Montana – North Dakota? Middle Member Bakken Play

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Montana North Dakota?Middle Member Bakken Play

• Julie A. LeFever
• North Dakota Geological Survey

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Williston Basin
SK
AB
MB
MT
ND
SD
WY
Richland Co.
McKenzie Co.
MT
ND
Study Area
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Bakken Formation

• Geology
• Stratigraphy
• Lithology
• Depositional Environments/History
• Age
• Source Rock Potential

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Stratigraphy

• Three Forks Formation (Devonian)
• Conformable Unconformable
• 250 ft thick
• Shales, dolostones, siltstones, and sandstones
• Sanish Sand
• Sublittoral to supralittoral

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Three Forks Fm.
10608 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Stratigraphy

• Bakken Formation
• Nomenclature
• Defined in 1953
• Amerada Petroleum - 1 H.O. Bakken
• Restricted to the Subsurface
• 105 ft thick
• upper and lower shale
• middle limestone member

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Isopach of the Bakken Formation
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Distribution of the Bakken Shale
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StratigraphyBakken Formation

• Lithology
• Lower Shale Member
• 50 ft thick
• Dark brown to black, fissile, non-calcareous,
  organic-rich shale
• Quartz, pyrite
• fossils - conodonts, algal spores, brachiopods,
  fish teeth, bones, and scales
• Fractured with oil staining

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Isopach of theLower Bakken Shale
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Bakken/Three ForksContact
10604.5 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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StratigraphyBakken Formation

• Middle Member
• 85 ft thick
• 5 different lithofacies
• Calcareous siltstone to sandstone, dolostone,
  silty limestone, and oolitic limestone
• Locally productive

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Isopach of theMiddle Bakken Member
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Lithofacies of the Middle Member
Upper Shale
Lithofacies 5 - Siltstone
Lithofacies 4 Interbedded Dark Grey Shale
and Buff Silty Sandstone
Lithofacies 3 - Sandstone
Productive
Lithofacies 2 Interbedded Dark Grey Shale
and Buff Silty Sandstone
Productive
Lithofacies 1 - Siltstone
Lower Shale
(From LeFever and others, 1991)
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Middle MemberLithofacies 2
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Middle MemberLithofacies 2
10585 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Upper Shale/Middle MbrContact
10582 ft
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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StratigraphyBakken Formation

• Upper Member
• Maximum extent of the Bakken
• 23 ft thick
• Conformable and Unconformable
• Laminated to massive with poorly sorted beds of
  silt-sized material
• Lag sandstone

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Isopach of theUpper Bakken Shale
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Bakken FormationUpper Shale Member
10580 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Stratigraphy

• Lodgepole Formation
• Conformable
• 900 ft thick
• False Bakken Pelmatozoan Limestone
• 5 major lithofacies representing a marine
  transgression

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False Bakken
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Lodgepole Fm.False Bakken
10562 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Lodgepole Fm.Pelmatozoan Limestone
10564 ft.
SESW Sec. 13, T.23N.,R.56E. AHEL 1 H8 Nevins
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Bakken Formation

• Depositional Environments/Age
• Stratified water column offshore, marine
  environment
• Bakken Shales
• Anoxic bottom conditions
• Middle Member
• Aerobic marine to marginal marine conditions
• Devonian/Mississippian

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Depositional History

• Three Forks Formation
• Shallow marine to terrestrial sedimentation
• Bakken Formation
• Transgression
• Shales anoxic conditions
• Middle Member normal, shallow marine
• Non-deposition/erosion
• Lodgepole Formation
• Normal marine conditions

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Source Rock Potential

• Total Organic Content 0 to 40
• Decrease towards depositional edge
• Kerogen
• 70-90 amorphous
• 0-20 herbaceous
• 30 coaly
• 5 woody
• Formed in subaquatic oxygen-restricted environment

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Source Rock Potential

• Hydrocarbon Generation
• Depth of 9000 ft
• 100o C
• Volume of Oil Generated
• Up to 413 billion barrels (ND MT)

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Immature
Onset of Generation
Intense Generation
Source Rock Maturity Zones
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Richland County
80 Producing Fields1. Red River Fm2. Madison
Fm 3. Bakken Fm4. Duperow Fm5. Interlake
Fm 20 Fields produce(d) from the Bakken Formation
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Bakken FormationRichand County, MT

• Historically 46 wells have produced
  from the Bakken a few commingled wells
• Currently 31 wells reported production
  in 2000 Total production for 2000 145,323
  bbls oil

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Richland County

• 555 Wells Examined inRichland County
• Data Included
• Last Charles Salt
• Lower Lodgepole
• Bakken Formation
• Porosity zone
• Three Forks Formation
• Devonian Prairie Salt
• Combined with Existing
• ND Data

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Extent of Data
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BLCS Structure Map
ft
Contour Interval
Montana
North Dakota
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Formation Limits
Bakken Formation
Upper
Middle
Lower
Prairie Salt Edge
Montana
North Dakota
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Isopach of the Bakken Formation
ft
Contour Interval
Montana
North Dakota
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Isopach of the Lower MemberBakken Formation
Bakken Limit
ft
Contour Interval
Montana
North Dakota
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Isopach of the Upper MemberBakken Formation
ft
Contour Interval
Montana
North Dakota
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Isopach of the Middle MemberBakken Formation
ft
Contour Interval
North Dakota
Montana
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Balcron Oil - 44-24 VairaSESE Sec. 24, T.24N.,
R.54E.
GR
Density Porosity
Lodgepole Fm.
10000
upper
Bakken Fm.
middle
Three Forks Fm.
Neutron Porosity
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Bakken Middle MemberPorosity Zone
Porosity Zone Contours
ft
70
65
60
55
50
45
40
Contour Interval
35
30
25
20
15
10
5
0
Montana
North Dakota
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Bakken Middle MemberPrairie Salt
Prairie Salt Edge
ft
Contour Interval
Montana
North Dakota
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Bakken Middle MemberPrairie Salt
Prairie Salt
ft
Contour Interval
Montana
North Dakota
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Middle MemberPorosity Zone

Contour Interval
McKenzie Co.
Richland Co.
Contour Interval 2 ft.
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Bakken Middle MemberSandstone Unit
ft
Richland Co.
McKenzie Co.
Contour Interval
Montana
North Dakota
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Shell Oil Company - 12-6-44 U.S.A.SENWNW Sec.
6-T.148N.-R.104W.
Density Porosity
GR
Lodgepole Fm.
Upper Shale
Bakken Fm.
10600
MiddleMbr
Neutron Porosity
Three Forks Fm.
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Can the Bakken Play Extend into North Dakota?

• YES!
• Production from the same interval
• Mappable log characterisitics from MT into ND
• Prominent trends illustrated on Bakken maps
• Other intervals within the middle member that
  have similar potentials