Deep under the North Sea, an orchestra of transformers, choke manifolds, pumps and valves whirs an improvised subsea symphony. The audience is a 500-pound electronic ear whose design is a trade secret.
The ear pipes the sounds through a cable to a floating control room packed with computer servers and engineers analyzing every hiss. Like the most discerning music critics, they are listening for odd harmonies, vibrations, cracks and other signs of trouble. “An acoustic signature from a piece of equipment is like a fingerprint from a human,” says Fabian Dawson, sales manager from GE Measurement and Control. “We can filter out the background noise, like marine life, and listen only to the things that we want to. No two leaks or pumps are going to sound the same.”
Call it Shazam, the popular app that can identify songs playing around you, for the deep sea.
The team is using data from existing subsea installations to build a huge data library of sounds. The more sounds, the better the predictive capabilities of the system. Like other Industrial Internet technologies, it could help customers detect problems before they get out of hand and pare down unplanned downtime. GE estimates that a 1 percent productivity increase in the oil and gas industry from the application of Industrial Internet yields approximately $90 billion in savings.
The team is particularly keen on catching “rogue sounds,“ Dawson says. “You are looking at the correlations between the pieces of the equipment emitting both the electrical and acoustic signals and sometimes there is a signature there you can’t trace,” he says. GE data scientists and engineers are working on algorithms that can pin them down and add them to the library.
Dawson says that the system can be up to 10,000 times more accurate than traditional “mass balance” type of leak detection technology. These systems measure differences in the amount of oil and gas flowing through pipes to detect leaks.
The deep water ear, officially called Subsea Condition Monitoring System, is known as the cage because it looks like a large birdcage (see above). The design uses special crystals that respond to sound wave vibrations and convert them into electricity. (Engineers call this effect “piezoelectricity.”) One ear can listen to sounds within a 1,600 foot radius.
But the system can do more than that. An array of carbon rods attached to the device can detect changes in the electromagnetic field generated by electrical cables, pumps, motors and other electrical equipment.GE data scientists and engineers are working on algorithms that can pin them down and add them to the library. It can also spot ground faults and defective isolation. “You can determine the rpm of a compressor from the acoustic signal, and then you can determine how hard it is working from the electrical signal,” Dawson says. “Taken together, they will tell you what the efficiency is.”
Workers deploy the cage by lowering it down the side of a ship from a crane. They use ROVs to secure it to a piece of subsea equipment or to the sea floor. “It’s a simple, X-marks-the-spot procedure,” Dawson says.
The system is already working at some 130 sites in the North Sea operated by Statoil, ENI, and Shell, and off the coast of Africa. GE introduced it to American customers in 2013.