Cumulative Oil Production By Formation Through December, 2011 // 2011 North Dakota Oil Production by Formation -- The Williston Basin, North Dakota, USA

A reader asked if there was any data on what percentage of wells currently producing in the Williston Basin are "Bakken" wells.  ~ 3,400 "Bakken" wells/6,662 total --> 50%. Approximately 150 wells come off confidential list each month in 2012, and about 130 of them will be "Bakken Pool" wells, gradually pushing the overall percentage up.

Data from NDIC website. This was not a "cut and paste." There could be errors on my part; it has not been proofread or double-checked.

Pool (NDIC designations) and number of wells

Cumulative Oil Production By Formation Through December, 2011 (a total of all wells that have been drilled and produced any amount of oil since 1951. About half of these wells are no longer producing -- see next set of data points).

• Bakken: 3,578
• Bakken/Three Forks: 14
• Birdbear: 171
• Cambro/Ordovician: 5
• Dawson Bay: 14
• Deadwood: 1
• Devonian: 138
• Duperow: 344
• Gunton: 11
• Heath: 197
• Interlake: 1
• Lodgepole: 52
• Lodgepole/Bakken: 1
• Madison: 5,523
• Midale/Nesson: 47
• Mission Canyon: 1
• Ordovician: 123
• Ratcliffe: 4
• Red River: 708
• Red River B: 545
• Red River C: 1
• Sanish: 84
• Silurian: 221
• Souris River: 2
• Spearfish: 39
• Spearfish/Charles: 210
• Spearfish/Madison: 98
• Stonewall: 124
• Stony Mountain: 2
• Three Forks: 4
• Tyler: 81
• Tyler A: 7
• Winnipeg: 3
• Winnipeg/Deadwood: 6
• Winnipegosis: 55

Total: 12,415

 2011 North Dakota Oil Production by Formation (these are wells that were active at least at some point during the 2011 calendar year and produced at least a barrel of oil).

• Bakken: 3,345
• Bakken/Three Forks: 9
• Birdbear: 102
• Cambro/Ordovician: 2
• Dawson Bay: 3
• Deadwood: 0
• Devonian: 55
• Duperow: 112
• Gunton: 2
• Heath: 38
• Interlake: 0
• Lodgepole: 34
• Lodgepole/Bakken: 0
• Madison: 2,051
• Midale/Nesson: 42
• Mission Canyon: 1
• Ordovician: 50
• Ratcliffe: 4
• Red River: 183
• Red River B: 272
• Red River C: 0
• Sanish: 44
• Silurian: 48
• Souris River: 0
• Spearfish: 26
• Spearfish/Charles: 97
• Spearfish/Madison: 38
• Stonewall: 44
• Stony Mountain: 1
• Three Forks: 1
• Tyler: 37
• Tyler A: 2
• Winnipeg: 0
• Winnipeg/Deadwood: 2
• Winnipegosis: 17

Total: 6,662