ENHANCED OIL RECOVERY INITIATED WITH ZERO EMISSION IN-SITU COMBUSTION

摘要

The invention provides an enhanced oil recovery process that may be used in light oil reservoirs, and which is particularly beneficial in high-relief formations. The process includes an initial injection of air into the formation through an injection well to support the in-situ combustion and mobilize formation fluids. Produced flue gas is recovered and recycled into the formation by injection through an injection well. Initially, gas production is restricted for the purpose of increasing the gas injection to recovery ratio to pressurize the formation. With an increase in formation pressure, the rate of air injection is gradually reduced as the rate of recovered flue gas injection increases. Combustion front propagation in the formation is controlled by the rate of production at each actively producing well to ensure good horizontal sweep across the well and to prevent channeling to one or more production wells.