Reserve Categories are industry-standard terms that are finer subdivisions of the PRMS “Reserves” Class.
Reserve Categories (on the left) are compared to the PRMS terminology (on the right) below:

 

Common Industry Terminology

PRMS Terminology

Abbreviation Description PRMS Resource Category Equivalence
(from Figure 1.1)
PRMS Maturity sub-Class
(from Figure 2.1)
1P, TP Proven, Total Proved P1, Proved, Low, 1P, P90 Any Reserves sub-class
2P Proved + Probable 2P, Best Estimate, P50, Any Reserves sub-class
3P Proved + Probable + Possible 3P, High, P10 Any Reserves sub-class
P1 Proved P1, Proved, Low, 1P, P90 Any Reserves sub-class
P2, PB, TPA Probable, Total Probable Additional;
the difference between 2P and 1P
P2, Probable Any Reserves sub-class
P3, PS, TPS Possible, Total Possible Additional;
the difference between 3P and 2P
P3, Possible Any Reserves sub-class
PDP Proved Developed Producing P1, Proved, Low, 1P, P90 On-Production
PDNP Proved Developed Non-Producing P1, Proved, Low, 1P, P90 On-Production*
PD Proved Developed; the sum of PDP and PDNP P1, Proved, Low, 1P, P90 On-Production*
PUD Proved Undeveloped P1, Proved, Low, 1P, P90 Approved for Development; Justified for Development
PNP Proved Non-Producing; the sum of PNP and PUD P1, Proved, Low, 1P, P90 Any Reserves sub-class

*PDNP, and PD are included in the PRMS “On-Production”
sub-maturity class because that class is defined as “Producing or capable of Producing”