1 Scope

This document provides requirements for demonstrating that the site in question is adequate to provide safe, long-term containment of CO₂, for demonstrating that the CO₂ flood is operated in a way to assure containment of the CO₂ in the EOR complex, and for quantifying associated storage.

This document applies to CO₂ that is injected in enhanced recovery operations for oil and other hydrocarbons, including natural gas, (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 can be utilized for optional calculations to quantify the portion of associated storage comprised of anthropogenic CO₂ (see Annex A).

This document does not apply to quantification of CO₂ injected into reservoirs where no hydrocarbon production is anticipated or occurring.

Storage of CO₂ in geologic formations that do not contain hydrocarbons is covered by ISO 27914 even if located above or below hydrocarbon producing reservoirs. If storage of CO₂ is conducted in a reservoir from which hydrocarbons were previously produced but will no longer be produced in paying or commercial quantities, such storage would be subject to the requirements of ISO 27914.

This document addresses:

1. safe, long-term containment of CO₂ within the EOR complex;

2. CO₂ leakage from the EOR complex through leakage pathways; and

3. on-site CO₂-EOR project loss of CO₂ from wells, equipment, or other facilities.

This document does not address the following:

4. lifecycle emissions, including but not limited to CO₂ emissions from capture or transportation of CO₂, on-site emissions from combustion or power generation, and CO₂ emissions resulting from the combustion of produced hydrocarbons;

5. storage of CO₂ above ground;

6. buffer and seasonal storage of CO₂ below ground (similar to natural gas storage);

7. any technique or product that does not involve injection of CO₂ into the subsurface; and

8. emissions of any greenhouse gases (GHGs) other than CO₂.