CPC E21B 43/164 (2013.01) | 24 Claims |
1. A method for oil recovery, comprising:
injecting thickened CO2 into the top of a reservoir containing oil, wherein the thickened CO2 comprises a thickener comprising a mixture of a copolymer with propylene carbonate, allyl ethyl carbonate, dimethyl carbonate, white oil, silicon, oil, or petroleum ether, or combinations thereof;
forming an interface between the thickened CO2 and the oil;
mobilizing the oil with unthickened CO2, wherein the unthickened CO2 is injected after the thickened CO2; and
recovering the oil with a recovery well drilled below the reservoir.
|