CPC E21B 43/164 (2013.01) [C09K 8/594 (2013.01); E21B 43/25 (2013.01)] | 10 Claims |
1. A method for recovering hydrocarbons from a hydrocarbon bearing formation, comprising:
introducing a first solution into a target zone of the hydrocarbon bearing formation, the first solution comprising a first salt;
introducing a second solution into the target zone of the hydrocarbon bearing formation, the second solution comprising a second salt and a foaming agent,
wherein the first salt and the second salt produce a nitrogen gas, and
wherein the nitrogen gas and the foaming agent produce a foam formed in-situ within the target zone;
maintaining the hydrocarbon bearing formation to propagate the foam to at least one high permeability zone in the hydrocarbon bearing formation to form a foam barrier; and
after forming the foam barrier, introducing CO2 into an upper portion of the formation gravitationally above the foam barrier, to form a gas cap having a gas front that is separated from the hydrocarbons by the foam barrier.
|