1. The Saskatchewan Bakken: Unconventional, Conventional or All of the Above
Dan Kohlruss, Erik Nickel and Jeff Coolican
Saskatchewan Geological Survey and PTRC

2. Why the Bakken?
Study Area
Stratigraphy and Sedimentology
Reservoir Differences : Conventional vs “Unconventional”
Mapping and Depositional Model
Trapping models
Conclusions

3. 2500 Wells
This slide illustrates the explosive growth in Bakken production from Southeast Sask over the last five years.
As of September 11, 2009, there were 1,506 wells capable of producing Bakken oil in southeast Saskatchewan, of which 1,429 were drilled since
January 1, 2004.
Bakken oil production in southeast Saskatchewan has increased from 600 barrels per day in January 2004 to a peak of just over 58,000 barrels per day in March 2009.
The recent drop in Bakken production is certainly due to the economic downturn as producers wait for a rebound in stable prices prior to resuming their Bakken development activities. 3

4. Bakken in SE Sask
The contribution of the Bakken production to the stream coming out of SE Sask is becoming quite significant, forming close to one-third of total output from the region compared to relatively nothing not that long ago.

5. Bakken in SE Sask
The Bakken Formation can be found in a broad region within a geological feature known as the Williston Basin.
This basin extends over 200,000 square miles and lies beneath most of North Dakota and stretches to South Dakota, Montana, southeast Saskatchewan and southwest Manitoba.
At least 25% of the basin lies beneath southeast Saskatchewan.
The Encyclopedia of Saskatchewan at

6. Late Devonian (Famenian) Paleogeography ≈360 Ma
From Blakey, NAU Geology 2006
Study Area
Late Devonian (Famenian) Paleogeography
≈360 Ma
Old Red Sandstone
Continent
Antler Orogeny
Prophet Trough
Equator
SGA
Antler Foreland
Basin
Swiftcurrent
Platform
Williston
Basin
Appalachian Foreland
Basin
30 s

7. Early Mississippian Paleogeography
Old Red Sandstone
Continent
Antler Orogeny
Prophet Trough
SGA
Antler Foreland
Basin
Williston
Basin
Appalachian Foreland
Basin
From Blakey, NAU Geology 2006

9. Brockton-Froid Lineament

10. Mississippian Three Forks Group Bakken Fm
This sequence lies immediately beneath the Mississippian limestone and dolomites that have been the dominant producing zones of the Williston Basin for over fifty years.
Development of shallower Mississippian and Jurassic formations of the region has taken place due to greater producibility and less drilling required to access the reserves. This activity has resulted in the development of such well-known pools as Weyburn, Midale and Steelman to name a few.

11. Bakken Stratigraphy
Nickel and Kohlruss 2010

13. Higher porosity in general more consistent
Core Analysis
Approx 105 analyzed core
Over 1000 total data points
Unit B
Higher porosity in general
more consistent
Direct correlation between porosity and permeability
Conventional traps
Unit A
considerably lower porosity and permeability
More highly variable
Many data points on lower limits of detection
Unconventional
Nickel et al 2011

14. Modified from Kohlruss and Nickel 2009

15. Unit B Isopach
Modified from Kohlruss and Nickel 2009

16. Bakken Depositional Model:
Prograding Delta: Forced or Normal Regression?
1.) Unit A deposited in a prograding, regressive setting
2.) Continued regression and erosion of Unit ‘A’ proximal prodelta deposits, and deposition of the unit ‘B’ delta-front sediments.
3.) Unit C deposited in a transgressive setting

17. From Kohlruss and Nickel 2009 (modified after Plint 1988)

18. Hydrogeological Implications and Trapping
Modified from Khan and Rostron, 2002

19. Viewfield Trapping Model
Modified after Kohlruss and Nickel 2009

20. Modified from Kohlruss and Nickel 2009

21. Unit B Isopach
Modified from Kohlruss and Nickel 2009

23. Modified from Kohlruss and Nickel 2009

25. Kreis et al, 2006

26. ?
Kohlruss and Nickel 2009

27. Modified from Khan and Rostron, 2002

29. Maryfield Bakken-Torquay Sub-crop Play
Christopher 1961

35. Hummingbird area trapping model
Modified from Smith and Pullen, 1967

36. Modified from Khan and Rostron, 2002

37. Dome et al Hummingbird W2
2260.4m
Imperial Constance W2
2054.9m
“Flaser Bedded Facies”

38. Imperial Constance W2
Dull yellow fluorescence
Immediate green cut

39. Bakken Future Activity Potential
Legend:
Crown Leases
Freehold (private) Rights
Bakken Wells
Other Oil Wells ?
This map shows the availability of oil and gas rights in SE Sask. The white areas have rights available. 39

40. 12m OCM Constance area 341m G+OCM Land availability OC in Core 6m ocm
Crown Land Disposed
Free Hold
12m OCM
Constance area
Land availability
341m G+OCM
OC in Core
6m ocm

41. Bakken Friendly Royalty Regime
Bakken horizontal wells qualify for a very favorable Royalty Incentive Volume
For the first 40,000 to 100,000 barrels produced, the royalty rate is 2.5% or less!

42. Conclusions
Bakken drilling outside of Viewfield but currently widespread
Viewfield is a combination of a stratigraphic and permeability trap aided by a strong hydrogeological component.
Outside of Viewfield, structure plays an important role
Combination of facies pinch-out and possibly associated heat flow anomaly at Pinto/Bienfait?
Salt tectonics at Hummingbird/Roncott/Constance
The future of the Bakken play is likely in structural and Stratigraphic traps like seen in Hummingbird pool and Pinto-Bienfait area

43. My colleagues at the Saskatchewan Geological Survey
ACKNOWLEDGEMENTS
Erik Nickel
Jeff Coolican
Kim Kreis
My colleagues at the Saskatchewan Geological Survey