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Thomas M. Finn

Publications and source records attributed to Thomas M. Finn.

137 records · Page 8Linked to original sources
USGS2007

Source rock potential of upper cretaceous marine shales in the Wind River Basin, Wyoming: Chapter 8 in Petroleum systems and geologic assessment of oil and gas resources in the Wind River Basin Province, Wyoming

Seventy-eight samples collected from marine shales from the Cretaceous Mowry Shale, the lower part of the Frontier Formation, and the lower shaly and upper sandy members of the Cody Shale in the Wind River Basin, Wyoming, were analyzed using Rock-Eval and total organic carbon analysis to determine the source rock potential. Results indicate that the Mowry Shale has a generative potential based on organic richness that is considered to be fair to very good, and hydrogen indices and S 2 /S 3 ratios indicate a capability to generate both oil and gas. Maps of the Mowry indicate that it is most organic rich and oil-prone in the eastern part of the basin. Results of total organic carbon and Rock-Eval analyses for the Frontier Formation indicate that it is composed of mainly type III gas-prone kerogen, with organic richness levels that are generally poor to fair. Results of similar analyses of samples from the lower shaly member of the Cody Shale show a generative potential ranging from fair to excellent, and hydrogen indices and S 2 /S 3 ratios indicate that it is capable of generating both oil and gas. Maps showing the distribution of kerogen types and organic richness for the lower shaly member of the Cody Shale are similar to the Mowry and show that lower shaly member of the Cody is more organic rich and more oil-prone in the eastern part of the basin. Analyses of samples of the upper sandy member of the Cody Shale indicate that it has little or no potential as a source rock. Thermal maturity mapping based on vitrinite reflectance measurements in the coal-bearing post-Cody Upper Cretaceous and Paleocene rocks shows that Upper Cretaceous marine shales in the deeper parts of the Wind River Basin are thermally mature to overmature with respect to hydrocarbon generation.

Wyoming↗
USGS2007

Subsurface stratigraphic cross sections of cretaceous and lower tertiary rocks in the Wind River Basin, central Wyoming: Chapter 9 in Petroleum systems and geologic assessment of oil and gas resources in the Wind River Basin Province, Wyoming

The stratigraphic cross sections presented in this report were constructed as part of a project conducted by the U.S. Geological Survey to characterize and evaluate the undiscovered oil and gas resources of the Wind River Basin (WRB) in central Wyoming. The primary purpose of the cross sections is to show the stratigraphic framework and facies relations of Cretaceous and lower Tertiary rocks in this large, intermontane structural and sedimentary basin, which formed in the Rocky Mountain foreland during the Laramide orogeny (Late Cretaceous through early Eocene time). The WRB is nearly 200 miles (mi) long, 70 mi wide, and encompasses about 7,400 square miles (mi 2 ) (fig. 1). The basin is structurally bounded by the Owl Creek and Bighorn Mountains on the north, the Casper arch on the east, the Granite Mountains on the south, and the Wind River Range on the west.

Wyoming↗
USGS2007

New vitrinite reflectance data for the Bighorn Basin, north-central Wyoming and south-central Montana

The Bighorn Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 10,400 mi2 in north-central Wyoming and south-central Montana (fig. 1). Important conventional oil and gas resources have been discovered and produced from reservoirs ranging in age from Cambrian through Tertiary (Fox and Dolton, 1989, 1996a, b; De Bruin, 1993). In addition, a potential unconventional basin-centered gas accumulation may be present in Cretaceous reservoirs (Johnson and Finn, 1998; Johnson and others, 1999). The purpose of this report is to present new vitrinite reflectance data to be used in support of the U.S Geological Survey’s assessment of undiscovered oil and gas resources of the Bighorn Basin. These new data supplement previously published data by Nuccio and Finn (1998), and Yin (1997), and lead to a better understanding and characterization of the thermal maturation and burial history of potential source rocks. Eighty-nine samples of Cretaceous and Tertiary strata (fig. 2) were collected and analyzed—15 samples were from outcrops around the margins of the basin and 74 samples were well cuttings (fig. 1). Forty-one of the samples were shale, two were carbonaceous shale, and the remainder from coal. All samples were analyzed by vitrinite reflectance to determine levels of thermal maturation. Preparation of samples for reflectance analysis required (1) crushing the larger pieces into 0.25-to 1-mm pieces, (2) casting the pieces with epoxy in pre-cut and drilled plugs, and (3) curing the samples overnight. Subsequently, a four-step grinding and polishing process was implemented that included sanding with progressively finer sandpaper (60 and 600 grit) followed with a two-step polishing process (0.3 and 0.05 micron). Vitrinite reflectance measurements were determined at 500 X magnification using plane-polarized incident white light and a 546-nm monochromatic filter in immersion oil. For samples containing sufficiently high quality vitrinite, at least 25 measurements were recorded. For samples of poorer quality, either due to a poor polish or to the presence of mineral or other inorganic material, fewer measurements were recorded. Analytical results are given in tables 1 and 2.

Open-File Report↗
USGS2006

Vitrinite Reflectance Data for the Wind River Basin, Central Wyoming

Introduction: The Wind River Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 7,400 mi2 in central Wyoming. The basin boundaries are defined by fault-bounded Laramide uplifts that surround it, including the Owl Creek and Bighorn Mountains to the north, Wind River Range to the west, Granite Mountains to the south, and Casper Arch to the east. The purpose of this report is to present new vitrinite reflectance data to be used in support of the U.S Geological Survey assessment of undiscovered oil and gas resources of the Wind River Basin. One hundred and nineteen samples were collected from Jurassic through Tertiary rocks, mostly coal-bearing strata, in an effort to better understand and characterize the thermal maturation and burial history of potential source rocks.

