iNPIPE PRODUCTS™ was approached by a contractor regarding a upcoming shutdown on an offshore facility in the Southern North Sea. A class 2”ns cl-1500# wrap-around situated on the 24”ns export riser pipeline was in need of rectification/replacement.

iNPIPE PRODUCTS™ was requested to review the problem and revert with suggested solutions based upon their extensive experience and proven isolation technologies and products.

Following an internal review of the information provided by the client, and a site survey being conducted by iNPIPE PRODUCTS™ the technical solution was provided to the contractor. The concept, which was subsequently approved by the client, consisted of a triple tyred isolation tool. A one-off launch and retrieval Launch / Test-Can also had to be designed to insert and retrieve the tool – this was to ensure containment to allow for subsequent nitrogen testing following repair works.

The isolation tool was inserted into a vertical 24” section, using a Launch / Test-Can, then positioned through a 30” section, including valves and set in a 24” section beyond the 2” nozzle to be replaced. In total, the tool was pushed into position some 10m from the launch point.

Following installation of the Launch-Can the system was deployed; positive isolation was provided by the remote hydraulic system. The system allowed for remote pressure monitoring of:

• Downstream pressure
• Seal pressure
• Annulus Pressure, (Double Block & Bleed facility)
• Test Pressure

Following the repair works, the pipe section from the Launch / Test Can was filled and pressurized with nitrogen. This enabled the client to carry out test of their repair without having to fill large sections of the piping system, shortening their shutdown window considerable.

The system provided both positive isolation to allow hot work repairs, while maintaining a safe working environment, as well as allow localized pressure test.