The document discusses the concept of play type assessment in resource exploration within the oil and gas industry, focusing on its importance for effective portfolio management, risk assessment, and exploration strategies. It outlines methodologies for evaluating geological conditions, determining potential oil and gas resources, and provides examples from various countries like Canada, the U.S., Norway, and the UK. The document underscores the necessity of integrating play-level and prospect-level assessments to optimize resource management and exploration efforts.

1. Exploration Plays
Resource Assessment and Portfolio Management through
use of Play Type assessment
Stig-Arne Kristoffersen

2. Outline of talk
Definitions
Why play type assessment?
Global use of play type in resource assessment
Goal and measures

3. About presenter
Stig-Arne Kristoffersen, www.lulu.com/stig
Bachelors Marketing Economy www.bh.linkedin.com/in/stiga
PhD, Geophysics – Reservoir Characterization
25+ years international experience within the oil and gas industry
Corporate exec with substantial corporate experience.
Focus on knowledge based information within oil and gas industry
and energy contract drafting and asset negotiations.
Broad experience in all aspects of geosciences, telecom
and marketing/ sales management. Direct experience with energy business,
technical consulting and venture capital.

4. For a Starter - Definitions
a prospect is a singular trap feature or structure.
a play type is a regional area of similar geological conditions that embraces a number of prospects.
an unsuccessful prospect does not end the play type potential, but if any of the play type factors are zero then all prospects
within this play type will be dry.
geologic risking must be applied at two levels; the prospect level and the play type level.
the assessment is based on geologic elements of a Total Petroleum System (TPS), including characterization of hydrocarbon
source rocks (source-rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and
petrophysical properties), geographic defined area, and hydrocarbon traps (trap formation, timing, and seals). Using these
criteria, a stratigraphic confined Composite TPS for oil and gas resources is made, called play type or Assessment Unit (AU).
Assessment unit (AU) is used by the USGS instead of Play types, but they are essentially identical
Common risk segment (CRS) maps are established for each play in each basin. The CRS maps assist establishing the play risk. This
is then followed by an assessment of the yet-to-find (YTF) potential in these plays.
YTF can be determined by the area yield method is based on richness or yield estimation. The richness is the ultimate recoverable
resources per area unit. A geological analogue reference area is used to provide an estimate of the richness. The reference area
has to be representative of the play i.e. same reservoir, source rock and trapping mechanism and is a relatively well explored area.
The richness is then applied to the assessment area, i.e. where the play is believed to work.
YTF can also be determined by the field size distribution method is based on a more extensive knowledge of a play and requires
an estimate of number of potential prospects, their size ranges and associated chance of success. The size ranges are established
based on estimates of different parameters such as area of closure/trap and reservoir and fluid properties as well as known sizes
of discoveries in the play. Estimates of trap densities are used to define the number of potential prospects.
Understanding Play Types – focus your exploration efforts

5. Why Play Type Assessment?
Focus exploration efforts – through active Portfolio
Management
Assess exploration potential versus risk and play
Determine enter – exit strategies for various play types
Enable a better economic assessment based on play type
complexities and areas (exploration cost of play type)
Historic and future play type volumetric profiles
(creaming curve)
Amount of prospects per play type and region and their
mean prospect sizes
Optimal Resource Management
Knowledge driven Analytical database ensure a focused Exploration

6. Global Use of Play type Assessment
Canada
U.S
Norway
West Africa
UK
Russia
Brazil
I will focus on the first 5 countries in this presentation
(Refer to separate presentation for the other countries)
Both mature and immature regions around the world benefits from play type analysis

7. Canada
Since the mid-90’s Canadian Authorities have implemented the use of Play types to
perform resource assessment and to focus their exploration efforts, both onshore and
offshore.
We present an example from Yukon Territory in Canada. Other areas in Canada are not
covered in this presentation.
Play type analysis revitalized parts of Canadian exploration efforts

