Weyburn-Midale CO₂ Project

How CO₂ increases oil recovery

1. CO₂ is injected, along with water, deep underground (approx. 1,500 metres) into a depleted oil field. The CO₂ used by Cenovus and Apache comes from the Dakota Gasification Plant near Beulah, North Dakota. There, the gas is captured after coal gasification (rather than vented to the atmosphere), liquefied by compression and pipelined 320 km north to the oil fields. It is the first man-made source of CO₂ being used for enhanced oil recovery.
2. In an operating strategy that alternates gas and water injection, CO₂ injection increases reservoir pressure and oil fluidity, enabling oil to escape from rock pores and flow more readily toward production wells. As a general rule, it takes about 8,000 cubic feet of CO₂ to get an extra barrel of oil.
3. Much of the injected CO₂ is pumped to the surface together with oil and water, then separated and re-injected. At the end of the enhanced oil recovery period, virtually all injected and recycled CO₂ is permanently stored.

Research from the Weyburn-Midale CO₂ Project ensures that CO₂ used for enhanced oil recovery remains safely stored underground.

Click below to view the animation of the storage process: