| 摘要 |
A process for in-situ enrichment of gas used in miscible flooding in a subterranean hydrocarbon-bearing reservoir. A drive gas such as methane, lean natural gas, nitrogen, carbon dioxide or mixtures thereof is used to immiscibly displace formation hydrocarbons. After gas breakthrough the produced fluid is separated into oil and gas components. The separated gas, which has been enriched with intermediate hydrocarbon compounds extracted from the formation hydrocarbons, is mixed with the drive gas injected into the reservoir so as to enrich the injected gas sufficiently to cause miscible displacement of the formation hydrocarbons. When the drive gas is carbon dioxide, methane and/or nitrogen may be extracted from the separated gas prior to being mixed with the drive gas. |
