For Total, innovation and technology have always played an important role in exploring, extracting, and producing oil and gas from the Danish North Sea. This is why, in 2018, Total partnered with SubC to develop the Jacket Crawler—a robot that remotely completes risky, manual, and highly weather-dependent work usually accomplished by skilled divers and crew.
MITIGATING THE RISKS IN THE DANISH NORTH SEA
The Jacket Crawler revolutionizes the way in which offshore platform structures are inspected, cleaned and removed near the sea surface. This work is vital, as these steel structures are extra vulnerable to the risk of corrosion due to their contact with the seawater.
Traditional methods of working at the waterline of Danish North Sea platforms are inherently high risk, expensive, and inefficient. The tailormade, innovative Robotic Jacket Crawler has helped mitigate these operational risks for the important Tyra Redevelopment Project. Typically, inspecting the offshore structures and removing marine growth in the ‘splash zone’ requires rope, crew and divers, and maximum wave heights of one meter—a rarity in the North Sea. Divers often compare working on these tasks to working in a washing machine, where they must keep a secure hold on the platform and avoid getting trapped under the structure’s parts. With this in mind, the Jacket Crawler was designed to be remotely controlled to keep crew a much safer 20 meters above the dangerous work area.
HOW DOES IT WORK?
The Jacket Crawler clamps onto a structure using hydraulic pistons to move around on the supportive steel frame known as the jacket. Wheels mounted on the robot’s clamps permit rotation around the structure. The Jacket Crawler presses with a force of up to 500 kilos to ensure a firm grip, regardless of position and wave impact. This allows the Jacket Crawler to operate in wave heights up to two and a half meters.
Three distinct features of the Jacket Crawler were successfully used as part of the Tyra Redevelopment Project:
- Wall thickness measurements: Using ultra-sonic measuring technology, the Jacket Crawler measures wall thickness with a 0.1-millimeter tolerance.
- Marine growth removal: Equipped with a high-pressure cleaner operating at 500 bars (the equivalent to cleaning with 25 liters of water per minute), the Jacket Crawler removes marine growth to improve the precision of wall thickness measuring and reduce the wave load on the structure.
- Removal of structural members: Using a wire cutting tool, the Jacket Crawler cuts and retrieves structural members of up to 1000 kilos.
INNOVATION, DEVELOPMENT AND IMPROVEMENT
Combining the know-how and pioneering spirit of both the Total and SubC engineers, the integrated team developed the Jacket Crawler in just four months. The Jacket Crawler’s first platform inspection was on the Tyra platform in February 2018. Following this task, our engineers identified further opportunities to leverage the Jacket Crawler in the splash zone and improved the prototype to meet these functionalities.
Due to the versatility of the robot, Total views the Jacket Crawler as having the potential to play an integral role in replacing conventional methods of maintaining platform structures with a safer and more cost-efficient solution. By eliminating the need for rope, diving vessels and specialized crew, the Jacket Crawler can help the crew safely complete all activities while saving approximately 30% of the costs.