The most effective permanent safe storage is in sites of sufficient depth (typically deeper than 800 meters) with adequate capacity and an overlying sealing system to ensure containment of fluids.
Depleted oil reservoirs, such as the one chosen for the ACTL Project, make ideal sites for secure and permanent CO₂ storage because their inherent trapping has securely stored oil and gas for millions of years. Reservoir simulation modeling on the formations in the Clive field have demonstrated the same conditions that have trapped gas in the reservoir for millions of years will enable storage of CO₂ over similar timeframes.
CO₂ is permanently stored deep within the Clive Leduc Reservoir, protected by numerous impermeable barriers
In the reservoir, CO₂ will be trapped within the tiny pore spaces between the grains of the rock formation. Over time, the injected CO₂ will dissolve in water already in the rock formation and it may combine chemically with the rocks trapping the CO₂ even more securely. At Clive, the CO₂ is stored approximately two kilometres underground sealed by multiple impermeable rocks that provide numerous barriers and at the conclusion of the injection phase, wells will be plugged and abandoned to establish long-term permanent CO₂ storage.