State Mineral Resources Director Lynn Helms says the Tyler Formation is most likely one-third to one-half the size of the Bakken in terms of coverage area and oil reserves. The Tyler lies about 2,000 feet above the Bakken. The Tyler Formation above the Bakken encompasses nearly all of western and southwestern North Dakota and extends into South Dakota. The Bakken covers some 25,000 square miles in North Dakota, Montana, Saskatchewan and Manitoba. Officials believe more than 4-8 billion barrels of oil can be recovered using current technology.
“From the conventional standpoint (vertical wells) the wells drilled into the Tyler sandstones are better producers than most of the vertical wells drilled into the Bakken/Three Forks,” Nordeng said. “This is because the Tyler contains reservoir rocks (sandstones) that allow economic oil production from vertical wells whereas the Bakken/Three Forks wells (outside the Antelope Field) do not. However, the new horizontal Bakken/Three Forks wells are much better producers, at least initially, than the old vertical Tyler wells