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Petroleum Reserves & Resources Estimation – PRMS Applications
Guidelines Document

25 – 26 September 2012

Mexico City, Mexico | Presidente Intercontinental

Technical Agenda

Tuesday, 25 September, 0900-0930


Session Chairpersons: Satinder Purewal, EER Limited; Gustavo Hernadez Garcia, Pemex
Keynote Speaker: Carlos Morales Gil, Director de Pemex Exploración y Producción


Session I: PRMS Application Guidelines: Overview

Session Chairpersons: Satinder Purewal, EER Limited; Gustavo Hernandez Garcia, Pemex

Current and past representatives of the SPE Oil and Gas Reserves Committee (OGRC) describe PRMS and the Application Guidelines, discuss the major changes to prior guidance and provide insight into ongoing activities to assist in its implementation of the Application Guidelines document published in November 2011.

  • PRMS – Development process
  • PRMS Application Guidelines – Key principles
  • PRMS Application Guidelines status and SPE support


  • John Etherington, PRA International
    PRMS Implementation Status
  • Satinder Purewal, EER (AS) Ltd
    PRMS Application Guidelines

  • Alfonso Rodriguez Torres, PEMEX
    PRMS Overview


Session II: Seismic Applications

Session Chairpersons: Pierre-Louis Pichon, Total; Guillermo Perez Cruz, UNAM

An overview is presented of the guidance provided in the PRMS-AD on the role of geophysical technology in reserves estimation and classification. This will be illustrated with a couple of integrated case studies, focusing on using seismic for structural definition, fault analysis, fluid contacts, reservoir development and flow surveillance purposes and its implications on reserves and resources estimates.


  • Pierre-Louis Pichon, Total
    Overview PRMS-AG on the Role of Geophysical Technology in Reserves Estimation and Classification
  • Leonardo Aguilera Gómez, PEMEX
    Seismic Applications to Book Reserves in Mexico - Examples
  • Marco Flores Flores, PEMEX
    Introduction to Workshop Roadmap and Plenary Discussion


Session III: Deterministic and Probabilistic Methods

Session Chairpersons: Enrique Morales, SGS Horizon; Brad Gouge, Murphy Oil Corp

Our industry is currently divided on the applicability of probabilistic methods to reserves assessment and reporting. Most post-discovery assessments are based on deterministic geologic, engineering and economic models that represent different levels of uncertainty. In the pre-discovery exploration phases with limited information, our industry typically applies probabilistic methods. Some believe that probabilistic methods should be applied throughout the life of a reservoir. Is some sort of hybrid feasible to bring together these two polarized views?

  • Deterministic assessment methods
  • Probabilistic assessment methods
  • Hybrid methods for reserves and resource estimates


  • Brad Gouge, Murphy Oil Corp
    Assessment of Resources using Deterministic Procedures
  • Luis Ramos Martinez, PEMEX
    Probabilistic and Hybrid Approaches to Resource Determination
  • John Etherington, PRA International
    Global Experience in Deterministic and Probabilistic Resource Estimation
  • Oscar Dario Xochipa Lopez, PEMEX
    Probabilistic and Deterministic Reserves Assessments—Crudo Ligero Marino Project-Gulf of Mexico


Session IV: Aggregation of Reserves

Session Chairpersons: David MacDonald, BP; Luis Ramos Martinez PEMEX

Available literature describes the pros and cons of reserves and resources aggregation, companies adapt their reserves/resources aggregation approaches to meet corporate objectives (e.g. portfolio analysis, external and internal disclosures),company’s accounting organizations call for specific aggregation approaches for proper determination of depreciation and other financial calculations as per IAS/IFRS, FAS/FASB, US GAAP, etc., accounting firms and regulatory bodies will be very strict and specific on how reserves are aggregated and disclosed. Gas commercial agreements between buyers and sellers will, in some cases, call for a realistic assessment on the ability of the seller to deliver on the gas commitments to be agreed upon, taking proper account of uncertainties and portfolio issues (e.g. number of fields supplying gas, dependencies between fields, etc.). The PRMS “Project” definition raises an interesting concept in the aggregation of reserves, linking an investment decision to the “Project” and to the accounting aspects and aggregation approach that can be used to estimate reserves. These issues, as well as some global and specific local issues on this topic, will be part of this session.