8. Yukon Oil and Gas Resource Assessment
Eagle Plain
Beaufort-Mackenzie Basin
Visualize the potential of all basins onshore and offshore Yukon territory
4
2
9
6

9. Yukon Oil and Gas Resource Assessment
http://www.emr.gov.yk.ca/oilandgas/oilgas_resource_assessments.html#Beaufo
-Mackenzie_Basin_Oil_and_Gas_Resource_Assessment
An overall picture of the exploration potential in one go

10. U.S
Since the mid-90’s several efforts have been made to create an national database to assist the geoscientists and
the decision makers to arrive at an efficient exploration strategy for the national oil and gas resources, both
onshore and offshore.
These efforts enabled U.S authorities to establish;
• What play type has highest/ lowest potential versus risk profile within each region
• What the total potential versus risk profile within each region
• What play types to enter and exit within each region and overall
• Overall potential for oil, gas and NGL within U.S territories, both onshore and offshore
• Economic potential for each play type and region
Visualize the potential through the whole stratigraphy in all states

11. USGS 1995 Oil and Gas Assessment
http://energy.cr.usgs.gov/oilgas/noga/1995.html

12. 46 conventional and 3
unconventional play
types within this
province.
Both Text and GIS format
data
USGS 1995 Oil and Gas Assessment
Focus Exploration Efforts fitting Your Exploration Strategy and risk willingness
Western Gulf Province (047)

13. http://energy.cr.usgs.gov/oilgas/noga/index.html
USGS 2007 Oil and Gas Assessment

14. USGS 2007 Oil and Gas Assessment
Focus Exploration Efforts fitting Your Exploration Strategy and risk willingness
GULF COAST ASSESSMENT AREA

15. USGS 2007 Oil and Gas Assessment
Focus Exploration Efforts fitting Your Exploration Strategy and risk willingness

16. Resource Assessment Alaska
Extract from Shell study done in 2006 – Conclusions and Summary
www-
static.shell.com/static/usa/.../ec
onanalysisofoffshoreogdevpt.p
df)

17. Norway
National Petroleum Directorate initiated a joint venture project with the oil and gas industry in
late 1990. This effort has culminated in a web based portal for key exploration and production
data. The key element in Norwegian authorities resource assessment has been the definition of
play types along its offshore continental shelf areas.
Norwegian Authorities use the play type distribution analysis for strategic decisions on areas to
explore to fulfill their targets of production set out in the objectives for Norwegian oil and gas
production part within OPEC.
Resource Management through proper Portfolio Management

18. Norway
http://npd.no/en/Topics/Geology/Temaartikler/Geological-plays/

19. Norway
Play type distribution enable Optimized Resource Management

20. Norway
Play type distribution enable Optimized Resource Management

21. Norway
Resource Management through thorough Play Type understanding

22. Norway
Resource Management require understanding of resource classes

23. Norway
• 33 of which have been confirmed by proving hydrocarbons
• In the North Sea, where exploration has been taking place longer than elsewhere, as many as 75%
of the plays have been confirmed.
• 9 of 20 have been confirmed in the Norwegian Sea
•Only 6 of 23 plays in the Barents Sea have been confirmed.
•73 % of the estimate of the undiscovered resources is in confirmed plays
Plays can be defined in various ways. In every case, an assessment has to be made of how large an area
and how much of the rock succession is to be included. The oil companies or others can present a
different number of plays based on other methods or assessments of the geology. The plays may be of
different sizes and have different estimates of resources.
There are defined 68 plays on the Norwegian continental shelf

24. Norway
Play type distribution assist understanding risks and potential distribution

25. Norway
displays can be used to;
• determine remaining potential
for specific play types
• make strategic decision when to
enter and exit specific play types
• identify where we are in
evolution of play type based on
creaming curve
• high grade remaining
opportunities and focus
exploration program
When to enter and exit a Play type – based on history and future potential
Middle Jurassic Play type – UK, Norway and Denmark

