The North Dakota Devonian

Perhaps the best and most recent (2013). Google: geologic assessment of technically recoverable oil in the Devonian and Mississippian Bakken Formation; the first hit should provide a link to a PDF.

A more recent assessment of the Devonian in southeastern Saskatchewn. Google stratigraphy and reservoir characterization of the Upper devonian yang; one should be able to quickly find the link to a PDF for this article. This is a timely article with this note from earlier this week:

Kansas: ranked #1 worldwide of most attractive places for petroleum investment among 39 jurisdictions with small reserves. #2 -- Saskatchewan; #3 -- South Australia. 

From AAPG Datapages archives, dated 1987: overview of Duperow (Devonian) production in the Williston Basin --

The Duperow Formation (Frasnian) is present over a large area from the Sweetgrass arch in Montana to eastern North Dakota and from southern Saskatchewan to South Dakota. Sediments of the Duperow Formation are interpreted to consist of a series of consecutive shoaling-upward carbonate cycles deposited over a broad backreef area of the Devonian Elk Point seaway.

A representative cycle consists of a lower subtidal member, a middle intertidal member, and an upper supratidal member.

The Duperow Formation is productive in the U.S. portion of the Williston basin.

Production occurs anywhere in the section where there is porosity or intense fracturing, but is primarily from dolomitized stromatoporoid banks.

Production is coincident with the central portion of the basin.

The properties of Duperow hydrocarbons are variable and are interpreted to indicate two possible sources. The Bakken Formation may have sourced most Duperow reservoirs along the Nesson anticline. Other Duperow reservoirs in the Williston basin may have been self-sourced.

Three types of Duperow traps have been identified in the Williston basin.

• the first type is structural, which is the most productive and is common on the Nesson anticline

• the second type is structural-stratigraphic, which is the most commonly occurring trap and is present on the Billings nose

• the third type is stratigraphic-unconformity, which is uncommon and present only on the eastern flank of the Cedar Creek anticline.

Links:

• Overview of the petroleum geology of the North Dakota Williston Basin, North Dakota Geological Survey, undated, but appears to have been written in 2000; previously posted

Some impressive Devonian wells:

• 35, IA/263, Hess, Beaver Lodge-Devonian Unit H-310, Beaver Lodge, t3/60; cum 2.091440 million bls 6/17; still producing 775 bbls/month 6/17;  off-line as of 7/17;
• 718, IAW/188, Hess, Beaver Lodge-Devonian Unit F-311, Beaver Lodge, t6/65; cum 1.869286 million bbls 8/15;
• 1403, 351, Hess, Beaver Lodge-Devonian Unit B-304, Beaver Lodge, t11/57; cum 2.535723 million bbls 10/17; still producing almost 2,000 bbls/month, 6/17;
• 2009, 179, Enduro, North Dakota C A 2, McGregor, t12/58; cum 1.297038 million bbls; still producing about 650 bbls/month, 10/17; going on 59 years of age;
• 2150, 387, Amerada/Hess, Herfindahl + Davidson #1, Beaver Lodge, Devonian pool, Beaver Lodge field, s1/59; t4/59; AL; cum 918,970 bbls as of 7/74; last production numbers in 1974: 4,000 bbls/month; still listed as active;
• 2501, PA/115, Hess, BLDU G-311D, t1/60; cum 1.11 million bbls 4/01; last production in 1997;  SWD;
• 2515, PA/306, Hess, Beaver Lodge-Devonian Unit C-303, t2/60; cum 1.335636 million bbls; last produced 5/09 (55 years of production)
• 3900, 102, Hess, Beaver Lodge-Devonian Unit D-307, Beaver Lodge, t11/65; cum 1.05724 bbls 10/17; back on active status as of 8/17;
• 3983, 234, Enduro Operating, North Dakota C A 3, a Devonian well, vertical, 320-acre spacing, t1/66, cum 1.388897 million bbls; 10/17; celebrated its 51st anniversary January, 2017; still producing about 500 bbls/month, 6/17;
• 8499, PA/1,652, Citation Oil & Gas, Skachenko A 1, Jim Creek, Duperow pool, t10/81; cum 1.536 million bbls; last produced 11/11; 30 years of production (see first comment)