how does CO2 stay in ground after pushing oil from old wells?

Question

1. week of 10-29-06, science channel showed evidence that coal is burned in large plant to create high-pressure CO2 that is then pumped into canadian & us oil wells thought to be dry. but oil exists in rocks, & the CO2 pushes it out. how can it be that the CO2, a gas, stays down in the earth and never comes out as CO2? ... 2. in addition, what other means are now used to get extra oil out of the earth where it has already been drilled?
3. what is there to that "peak oil" theory that says that petroleum is forever being produced by processes at the center of the earth, which will create an infinite source of petroleum??? i think all oil comes from pressures of waters and sediments upon carbon-based life forms, not from volcanic activity or magnetism at center of the earth.

Answer 1

The CO2 simply displaces another gaseous product. CO2 is used because of its low cost, high expansivity, and fairly low reactivity. Some of it is returned to surface with the gas. In fact there are wells in Utah that produce 60 % and higher CO2 with the gas. These haven't been developed due to the expense of separating the two.

Other means of "production enhancement" (what we call it), is water injection to displace gas, hydraulic fracturing to increase the overall reservoir tapped by a single well, chemical treatments to increase permeability of the formation rock, and formation mapping. With modern computing power and technology, it is possible to drill the hole to the ideal location to tap the best part of the formation. It is even possible to reenter a hole with a drill, and directional drill to a new formation.

The idea of oil being derived from geological sources is not new, and actually has some followers (even among those that should know better if its baloney). What gets me is that it is can't be shown definitively either way.

It could also be from sources we haven't really thought of, such as subterranean bacteria. We only recently have been discovering that bacteria can live in really hostile places, and they do occur in oil and gas wells. They live in the water on the oil-water interface, and can produce paraffins and sulfides from the nutrients they get in the hydrocarbons. They are typically thought of as being introduced into the well with the water.