Subsea 7, UK, has announced that following a three-year development, testing and qualification programme, its new subsea hot tap technology, Subsea Grouted Tee (SSGT), has completed offshore trials in the North Sea.
Following an extensive DNV-approved onshore testing programme in test tanks and laboratories, the offshore trials of the SSGT technology involved the mobilisation 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 utilised 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.
"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," commented John Mair, Global Technology Manager for Subsea 7.
