Tracking down fugitive emissions

Damian Barrett - director of GISERA and the Onshore Gas Programme at CSIRO

Damian Barrett - director of GISERA and the Onshore Gas Programme at CSIRO

CSIRO researchers have found that current levels of fugitive emissions of methane from a Queensland and New South Wales survey area are within satisfactory guidelines.

The team has been conducting world leading research on fugitive emissions and the influence of coal seam gas on the amount of methane in the atmosphere.

The researchers are devising new methods that could help companies improve the popular opinion of natural gas as an energy source and better monitor these emissions by identifying their source.

Research director for the Onshore Gas Programme at CSIRO, Damian Barrett said “Leaks generally come from flanges or seals that, once they are tightened up reduce to insignificance. So it’s actually quite straight forward in most cases to rectify leaks that have been detected.

“The more difficult problem is getting a method that is rapid and efficient at detecting these leaks across a large number of distributed wells, and that’s what we have been trying to do.”

Dr Barrett said “The measurement of leaks from pipelines is fairly well covered by existing instrumentation and methods. What our particular research interest here is around undertaking these more difficult measurements associated with more diffuse sources of methane.

“With a large number of distributed CSG wells and associated infrastructure, it’s a lot more difficult to pinpoint leaks in those systems, rather than a transport pipeline. Our methods are particularly tailored to this sort of problem.”

The CSIRO team found that by modelling the results of methane concentration levels around sources and combining the data with meteorological measurements such as wind speed and direction, they were able to monitor the flux of methane and more accurately locate the sources.

According to the US Environmental Protection Agency (EPA), molecule for molecule the comparative impact of methane on climate change is more than 25 times greater than carbon dioxide over a 100-year period.

The EPA adds that approximately 60 per cent of globally emitted methane comes from human activities. It is therefore critical to identify what and where this radiatively active gas is being released into the atmosphere and to reduce the amount escaping.

Fugitive emissions
The researchers looked to find what level of emissions was acceptable before gas power generation became more damaging to the atmosphere than coal power generation.

The consensus is that if fugitive emissions are around 2-3 per cent of upstream production, the greenhouse gas savings are positive compared to the coal power stations. However, between 3-4 per cent the savings evaporate and higher than this causes a reverse in the equations – meaning the process is less efficient than modern coal.

According to Dr Barrett, most of the measurements taken were largely below 1.5 per cent, which is to be expected given that the wells were constructed in drilled in a highly regulated environments using industry best practice. This means GHG benefits would be preserved relative to conventional coal fired power stations if replicated across the industry.

Dr Barrett is also the director of CSIRO’s Gas Industry Social and Environmental Research Alliance (GISERA) that collaborates with APLNG and QGC. The alliance carries out independent research on social and environmental issues of interest to communities in gas production regions.

Once the method used by the CSIRO team has been refined, Dr Barrett believes the work will be continued by governments; but more likely by companies. “There is potential for businesses to adhere to that method and take the monitoring on themselves.

“It’s all about ensuring information and observations that are generated around environmental concerns are made available transparently to those communities to reassure them that the conditions of operations meet very high standards.

“Once the gaining and maintaining of trust between companies and communities will allow the potential for future developments.”

This article is a sample from a longer story that will appear in the next edition of Gas Today. To make sure you can read the entire story subscribe here to hear more about how CSIRO carried out this research.

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