[ewhanley]

Pressure is only part of the equation. The pressure gets it to the field economically and does boos reservoir pressure, but co2 injection has more to do with miscibility with hydrocarbons at relatively low pressures. Miscibility yields viscosity reduction and swells the oil to improve displacement and mobility, particularly in heavier crude. Couple that with pressure and you can dramatically improve recovery factor.

[telgareith]

That sounds like a lot of it ends bound to, and thus comes up with, the oil/crude.

[ewhanley]

It absolutely does and has to be stripped out in processing. It typically gets compressed and reinjected over and over again

[alach11]

Exactly. And getting back to the original poster's comment "the CO2 starts underground and ends up underground"... that assumes there are no leaks anywhere in the process.