James Fisher’s HydroDigger in action

Fisher Offshore’s advanced underwater excavation system demonstrates its highly flexible capabilities across a range of projects.

The HydroDigger is an advanced form of contactless subsea excavation equipment that can be deployed over a vessel's side and operated remotely and safely from the deck using its integrated launch and recovery system.

It operates by delivering a precisely controlled column of water onto the seabed, fragmenting the surface and displacing soil, sediments, rocks and other surface materials.

"It provides a complete package that’s appropriate for a wide range of functions, from excavations for new pipeline systems, for example, through to the decommissioning and burial of life-expired installations in accordance with regulatory requirements,’ says Steve Gray, project manager, at Fisher Offshore.

Summary

The work scope was to recover a 40 metre length of damaged flexible flowline which was buried under 1 metre of drill mud in the Osprey Field, North Sea. The HydroDigger was used to dredge the drill mud off the flowline to expose it for disconnection.

Who:

Integrated Subsea Services

Services provided:

• Subsea excavation
• Control system
• Real-time sonar monitoring

Benefits delivered:

• Simple and rapid deployment
• Highly flexible capabilities across a range of projects
• On-budget and on-time

Download the Mass flow excavation: James Fisher's HydroDigger in action case study.