NETL is battling the destructive effects of corrosion and other risks to the natural gas pipeline infrastructure by developing fiber-optic sensor systems that can monitor vital natural gas pipelines from within. The data will provide critical information for early detection and help avoid expensive pipeline failures to maintain affordable, reliable energy for consumers.

Natural gas pipelines are arteries that fuel many of the nation’s fossil-energy power plants. However, like all metals, every inch of pipe is susceptible to corrosion. According to worldwide corrosion authority NACE International, corrosion adds billions of dollars to operation and maintenance expenses each year. Amongst other benefits, mitigating these preventable costs could result in lower energy bills for consumers.

In prior research, NETL researchers developed novel fiber-optic sensors and sensor materials. Now, the same team is turning its attention to technologies that measure fiber-optic sensor data. The devices are called interrogators, and they can help analyze miles of fiber optic data to give a clearer picture of what’s going on inside of the pipe.

While optical fiber sensors have continued to decrease in cost since their introduction, the interrogators used to analyze the sensor results are still relatively expensive and stand as a major roadblock in the widespread deployment of fiber-optic sensor systems in pipelines and other applications.

“We are working on two new types of interrogators that could be more cost-effective by integrating advanced hardware, signal processing and data analytics techniques” said Paul Ohodnicki, Ph.D., of NETL’s Functional Materials Team. “Additionally, these devices will be more accurate and work over a much longer distance, providing new information not previously accessible.”

Two types of interrogators currently being investigated by the NETL researchers are based on Brillouin optical time domain analysis (BOTDA) and optical frequency-domain reflectometry (OFDR). While each type of interrogator has its own specific limitations and advantages, overall these technologies have shown great promise as potential long-distance and low-cost solutions for pipeline monitoring systems.

“BOTDA and OFDR interrogators with enhanced performance, reduced cost and additional functionality will represent significant steps forward for this kind of technology,” said Ohodnicki. “We are targeting large dynamic range and optimized resolution with high signal-to-noise ratios, which will provide an enhanced monitoring capability at lower effective costs.”

NETL’s work developing fiber-optic interrogators is helping to bolster the nation’s natural gas infrastructure, which is key to sustaining economic growth and fueling industry. Research breakthroughs like this also serve to strengthen pipeline integrity, resilience and operational reliability; improve efficiency; and reduce pipeline emissions, all to improve the economics of natural gas delivery in the United States.