InstructionIn force
Reserves and resources classification instruction
On approval of the Instruction on the classification of deposit reserves and forecast resources of minerals, including unconventional hydrocarbons
The English title is an unofficial translation.
The new 2026 instruction sets uniform principles for classifying reserves and forecast resources of all minerals, including unconventional hydrocarbons; for oil and gas it keeps the national system of reserve categories A, B, C1, C2 and resource categories C3, D0, D1, D2.
What matters for an oil & gas company
- Proven reserves are developed (A, B) and explored (C1); preliminarily estimated reserves are C2; prospective resources are C3; forecast resources are D0, D1, D2; geological reserves are split into profitable (recoverable) and unprofitable.
- Hydrocarbon reserves and resources are subject to state expertise; re-estimation is mandatory if A+B+C1 reserves change by more than 10% for large fields or 20% for other fields.
- No reference to international classification systems (PRMS, UNFC) was found in the text of the instruction.
The summaries are for orientation and are not legal advice. Only the official text is legally binding. Checked in September 2026.