Meg Chesshyre reports on how mini ROV systems have advanced significantly and, thanks to their size, they can get up close and personal.
Deep Trekker’s DTG2. Images from Deep Trekker.
“It’s not just a camera in the water anymore,” Cody Warner, business development, Deep Trekker, told the Oceanology International conference in London this spring. He was presenting a paper on how asset management can be improved with the use of mini remotely operated vehicles (ROVs), such as the Deep Trekker range.
“We are now using sonars, usbl (ultra short baseline) positioning systems. We’re able to have a look outside of [in addition to] getting visual feed,” he said. It is possible to have data from acoustic feeds, to use thickness gauges and CP (cathodic protection) probes, grabber arms, navigation sensors, samplers, many different attachments. “This is a great way to have an external look ... almost double-checking.”
Mini ROV systems can be used to provide historical data for classification surveys of floating production vessels (FPSOs), or other vessels; inspection for damage; inspection for cleaning, fouling; monitoring dive teams at work. Ownership of mini ROV means that the asset owner does not have to rely on third parties.
Warner said that achieving the full lifespan of assets was very important for earning a positive return on investment. Assets are also being used for longer, with the range of FPSOs being extended from 15-25 years.
Deep Trekker’s DTX2.
Right now, there were only three ways to have a live video stream subsea; divers, workclass ROVs and mini ROVs. Some projects, such as welding, need a diver. Platform construction involving large weights need work class ROVs. For inspections, the first two options were often too expensive for a single asset to own on its own. Using a mini ROV is a more efficient option, Warner said.
Deep Trekker was founded in 2010 with a mission to bring fully capable yet portable and accessible ROVs to market. The company is headquartered in Ayr, Ontario, Canada, with all engineering and manufacturing done in house. Based on a clean sheet design, the first product, DTG2, was introduced in August 2011. The first mini ROV was sold to a Norwegian fish farm. Since then, more than 1000 vehicles have been sold in 69 countries, many involved in hydroelectricity projects as well as offshore energy. Offshore clients have included Noble Drilling in Australia and Sea View in Trinidad and Tobago.
For the offshore market, Deep Trekker mini ROV systems offer an alternative, or complement to sending divers down to do emergency or routine inspection work, Warner said. They can be easily deployed by one to two-man teams, and can be launched anywhere without the need for large crane structures, or a generator. The onboard rechargeable batteries require no topside power.
The 270° camera rotation results in efficient inspection. The pitching system allows the ROV to go where it is too small or dangerous for divers. There is no maintenance, no o-rings to service, grease or replace. The mini ROVs just need to be kept clean and charged. Undersea installations at sea-based wind and solar installations can easily be done from a boat. The DTG2 weighs only 8.5kg and has a ca.150m depth rating. The larger DTX2 has a 305m depth rating, well within topsides range for platform legs and undersides. It works in higher currents and can perform lateral inspections.
Deep Trekker announced in March the integration of Tritech International’s Gemini 720is multi-beam sonar with its DTX2 vehicles. The new Gemini 720is integrates with a custom mount and the Deep Trekker control console or other laptops.