In energy geology, how are reserves differentiated from resources?

• A. Reserves are quantities that have not yet been demonstrated to be economically recoverable.
• B. Reserves are quantities known with high confidence to be economically extractable with current technology; resources are total identified and undiscovered amounts not all currently economical.
• C. Reserves include both discovered and undiscovered resources, regardless of economics.
• D. Resources are only the portion currently available and economical to extract.

Answer: (B)

In energy geology, the key distinction is about economic feasibility with current technology and prices. Reserves are the portion of a resource base that can be recovered economically right now, with a high level of confidence, using existing technology and market conditions. Resources, on the other hand, encompass all identified quantities plus undiscovered amounts, including portions that are not presently economical to extract. So the statement that reserves are quantities known with high confidence to be economically extractable with current technology, while resources are the total identified and undiscovered amounts not all currently economical, best captures this difference. The other descriptions mix in economics incorrectly or constrain resources to what is currently economical, which isn’t how the terms are used.