Going deep, but still some way to go

Elaine Maslin

November 1, 2015

ROV technology developers gave an update on their progress at the Subsea UK ROV Conference. Elaine Maslin reports on some progress, as well as where one operator thinks ROV and AUV technology could improve.

Platform-based ROV being deployed. Photo from iStock.

After a string of boom years, like most in the industry, the remotely operated vehicle (ROVs) sector is looking forward to a slow 12-18 months.

Longer term, demand will pick up and how and what ROVs are used for and look like is evolving.

Traditionally mostly used for drilling support, demand is shifting towards deep and ultra-deepwater marine construction support demand and longer term inspection and maintenance focused deployments.

The result is a developer market striving to provide ever higher capability systems, Oceaneering’s Nexxus, Forum’s XLX-Evo and the UHD-III to name a few, Kieran O’Brien, analyst at Infield Systems, told the Subsea UK ROV Conference in Aberdeen late September, with retirement rates on older units likely to increase.

But, it isn’t all just about higher capability. What role new types of subsea robotics can play in the subsea fields of the future, remains under the microscope. For some, a step change is needed in the market to offer new solutions for new environments and subsea technologies.

James Jamieson, technology manager at Subsea 7, says throughout the development of ROV systems, there has been gradual improvements and then step changes, driven by technical requirements in the market, such as the original step from using divers to ROVs.

Subsea 7’s AIV. Photo from Subsea 7. 

Today, work class ROVs are pretty mature, he says, thanks to gradual improvements over the years.

“Nothing has really changed much in the last few years apart from them getting more reliable,” he says.

“Things are stabilizing. They are expected to work consistently. If they break down you can fix them quickly. There’s always a challenge to make things better. Today’s challenge is to lower cost and to have 100% reliability.”

Subsea 7 is looking to initiate another step change with its AIV, an autonomous vehicle with lower costs because it would not rely on a support vessel.

The use of such a vehicle would be for planned and unplanned condition monitoring, wide area inspection around a vessel, potentially with multiple units operating and the vessel moving away, or a unit being hosted on the sea bed.

Subsea 7’s goal is for it to be able to navigate around the sea bed without obvious external references, using simple robust mission planning and advanced navigation, through which it can locate itself, and to be able to hover and inspect things, safely. Further, it would also be expected to perform tasks involving physical interaction with the subsea infrastructure.

Challenges for such a unit include launch and recovery, from a ship, via a basket deployment system, or from a subsea docking station, for which it would need to be reliable enough to be on the sea bed for months at a time, no longer reliant on weather or a vessel. How to automate it so that it can self-diagnose and inform an operator what needs changing is also on Subsea 7’s hit list.

Jamieson says that Subsea 7’s development program for the AIV is taking in four steps – making the unit first “see”, then “sense”, then “touch” and finally “do”. For the navigation systems, Subsea 7 has been working with SeeByte.

“We are at one (see) and (sense),” Jamieson says. “Touch is difficult, but it is next. The challenge at the moment is that we gather a vast amount of data.”

Another challenge will be getting such technology adopted. Efforts to create a similar system have been made in the past and have yet to be deployed.

But, despite the move towards making the system “touch and do”, this is not a system to replace the ROV, just as the ROV didn’t ultimately remove the diver from the subsea workspace. It will be a new tool to compliment what is available and offer a new solution to life of field inspection and maintenance work from the likes of floating production systems.

Peter MacInnes, vice president, sales and marketing, FMC Schilling Robotics, offered a “what if” scenario for the ROV industry, posing systems that could be more productive, more consistent, make better use of data and are easier to repair, using examples of where such technologies are in use already.

Despite uptime being around 98%, according to ROV operators, oil firms’ view is that it’s more like 20-80%, due to time lost around running multiple trips to the surface to change out tooling or acquire additional consumables.

Schilling Robotics close up. OE staff photo. 

“The ROV should be able to remain on sea floor with a tooling package,” he says, by using sea water instead of hydraulic oil, and integrating this into the manipulator arm, removing any potential oil leakage to the environment and the need to write leak reports. “On the surface, the user just selects what he wants and the ROV selects the tool. This is a common in modern day machining, the operator just instructs and the machine does it,” MacInnes says.

An operation like connecting a hot stab could take eight, 15, or 25 minutes or even an hour, depending on the operator, due to the skill involved and training largely only being on the job. “Imagine a world where all three can do it in eight minutes by using automation simplifying how the task is done,” he says. “In the real world, we have collision avoidance systems and automated parking on cars.”

Currently, data generated during a job is stored on a CD-ROM or hard drive and then never looked at again unless there is an incident. “Imagine a world where ROV data is compiled and synchronized with the video data you capture, all of which is readily available and when you play it back you can select which elements of the data you want to see in the video,” he says. “The existence proof is agriculture. Today’s tractors have a tremendous amount of automation, automated crop reporting, automated navigation, automated steering and analysis of soil real time to determine where and how much fertilizer should be added.” Finally, real-time diagnostics and plug and play repair systems, connected to onshore or tools like iPads, could lower repair times. He cites real-time condition monitoring in today’s offshore wind turbines as how others are already doing this.

But, while ROVs have become well-established and ROV manufacturers are striving to offer ever more clever systems, there are still those yet to be fully converted.

Richard Stark, Apache North Sea project services manager, said ROV work on the Forties field, one of the large most iconic fields in the basin, has been limited to infield pipeline work and cathodic protection systems, and tying in Apache’s first subsea tie-back, Bacchus in 2013.

It is not for lack of subsea infrastructure – Forties has 17 infield pipelines, three subsea wells, and 11 subsea structures. But, Apache has mostly used divers for the work it needs doing.

However, since its purchase of the Beryl fields in 2012, from ExxonMobil, the firm has had more exposure to ROVs. The Beryls, which has two hubs, Beryl A and Beryl B, have significantly more infrastructure, with 62 pipelines, 45 subsea wells (of different types and vintages), 47 subsea structures, and the 250km-long SAGE pipeline. Apache also has two semisubmersibles drilling at the Beryls, both with ROVs, as well as use of the Well Enhancer, which also has an ROV.

Apache recently carried out its first platform-based ROV survey of its jackets, caissons and risers, flying in a VideoRay ROV for some of it, which look up little space and could be flown in at short notice, saving space and costs, Stark says.

In another move new to Apache, the firm used an AUV to inspect the SAGE pipeline. But, the choice to use ROVs and or AUVs is still not clear cut, Stark says. While they see a lot of work needing to be done on the old Beryls subsea infrastructure, “it’s not necessarily designed for ROV intervention,” he says. This leads to using divers, “especially on wells where a lot of work is needed to convert non-ROV capable equipment to ROV capable equipment.”

He says while platform based ROVs are “definitely the way to go”, the footprint required to host larger ROV systems makes them difficult to accommodate on older facilities like Forties. The AUV inspection worked, but they would have liked better definition, speed and fewer wave height restrictions for deployment, added Stark.

ROVs have come a long way and are entering a new age, but for some this work horse and AUVs still have some way to go to prove their worth.