  • Gildardo Guerrero Cruz, PEMEX
    PRMS Guidance for Aggregation
  • Enrique Morales, SGS Horizon
    A Case for Probabilistic Addition of Fields within a Project
  • Rodolfo Camacho Velazquez, PEMEX
    Aggregation Issues


Wednesday, 26 September, 0900-1030

Session V: Commercial Consideration in Evaluation of Reserves and Resources

Session Chairpersons: Frank Denelle, Shell; Vinicio Suro Pérez, IMP

The commercial evaluation of petroleum reserves and resources is a process by which the value of investing in existing and planned petroleum recovery projects is determined. Just as there are inherent uncertainties in physically recoverable petroleum volumes, there are also uncertainties regarding costs, prices, taxes and fiscal terms. Beyond these uncertainties, there may be marketing, legal, environmental, social or governmental contingencies that must be addressed prior to deeming any discovered resource a Reserve versus a Contingent Resource. This session will focus on addressing these topics of value uncertainties and associated contingencies.


  • Mario Vazquez Cruz, PEMEX
    "Economic Evaluation Of Petroleum Projects – Guiding Principles And Application Example"
  • TBC
  • Ulises Neri, CNH
    Aggregation Issues


Session VI: Unconventional Resources

Session Chairpersons: John Lee, University of Houston; Néstor Martínez-Romero, CNH

Unconventional resources exist in petroleum accumulations that are pervasive throughout a large area and that are not significantly affected by hydrodynamic influences. Examples to be discussed included coal bed methane (CBM), shale gas and natural bitumen. There are also projects which are on the boundary between conventional and unconventional; this includes tight gas, heavy oil, and complex condensate reservoirs. While the assessment techniques may differ dramatically, the end result of the assessment is an uncertainty distribution of marketable petroleum products and the classification principles still apply.

  • Reserves estimates in complex low permeability formations
  • CBM projects – assessment challenges
  • Shale gas resource assessment methods
  • Bitumen mining and in-situ production


  • Roberto Aguilera, University of Calgary (presented by John Lee)
    Tight Gas Assessments
  • Geoff Barker, RISC (presented by John Etherington)
    CBM Resource Assessments
  • Creties Jenkins, DeGolyer and MacNaughton (presented by John Lee)
    Shale Gas Resource Assessments


Session VII: Reserves Entitlement

Session Chairpersons: Aquiles Rattia, Repsol; William Strawbridge, ExxonMobil; Jose Alfonso Rodríguez-Torres, PEMEX

The rapid evolving and stringent conditions imposed in contractual agreements and fiscal system in the oil countries around the world makes resource entitlement and recognition attempts by oil companies a major reporting issue. This session will be geared to understand the nature and main features of typical fiscal systems around the world; regulations comparison, the Division of Profit and the Government Take concepts, and discussion of key criteria’s and contract elements for entitlement calculation and reserves recognition.


  • Aquiles Rattia Regalado, Corporate Reserves Director Repsol Madrid
  • William Strawbridge, Reserves Manager, ExxonMobil
    Resources Entitlement and Recognition
  • Edgar Rangel Germán, CNH
    Legal Aspects in Mexico
  • Aquiles Rattia Regalado
    Regional Petroleum Contracts and Reserves Recognition


Session VIII: Other Issues

Session Chairpersons: John Etherington, PRA International; Francisco García-Hernández, PEMEX

Several major issues that play a part in production measurement and operations must be considered in reserves and resource evaluations.

  • Lease fuel
  • Measurement points
  • Integrated operations PUDs > 5 years
  • Key regulatory differences between PRMS and SEC
  • How other (non-US) regulatory bodies are embracing PRMS in their requirements (e.g. Canada, UK, ESMA, Australia, Hong Kong, Latin America)
  • Why companies are not reporting 2P or 3P, etc.


  • Satinder Purewal, EER (AS)
    Production Measurements and Operational Issues
  • Enrique Morales, SGS Horizon
    PUD's > 5 Years in the "Books" 
  • Luis Macias Chapa, PEMEX
    Implications of Reserves Evaluation in Unitization and Unit Operation Agreements for Transboundary Reservoirs         


Conclusion/Workshop Closing