Remote drone inspection technology continues to grow in sophistication and capabilities. In the recent inspection of a 19.4 meter high oil tank on board an FPSO in Norway, the video shot by the drone was interpreted in real-time by an algorithm to detect cracks in the structure. It marked the latest step in a technology qualification process that promises to make tank inspections safer and more efficient.
The inspection involved the FPSO Petrojarl Varg, operated by Altera Infrastructure (the former Teekay Offshore Partners LP) and was carried out by Scout Drone Inspection and DNV GL, who have been working together to develop an autonomous drone system to overcome the common challenges of tank inspections.
In conventional inspections, costs can run into hundreds of thousands of dollars as the tank is taken out of service for days to ventilate and construct scaffolding. The tanks are also tough work environments, with surveyors often having to climb or raft into hard to reach corners.
Using a drone in combination with an algorithm to gather and analyze video footage can significantly reduce survey times and staging costs, while at the same time improving surveyor safety.
“We’ve been working with drone surveys since 2015,” said Geir Fuglerud, Director of Offshore Classification at DNV GL – Maritime. “This latest test showcases the next step in automation, using AI to analyze live video.
The drone, developed by Scout Drone Inspection, uses LiDAR (light detection and ranging) to navigate inside the tank as GPS-reception is not available in the enclosed space. A LiDAR scan creates a 3-D map of the tank and all images and video are accurately geo-tagged with position data.
During the test, the drone was controlled by a pilot using the drone’s flight assistance functions, but as the technology matures it will be able to navigate more and more autonomously.
DNV GL has been developing artificial intelligence to interpret the video to spot any cracks and says that eventually the camera and algorithm will be able to detect anomalies below the surface such as corrosion and structural deformations.
“This is another important step towards autonomous drone inspections,” said Nicolai Husteli, CEO of Scout Drone Inspection, a company spun out by the Norwegian University of Science and Technology. “Up until now the process has been completely analog but technology can address the urgent need to make the process more efficient and safer.”
Altera Infrastructure hosted the test on Petrojarl Varg as part of its drive to improve safety and efficiency through innovative technology. The video was livestreamed via Scout Drone Inspection’s cloud-system back to Altera Infrastructure’s headquarters in Trondheim, where the footage was monitored by engineers. DNV GL was also able to simultaneously watch the footage, opening up the possibility for stakeholders to work together from different locations.