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The Saskatchewan Bakken: Unconventional, Conventional or All

of the Above

Dan Kohlruss, Erik Nickel and Jeff CoolicanSaskatchewan Geological Survey and PTRC

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•Why the Bakken?

•Study Area

•Stratigraphy and Sedimentology

•Reservoir Differences : Conventional vs “Unconventional”

•Mapping and Depositional Model

•Trapping models

•Conclusions

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2500 Wells

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Bakken in SE Sask

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Bakken in SE Sask

The Encyclopedia of Saskatchewan at http://esask.uregina.ca/entry/williston_basin.html

www.er.gov.sk.caFrom Blakey, NAU Geology 2006

Study Area

Late Devonian (Famenian) Paleogeography≈360 Ma

Antler Orogeny

Equator

Old Red Sandstone Continent

Appalach

ian Fo

relan

d

Basin

Antler Foreland Basin

WillistonBasin

Prophet Trough

SGA

Swiftcurrent

Platform

30 s

www.er.gov.sk.caAntler O

rogeny

Old Red Sandstone Continent

Appalach

ian Fo

relan

d

Basin

Antler Foreland Basin Williston

Basin

Prophet Trough

SGA

From Blakey, NAU Geology 2006

Early Mississippian Paleogeography

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Brock

ton-

Froid

Linea

ment

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Bakken Fm

Mississippian

Three Forks Group

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Bakken Stratigraphy

Nickel and Kohlruss 2010

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0.01 0.1 1 10 1000

0.05

0.1

0.15

0.2

0.25

K90 vs PorosityUnit B

0.01 0.1 1 100

0.020.040.060.08

0.10.120.140.160.18

0.2

K90 vs PorosityUnit A

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

www.er.gov.sk.caModified from Kohlruss and Nickel 2009

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T1

T2

T3

T4

T5

T6

T7

T8

T9

T10

T11

T12

T13

T14

T15

T16

T1

T2

T3

T4

T5

T6

T7

T8

T9

T10

T11

T12

T13

T14

T15

T16

R30W1R31R32R33R34R1W2R2R3R4R5R6R7R8R9R10R11R12R13R14R15R16R17R18R19R20R21R22R23R24R25

R30W1R31R32R33R1W2R2R3R4R5R6R7R8R9R10R11R12R13R14R15R16R17R18R19R20R21R22R23R24R25

0 m

1 m

2 m

3 m

4 m

5 m

6 m

7 m

8 m

9 m

1 0 m

11 m

1 2 m

1 3 m

1 4 mHorseshoe pattern

Viewfield

Contour Interval = 50m Bakken Producing Wells

0 10 20 30 40

Kilometres

Unit B Isopach

Modified from Kohlruss and Nickel 2009

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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

www.er.gov.sk.caFrom Kohlruss and Nickel 2009 (modified after Plint 1988)

www.er.gov.sk.caModified from Khan and Rostron, 2002

Hydrogeological Implications and Trapping

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Viewfield Trapping Model

Modified after Kohlruss and Nickel 2009

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Modified from Kohlruss and Nickel 2009

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T1

T2

T3

T4

T5

T6

T7

T8

T9

T10

T11

T12

T13

T14

T15

T16

T1

T2

T3

T4

T5

T6

T7

T8

T9

T10

T11

T12

T13

T14

T15

T16

R30W1R31R32R33R34R1W2R2R3R4R5R6R7R8R9R10R11R12R13R14R15R16R17R18R19R20R21R22R23R24R25

R30W1R31R32R33R1W2R2R3R4R5R6R7R8R9R10R11R12R13R14R15R16R17R18R19R20R21R22R23R24R25

0 m

1 m

2 m

3 m

4 m

5 m

6 m

7 m

8 m

9 m

1 0 m

11 m

1 2 m

1 3 m

1 4 mHorseshoe pattern

Viewfield

Contour Interval = 50m Bakken Producing Wells

0 10 20 30 40

Kilometres

Unit B Isopach

Modified from Kohlruss and Nickel 2009

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www.er.gov.sk.caModified from Kohlruss and Nickel 2009

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www.er.gov.sk.caKreis et al, 2006

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?

Kohlruss and Nickel 2009

www.er.gov.sk.caModified from Khan and Rostron, 2002

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Maryfield Bakken-Torquay Sub-crop Play

Christopher 1961

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www.er.gov.sk.ca

www.er.gov.sk.caModified from Smith and Pullen, 1967

Hummingbird area trapping model

www.er.gov.sk.caModified from Khan and Rostron, 2002

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Dome et al Hummingbird14-1-2-19W2

2260.4m

Imperial Constance8-36-3-29W2

2054.9m

“Flaser Bedded Facies”

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Dull yellow fluorescenceImmediate green cut

Imperial Constance8-36-3-29W2

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Legend:

Crown Leases

Freehold (private) Rights Bakken Wells Other Oil Wells

Bakken Future Activity Potential

?

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Constance area Land availability

Crown Land Disposed

Free Hold

6m ocm

OC in Core

12m OCM

341m G+OCM

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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!

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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

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ACKNOWLEDGEMENTS

Erik Nickel Jeff Coolican

Kim KreisMy colleagues at the Saskatchewan Geological Survey