New Decommissioning Cutting Tool Passes Tests

A new cutting and sealing tool for the decommissioning sector has been put through its paces in Balmoral Subsea Test Center's submersion tanks in Aberdeen, UK.

Accrington-based Allspeeds, manufacturer of Webtool hydraulic remotely operated vehicle (ROV) cutters and systems, was awarded a contract by Chevron USA to develop an environmentally friendly, fast intervention tool (FIT) for subsea pipeline decommissioning work.

The tool is designed to cut and seal pipework to prevent marine environment contamination removing the need for a containment dome during operations.

The concept of the FIT relies on a single system that is capable of multiple actions.

The pipeline is initially lifted from the seabed and secured to the tool. It is then crimped in two places either side of the cutting point to create a cavity without rupturing the pipe wall.

The pipe is then pierced between the two crimped sections to prevent any escape of contaminants and a sealant is injected into the cavity to create a ‘rubberized’ plug. Finally, the pipe is cut through the sealed section creating an additional crimp point and separating the pipe into two pieces.

The pipe ends are now fully sealed with the crimps preventing any release of pollutants.

When the FIT operations have concluded the tool is removed topside, reset and positioned further along the pipe to repeat at pre-designated lengths creating practical sections of pipe for surface recovery.

The crimped pipeline before and after sealing and cutting (Photo: Balmoral Group)

Rory McGarry, technical director with Allspeeds, said, “We were delighted with the way the tool performed under test conditions and with Balmoral’s facilities and engineering support.”

Test house manager at Balmoral, Derek Weir, said: “This was a complex procedure which involved a number of tests. I believe this demonstrates the flexibility and capabilities of our facility which are now being widely used by the oil and gas, renewables, oceanographic, defense and valve production sectors.”

With the FIT successfully completing rigorous testing at the Balmoral Subsea Test Center in Aberdeen, Allspeeds is proceeding to full manufacture of production versions.