A CO2CRC research project, the Otway Stage 2C project, has provided important findings into carbon dioxide (CO2) injected deep underground as part of the emissions reduction technology known as carbon capture and storage (CCS).
CO2CRC injected 15,000 tonnes of CO2 approximately 1500 metres underground at its Otway National Research Facility located in Nirranda South, Victoria. The CO2 was injected into a saline aquifer between December 2015 and April 2016. The CO2 plume was then detected and tracked during the injection and in the years after. The monitoring was done primarily using an array of geophone receivers buried just under the surface to detect the seismic signal paired with conventional vibroseis where a seismic signal is produced by a truck-mounted seismic vibrator. Surface orbital vibrators were also successfully trialled as a seismic signal source enabling monitoring data to be acquired continuously.
The research, led by Curtin University and supported by CSIRO and Lawrence Berkley National Laboratory, USA, demonstrated that a small amount of CO2 (as little as 5000 tonnes), can be detected using seismic monitoring tools and its movement underground successfully mapped. The demonstration provides CCS stakeholders with confidence that any movement of the injected CO2 outside of the storage complex can be quickly detected. The project also trialled a variety of new seismic monitoring techniques.
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“The ability to reliably predict the movement of CO2 and optimise the use of seismic monitoring to validate the plume migration path will be invaluable to CCS project operators and regulators around the world,” said David Byers, CEO of CO2CRC.
“Our success with the Stage 2C project in observing the behaviour of a small CO2 plume and understanding the resolution and sensitivity of seismic monitoring has paved the way for CO2CRC’s biggest project to date: Otway Stage 3,” he said.
In 2019, work on Otway Stage 3 began with the expansion of infrastructure at the Otway National Research Facility through the drilling of four new 1600-metre-deep monitoring equipped with the latest technologies in fibre optics sensing and subsurface gauges.
Otway Stage 3 will demonstrate the next generation of sub-surface monitoring technologies and improve the efficiency of storage monitoring. These new technologies provide data quicker and cost significantly less than the seismic surveys currently used with initial estimates showing cost savings of up to 75 per cent,” Mr Byers said.
A workflow for verifying the stabilisation of the CO2 plume using seismic data and dynamic modelling has been developed under Stage 2C and will be tested in the next phase of the project, expected to be completed by June 2020.
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“Our hope is that the applied scientific and technological research conducted at CO2CRC’s Otway National Research Facility will lead to more CCS projects around the world, allowing CCS to play a vital role in meeting the dual challenge of reducing emissions across all major industry sectors while meeting the growing global demand for affordable and reliable energy,” Mr Byers said.
CO2CRC Limited is one of the world’s leading CCUS research organisations, having invested more than A$125 million to develop and deliver better and more cost-effective technologies for CCUS. As owner and operator of the Otway National Research Facility CO2CRC commissions and undertakes research projects with partners worldwide.
The CO2CRC Otway Stage 2C project is jointly funded through its industry members and research partners, the Australian Government, the Victorian State Government and COAL21 through ANLEC R&D.