Improving CO2 Injection

Improving injection and sweep efficiency of CO2 can reduce costs and increase the storage potential of reservoirs

Microbubble CO2 injection

Preliminary studies show that CO2 microbubble (10-100 µm diameter) injection can both improve CO2 sweep efficiency and enhance CO2 storage capacity within a CCS storage site.

The proposed collaboration between Japanese Research Institute of Innovative Technology for the Earth (RITE) and CO2CRC provides an almost unique opportunity to undertake a timely evaluation of an exciting new technology that has the potential to not only decrease the costs and to improve technical efficiencies of CCUS, but also to fundamentally change its geologic and geographic applicability.


A fundamental challenge to the widespread roll-out of CCS is identifying economic CO2 storage capacity proximal to existing / future emission sources. Sedimentary basins hold a mixture of reservoir types, with high-quality reservoirs being less common.

Solutions to improve the economic potential of poor to moderate reservoirs for CO2 storage is required.

CO2CRC and RITE jointly propose to assess a new CO2 injection technology developed by RITE, Microbubble CO2 injection, which can potentially enable lower quality reservoirs as viable storage candidates. Preliminary studies show that CO2 microbubble (10-100 µm diameter) injection can both improve CO2 sweep efficiency and enhance CO2 storage capacity within a CCS storage site.

Microbubble injection could increase effective storage capacity and reduce the required number of wells for CO2 injection and hence reduce CO2 storage project CAPEX.

The research project

To date, no field trial of Microbubble CO2 injection technology within a dedicated CCS site has occurred. For the technology to mature, field testing is required.

CO2CRC and RITE intend to undertake an assessment of CO2 microbubble injection technology, focussed upon the geology and infrastructure at the OITC.

The OITC is uniquely equipped globally to undertake this field-scale trial of microbubble technology.

This proposal is strongly aligned to the Federal Government’s intent for international collaboration to drive the development of low-cost, low-emissions technologies.



To mature microbubble technology, laboratory analysis (phase 1) and field-based technology trial (phase II) will evaluate the performance of Microbubble CO2 injection, within a well-constrained CCS field setting, using the CO2CRC’s OITC data, sample and ultimately site.

Phase I will test Microbubble CO2 injection on OITC core samples, which reflects a typical reservoirs range from poor to high quality.

In Phase II, the core results will be incorporated into a new, comprehensive reservoir model, used to plan a well-based testing program. A rigorous field-testing program of the Microbubble CO2 injection technology will be undertaken at OITC involving injection, monitoring and recovery of injected Microbubble CO2, and compared to a separate normal CO2 injection.

Expected outcomes

The project will quantitatively determine whether Microbubble CO2 injection technology can result (relative to normal CO2 injection) in:

A higher sweep efficiency
An improved storage capacity
Increased access to the low and medium porosity-permeability zones within the reservoirs
Improved CO2 dissolution and residual trapping processes
A delayed CO2 breakthrough time (compared to normal bubble injection).
A lower injection pressure at the bottomhole