With increasing demand for remotely operated vehicles, depth, cost, power and safety are powerful arguments
The development and subsequent growth in demand for remotely operated vehicles (ROVs) emerged due to a desire to explore depths and work beyond the reach traditionally carried out by divers.
Since their introduction in the 1950s, the capabilities of ROVs have evolved considerably and their use in the offshore industry has become increasingly widespread. In many but not all cases these machines now do the work that a diver once did. So, will these machines replace divers altogether and, if so, why?
The most notable difference is depth. The deepest reach of saturation divers is typically 300m below the surface, far less than the typical ROV standard of 3,000m. What’s more, some simple upgrades can enable an ROV to reach 6,000m with ease.
To put this in perspective, the oil & gas industry forecasts approximately 71% of new subsea field developments installed within the next five years will be in deep and ultra-deep waters, greater than 305m and 1,500m respectively.
ROVs are also more powerful. A typical workclass ROV has 200 horsepower, almost twice that of some excavator/tractors, so they are more effective at any heavy duty lifting, pushing and pulling tasks than a human.
Another factor where an ROV is a winner will be cost. If you compare the day rates for an ROV vessel they are significantly less than a dive support boat.
Finally, and most importantly, we have to consider safety. Although diving contractors have worked diligently and have demonstrated that commercial diving can be conducted safely, the fact remains that real risks still exist. ROVs mitigate this by removing the human element in any subsea operation.
With this in mind maybe the question should be why have ROVs not replaced divers already? The reality is that although these machines have evolved significantly a human diver is still more versatile and dexterous.
They can fit into smaller spaces, they are more adaptable and they can carry out a wider variety of tasks in one dive. Depending on the work, ROVs often have to be configured to do one specific role when deployed. This can be timely and expensive.
In addition, some of the older subsea fields were designed for intervention by divers and they are still the best tool for working in this environment.
Back to the original question, will ROVs replace divers?
No, or at least not in the short term. There are compelling reasons to use ROVs and it is likely that this will continue to increase, particularly for deepwater operations. However, divers will be required for shallow water work where either access or the dexterity of a human is needed.
Ryan Lumsden is global product director at Forum/Sub-Atlantic