Open-File Report↗
USGS2003

Assessment of the Mesaverde Total Petroleum System in Southwestern Wyoming Province: a petroleum system approach to assessing undiscovered oil and gas resources

The U.S. Geological Survey, in a recent assessment of the undiscovered oil and gas resources in the Southwestern Wyoming Province using a Total Petroleum System (TPS) approach, estimated a mean of 84.6 trillion cubic feet of gas (TCFG), 131 million barrels of oil (MMBO) and 2.6 billion barrels of natural gas liquids (BBNGL) that have the potential to be added to reserves over the next 30 years. Only a fraction of this, however, may be economically recoverable . Of the total estimate of 84.6 TCFG, a mean of 25.78 TCFG is in continuous-type reservoirs in the Mesaverde TPS. The Mesaverde TPS is defined as all reservoirs predominantly containing gas derived from the Mesaverde Group east of the pinchout of the Lewis Shale, which acts as a top seal separating the Mesaverde TPS from the overlying Lewis TPS. Continuous-type reservoirs in the Mesaverde TPS were subdivided into the Almond Continuous Gas Assessment Unit (AU) (mean of 13.35 TCFG), Rock Springs-Ericson Continuous Gas AU (mean of 12.18 TCFG), and the Mesaverde Coalbed Gas AU (mean of 0.25 TCFG). Geologic analysis was used to determine the favorable ?sweet spots? for potential gas resources. The Almond AU has been heavily explored at depths less than 11,000 ft, thus additions to reserves will most likely be the result of infill drilling in existing fields and the discovery of sweet spots at depths greater than 11,000 ft. There is much uncertainty in the size of undiscovered resource in the Rock Springs-Ericson AU because potential reservoirs are only sparsely explored. Only a small fraction of in-place coal-bed gas is considered to be recoverable because of low permeability and problems posed by produced water.

Open-File Report↗
USGS2002

Vitrinite reflectance data for the Greater Green River basin, southwestern Wyoming, northwestern Colorado, and northeastern Utah

The Greater Green River Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 25,000 square miles in southwestern Wyoming, northwestern Colorado, and northeastern Utah (fig. 1). Important conventional oil and gas resources have been discovered and produced from reservoirs ranging in age from Cambrian through Tertiary (Law, 1996). In addition, an extensive overpressured basin - centered gas accumulation has also been identified in Cretaceous and Tertiary reservoirs by numerous researchers including Law (1984a, 1996), Law and others (1980, 1989), McPeek (1981), and Spencer (1987). The purpose of this report is to present new vitrinite reflectance data to be used in support of the U.S Geological Survey assessment of undiscovered oil and gas resources of the Greater Green River Basin. One hundred eighty-six samples were collected from Cretaceous and Tertiary coalbearing strata (figs. 1 and 2) in an effort to better understand and characterize the thermal maturation and burial history of potential source rocks. Two samples were from core, one from outcrop, and the remainder from well cuttings. These data were collected to supplement previously published data by Law (1984b), Pawlewicz and others (1986), Merewether and others (1987), and Garcia-Gonzalez and Surdam (1995) and are presented in table 1.

Colorado, Utah, Wyoming↗
USGS2001

Potential for a basin-centered gas accumulation in the Raton Basin, Colorado and New Mexico

The Raton Basin appears to contain a significant continuous or basin-centered gas accumulation in sandstones of the Upper Cretaceous Trinidad Sandstone and Vermejo Formation and Upper Cretaceous and Paleocene Raton Formation. The accumulation is underpressured and occurs at comparatively shallow (<3,500 ft) depths. The sandstones are interbedded with coal beds that are currently being developed for coal-bed methane, and the coals are the likely source for gas found in the sandstones. Based on analogs with other Rocky Mountain basins, relatively water-free production should occur where levels of thermal maturity in the coals exceed a vitrinite reflectance value of 1.1 percent. This level of thermal maturity occurs over much of the central part of the Raton Basin. Because of the shallow depths, some of the accumulation has probably been degraded by surface water invasion.

Colorado, New Mexico↗
USGS2001

Potential for a basin-centered gas accumulation in the Albuquerque Basin, New Mexico

The potential that a basin-centered or continuous-type gas accumulation is present in the Albuquerque Basin in central New Mexico was investigated. The Albuquerque Basin is one of the many rift basins that make up the Rio Grand rift system, an area of active extension from Oligocene to recent time. The basin is significantly different from other Rocky Mountain basins that contain basin-centered gas accumulations because it is actively subsiding and is at near maximum burial and heating conditions at the present time. Burial reconstructions suggest that Cretaceous-age source rocks began to generate gas in the deeper parts of the basin about 20 million years ago and are still generating large amounts of gas. The high mud weights typically used while drilling the Cretaceous interval in the deeper areas of the basin suggest some degree of over-pressuring. Gas shows are commonly reported while drilling through the Cretaceous interval; however, attempts to complete gas wells in the Cretaceous have resulted in subeconomic quantities of gas, primarily because of low permeabilities. Little water has been reported. All of these characteristics suggest that a basin-centered gas accumulation of some sort is present in the Albuquerque Basin.

Bulletin↗