Once LDCE confirms the operational plans and well construction meets regulatory requirements, it will grant the Class VI permit so operators can begin storing CO2.
- Process: CO2 is pumped more than a mile down the well into the storage layer where it mixes with the brine that exists within the pores of the storage layer. This brine is so salty it cannot be treated for human use.
- Natural pressure: At about a mile deep, the brine moves through the pores of the storage layer because it is naturally under about 2,500 pounds per square inch (psi) of pressure.
- Added pressure: Injecting CO2 only raises the reservoir pressure slightly — about 1–8 percent near the well and 1–3 percent, further away across the storage zone.
- Locked in: The cap rock, which is hundreds of feet thick, keeps both the brine and CO2 sealed underground because it is impermeable and typically can withstand nearly twice the pressure, about 4,500 psi of pressure.
Once underground, although some of the CO2 remains mobile, either settling lower in the pore space or floating up under the cap rock, a large portion of the CO2 will actually dissolve into the brine. Over time, some of this dissolved CO2 will react with the minerals in the rock and solidify.