The Magazine for Underwater Professionals
VideoRay vehicle first deployed in the North Sea in November 2013 as an experimental emergency response system
A Pro 4 remotely operated vehicle from VideoRay, USA, spent 19 months operating continuously in the North Sea, in what is believed to be the longest uninterrupted deployment of a single ROV of any class.
The unprecedented operation began in November 2013 as an experimental emergency preparedness solution for Stinger Technology AS, Norway, a subsea services provider for the offshore oil and gas sector. The Pro 4 “resident ROV” was deployed off the coast of Stavanger, Norway, but was operated mainly from Stinger’s offices which are located nearly 250 metres inland. The ROV remained powered on and in full operating condition for the entire duration of the deployment. Before Stinger voluntarily ended the ROV’s deployment in May 2015, the submersible had not surfaced for repairs or even routine maintenance.
“Originally, we anticipated it would last about three months,” says Stinger chief executive officer Bjarte Langeland. “But the Pro 4’s endurance has obviously significantly outlasted any of our expectations.”
The goal for Stinger’s resident ROV project was to test the system’s limits, determine the implications of long-term continuous use underwater, and ultimately to prove the Pro 4 ROV as an extended or resident emergency preparedness solution.
The resident ROV could begin an inspection immediately after being called into action, thanks to its “home” position on the seafloor. Having an on-call ROV system can significantly reduce the time and resources needed for an ROV operation, especially in emergency situations when every minute counts.
Stinger also wanted to test the use of a resident ROV to monitor methane gas buildup, which can pose an enormous threat to offshore oil and gas operations. If left undetected, gas buildups can cause explosions, resulting in costly and even fatal damage to wells, platforms and the environment. These buildups are especially of critical concern in Norway, where methane levels have risen drastically over the last ten years due to melting permafrost and seepage from under the Arctic seafloor.
“While the ROV is a ‘remotely operated’ vehicle, standard operations require the pilot to stay fairly close to the system,” explains Langeland. “Our resident ROV project investigates how we can further remove the pilot from the physical ROV deployment, making it possible to involve multiple experts in real-time operations.”
The resident ROV was mostly operated remotely over a WiFi or “wide area” network, instead of directly from the Pro 4 integrated control box (ICB). All the standard Pro 4 equipment – submersible, ICB and tether – was still deployed as usual, but the ROV could be piloted from locations other than the deployment site. This allowed Stinger to operate the Pro 4 from its headquarters immediately, rather than waiting until a pilot could be got onsite.
“Eliminating the need for the operator to be physically near the surface unit for our ROVs has been a long term goal at VideoRay,” says Scott Bentley, VideoRay’s founder and chief executive officer. “Stinger’s innovation here is extremely impressive, and we are proud to partner with them on this project.”
Stinger has used VideoRay ROVs since 2010, after it conducted a technology screening to choose a small ROV to launch from a platform. “We chose the VideoRay Pro 4 because it was more powerful than any of the other options,” says Langeland.
One of the biggest challenges of distance piloting operations is maintenance. Standard preventive maintenance practices and visual inspections require the ROV to be recovered in between operations so that the pilot can identify any potential issues, conduct necessary repairs and replace any damaged or consumable parts. In lieu of standard procedures, Stinger developed new methods of maintaining its system without surfacing. The resident ROV was housed in a crate on the seafloor, which helps reduce the amount of biofouling that the ROV might experience through natural wear and tear of being underwater, and also keeps out any predators who may be too aggressively curious about its new neighbour in the North Sea. Every few days, a pilot “spun” the ROV’s thrusters to dislodge any debris that may have settled since its last deployment. Stinger also used a second Pro 4 ROV to monitor and visually inspect the resident ROV on a regular basis.
Several standard Pro 4 features lend themselves well to the successful distance piloting of the resident ROV. The VideoRay Pro 4 Cockpit control software includes several health status monitors that detect and alert the pilot to any internal malfunctions, such as leaks, overheating or lost communications. Cockpit also features an extensive interactive engine room where pilots can monitor the status of the thrusters, power supply and compass calibration. Other Cockpit features, such as auto-heading and auto-depth, dynamic compass and depth gauge and tether turn counter, make it possible to keep track of the resident ROV’s position at all times.
Although the ROV was always powered on, it was only in flight when needed. This helped conserve consumable parts, especially the cartridge seals which lubricate the thrusters.
Once the submersible was surfaced in May, Stinger completed a thorough evaluation of every component, from small screws to internal electronics. Though the company observed some surface growth, minor corrosion and salt accumulation on some of the hardware, every piece was still in working condition after spending nearly 14,000 hours in the North Sea.
Although Stinger is the first VideoRay customer to use remote wireless deployment in a commercial context, VideoRay has been experimenting with this idea for more than a decade. VideoRay’s first foray into remote wireless deployment was at the VideoRay International Partners Symposium (VIPS) in 2004 with a Pro 3 ROV using PC Pilot, the predecessors to the Pro 4 and VideoRay Cockpit. The ROV was deployed in Key Largo, Florida, USA, but could be piloted in real-time over the Internet by operators from Exton, Pennsylvania, USA, 1250 miles (2012 kilometres) away. Other examples of remote VideoRay piloting include the Mini Habitat Adventure programme at Marine Lab in Key Largo, and a 2008 promotion for Foster’s Beer in the United Kingdom where participants around the world could control the ROV from their own PCs.
“The wireless piloting set-up we used in 2004 was nowhere near as sophisticated as the Stinger system,” says Bentley. “However, the use of the PC Pilot control software instead of a built-in joystick did help determine the direction for our next generation of technology, the Pro 4. Similarly, Stinger’s innovative approach to resident ROV installation and remote wireless piloting will help inform the next generation of our technology and open doors for the rest of our users as they find new ways to implement VideoRay technology for faster, safer and more cost-efficient operations.”