Play-Based Exploration

Jan de Jager  Maarten Wiemer 
3 days

Business context

In the increasingly demanding search for valid exploration opportunities more and more companies have adopted a Play-based Exploration (PBE) approach to their exploration evaluations.  PBE is an evaluation process to arrive at an understanding of the fundamental logic of hydrocarbon plays, and should lead to better recognition of (remaining) exploration opportunities in a basin. It also provides a sound technical basis for ranking and prioritizing all exploration projects and activities.

The process is encapsulated in the "PBE pyramid": Basin à Play à Prospect. Basin evaluation is the solid foundation for all future work. Basin evaluation results in an understanding of the petroleum system(s) in a basin.  Grouping prospect and already discovered HC accumulations into Plays, allows better and more consistent understanding of prospect risks and of potential HC volumes. Play evaluation leads to a portfolio of leads that can be matured further into drillable prospects. The PBE approach also includes statistical methods to arrive at a "yet-to-find" hydrocarbon volume in a basin or play.

Who should attend

This course is designed for all geoscientists working in exploration: from technical assistant to exploration manager.  Also portfolio analysts will find this a very instructive course. 

Course content

The course explains all elements PBE approach in a practical workflow, illustrated with several real examples.  

The heart of the course is a day-long hands-on exercise.  Based on real data from a rich HC province, groups of 4 to 6 participants will be charged with making A2-size structure, reservoir, seal and charge maps; the four main play elements. The produced maps must then be presented and will be discussed.  In the following stage, each of the groups must combine the essential subsurface data and understanding in a Play Map.  Also these are then presented and discussed. Finally, based on the maps and earlier discussions, the groups must make so-called Common Risk Segments (CRS) maps of the four play elements and a Combined CRS (CCRS) map.  These maps display the perceived risks across the basin, and highlight the most prospective area(s) with their potential extensions.

In addition, aspects as Play POS and Prospect-specific POS (POS = Probability of Success) are explained, and the method of how the PBE approach can result in an assessment of yet-to-find HC volumes is discussed.

Learning, methods and tools

The course is full with exercises and opportunities for discussion, and will feel like a hands-on workshop. At the end of the course the participants will have a good understanding of the added value of the PBE approach, and should be able to apply this in their day-to-day work.

In addition to the day-long exercise of Day 2, there are many smaller exercises that should lead to a better understanding of the main messages and learnings.  Several real examples will be presented of where the PBE approach has resulted in a better understanding and in insights that would otherwise probably not be gained.

Hand-out material in paper and/or electronic format will be provided.  A separate workbook contains exercises and some additional information. 

Specific wishes for the course contents can be accommodated.  For in-house courses it is also possible to do the main hands-on exercise of Day 2 on a focus basin of the company itself, if the company can supply the basic information that is required to build that exercise.  As this will require extra preparation time, additional costs will apply.

Day by day programme

Day 1  

General introductions          

  1. Introduction to PBE: In this module the main concepts and terms are introduced, and the main steps of the PBE approach are explained.  Later in the course all will be dealt with in more detail.  The intention is to give the course participants an early idea of what will be covered, to make sure that the logic of the approach is appreciated.  Concepts that will be introduced (and that will be dealt with later in more detail):
    - What is a play map (geology)
    - What are CRS and CCRS maps (relative risk)
    - Field-size distributions and lead count maps
    - Play POS and Prospect POS
    - Yet-to-find
    - Prospect ranking (within plays)

  2. Play Mapping: What is a play, and how are plays defined; stratigraphically and aerially.  The elements that should be displayed on a Play map.  The module ends with an exercise where groups of participants are asked to draw the essential elements of a play of their choice on a provided A0 template. This is followed by presentations and discussions of the produced illustrations and a discussion of the value of Play maps. 

  3. The PBE Pyramid: Explanation of the importance of understanding the basin type and basin evolution is a basis for sound prospect/opportunity assessments.  The value of the "Play concept" is illustrated with an exercise.  Other exercises include the construction of a chrono-stratigraphic chart and recognizing basin cycles from a cross-section of basin.  Examples will be presented to demonstrate the added value of the PBE approach: 1) Norwegian Atlantic margin with an unexpected source for reservoir sands, 2) Santos Basin of Brazil with a pre-salt (syn-rift) play based on an African analogue, and 3) the importance of knowing the basement composition for realistic heat flow understanding, illustrated with examples from Nigeria and the Saudi plate.

Day 2

Recap Day 1

  1. Building a Play Map: An exercise in groups of 4-5 staff, based on the Southern North Sea.  Pre-reading material for this exercise will be provided.  The actual exercise is preceded by an introductory presentation on the regional geology, petroleum system and main plays of the area.
    Each group will be supplied with the following maps at A1-scale: Base map; Structural elements map; Depth map to top reservoir; Thickness and reservoir facies maps; Thickness and presence of seal; Extent and maturities of source rocks; discovered fields (as per 1970); Regional cross-section(s).
    As a first step. the groups must make summary maps for Structure, Reservoir, Seal and Charge, which are presented and discussed.
    Secondly, each group makes a play map by indicating the essential information that influence prospectivity for all 4 play elements.  The resulting map must make clear why the play works where it does, potential extensions of the play, and areas of increased risk. Each group is to present results in 10 minutes.   This is finalised by a general discussion on learnings.

  2. CRS Mapping: Preceded by an explanation of what a Common Risk Segment (CRS) Map is, the groups are charged with making CRS maps for Structure, Reservoir, Seal and Charge, and to combine these in a Combined CRS (CCRS) Map.
    Based on these exercises participants will know how to go about making Play and CRS Maps, and they will understand the difference between the two.
    The day ends wit a presentation of what 45 years of exploration and production in the Southern North Sea (since 1970) has resulted in

Day 3

Recap Day 2 

  1. Play POS and Prospect-specific POS: It will be explained what Play POS is, and why and how it can be used.  Guidelines are given for a consistent use of Play POS in unproven play segments, avoiding "double-dipping".  An exercise on estimating Play and Prospect-specific POS will enhance understanding.
  2. Play Statistics: This module deals with:
    - Field-size distribution plots; what they are and how they are made. It will also be demonstrated with a simple exercise how they change with ongoing exploration activities.  Pitfall are discussed.
    - Creaming Curves; how creaming curves can tell us something about the maturity of a play.  Many examples of real HC basins are given, and their shapes are explained in context of the play complexity and exploration activity levels.
    - "Yet-to-find" volume; statistical methods that are being used to establish the volume of yet to be discovered hydrocarbons within a play or basin are explained.  An exercise is designed to apply some of the methods and at the same time the exercise provides a basis for discussing pitfalls and shortcomings of a purely statistical method.
  3. Course summary: A brief summary of the main learnings of the course and a last opportunity to discuss any issues