Page 19 - EngineerIt July 2021

MEASUREMENT

Reducing gas leaks
While eliminating gas leaks completely is
impossible, good pipeline maintenance
can help to reduce them. When laying
pipelines, it is important to consider
right-of-way clearing. All debris should
be removed to help avoid pipeline
damage. It is also important that all
pipelines undergo rigorous tests,
including hydrostatic testing, to ensure Being able to gather accurate gas concentration data over large areas whilst moving at
the pipes can perform under pressure. All speed means that UAV solutions offer a fast, low cost and safe methodology for identifying
pipelines should be monitored for signs potential leakage points, especially when compared to traditional techniques. One
of corrosion, and a proactive inspection example of how drones are being utilised as part of mobile gas leak detection is ABB’s
and maintenance schedule should be put HoverGuard™ UAV-based gas leak detection system. At the heart of the system is a high
in place to help maintain pipelines and sensitivity analyser capable of measuring methane concentrations at rates of up to 2,5Hz.
avoid gas leaks. The analyser uses a principle called Off-Axis Integrated Cavity Output Spectroscopy
(OA-ICOS); this works by using a tunable laser source that produces light at a selected
Advancements in gas leak wavelength for interacting with the target gas being analysed.
detection With a sensitivity over 1,000 times higher and a responsivity far faster than
While pipeline maintenance is important, conventional leak detection technologies, the OA-ICOS method enables the analyser
gas leak detection systems play a critical to detect single parts per billion (ppb) levels of the target gases every second, enabling
role to help find the source of leaks variations in atmospheric concentrations to be quickly measured from long distances
when they occur. Traditional methods where other technologies would be ineffective.
are however slow, inaccurate and By enabling the drone to sample the air at a rate of five times per second as it flies, this
insensitive. To help tackle the problem approach offers a number of advantages over other techniques, such as accuracy and the
of locating gas leakage, operators have speed at which it can collect data.
been looking to new developments in To enable the exact location of a leak to be pinpointed, the HoverGuard solution also
technology to replace traditional manual- combines an anemometer and GNSS (global navigation satellite system) sensor to gather
based methods. data on wind speed and position, together with innovative mapping software which uses
One solution being widely deployed the data to produce detailed reports on leak locations and relative sizes. Since they can be
is the use of sensors based IoT shared either directly or via the cloud, these reports can easily be made available to help
technologies, which detect leaks by pipeline operators to devise a suitable find-and-fix strategy.
measuring key parameters such as
pressure, flow and temperature. While The future
these can be effective in detecting leaks, The digital age has transformed natural gas leak detection practices, enabling exponential
this is limited by their proximity to the leak improvements in sensitivity, accuracy, speed and cost. While eliminating all gas leaks is
and the sheer number of sensors that impossible, UAVs will play an important role in helping companies to tackle leaks as quickly
are needed to service a typical pipeline, and safely as possible. n
especially in situations where there may
be multiple leaks per kilometer of pipeline. References
Another innovative solution to address 1. Key aspects of the Paris Agreement | UNFCCC
these drawbacks is the use of mobile 2. Rising Methane Emissions Could Derail the Paris Agreement - Eos
gas leak detection platforms, including, 3. www.iea.org/reports/driving-down-methane-leaks-from-the-oil-and-gas-industry
most recently, the use of unmanned aerial
vehicles (UAVs) such as drones, which
are fitted with powerful miniaturised gas About the author
analysers capable of detecting variations Doug Baer, Ph.D., is the global product line manager for
in ambient methane gas concentrations Laser Analyzers at ABB Measurement and Analytics
– normally about 2ppm – with a Division. He invents, develops, manufactures and sells
precision of parts per billion (ppb). laser-based instrumentation for ultra-sensitive and
accurate measurements of gases, liquids and isotope
The rise of UAVs ratios for atmospheric and environmental monitoring,
When methane is leaking from a pipeline, industrial process control and homeland security. Based
it is carried by the wind, mixing with the in San Jose, CA, Doug is an inventor of ABB’s patented
air and decreasing in concentration as it laser-based technology and the industry-leading
travels further from the point of origin. By natural gas leak detection platform. Before joining
passing the airborne analyser through the ABB, Doug was the president of Los Gatos Research.
methane diffused in the air, the methane He has degrees in Mechanical Engineering (Ph.D., M.S., Stanford University) and in
can be detected, and its concentration Engineering Physics (B.S., University of California Berkeley).
levels measured.

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