Definition :
Enhanced Oil Recovery (EOR) consists in injecting CO2 and water into existing Oil reservoir to improve the Oil recovery. Part of the CO2 injected (Around 40%) remains captured underground.
Oil & Gas companies such as Oxy or Total invest in CO2 capture and underground injection mainly for EOR or to stabilize empty reservoirs that may cause landslides otherwise.
^1: Energy.gov, https://www.energy.gov/fe/science-innovation/oil-gas-research/enhanced-oil-recoveryupdate_of_financial_data_for_coal_fired_chp_plants_may17_july17.pdf