| Russian | A | B | C1 | ABC1 | C2 |
|---|---|---|---|---|---|
| proved developed producing | proved developed nonproducing | proved undeveloped | proved | probable + possible | |
| SPE | PD | PUD | P90 | P50 + P10 | |
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology / Reserves Classification