Getting down to deep business

Emma Gordon

December 1, 2016

Despite oil’s instability over the last few years, the underwater vehicle market is set for modest growth as well as a breakthrough in resident vehicle technology. Emma Gordon reports.

Subsea 7’s AIV. Image from Subsea 7.

Fully resident electric vehicles could be on the market in around four to seven years, it was claimed at a subsea vehicle focused event in Aberdeen late September.

Realizing such a vision will mean a step change in support infrastructure on the seabed. But, the challenge isn’t putting off continued efforts to bring resident robots to the subsea business.

One such project is Subsea 7’s autonomous inspection vehicle (AIV), principally designed to support activities such as outline surveys and seabed mapping, covering huge swathes of the seabed.

The AIV was developed to remove restrictions that can limit the value of conventional autonomous underwater vehicle technology, specifically high vessel dependency and weather-sensitive launch operations.

With no tether – enhancing its maneuverability into confined spaces – the AIV overcomes these challenges by using a dedicated launch and recovery basket that can be deployed in a number of ways to the seabed.

After mission completion, the AIV can remain in its basket until the vessel returns for the recovery operation.

Lee Wilson, engineering manager with Subsea 7, is responsible for the overall project and technical management of the AIV. Next up for the team is developing a seabed-hosted AIV, removing the need for launch and recovery operations, and expanding its capabilities to include tasks such as light intervention and leak detection.

“Imagine how valuable it would be to do inspections or intervention without the vessel hanging around,” Wilson says. “That unlocks huge value and potential.”

In the short-term, a major challenge the team faced was making sure the AIV could re-enter its basket – the vehicle’s subsea “home” – successfully, every time.

SeeByte’s Chris Sotzing, the project and engineering manager for the AIV’s software systems, likened this process to parking a helicopter in a small garage.

“It’s a bit of a challenge. You have to do it fully autonomously, and you have to do it every time,” he says. “We need to know where the basket is, fly to that basket, calculate this sweet spot [the central entry point], and you need to be able to get in every time, otherwise you kill the business case.”

Saab's Sabertooth ROV. Image from Saab.

Using a world model that gives the position of structures, including pipelines, risers and connections, as well as the baskets, the vehicle determines the best route home from any point in the world. Then, when within range, it uses acoustics to position and home in on the basket’s location before calculating the precise entry point using sonar.

Sotzing says that offshore test success rates have been very high with Wilson adding, “This isn’t pie in the sky. It’s not a lab test, or a tank test, We’ve been offshore with Shell. The ability is here now and we can use it in multiple ways.”

Similarly, Matt Bates, sales director Saab Seaeye says the ultimate step for electric underwater vehicles is having a resident system truly capable of undertaking all field support tasks. He adds that realizing this vision means a step change in support infrastructure on the seabed.

Bates says that over the past three decades electric vehicles have taken on a greater range of subsea tasks, such as Eni Norge and Tecnomare’s Clean Sea program using the Sabertooth hybrid vehicle to detect early stage spills.

He sees the introduction of tetherless hybrid electric vehicles capable of carrying out routine inspection and monitoring tasks, with increased light intervention capability, possible in three to five years, with fully resident electric vehicles on the market in around four to seven years.

“Generally speaking there are no massive stumbling blocks to achieving this [vision]; there are lots of engineering challenges and specifically commercial, legal and contracting challenges,” he says.

The next few years are set to be telling for the ROV sector, specifically whether technology and innovation can reliably deliver more autonomous technology capable of undertaking more tasks subsea, particularly with the shift towards deep and ultra-deep reservoirs.

Deep down data

The UHD Gen III ROV. Photo from FMC Technologies.

The impact of improved inspection technology and data collection on operational efficiency was also under the microscope at Subsea UK’s Underwater Vehicles Conference.

Access to live 3D data potentially opens the door to significant cost savings for subsea operators at a time when smarter and more efficient operations are a requirement, not a luxury.

“What if I told you now that every single ROV (remotely operated vehicle) out there already had the equipment to perform live 3D scanning,” asked Sam Bromley, managing director, Whitecap Scientific.

Powered by a computer on a host vessel, the company’s ROV3D technology produces live 3D data using existing ROV cameras: generating interactive information at the point of inspection. This includes real-time inspection feedback, measurement and spatial logging.

Bromley says that the technology was used on the Hibernia field, offshore Newfoundland, in the North Atlantic, generating 31 hours of 3D data: saving time on retooling for measurements, speeding up reporting, and ultimately saving six hours of ROV inspection time.

“This [time] was used to expand the scope, look at secondary targets, and deliver a much more valuable, more complete report,” he says.

Similarly, Scott Gray, operations manager at Seatronics, said that underwater laser scanning – used for subsea survey, inspection and engineering operations as well as increasingly for integrity management – can ultimately reduce vessel and ROV time.

Seatronics’ partner 2G Robotics’ underwater laser scanners can be deployed by ROV, AUV, or diver for stationary or dynamic scanning. 

Gray says that time for the signal to reach the receiver is instant, and the scanners generate submillimeter-resolution 3D models of subsea assets and environments from which accurate – and contactless – measurements can be taken.

“We’re staying well away from the assets while we’re doing it; producing real-time data; all processed subsea and sent back topside,” he says. 

“And there’s the added value that not only are we getting hub-to-hub measurement and inclination, we’re getting a digital terrain model of the seabed as well. It comes pre-calibrated,” he adds. “Essentially, the key thing we’re looking at is reduced vessel time, reduced ROV time, which is ultimately a money saver. 

Market demand drivers

The Nexxus ROV working in the Gulf of Mexico off the Olympic Intervention IV vessel. Photo from Oceaneering International.

Despite a drop of almost 32% in ROV demand since 2014, long-term growth of 2.5% CAGR is expected up to 2020, with deepwater plays a key factor, says Kieran O’ Brien, energy researcher, Infield Systems.

The drilling market, which accounts for around 63% of total ROV demand, has seen the sharpest drop, although a gradual recovery of 6% CAGR by 2020 is anticipated, thanks to improving market conditions.

O’Brien, speaking after Subsea UK’s Underwater Vehicles Conference in Aberdeen late September, says operational expenditure-related demand is less sensitive to volatility in the energy market.

“Field operators essentially pressed the panic button and cut both capex and opex-related projects,” he says, due to the sharp fall in the oil price.

“Inspection and maintenance cannot, however, be delayed indefinitely, and because of HSE (health and safety and environment) and production efficiency concerns,” he adds. “These activities are expected to come back in a big way. We expect to see significant growth in the repair and maintenance markets, and the intervention market.”

And, with operating efficiency and reliability front of mind, there is a demand for innovation and engineering to deliver underwater vehicles that are increasingly autonomous, and capable of carrying out more subsea tasks.

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ROV in residence