Hydrocarbon Potential

1
Hydrocarbon Potential of the Bakken
Formation, North Dakota Julie A. LeFeverNorth
Dakota Geological Survey
Geologic Investigation No. 15
2
Williston Basin
Canada
Richland County
Study Area North Dakota Montana
ND
SD
MT
3
Middle Member of the Bakken
Canada
MT
ND
4
Richland County, MTStratigraphy
North
South
Mississippian Lodgepole Formation
Upper Shale Member
Transitional Facies L5
Upper (Productive)
Mississippian Bakken Formation
Lithofacies 2
DevonianThree Forks
Lower
Transitional Facies - L1
Lower Shale Member
5
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
6
Bakken Middle Member Montana Porosity Zone
Prairie Salt
Montana
North Dakota
7
Canada
Canada
Bakken Play In North Dakota
Divide
Burke
Bottineau
Renville
Williams
Mountrail
McHenry
Ward
Montana
McKenzie
McLean
Northern Play
Dunn
Oliver
Billings
Stark
Southern Play
8
SENW Sec. 11, T160N, R95W Conoco, Inc. - 17
Watterud A
GR
Res
Lithofacies 3
Central Basin Facies
Upper L2
9
Lithofacies 3 Sandstone
CANADA
Index Map
Montana
10
Middle Member Bakken Play

• Richland County, MT
• Two laterals to a 1280 spacing unit
• Well is stimulated with large fracture treatment
  
• 920,000, gelled water/sand frac
• 500-700 BOPD initially
• Virtually no water
• Production
• 2000 2,618,982 BO
• 2003 5,284,378 BO
• 2004 12,849,141 BO

11

• North Dakota
• One to two laterals 640 to 1280 spacing unit
• Well is stimulated with large fracture treatment
  
• 6 wells off tight hole
• IPs
• L3 Lithofacies
• 87 to 140 BOPD 130 to 150 MCF 125 to 142 BWPD
• L2 Lithofacies
• 41 to 263 BOPD 42 to 177 MCF 0 to 27 BWPD

12
Middle Bakken Reservoir
13
Middle Member Bakken Porosity

• Matrix porosity
• Primary
• Secondary
• Fracture porosity
• Related to Tectonics
• Regional
• Salt tectonics
• Related to HC Generation

14
(No Transcript)
15

16
(No Transcript)
17
Tectonic FracturingSalt Dissolution
Canada

• Complete or Partial Dissolution of the Prairie
  Salt
• Depositional Edge
• Overlying Basement Structures
• Other Geologic Features

Upper Shale
Middle Member
Montana
Lower Shale
Bakken Limits
Prairie Salt Isopach
18
Regional Fractures
Canada
Antelope Structure
?
Lower Bakken Shale
?
Montana
Heart River Fault
?
19
(No Transcript)
20
Upper Bakken Shale
SWSW Sec. 5, T43N, R99W Texaco, Inc - 1-5
Thompson
Canada
HF/E
M
VF/E
Montana
North Dakota
21
(No Transcript)
22
10427 ft
Upper Bakken Shale
10440 ft
Lithofacies 4
23
10446 ft
Lithofacies 3
10451 ft
Central Basin Facies
24
10456 ft
Upper Lithofacies 2
10462 ft
Lower Lithofacies 2
25
Conclusions

• Lithofacies are present basinwide
• Primary reservoir porosity may be enhanced by
  diagenesis, tectonic fractures, and/or fractures
  from HC generation
• Porosity enhancement is not restricted to a
  single lithofacies within the Middle Member

26
Conclusions

• The presence of vertical fractures in areas of
  intense HC generation may affect the outcome of
  stimulation treatment.