This document applies to carbon dioxide (CO₂) that is injected in enhanced recovery operations for oil and other hydrocarbons (CO₂-EOR) for which quantification of CO₂ that is safely stored long-term in association with the CO₂-EOR project is sought. Recognizing that some CO₂-EOR projects use non-anthropogenic CO₂ in combination with anthropogenic CO₂, the document also shows how allocation ratios could be utilized for optional calculations of the anthropogenic portion of the associated stored CO₂ (see Annex B).