Flangeless Subsea Launcher Debuted at Subsea Expo

Currently, temporary subsea launchers are designed for flanged pipe connection to allow maintenance pigs and isolation plugs to be deployed and recovered for pipeline maintenance or repair operations, however, flanged connections limit the location of where a subsea launcher can be attached.

The STATS designed flangeless solution, which was this week launched at the Subsea Expo exhibition in Aberdeen (February 3-5), can be efficiently lowered to the seabed and introduced to an open pipe end without the need for hyperbaric welding.

STATS Group director of EPRS and subsea services, Dale Millward, said: “Demand for this technology is growing and we have seen global enquiry levels increase in recent months. We are currently designing and manufacturing an ROV compatible launcher as part of an intervention and repair project on a damaged subsea pipeline for a major operator in the South China Sea.

“Our client centered approach and extensive engineering capabilities allows us to develop cost-effective solutions to meet their exact requirements and overcome their pipeline integrity issues.”

Once the ROV operated launcher is lowered to the seabed at location and introduced to the open pipe end, a manipulator clamp mounted at the front of the launcher is positioned and secured onto the pipe, and retracted towards the launcher pulling the launcher centrally on to the open end of pipe until fully installed.

The launcher housing incorporates the lock and seal module which when actuated provides a secure connection to, and seal against, the outside diameter of the pipe using STATS proven lock and seal technology. Once actuated, the locks prevent movement of the pipe during pigging operations and the seal provides a leak tight barrier.

The Aberdeenshire-based company have recently supplied a Flangeless Subsea Launcher with a total of six 32” Remote Tecno Plug isolation tools for a project in the Black Sea.

This equipment will enable pipeline flood prevention and wet buckle recovery solutions during pipe laying operations, providing contingency equipment to isolate the pipeline in the event of a wet buckle.

Once the Remote Tecno Plug is deployed into the pipeline the FSL can be removed from the pipeline and recovered to the surface. STATS can then provide a Pipeline Retrieval Tool (PRT) which grips and seals on the internal diameter of the pipe and provides a recovery method to pull the pipeline to the surface.

Prior to recovery, nitrogen is pumped through the PRT to pig the Remote Tecno Plug to the desired set location, which also serves to dewater the pipeline making it lighter and easier to recover to the surface. Once the Remote Tecno Plug is set and the double block and bleed isolation is confirmed, the pipeline can be safely recovered to the vessel to allow the continuation of pipe laying operations. The Remote Tecno Plug will remain in position until laying activities have been completed and recovered to the closest onshore or subsea temporary head.