DOE Developing Water-Detecting Fiberoptic Nets for Pipelines
There is an old adage that “rust never sleeps,” which is especially true for pipeline operators who must be on their toes around the clock to head off corrosion that could cause a major line to spring a leak or fail altogether.
Monitoring pipelines carrying oil products and natural gas for leaks and indications that corrosion has gotten a foothold is more important than ever as the gas infrastructure grows with more pipelines being laid, especially underground or along the offshore seabed where visual inspections are a daunting challenge.
Current monitoring does a respectable job of detecting small leaks and patches of corrosions, but the alarm is raised after the corrosion process begins. Meanwhile, the droplets of water that form inside the pipe, either through condensation or seepage from the outside, are quietly setting the stage for future corrosion of metal pipes — and the need for short-notice repair or replacement.
The U.S. Department of Energy’s National Energy Technology Lab (NETL) is putting in some long days developing a new monitoring technology based on fiberoptic wires that will detect water intrusion when it very first appears. The early warning should enable operators to remove the water more quickly and head off corrosion issues before they occur.
“Because water serves as the electrolyte that sustains the corrosion processes internal to the pipeline, condensed water is an early indicator for the potential onset of corrosion,” said Paul Ohodnicki, a materials scientist with NETL’s Functional Materials Team in Pittsburgh. “So, by detecting water condensation, the operator could then take action to prevent corrosion before it has an impact on pipeline integrity.”
The NETL research, which is still in the laboratory phase, aims to create a fiberoptic net that covers the entire interior wall of the pipe. The fibers will carry laser light that will react to water with a change in its wavelength. Technicians monitoring the network will see the changes in wavelengths and know the exact size and location of the water droplets.
“We also have concepts under development as an extension of this project which would allow us to also characterize the chemistry of the condensed water, providing additional information,” Ohodnicki told Daily Energy Insider. “For example, the pH of the condensed water plays an important role in the degree to which corrosion will occur.”
Ohodnicki said the NETL was carrying out further testing, but the results looked promising and were presented in April at the COROSSION 2018 conference in Phoenix. NETL is also currently seeking a provisional patent on the technology.
Additionally, the lab is working on a method of embedding fiberoptic threads within the protective coatings on pipeline walls. If corrosion sets in, the fibers would break down and trigger an alert to the pipeline control room.
“Ultimately, we envision an ‘intelligent pipeline’ enabled by advanced technologies, including embedded sensors, protective coatings and liners, and geospatial data analytics,” said Ohodnicki, who added that the NETL was also looking at ways to adapt the fiberoptic strategy to other energy assets, such as power transformers, oil wells, and carbon storage sites.
Moreover, the energy industry has already jumped aboard the fiberoptic bandwagon. The basic idea has been used for many years by telecommunications companies to ferret outbreaks and other glitches in its voice and data lines. New pipelines, in particular, are featuring fiberoptic leak detectors as a means of averting a disastrous gas leak or oil spill that would prove far costlier than the up-front installation costs.
Southern California Gas Company this summer announced it was installing fiberoptic leak detectors along a seven-mile high-pressure gas pipeline being built in the Bakersfield area. Along with detecting outright leaks, the network will also pick up acoustical changes and vibrations that will alert operators to unauthorized construction work taking place along the pipeline, which could pose the threat of an accidental rupture of the line.
“This technology provides our engineers with a critical early warning system that can prevent damage to our lines and help us mitigate leaks more quickly,” Deanna Haines, director of Gas Engineering for SoCalGas, said in a statement.
In Canada, Husky Oil is fitting fiberoptic sensors to the 20-inch crude pipeline and 8-inch condensate line that will eventually replace its 16 TAN line, which suffered a major break in 2016, spilling some 1,415 barrels of petroleum into the North Saskatchewan River and its adjacent valley.
The Global Leak Detection Market report issued by Market Insights last fall projected the value of the worldwide fiberoptic sensor market, including pipelines, to grow to more than $1.37 billion by 2021. With major players including Siemens Ag, Honeywell International, and Baker Hughes leading the charge, the future appears bright for the next generation of sensors that are being conceived and developed at NETL.
