two pipelines, electrically connected via RetroClamps™

Deepwater Corrosion Services was contracted by Stone Energy to supply and oversee the installation of four RetroSled™ anode sleds on to two subsea pipelines in the Gulf of Mexico. One RetroSled™ was installed on a 10” line and three RetroSleds™ were installed on the 6” line. Both pipelines are located in the SS-113 block.

The RetroSleds™ were installed by divers working from a jack-up boat. Once the correct pipeline was found using Mesotech operated by an Oceaneering technician, the RetroSleds™ were attached to RetroClamps™ using Dual Tie-Back cables topside by a Deepwater Corrosion Services technician. Continuity between the RetroSled™ and RetroClamps™ were checked using a multimeter.

Once continuity was confirmed, the RetroSled™ and RetroClamps™ were over-boarded and lowered to the final installation location using the boat’s crane. Once on the seabed and oriented parallel to the pipeline at the correct installation location, the divers removed the rigging and attached the RetroClamps™ to the pipeline. Installation location 3 on the 6” pipeline and location 4 on the 10” pipeline were found to have 1.5” of concrete weight coating (CWC) covering the pipe. Due to the RetroClamps™ being sized to fit bare pipe, the CWC had to be removed prior to installing the RetroClamps™ at these 2 locations. Removing the CWC increased the installation time by approximately 3 hours per location.

CP readings were taken on the pipeline before and after the installation of each RetroClamp™ to confirm continuity.

All four RetroSleds™ were successfully installed and were providing cathodic protection to both pipelines. Installation time from lifting the RetroSled™ off the deck to installing the RetroClamps™ and taking final CP readings was on average 25 minutes per location once the pipeline was located and cleaned of any coating.

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