An LSU professor's research into better detecting small leaks in underwater oil and gas pipelines before they create environmental disasters has led her to a solution using fiber-optic cable.
The cables, which use strands of glass fiber inside insulated casing to send pulses of light, are used for networking and communications. Fiber-optic cable is relatively inexpensive, so it could be wrapped along the length of pipelines, says Jyotsna Sharma, an LSU petroleum engineering assistant professor.
A pipeline leak would cause a vibration on the cable, which would alert workers of a potential breach.
"The key advantage we have with fiber optic cable is that the whole fiber is sensory," Sharma said. "It increases the 'visibility' of leaks tremendously."
It would beat current methods of leak detection, such as placing pressure gauges every 100 feet along a pipeline, Sharma said.
"Even with that, it's hard to detect with reliability where the pipeline is leaking," she said.
The research by Sharma and LSU graduate student Gerald Ekechukwu was published last month in a leading international science journal, Nature.
Part of the funding for the research came from the nonprofit National Academy of Sciences' Gulf Research Program, founded as part of legal settlements with the companies involved in the 2010 Deepwater Horizon oil spill disaster in the Gulf.
Sharma is also co-principal investigator of related research into making fiber optic cable even more sensitive to pipeline leaks. The principal investigator she's working with is Albert Marino, associate professor in physics and astronomy at the University of Oklahoma.
The research, funded by a $750,000 grant from the U.S. Department of Energy, aims to find a different source of light for the fiber optic cable that would reduce the noises in and around it, such as sounds from the surrounding water.
"The fiber doesn't know if the noise is coming from a leak or the waves -- and the fiber has its own noise level," Sharma said.
The new research, now in its early stages, is looking at how a different form of light, called a quantum state of light, could be made portable for underwater fiber optic cables, Sharma said.
"Right now, quantum light sources are in big lab equipment, with big generators," she said.
Sharma and Marino are working with the Oak Ridge National Laboratory in Tennessee on a three-year project to develop a portable quantum light source.
At some point, the team will be able to test their findings in LSU's 5,000-feet-deep test well. The well, which has a permanent cement covering, is a feature of the university's Petroleum Engineering Research, Training and Testing Lab. Sharma said researchers use water and non-flammable nitrogen for research work in the well.
"Major oil and gas companies are excited about the research we're doing," she said. "Optic fiber has so much potential to make the oil and gas industry safer."