• Oil and gas

The first cut is the deepest

Fisher Offshore proves its ability to offer truly bespoke engineering solutions on complex deep sea pipe cutting job off the Ivory Coast.

For many years Fisher Offshore has been known and respected as a company which rents a variety of highly specialised subsea tooling equipment, but a contract this year off the Ivory Coast in West Africa has lifted it to a new level.

The team was initially contracted to help cut existing spools (pipelines) to make space for the expansion of a major oil field off the coast of West Africa. However, the job became increasingly complex as it became clear it would need to re-design and re-configure the equipment to cope with operational complications and the extreme depth.

In the North Sea, where Fisher Offshore is an acknowledged specialist, the seabed is rarely deeper than 200m, but this oil field, at 1200m presents unique and unprecedented challenges for the cutting equipment.

The work required a complex series of cuts to be made on piggy back spools 1200m under the surface using a subsea diamond wire saw cutting tool (DWS), manoeuvred by ROVs under instruction from a light construction vessel.

The Fisher Offshore team created a bespoke framework with buoyancy units to allow the DWS to work well outside its normal tested parameters.

‘The equipment hadn’t been used at that depth before and we had to upgrade key components to allow it to withstand the expected pressures,’

explains Fisher Offshore business development manager, Mark Mellor.

‘The weight of the machinery presents huge challenges at this depth and the tool had to be used in a vertical position – making the buoyancy positioning demands very specific. The job was such a great success that the client and the oil field management company involved have both separately offered additional deep-sea cutting work as a result.

Its ability to deliver bespoke solutions like this puts Fisher Offshore in a very strong position for forthcoming decommissioning work in the North Sea, with Mark confirming;

‘We can take any scope of work and engineer it through to fruition.’