Enhanced Oil Recovery
EOR is an acronym for Enhanced Oil Recovery which refers to the technologies employed to existing producing oil reservoirs or to extend the life of otherwise depleted oil reservoirs. It is often considered to be the third stage (tertiary recovery) of oil production, after the primary stage (post discovery), and secondary stage (water flood or gas cycling), both of which are known as traditional oil recovery, and EOR currently accounts for approximately 10% of all oil produced in the United States.
EOR technology can take one of four different forms: gas injection, chemical injection, thermal processes, or other less conventional forms. Gas injection utilizing carbon dioxide (CO2) under pressure at miscible conditions currently accounts for approximately half of all EOR oil production (or 5% of total oil production) in the United States. Applied to fields that have undergone primary and secondary recovery stage techniques which may produce up to 35% to 40% of the original reservoir oil in place (OOIP), miscible CO2 gas injection technology can add a further 25% to 30% of incremental OOIP recovery.
Please click on this link for a video presentation of how CO2 EOR works.