CARBON DIOXIDE AND HYDROCARBON SOLVENT FLOODING IN A STEEPLY DIPPING RESERVOIR

摘要

The disclosed invention is a method of conducting a miscible carbon dioxide and hydrocarbon solvent flood in a steeply dipping reservoir. A mixture of carbon dioxide and light hydrocarbon solvent is injected in the updip end of the reservoir in such a ratio as to achieve at least multiple contact miscibility between the mixture and the formation hydrocarbons. As the flood front moves downdip with increasing formation pressure, the amount of injected enriching hydrocarbon solvent is decreased while multiple contact miscibility is maintained in the flood front. Hydrocarbons and carbon dioxide are recovered from at least one production well downdip of the injection well.