Researchers Discover Cost-Effective Technique for Monitoring Carbon Dioxide Present Underground

A cost-efficient method for monitoring the storage of carbon dioxide deep underground has been discovered by scientists.

Experiments of their method conducted at a site in Australia were successful and will help to provide information on the development of Carbon Capture and Storage (CCS) technology.

This requires CO₂ from industrial sources and power stations being stored deep underground, to avoid emissions contributing to climate change.

Oxygen testing

In the initial trial researchers studied the various forms of oxygen in water samples from rocks present underground at the storage site located in the Otway Basin, in south eastern Australia.

The researchers discovered that the composition of oxygen was changed by the reservoir's waters when in contact with bubbles of the captured CO₂.

An uncomplicated method to measure the amount of CO₂ stored in the rock is to analyze water samples for this modified form of oxygen.

Locking away gas

The experiment highlights that underground rocks rapidly retain injected CO₂ and preserve the CO₂ like air being captured inside a foam sponge.

Universities of Edinburgh and Australian research organization CO2CRC conducted the research. Researchers point out that the new technique is a cost-efficient monitoring solution, as they only have to measure CO₂ injected into a site and samples of water obtained before and after injection in order to detect the amount of CO₂ that has been trapped.

The research was supported by the UK Carbon Capture and Storage Research Centre and CO2CRC, and was published in the International Journal of Greenhouse Gas Control.

Our results highlight the promising potential of using oxygen compositions to monitor the fate of CO₂ injected underground. This method is simple and cheap, and can be easily combined with other monitoring techniques for CCS projects in the UK and beyond.

Dr Sascha Serno, School of GeoSciences

“Understanding the fate of CO₂ injected into the underground for storage is essential for engineering secure CO₂ stores. Our work with our Australian partners paves the way for better understanding of the fate of CO₂ when we inject it underground.” - Dr Stuart Gilfillan, School of GeoSciences.