Study Shows Fault Lines Do Not Hinder Safe CO2 Storage

A study has confirmed that carbon dioxide (CO₂) emissions can be trapped and securely stored in underground rocks, even if there are geological faults in the area.

The study also showed there is minimal chance of the gas seeping out of the fault lines back into the atmosphere.

The findings are further indication that an upcoming technology called Carbon Capture and Storage (CCS), wherein CO₂ gas emissions from industry are collected and conveyed for underground storage, is dependable.

This kind of method can decrease CO₂ emissions and help to restrict the effect of climate change.

If extensively adopted, CCS could help match targets fixed by the 2015 UN Paris Agreement, which aims to restrict climate warming to below 2 °C compared with pre-industrial levels.

Long-term approach

The newest findings, from tests done on a naturally occurring CO₂ reservoir, may answer public doubts over the suggested long-term storage of CO₂ in depleted oil and gas fields.

Researchers from the Universities of Edinburgh, Freiburg, Heidelberg, and Glasgow examined a natural CO₂ repository in Arizona, US, where gas travels to the surface via geological faults.

Safe storage

Scientists used chemical analysis to measure the quantity of gas that had escaped the underground store for more than almost half a million years.

They discovered that a tiny quantity of CO₂ escaped the site annually, well within the safe levels required for effective storage.

The research, reported in Scientific Reports, was aided by the European Union and Natural Environment Research Council.

This shows that even sites with geological faults are robust, effective stores for CO₂. This find significantly increases the number of sites around the world that may be suited to storage of this harmful greenhouse gas.

Dr Stuart Gilfillan, School of GeoSciences, University of Edinburgh

The safety of carbon dioxide storage is crucial for successful widespread implementation of much-needed carbon capture and storage technology. Our research shows that even imperfect sites can be secure stores for hundreds of thousands of years.

Dr Johannes Miocic, University of Freiburg