N124 Play Fairway Analysis and Prospect Evaluation: Key Concepts and Techniques

Course Facts

Course Code:
5 days
4.0 Continuing Education Units
40 Professional Development Hours
Certificate Issued Upon Completion


The course covers the essential principles, concepts and methods involved in subsurface play fairway analysis, prospect evaluation, chance of success (COS) assessment, the calculation of prospect volumetrics and petroleum economics. A series of integrated exercises are used to provide hands-on experience and reinforce the key learning points.

Duration and Training Method

A five-day classroom course.  The method of teaching will be classroom lectures and instruction supported by practical exercises in play fairway mapping, risking, prospect evaluation and petroleum economics.

 Participants will learn to:

  1. Examine a working petroleum system and understand the key elements required for exploration success.
  2. Construct play fairway maps and use them to express the regional distribution and effectiveness of these key elements to identify the best areas for exploration.
  3. Use play fairway maps in determining the probability of finding hydrocarbons and understand the dependency between discoveries, prospects and leads within the same play.
  4. Appraise the factors involved in assessing the “probability of finding hydrocarbons”, how to assign numerical values to these factors and calculate the overall result.
  5. Demonstrate the difference between the “probability of finding hydrocarbons” and the “probability of making a commercial discovery” and how to calculate the latter.
  6. Illustrate how the probability of finding hydrocarbons can be modified:
    a. In the light of new information (dependence)
    b. Based on seismic data and the potential presence of direct hydrocarbon / direct fluid indicators such as fl at spots, phase / amplitude changes
  7. Examine the key volumetric input parameters and understand how to determine appropriate ranges of values for each, taking uncertainty into account, which type of distribution to use and why.
  8. Calculate resource volumes (oil and gas) and understand what a Monte Carlo simulation actually does and why this methodology is used.
  9. Examine the essentials of petroleum economics in terms of:
    a. What input data are required
    b. Description, defi nition and calculation of the key metrics, such as net present value and expected monetary value and how they are used
    c. The different types of agreements and contracts, how the risks and rewards are split between the exploration company and the host country and who owns the mineral rights

Through a mixture of lectures and exercises, this course will lead participants through the key constituents of a working petroleum system, and will describe a methodology to express the effectiveness of these elements through the construction of play fairway maps. Play fairway mapping results are combined with chance of success assessment techniques and prospect economics considerations to provide an holistic view of prospect evaluation.

Oil and gas companies base their exploration budgets and associated drilling programmes on prospect inventories that are based on chance of success assessments, resource estimates and rankings derived from individual prospect evaluations. Overall within the industry the assessment as to the probability of finding hydrocarbons in a prospect is now reasonable but there remains a strong tendency to over estimate prospective resources. This course looks at approaches to counter this.

All of the key volumetric parameters will be reviewed and explained. The application of Monte Carlo software and the use of appropriate parameter distributions will be explained. The dependencies between reservoir parameters, fluid types, recovery factors and recovery mechanisms will be analysed.

Introduction and Learning Goals

Play Fairway Concepts - Overview

  • Definitions
  • General Observations and Examples

Risk Assessment (Chance of Success - COS)

  • What is meant by the chance of success and what are we assessing?
  • Levels of Assessment
    -Regional (Play) versus Local (Prospect Specific) Elements
  • Combining Play and Prospect Specific Elements - Overall COS
  • Assigning Probability Values to COS
  • Pitfalls and Remedies
  • Risk versus Uncertainty

Play Fairway Mapping – Methodology and Exercises

  • Wessex Basin, Onshore UK - A Working Petroleum Play
  • Description of the Regional Geology
  • Review and discuss critical factors in the evolution of the basin
    -Timing of trap formation v hydrocarbon generation.
    -The impact of structural inversion during the Tertiary
    -Relative distribution of reservoir and source rocks
  • Exercises – Creation of Play Fairway / Common COS Segment Maps

Prospect Assessment - Volumetrics

  • Calculation of Resources – Overview
  • Deterministic versus Stochastic Methods
  • The Volumetrics Equation
    -Defining Gross Rock Volume (GRV)
    -Area Depth Plots
    -Application of Geostatistics
  • GRV Modifiers
    -Net to Gross
    -Porosity (and Permeability)
    -Petroleum / Water Saturation, Pressure Gradients, Contact Definitions and Hydrodynamics
    -Formation Volume Factor / Gas Expansion Factor
    -Recovery Factor
  • Methodologies
  • Exercises

Risk Modifications

  • Independent vs Dependent Reservoirs / Prospects / Bayes Theorem
    -Definitions, Dependency, Probability Trees, Exercises
  • DFI / DHI COS Modification
    -Geophyscial Context
    -Approaches to DFI / DHI COS Modification


Essentials of Prospect Economics

  • Why, When and How?
  • Chance of Commercial Success (COCS) and Chance of Economic Success (COES)
    -Definition and Calculation
  • Inputs to Economic Assessment
  • Key Concepts and Metrics e.g.
    -Discounted Cash Flow and Net Present Value (NPV)
    -Expected Monetary Value (EMV)
    -Internal Rate of Return (IRR)
  • Exercise (NPV and EMV calculation)
  • Overview of Types of Agreements
  • Exercise

Who should attend

Any subsurface professionals who are seeking training in play fairway mapping and the calculation of prospective resource estimates for prospects. The course may also be valuable for exploration team leaders and managers who are responsible for coordination of an exploration team and also prospect economic specialists seeking an overview of the geological/ geophysical variables and uncertainties that are used in economic evaluations.

Prerequisites and linking courses

Prerequisites - it is assumed that participants have a basic knowledge of petroleum geology, seismic, well logs and petroleum exploration data prior to attending this course.

Linking Courses - other courses in the NautilusTraining Alliance portfolio that are relevant include:

  • N006: (Introduction to Reservoir Engineering)
  • N014: (Petroleum Economics and Risk Analysis)
  • N019: (Play Fairway Analysis: A Tool for Effective Exploration and Risk Quantification, Dorset, UK)
  • N031: (Prospect Evaluation and Volumetric Methods)
  • N089: (Risk Analysis for Petroleum Exploration - USA)

Click on a name to learn more about the instructor

Martin Stephenson