From March 29, 1986 to June 19, 2017, a total of 11,826 horizontal oil and gas wells were completed in North Dakota . These wells have produced 2.10 billion barrels of oil in North Dakota.
Of the 593 fields listed by the North Dakota Department of Natural Resources , only 344 (58.0%) have any oil production data from horizontal wells.
In fact, just two fields, the Parshall and Sanish, account for 13.5% percent of the total production.
More than a majority of the production (57.1%) comes from the top 10% of fields. Many of these fields, like the Parshall and Sanish, are among the eastern-most producing fields.
Two formations have accounted for 98.2% of the cumulative oil production: the Middle Bakken (1,438 million barrels) and Three Forks (622 million barrels).
Similar to the overall trend for North Dakota, the heart of the Middle Bakken and the Three Forks lies within the eastern-most fields.
This production center lies in close proximity to a geological structure - a fold known as the Nesson anticline.