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The Saskatchewan Bakken: Unconventional, Conventional or All of the Above Dan Kohlruss, Erik Nickel and Jeff Coolican Saskatchewan Geological Survey and PTRC. Why the Bakken? Study Area Stratigraphy and Sedimentology Reservoir Differences : Conventional vs “Unconventional”
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The Saskatchewan Bakken: Unconventional, Conventional or All of the Above Dan Kohlruss, Erik Nickel and Jeff Coolican Saskatchewan Geological Survey and PTRC
Why the Bakken? • Study Area • Stratigraphy and Sedimentology • Reservoir Differences : Conventional vs “Unconventional” • Mapping and Depositional Model • Trapping models • Conclusions
Bakken in SE Sask The Encyclopedia of Saskatchewan at http://esask.uregina.ca/entry/williston_basin.html
Late Devonian (Famenian) Paleogeography ≈360 Ma Old Red Sandstone Continent Antler Orogeny Prophet Trough Equator SGA Study Area Swiftcurrent Platform Williston Basin Antler Foreland Basin Appalachian Foreland Basin 30 s From Blakey, NAU Geology 2006
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
Mississippian Bakken Fm Three Forks Group
Bakken Stratigraphy Nickel and Kohlruss 2010
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
Unit B Isopach Modified from Kohlruss and Nickel 2009
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
Hydrogeological Implications and Trapping Modified from Khan and Rostron, 2002
Viewfield Trapping Model Modified after Kohlruss and Nickel 2009
Unit B Isopach Modified from Kohlruss and Nickel 2009
? Kohlruss and Nickel 2009
Maryfield Bakken-Torquay Sub-crop Play Christopher 1961
Hummingbird area trapping model Modified from Smith and Pullen, 1967
Dome et al Hummingbird 14-1-2-19W2 2260.4m Imperial Constance 8-36-3-29W2 2054.9m “Flaser Bedded Facies”
Imperial Constance 8-36-3-29W2 Dull yellow fluorescence Immediate green cut
Legend: Crown Leases Freehold (private) Rights Bakken Wells Other Oil Wells Bakken Future Activity Potential ?
Crown Land Disposed Free Hold 12m OCM Constance area Land availability 341m G+OCM OC in Core 6m ocm
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!
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
ACKNOWLEDGEMENTS Erik Nickel Jeff Coolican Kim Kreis My colleagues at the Saskatchewan Geological Survey