NDE Offshore

Our diving services include inspection, repair, and maintenance (IRM), support for infrastructure installation, ROV assistance, and laying flexible pipes and cables.

NDE Offshore provides extensive subsea solutions utilizing advanced equipment and a certified operational team.

Our services include inspection, repair, and maintenance (IRM), support for infrastructure installation, ROV assistance, and laying flexible pipes and cables. We undertake small and large assignments and provide emergency services.

Our diving projects can include inspections, drilling, or salvage. We can assist in complex projects that require certain skills and equipment to be safely carried out.

NDE Offshore has the required certifications.

Our services include:

  • Inspection, repair & maintenance (IRM) of infrastructures, and installation support.
  • NDT Inspection of offshore structures and pipelines
  • Spool piece installations and tie-ins
  • Pipeline refurbishment and repairs
  • Subsea cathodic protection
  • Installation of supports to pipelines, flow lines, and cable tie-ins
  • Subsea intervention in assistance of installation of platforms, SBMs, and FPSOs
  • Salvage works

Services

As with all projects, detailed planning before the start is crucial to achieving the best and most efficient result.

There are different diving techniques, here we list a few of them.

Surface Supplied Diving 

Air Diving:

Air diving is the most common and least complicated diving technique. It can be performed from 0 to 50 meters, but it is at the deeper end of the scale, with very limited bottom time.

Nitrox Diving:  

Nitrox is a mixture of nitrogen and oxygen in different proportions than the composition of air. Breathing a gas with higher oxygen content than air allows longer bottom time without incurring a higher decompression obligation. This is because the partial pressure of nitrogen (rather than depth per se) and time decide the table depth.

By substituting some of the nitrogen with oxygen it is possible to decompress according to a shallower table depth.

Mixed Gas Diving:

Mixed Gas diving refers to replacing the breathing gas of air/nitrox with a mix of Helium and Oxygen. The mix is called Heliox.

Cost Heliox

Because of the expensive gas, Heliox has to be premixed at a gas factory and transported to the site in gas quads.

Due to the cost of Mixed Gas diving, it is a cost-efficient solution at 40-50 meters of water depth.

Depth:  Although diving even up to 150 meters of depth is possible, the possible bottom time at the deeper end of the scale is significantly less. Deeper mixed gas diving is only suitable for uncomplicated short jobs rather than prolonged diving.

Saturation Diving

When diving to depths of 40-50 meters to perhaps more than 100 meters, the best option from a working perspective is to use saturation diving techniques. 

Saturation diving means the diver lives in a pressurized chamber and travels to and from the worksite in a pressured diving bell. In practical terms, this means that the diver only has to be pressurized down to actual working depth once during his entire work period. He will remain under this pressure throughout the job (which can last up to 30 days) in the chamber, and then when the job is complete, he is swapped out and will decompress in the chamber. 

Recourses, equipment, and personnel: 

Compared to other diving techniques, saturation diving is more demanding in terms of equipment requirements and personnel qualifications. Typically, 6 to 8 20-foot containers are required for a single operation. The workforce needed to manage a dive site typically ranges between 16 and 20 individuals, varying based on the specific project requirements.

Efficiency: Bottom time 

However, although there are several more personnel and equipment, the operation is much more efficient since a team using a mobile saturation Dive system can have up to 22 hours of efficient bottom time every 24 hours.

Comparing the different diving techniques, we can conclude that every project has specific needs and prerequisites.

To decide what type of diving to use, the following points need to be considered:

  • Depth of work
  • Type of work that needs to be done.
  • Type of vessel that is intended to be used.
  • 12/24-hour operation
  • Contingency/Emergency needs (Including specific Risk Assessments, etc)
  • Need for continuous work on the seabed.
  • Specific Qualification needs of personnel and experience.
  • Additional resources including personnel needed (electrical Power plants, Compressors, Cranes, Deck crew, etc) 

 

As in all projects, detailed planning before the start is crucial to achieving the best and most efficient result.

List of diving related references:

Learn more:

Contact us for more info: sales@ndeofshore.com