Oil is recovered from oil-containing formations employing alternate injection of carbon dioxide and a mixture of carbon dioxide and an additive comprising an intermediate hydrocarbon or tall oil to improve sweep efficiency. First, carbon dioxide is injected and fluid including oil is recovered from the formation until CO.sub.2 breakthrough occurs at the production well. Next, a mixture of carbon dioxide and an intermediate hydrocarbon or carbon dioxide and tall oil is injected and fluids produced until the injection pressure increases to a value about 10% above the injection pressure when injection of the mixture is initiated. Thereafter, carbon dioxide is injected and fluids including oil are recovered until carbon dioxide breakthrough occurs at the production well. The sequence of injection of carbon dioxide followed by injection of a mixture of carbon dioxide and an intermediate hydrocarbon or carbon dioxide and tall oil is repeated for a plurality of cycles to more completely sweep the full volume of the formation defined by the injection and production well. The process should be applied to a formation in which adequate communication exists.
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