Robots Taking Over The Job On Offshore Oil Drilling Platforms

“Well, now you have seen the individual sensors and special tools. Shall I put the robots into action?”

SINTEF scientist Pål Liljebäck is standing in the new NOK 80 million laboratory financed by Norsk Hydro. The lab covers only 30 square metres and lies deep in the basement of one of the Electro buildings on the SINTEF/NTNU campus on Gløshaugen in Trondheim. An orange robot arm hangs from a steel beam that spans the room at ceiling height, framed by large, sky-blue support beams.

At the control panel, Liljebäck has pre-programmed a huge range of rapid movements of the colossus inside the room. The robot arm glides silently back and forward on its beam, suddenly moves out in a wide arc to the left, and then straight towards the scientist, before turning downwards to the floor. Liljebäck says that the framework, traversing crane and robot arm weigh a total of seven and a half tonnes. It would not be a good idea to get too close.

Hydro wants to automate

Nor will the petroleum operators find themselves in close contact with the new robots when, if all goes according to plan, they are ready for installation in 2015. The operators will remain on land and control them from there, reducing both risks and costs.

Hydro (now StatoilHydro) has long been focusing on futuristic new technological solutions for extracting oil and gas; among them are robot-operated platforms.

“If we can automate our platforms, we will have an alternative to subsea platforms,” says Anders Røyrøy in StatoilHydro. “Both technologies are aimed at small and medium-sized field which are not exploited today because it is not profitable to use normal manned platforms. An automated platform doesn't need personnel, and therefore neither does it need fire systems, sound insulation, catering or a whole range of other installations. Automated platforms also have another advantage: whereas subsea systems statistically only manage to recover about 45 percent of the oil or gas in a reservoir, a topside platform can take out almost 55 percent. And then, maintenance at the surface is much simpler."

The whole platform will be adapted for the robots. In collaboration with both Hydro and Statoil, therefore, Aker Kværner started to draw up a rough layout of such a platform. With an internal layout in the form of shelves, these platforms might look like hi-tech warehouses, with the robots moving up and down the rows of shelves like fork-lift trucks.

The SINTEF test laboratory represents the next step, in which the scientists will find out how robots can be used to remotely monitor and control platform processes. The scientists are looking at the sensors and tools with which the robots will have to be equipped, and how the operators can safely and simply control the robots on the platform without them colliding with the process equipment.

Convincing

The research results that are emerging from SINTEF will demonstrate to Hydro that it would pay to automate. Within the company, there are still many people who are sceptical to the idea of robots. The new technology will have to be sold within the company, via convincing demonstrations.

And the results are starting to come in. Pål Liljebäck is proud to show off the various applications of the system. For example, the robots will be able to inspect the equipment on board the platform. Mounted on traversing beams, they move around, listen, take photographs and make measurements.

“Here you can see the “toolbox”, says Liljebäck, pointing to a stand in which four or five large drill-like heads are parked.

“Shall we connect up one of the tools?”

He seats himself at the control desk and operates the robot via a mouse. Soon he has got the robot arm to move down to the toolbox, where it picks up and connects a measurement device.

Liljebäck claims that the applications performed by the robot here are unusual. “We are creating a robotised inspection system. This is something quite different from industrial robots that stand by a production line and perform a well-defined task over and over again. This system will make it simpler for the operator on shore to carry out operations that may not have been planned in advance."

Spooky

The robot has connected a special instrument for measuring vibration and temperature to the end of its arm, and just a few seconds later the arm is pointing over the high protective fence and through the glass screen. On the right of the control desk are two highly coloured beings have appeared on a screen: the human occupants of the control room!

However, Liljebäck demonstrates how the robot measures vibration just a few minutes later, when he points the appropriate special instrument at a pipe in the laboratory that has just been made to vibrate. The measurement curve drawn on the computer screen will enable the shore-based operator to check that all is well.

“The challenges lie in ensuring that the robots are capable of performing predefined and programmed tasks – and are also able to function properly under unanticipated conditions. If the operator suddenly finds that he needs to inspect something or other under a pipework system, the robot must be able to do this,” says Liljebäck.

Avoiding collisions

Obviously, a lot of things have to be thought out carefully when human actions are replaced by robot movements. Sensors are one aspect of this. Another is the matter of operations that involve contact, such as when a robot has to pick up something from the floor. Contact operations are a particular challenge, because the robot is very strong and it can easily destroy the equipment with which it comes into contact, unless we keep its strength fully under control. The scientists have therefore fitted the robot with a force sensor that enables them to measure the forces exerted by its grippers, for example.

The robot is similar to a computer, in that it does exactly what it is told. Unlike a human being, it will not stop moving by itself or move aside if it collides with something else. On a platform where a number of robots are in operation, there could be collisions between them and other equipment. One of the systems on which the researchers are working has the straightforward aim of ensuring that the robot will never collide with anything.

“This is where our mathematicians come in,” explains Pål Liljebäck. “When we have 3D models of the robots and we know their positions, we can input these data into a 3D model that calculates the distance between the robot and other equipment. As long as the distance between them is greater than zero, there can be no collision.”

“We are pleased with the results and the progress of the project,” says Anders Røyrøy in StatoilHydro. “The next step after the technology has been handed over will be full-scale testing of certain parts of the system in order to see whether everything functions properly in its real environment.”

Competence/Gemini Centre

So far, some 15 to 20 scientists from four different SINTEF divisions have been involved in work at the robot lab. The Department of Technical Cybernetics at NTNU is also heavily involved. All of these research groups also form part of a newly established Gemini Centre for Advanced Robotics. Like the 12 other Gemini centres, the Advanced Robotics Centre aims to bring together all of SINTEF and NTNU's expertise within a particular field, in order to give them extra power. The scientific group at the Gemini Centre for Advance Roboticsconsists of 11 research scientists and six professors, and it offers advanced expertise for industry that ranges from subsea robotics to robots for inspection and maintenance.