How does carbon dioxide enhanced oil recovery work?

Carbon dioxide enhanced oil recovery is a tertiary extraction method used to harvest additional crude oil from depleted reservoirs by altering the oil's physical or chemical properties. While it is the most common form of enhanced oil recovery and leaves most of the injected carbon dioxide underground, it remains controversial regarding its true climate benefits due to energy-intensive operations and the eventual burning of the extracted oil. Around 80% of carbon dioxide captured annually worldwide is utilized for this process.

What we know

• Enhanced oil recovery, or tertiary recovery, is deployed after primary and secondary recovery methods are completely exhausted, raising total extraction from a reservoir up to 30%-60% or more. [2]
• Carbon dioxide injection is the most common enhanced oil recovery technique, functioning by altering physical or chemical properties of the oil to make it easier to extract. [2]
• Around 80% of carbon dioxide captured annually through carbon capture and storage is used for enhanced oil recovery. [3]
• US federal tax code incentives for enhanced oil recovery began in 1979 to boost domestic oil production. [2]

Still open

• There is ongoing controversy over whether using captured carbon dioxide for enhanced oil recovery is ultimately beneficial for the climate, given the energy-intensive nature of the operations and emissions from burning the recovered oil.

Where to go next

• the bigger pictureWhat is carbon capture and storage?
• how it workedHow does carbon dioxide flooding work in reservoirs?
• a case in pointWhat caused the failure and high costs of the Kemper Project?
• compared withWhat are primary and secondary oil recovery methods?
• whenWhen did tax incentives for enhanced oil recovery begin in the US?
• an unexpected connectionWhy is most captured industrial carbon dioxide sent into oil fields?Although carbon capture is frequently discussed as a climate mitigation tool to keep emissions out of the atmosphere, roughly 80% of all annually captured carbon dioxide is actually routed to oil fields to extract more fossil fuels.

Sources

• [1]enhanced oil recovery (Wikidata Q1049254) · CC0 1.0
• [2]Enhanced oil recovery · CC BY-SA 4.0
• [3]Carbon capture and storage · CC BY-SA 4.0
• [4]Carbon dioxide flooding · CC BY-SA 4.0
• [5]Kemper Project · CC BY-SA 4.0