Technology Status Report on Natural Gas Leak Detection in Pipelines

However, any opinions, findings, conclusions, or recommendations expressed herein are those of the author and do not necessarily reflect the views of the DOE". Natural gas consumption in the US is expected to increase 50% within the next 20 years (Anderson and Driscoll, 2000). At the same time, the gas delivery infrastructure is rapidly aging. The Department of Energy has stated that ensuring natural gas infrastructure reliability is one of the critical needs for the energy sector. The largest component of the natural gas infrastructure is the approximately 400 thousand miles of delivery pipelines. Therefore, the reliable and timely detection of failure of any part of the pipeline is critical to ensure the reliability of the natural gas infrastructure. This report reviews the current status of the technology for leak detection from the natural gas pipelines. The first part briefly reviews various leak detection methods used in the natural gas pipelines. The second part reviews the optical methods used for natural gas leak detection, and the final part reviews the potential sensors that can be used with optical methods. There are a variety of methods that can detect natural gas pipe line leaks, ranging from manual inspection using trained dogs to advanced satellite based hyperspectral imaging (Carlson, 1993; Scott and Barrufet, 2003). The various methods can be classified into non-optical and optical methods. The primary non-optical methods include acoustic monitoring Acoustic monitoring techniques typically utilize acoustic emission sensors to detect leaks based on changes in the background noise pattern. The advantages of the system include detection of the location of the leaks as well as non-interference with the operation of the pipelines. In addition, they are easily ported to various sizes of pipes. However, a large number of acoustic sensors is required to monitor an extended range of pipelines. The technology is also unable to detect small leaks that do not produce acoustic emissions at levels substantially higher than the background noise. Attempts to detect small leaks can result in many false alarms. Gas sampling methods typically use a flame ionization detector housed in a hand held or vehicle mounted probe to detect methane or ethane. The primary advantage of gas sampling methods is that they are very sensitive to very small concentrations of gases. Therefore, even very tiny leaks can be detected using gas sampling methods. The technique is also immune to false alarms. The disadvantages of the technology …