Weyburn-Midale

The IEAGHG Weyburn-Midale CO₂ Monitoring and Storage Project

This project, launched in 2000 and continuing through to 2011, has studied carbon dioxide (CO₂) injection and storage into two depleted oilfields in south-eastern Saskatchewan. 

The first phase, completed in 2004, sought to predict and verify that the Weyburn oil reservoir could securely and economically contain CO₂.  The second phase sought to expand upon the work of the first, and help to recommend a framework to encourage implementation of CO₂ geological storage on a worldwide basis.  The end result is to be the publication of a manual in early 2012 to recommend best practices for the geological storage of CO₂ in a depleted oil reservoir.

In 2005, the research project was expanded to include the Midale oil field, adjacent to the Weyburn field, where CO₂ is also being injected to enhance oil recovery.

Location

The project is operated in conjunction with two billion-dollar commercial CO₂ floods in Saskatchewan, Canada. 

Cenovus' Weyburn field and Apache’s Midale field are located in southeast Saskatchewan, Canada.

Approximately 8500 tonnes per day of the CO₂ are captured from an coal gasification facility – owned by the Dakota Gasification Company  located in Buelah, North Dakota.  The gas is compressed to a liquid phase and transported via a 320 km pipeline to the Weyburn and Midale oil fields for injection.  This is the first time that a man-made source of CO₂ has been used for enhanced oil recovery.

Approximately 6500 tonnes of new CO₂, daily, is injected into the Weyburn field.  Approximately 2000 tonnes is injected daily into the Midale field. 

CO₂-EOR (Enhanced Oil Recovery) in the Weyburn and Midale Oil Fields

CO₂ has been used as a solvent to help improve recovery from oil reservoirs for decades.   Oil field operators in West Texas, for example, have been injecting CO₂ into depleted fields for decades.

At Weyburn and Midale, CO₂ is injected along with water deep underground (approx. 1,500 metres) into the two depleted fields. 

In an operating strategy that alternates gas and water injection, the 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. Each tonne of CO₂ increases oil production in Weyburn by two to three barrels

Some of the injected CO₂ at both Weyburn and Midale is pumped back 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.  The Weyburn-Midale CO₂ Monitoring and Storage Project is ensuring that the CO₂ used for EOR will remain safely stored underground.