Subsea 7 says that following a 3 year development, testing and qualification program, its new subsea hot tap technology -- Subsea Grouted Tee (SSGT) -- has successfully completed offshore trials in the North Sea and further demonstrated the technology's deepwater, diverless potential.

Following an extensive DNV approved onshore testing programme in test tanks and laboratories, the offshore trials of the SSGT technology involved the mobilization of a subsea grout mixing and injection unit, complete with test tee assemblies, on Subsea 7's Seven Pelican dive support vessel (DSV). The skid mounted mixing unit was developed to enhance diver based hot tapping operations and also allows the SSGT technology to be utilized in deep water, where pumping from the surface could be challenging.

During the trials, the mixing unit was deployed to the seabed where divers carried out the installation and hook up operations. After grout injection into a test tee assembly followed by a 24 hour grout curing period, the unit was recovered to the vessel where the grout quality test was successfully performed.

John Mair, Global Technology Manager for Subsea 7, commented, "Subsea 7 has developed the capability to deliver this technology over the past three years because we believe it offers a safer and more cost-effective solution to traditional hot-tap intervention methods. The successful completion of the offshore tests further demonstrated the benefit and quality of mixing the grout on the seabed as opposed to pumping from the surface providing further evidence that the technology can also be considered for deepwater, diverless applications.

"This again demonstrates Subsea 7's commitment and capability related to technology development and our aim to be the Subsea Partner of Choice in our sector."

Tags: Subsea 7