26. Norway
UNCONVENTIONAL RESOURCES
Other deposits of oil and gas exist than those recovered in conventional oil and gas fields.
These are often called unconventional petroleum resources, which denote petroleum that
occurs naturally, independently of a traditional trap. Such resources can occur over large
areas and, unlike conventional oil and gas fields, be independent of a geological structure.
Examples are oil and gas shale, gas from hydrate, and oil and gas from coal, . Oil shale has
been exploited for oil production for several centuries. Unconventional, as a concept, does
not necessarily mean that it is something new or requires new technology; it just differs from
conventional oil and gas fields. Unconventional petroleum resources may also cover
petroleum that is manufactured industrially, for instance from coal.
Play type distribution assist understanding Unconventional resource potential

27. West Africa
Using a geology-based assessment methodology, there is estimated mean volumes of 71.7 billion barrels
(BBO) of oil, 187.2 trillion cubic feet (TCF) of natural gas, and 10.9 billion barrels (BBOE) of natural gas
liquids.
Goal was to assess the potential for undiscovered, technically recoverable oil and natural gas resources.
An assessment of four geologic provinces located along the northwest and west-central African coast
and extending offshore to a water depth of 4,000 meters. From north to south, the provinces are:
(1) the Senegal, containing the passive-marginal Senegal Basin of Middle Jurassic to Holocene age
(2) the Gulf of Guinea, characterized by transform tectonics
(3) the Niger Delta, containing more than 9,100 meters of sediments
(4) the West-Central Coastal, containing the Aptian salt basin and dominated by both rift and sag
tectonics including the Congo Basin.
Assessment of Undiscovered Hydrocarbon Resources of 4 West Africa Geologic Provinces

28. West Africa
Assessment of Undiscovered Hydrocarbon Resources of 4 West Africa Geologic Provinces

29. UK
Regional Play Fairway evaluation of the UK Central North Sea
UK authorities have not followed the same open line as their Norwegian counterparts in the North Sea
when it comes to Play overview and reporting.
Therefore most information about the UK sector of North Sea and other areas of exploration in the UK
is found in consultants reports.
One study I refer to is a study performed in the Central North Sea hydrocarbon province which offers a
wide variety of plays, many of which are still under-explored.
Further exploration potential also remains in open and licensed acreage that has been only partially
explored or not reviewed for a number of years. Continuing success has involved smaller discoveries and
exploration for deeper and more subtle structural and stratigraphic traps.
Seventeen plays with proven hydrocarbon resources have been identified in the Palaeozoic to Tertiary
section.
Play fairway maps were also produced to display the regional risk associated with each play.

30. UK
Regional Play Fairway evaluation of the UK Central North Sea
17 plays with proven hydrocarbon
resources have been identified in
the Paleozoic to Tertiary section.

31. UK
Regional Play Fairway evaluation of the UK Northern North Sea
The area contains the Viking Graben, East Shetland Basin, Beryl Embayment and East
Shetland Platform. The Northern North Sea hydrocarbon province has been extensively
explored and developed. However, exploration potential remains in open and licensed
acreage that has been only partially explored or not reviewed for a number of years.
12 plays with proven hydrocarbon resources have been identified in the Triassic to Eocene
section. Maps of reservoir, top seal and hydrocarbon charge distribution have been
combined to produce play fairway maps which display the regional risk associated with each
play.

32. UK
Regional Play Fairway evaluation of the UK Northern North Sea
12 plays with proven
hydrocarbon resources have
been identified in the Triassic
to Eocene section.

