Proven Reserves

Proven reserves, also called proved reserves, measured reserves, 1P, and Reserves, are business or political terms regarding fossil fuel energy sources. (see prove: usage). They are defined as a "Quantity of energy sources estimated with reasonable certainty, from the analysis of geologic and engineering data, to be recoverable from well established or known reservoirs with the existing equipment and under the existing operating conditions." These terms relate to common fossil fuel reserves such as oil reserves (see main article), natural gas reserves, or coal reserves.

Operating conditions includes operational break-even price, regulatory and contractual approvals, of which without these items cannot be classified as proven and are usually classified into probable. Price changes therefore can have a large impact on classification of proven reserves. Regulatory and contractual conditions may change, and also affect proven reserves amount.