| CPC E21B 41/0064 (2013.01) [E21B 43/168 (2013.01)] | 19 Claims |

|
1. A method comprising:
introducing carbon dioxide into a subterranean formation via one or more injection wells, the subterranean formation containing hydrocarbons and water, wherein the water is present in the subterranean formation in a water-bearing zone below the hydrocarbon-bearing zone;
mobilizing at least a portion of the hydrocarbons in a hydrocarbon-bearing zone of the subterranean formation with the carbon dioxide;
after mobilization with the carbon dioxide, producing the hydrocarbons from the hydrocarbon-bearing zone of the subterranean formation via one or more production wells;
introducing hydrogen to the subterranean formation via the one or more injection wells, the hydrogen displacing the carbon dioxide downward in the subterranean formation and promoting production of at least a portion of the water as the carbon dioxide is displaced downward;
storing the hydrogen in the subterranean formation above the carbon dioxide; and
producing at least a portion of the hydrogen from the subterranean formation via the one or more production wells, the one or more injection wells, or any combination thereof.
|