You are here

MIT and KFUPM researchers develop robots to rapidly detect pipeline leaks

25th June 2014

Researchers at MIT and King Fahd University of Petroleum and Minerals (KFUPM) in Saudi Arabia have devised a robotic system that can detect leaks at a rapid pace and with high accuracy by sensing and investigating pressure changes within pipelines

Christine Daniloff/MIT (Rendering of robotic device courtesy of the researchers.)
Christine Daniloff/MIT (Rendering of robotic device courtesy of the researchers.)

“This new system can detect leaks of just 1 to 2 millimeters in size, and at relatively low pressure,” said Dimitrios Chatzigeorgiou, a PhD student in mechanical engineering at MIT and lead author of the research papers. “We’ve proved that the concept works.”

The researchers have begun discussions with gas companies and water companies — the system can also detect leaks in water pipes, or in petroleum pipelines — about setting up field-tests under real-world conditions.

Chatzigeorgiou presented the concept this month at the International Conference on Robotics and Automation in Hong Kong, and at the American Control Conference in Portland, Ore.

Current acoustic tests are only effective for detecting sound and vibration in metal pipes, Chatzigeorgiou says, but plastic pipes tend to dissipate the sounds too quickly.

Such systems are also time-consuming and require expert operators, he says, whereas the small robotic device he and his collaborators have developed can move as fast as 3 mph through pipes, and are almost entirely automated. Ultimately, he says, such devices could be put into a system of pipes and left in place indefinitely, conducting automatic, nonstop monitoring of the system.

In addition to their potential for dangerous explosions, leaking gas pipes can be a significant contributor to global warming: Methane, the primary constituent of natural gas, is a greenhouse gas 25 times more potent than carbon dioxide. Leaks in water pipes can waste up to half the water in a system; oil-pipeline leaks can lead to toxic spills and prolonged, expensive clean-up operations. All of these systems could benefit significantly from improved leak-detection methods, Chatzigeorgiou says.

While existing detection systems work under certain conditions, Chatzigeorgiou says, there is not yet an approach that can efficiently detect leaks in all of these pipe systems.

“We believe this can solve the general problem.”

The new device could be produced in various sizes to fit different kinds of pipes, and should be effective in gas, water, and oil pipes.

“This technology allows for an unambiguous and reliable sensing of very small leaks that often go undetected for long periods of time,” said Kamal Youcef-Toumi, MIT mechanical engineering and co-author of the research papers.

The current device consists of two parts: a small robot, with wheels to propel it through pipes (or, in some cases, to simply be swept along by flowing liquid), and a drum-like membrane that forms a seal across the width of the pipe. When a leak is encountered, liquid flowing toward it distorts the membrane, pulling it slightly toward the leak site. That distortion can be detected by force-resistive sensors via a carefully designed mechanical system (similar to the sensors used in computer trackpads), and the information sent back via wireless communications.

This approach can sense a rapid change in pressure close to the leak itself, providing pinpoint accuracy in locating leaks.

It also allows for relatively rapid monitoring of large systems. At present, the 3 mph top speed of the device is imposed by the propulsion motors, not the detector itself, so faster surveying is possible.

Because of the sensitivity of the membrane, Chatzigeorgiou and his colleagues believe the system can detect leaks one-tenth to one-twentieth the size of those that can be detected by most of the existing methods.

At present, the system requires a fairly uniform pipe diameter, but the researchers are working on a version that will have more flexibility to deal with variations caused by damage, obstacles, or scale build-up inside pipes.

Co-author Rached Ben-Mansour, a professor of mechanical engineering at KFUPM, says that current leak-detection systems are quite expensive, typically costing USD 250,000 annually to monitor 100 kilometres of pipe. “We’re hoping this system will be much more affordable,” he commented.

Arnold Scott, vice-chairman and director of First Commons Bank, who was not involved in this research but mentored the group in the MIT USD 100,000 Entrepreneurship Competition, says this approach “is very important because of its size. It is the only [inspection device] small enough to fit inside of a 4-inch pipe. Many modern water systems are built using 4-inch pipe, so being able to inspect this pipe diameter is very important. Another important element is the reporting mechanism. Using GPS, this [device] can specifically locate and report the location of a leak in a pipe.”

The research was supported by KFUPM through the Center for Clean Water and Energy at MIT.

 

Reprinted with permission of MIT News (http://newsoffice.mit.edu/);

Got a news tip? Email news@oilandgastechnology.net