15,000 tonnes of CO2 stored in landmark study

Over 15,000 tonnes of carbon dioxide have been injected 1.5 km below ground at Nirranda South, Victoria, in a CO2CRC project which is said to prove the safety and long-term viability of CO₂ storage. The experiment has seen more than 120 terabytes of data — the equivalent of 480 average laptops — collected and sent to Perth for analysis.

In the recently completed injection trial, CO₂ was pumped into a saline rock formation over four months at CO2CRC’s Otway Research facility. Deep saline formations have securely held billions of tonnes of carbon underground for millions of years, demonstrating to scientists that rock formations are a natural and safe home for captured carbon.

The porous rocks contain a fluid trapped by cap-rock — in this case, water that is unusable because of its high salt or mineral content. These formations are widely found around the world and, critically, often in areas with high CO₂ emissions but with little oil and gas production. Their abundance means that the cost of transporting CO₂ from the emitting source (a power plant, for example) will make carbon capture and storage a cost-effective solution.

As part of the study, fibre-optic cables and a high-resolution buried receiver were fitted with automated communications devices so researchers could remotely observe and operate the advanced surface and subsurface monitoring system. The equipment tested offered several options to reduce the surface monitoring activities required to verify the CO₂ movement.

CO2CRC Chairman Martin Ferguson claimed the experiment proves that CO₂ storage is a low-risk method of emissions reduction, stating, “We can confidently inject, store and predict how the CO₂ will behave below ground.

“There is enough storage capacity to store our emissions for the next 200 years. The work of CO2CRC proves that if we effectively put CO₂ deep underground into these formations, we have a way of meeting global energy needs at the same time as tackling climate change.”

CO2CRC’s research partners — Curtin University in Western Australia, Lawrence Berkeley National Laboratory in the US and CSIRO — continue to work collaboratively on the analysis of the massive collection of data. It is expected to advance our understanding of the movement of carbon once injected deep underground.

“It’s hard to underestimate the significance of this work and its capacity to help the world move towards a low-carbon energy future,” Ferguson said.