Petroleum Reserves and Resources Definitions
The Society of Petroleum Engineers (SPE) Oil and Gas Reserves Committee, made up of international oil and gas experts, partners with several industry related societies to provide publicly available resources for the consistent definition and estimation of hydrocarbon resources. As part of this work, SPE offers free documents including the Petroleum Resource Management System (PRMS), the PRMS Application Guidelines, as well as a map to other systems, and standards for reserves estimating and auditing.
Petroleum Resources Management System

The Petroleum Resources Management System (PRMS) is a system developed for consistent and reliable definition, classification, and estimation of hydrocarbon resources.
The Oil and Gas Reserves Committee has completed the revision of the Petroleum Resources Management System (PRMS) and the SPE Board approved it in June 2018. The updated PRMS is a consensus of input collected from consulting and financial firms, government agencies, and E&P companies. The process included a 90-day public comment period, and required input and approval by six sponsoring societies: the World Petroleum Council, the American Association of Petroleum Geologists, the Society of Petroleum Evaluation Engineers, the Society of Exploration Geophysicists, the European Association of Geoscientists and Engineers, and the Society of Petrophysicists and Well Log Analysts.
- Download a .pdf of the 2018 PRMS
- Download the 2018 PRMS Errata
- Purchase a Bound Copy of the 2018 PRMS
Key Changes from PRMS 2007 to PRMS 2018
The 2018 PRMS update maintains the foundation principles contained in the PRMS 2007 and addresses many of the points in need of clarification that have been collected over the years. This document describes the key changes.
- PRMS 2018 Key Changes (pdf)
Translations
- PRMS 2018 Russian (pdf)
- Russian Errata v.1.02 (pdf)
- PRMS 2018 Spanish (pdf)
Reserves Classification Guidelines
The SPE Oil and Gas Reserves Committee (OGRC) released Guidelines for Application of the Petroleum Resources Management System (pdf) in 2011. The 221-page document replaces the 2001 “Guidelines for Evaluation of Reserves and Resources” with content expanded to focus on using the 2007 PRMS to classify petroleum reserves and resources.
The guidelines represent a collaboration of SPE, the American Association of Petroleum Geologists, the Society of Exploration Geophysicists, the Society of Petroleum Evaluation Engineers, and the World Petroleum Council. More than 40 subject matter experts were involved in writing and review of the guidelines. The effort was headed by Satinder Purewal, chairman of the OGRC’s Applications Document Subcommittee.
- Guidelines for Application of the Petroleum Resources Management System (pdf)
- Guidelines for Application of the Petroleum Resources Management System – Chinese translation (pdf)
Mapping of Reserve Definitions
Around the world, government agencies and other organizations use slightly different definitions. This mapping provides a comparison of many of these definitions.
- OGRC mapping (pdf)
Estimating and Auditing Standards for Reserves
To assist those responsible for estimating reserves, or auditing those estimates, a standard approach has been outlined, along with minimum qualifications for those involved in reserves auditing.
Joint Committee on Reserves Evaluator Training
The Joint Committee on Reserves Evaluator Training (JCORET) exists to meet the need for high-quality, industry-recognized training for individuals responsible for petroleum reserves and resources evaluation.
Historical Document Archives
- Petroleum Resources Management System - 2007 (pdf)
- PRMS Guide for Non-Technical Users - 2007 (pdf)
- PRMS Process - 2007 (pdf)
- Definitions Development to 2005
- Glossary of Reserves/Resources Terminology - 2005
- Estimating and Auditing Standards for Reserves - 2001 (pdf)
- Guidelines for the Evaluation of Reserves and Resources - 2001 (pdf)
- Petroleum Resources Classifications - 2000
- Petroleum Reserves Definitions - 1997
- Definitions of Oil and Gas Reserves – 1987 (pdf)
- Proved Reserves Definitions – 1981 (pdf)
- Definitions of Proved Reserves for Property Evaluation 1965 (pdf)
- White Paper: Why a Universal Language for Evaluating Reserves Is Needed