33. Integrated Play and Prospect Assessment
Integrated play and prospect assessment (Hood and Stabell, 2006) is designed to leverage the respective strengths
of play-level assessment of Yet-To-Find (YTF) potential and more detailed prospect-level assessment of risks and
resources. A successful marriage of the two approaches can maximize the application of both regional context and
local detail. The combined approach provides a basis for more realistic and fit for purpose assessment of the value of
concessions, blocks and areas of interest. When integrated in a common methodology and assessment framework,
play assessment can provide a direct reality check of prospect assessment while anchoring regional assessments with
data from calibration areas with mapped and assessed leads or prospects. Finally, the integrated approach provides a
sound basis for learning from experience and rapid assimilation of new data as plays and prospects are matured and
played out(Hood and Stabell, 2006).
The foundation for integrated play-prospect assessment is a feature-based approach to play assessment where we
consider both mapped and assessed features (prospects) as well as postulated features. Assessment of the YTF
potential in postulated features requires consistent counting, sizing and risking of the features. The approach
requires a common map-based (GIS) analysis framework where assessed and postulated features are positioned in
their regional context. Integration of plays and prospects is based on using a common database with both play and
prospect analyses. The analytical foundation is a flexible and comprehensive stochastic assessment engine. This
engine is used to assess individual play and prospect units. It is also used to aggregate the assessments over play
fairways, blocks, concessions or areas of interest -- while honoring all risk and volume dependencies.
In this paper we present an application of the integrated play-prospect assessment methodology to a set of frontier
plays in the North Falkland Basin. Current license holders have identified and assessed a number of relatively large
potential accumulations in some of the plays in the basin. However, significant areas have very limited data. One of
the main challenges for an integrated assessment of play and prospect potential is generating estimates of
potential smaller fields that have not been counted systematically due to uneven and coarse data resolution.
Another challenge is to capture the potential of stacked plays. The application presents how we can use effectively
both analog data and data from small calibration areas in the basin.
Klaus Dittmers, GeoKnowledge (Norway)
Per Audun Hole, GeoKnowledge (Norway)
Charles Stabell, GeoKnowledge (Norway)

34. CRS and YTF – terms used to focus exploration efforts
The project was carried out to quantify the undiscovered resource potential. Areas with high prospectivity were
documented and illustrated to increase our understanding of the exploration potential and help to focus our efforts.
Common risk segment (CRS) maps were established for each play in each basin followed by an assessment of the yet-
to-find (YTF) potential in these plays. This work provides a good technical foundation for future exploration.
In a first part, the workflow to create CRS maps will be illustrated. Six elements were assessed: the presence and
quality of the reservoir, the presence of a source rock and the possible migration from the mature areas as well as the
seal presence and integrity. An ArcGIS toolbox was developed to combine these different maps and build the total
CRS map. The available data density and quality vary from basin to basin. The notion of confidence was integrated to
show the resulting uncertainties.
The CRS maps are the basis for defining the YTF assessment areas. Depending on the available data and the
geological knowledge, two alternative assessment methods were used for estimating the YTF potential.
The area yield method is based on richness or yield estimation. The richness is the ultimate recoverable resources per
area unit. A geological analogue reference area is used to provide an estimate of the richness. The reference area has
to be representative of the play i.e. same reservoir, source rock and trapping mechanism and is a relatively well
explored area. The richness is then applied to the assessment area, i.e. where the play is believed to work. A basin will
illustrate this method.
The field size distribution method is based on a more extensive knowledge of a play and requires an estimate of
number of potential prospects, their size ranges and associated chance of success. The size ranges were established
based on estimates of different parameters such as area of closure and reservoir and fluid properties as well as
known sizes of discoveries in the play. Estimates of trap densities were used to define the number of potential
prospects. Another basin will demonstrate this method.
Alexandra Cournot, StatoilHydro (Norway)
Mustapha Zater, StatoilHydro (Norway)

35. Measures and Goals
active Portfolio Management
assess exploration potential versus risk and play
determine enter – exit strategies for various play types
enable a better economic assessment based on play type
complexities and areas (exploration cost of play type)
historic and future play type volumetric profiles (creaming
curve)
amount of prospects per play type and region and their
mean prospect sizes
optimal Resource Management
Ensure a Focused Exploration