Kenny's phony carbon storage program 4 billion dollars worth.

For carbon dioxide to become critical (liquid form) it takes the pressure of 2600 feet below the surface.

Generally putting it downhole means they are using the solvent attributes of this liquid to scarf up oil remains in a formation. When they do this, the carbon dioxide is absorbed into the oil making it more fluid, easier to pump. 

As this new mixture is moved to the surface, the pressure diminishes and carbon dioxide is released.  On the surface, this appears to be boiling oil.   

Weyburn Saskatchewan did this in a big way, importing carbon dioxide from North Dakota to put downhole to get more out of their formation.  Reports of this time describe a venting of gas out of the rig with the sound of a jet engine and it would go for hours before oil showed up.

This has been going on since 2008 and is costing billions!  Clean Energy Resources and Projects (CERP) | Natural Resources Canada (atlas.gc.ca)