C-Innovation completes Jolliet TLP decommissioning job

C-Innovation (C-I) reported Aug. 28 that it has successfully completed the decommissioning of the Jolliet tension leg platform (TLP) in the US Gulf of Mexico.

Jolliet was the first TLP placed in service in the Gulf, having been originally installed in 1989 in 1,725 ft of water.

In fact, the Jolliet facility was a TLWP – a tension leg well platform – a TLP equipped with a completion and workover rig. Its placement in Green Canyon block 184 represented a new deepwater milestone for the Gulf of Mexico at the time.

C-Innovation’s decommissioning contract involved the multipurpose support vessel (MSV) Island Venture, along with its ROVs, cranes, and back deck support services.

The scope of work for the Island Venture included the cutting of two flexible risers. The eight-inch and 10-in. risers were then abandoned in a pre-determined area on the sea floor.

Additionally, C-I was responsible for detaching 12 mooring tendons from the Jolliet TLP. These tendons, each over 1,700 ft long, were cut into 305 separate sections aboard the Island Venture and then transferred to an offshore support vessel for transport to a shore base for further processing.

The decommissioning operation was monitored by C-Survey using its three positioning tugboats.

George Wilson, project manager, C-I, said, “The C-I team executed the project safely and efficiently, completing it ahead of schedule without any accidents or incidents…work began on May 2, 2025, and the project was successfully completed on June 3, 2025.”