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Full-Text Articles in Physical Sciences and Mathematics

A Detailed Gravity Study Over A Known Devonian Carbonate Buildup: The Shell Golden Reef, Northwestern North Dakota, Stephen M. Braun Jan 1991

A Detailed Gravity Study Over A Known Devonian Carbonate Buildup: The Shell Golden Reef, Northwestern North Dakota, Stephen M. Braun

Theses and Dissertations

A detailed gravity study was conducted over the Shell Golden reef in the northwestern North Dakota portion of the Williston Basin. The Shell Golden reef has been previously interpreted to be reefal facies within the Winnipegosis Formation (Devonian) located at a depth of about 2400 meters. Based only on information from wireline logs and core from two boreholes, the Shell Golden well #34X-34 has been previously interpreted as a pinnacle reef with 70 meters of relief and undetermined diameter. The basin regime of the Elk Point shelf created an environment that allowed the growth and development of the Shell Golden …


Tectonic History Of Billings And Southern Mckenzie Counties, Southwestern North Dakota, John J. Crashell Jan 1991

Tectonic History Of Billings And Southern Mckenzie Counties, Southwestern North Dakota, John J. Crashell

Theses and Dissertations

Billings and southern McKenzie Counties contain about 40 active oil and gas fields. In the same area, two major structural highs and several minor ones can be recognized. The first of these, the Billings anticline, extends approximately 60 km (18 mi.) along a north-south line in central Billings County, and is composed of two parallel folds. A second major structure, here termed the Rough Rider anticline, lies west of the Billings anticline, and also extends about 60 km (18 mi.) along a north-south line from north-central Billings County into southern McKenzie County. Both of these structures are fault-bounded on their …


Fracture-Enhanced Porosity And Permeability Trends In The Bakken Formation, Williston Basin, Western North Dakota, Wayne B. Freisatz Jan 1991

Fracture-Enhanced Porosity And Permeability Trends In The Bakken Formation, Williston Basin, Western North Dakota, Wayne B. Freisatz

Theses and Dissertations

Fractures play a critical role in oil production from the Bakken Formation (Devonian and Mississippian) in the North Dakota portion of the Williston Basin. The Bakken Formation in the study area is known for its low matrix porosity and permeability, high organic content, thermal maturity, and relative lateral homogeneity. Core analysis has shown the effective porosity and permeability development within the Bakken Formation to be primarily related to fracturing.

In theory, lineaments mapped on the surface reflect the geometry of basement blocks and the zones of fracturing propagated upward from them. Fracturing in the Williston Basin is thought to have …


Erosion Of Fractured Banks, Lake Sakakawea, Western North Dakota, Mark C. Elliott Jan 1991

Erosion Of Fractured Banks, Lake Sakakawea, Western North Dakota, Mark C. Elliott

Theses and Dissertations

Shoreline erosion at Lake Sakakawea has exceeded originally predicted rates. This thesis is a continuation of a project, begun in 1983, to study erosion rates, causes, and prediction; the purpose has been to describe variations in fracture patterns in shoreline banks and assess their affects on erosion rates.

During the first phase of this project (1983-1986), average bank recession was rapid (l.Sm/yr) and factors related to wave action, including fetch, bank orientation, and beach composition, were most important. Since 1986, low lake levels have persisted and wave action has not been a factor; however banks continue to recede, but at …