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Scanning electron microscopic evaluation of broad ion beam milling effects to sedimentary organic matter: Sputter-induced artifacts or naturally occurring porosity?

Research examining organic-matter hosted porosity has significantly increased during the last decade due to greater focus on understanding hydrocarbon migration and storage in source-rock reservoirs, and technological advances in scanning electron microscopy (SEM) capabilities. The examination of nanometer-scale organic-matter hosted porosity by SEM requires the preparation of exceptionally flat g
Authors
Brett J. Valentine, Paul C. Hackley

Methane pore accessibility, densification, and accommodation by organic matter in the Niobrara Formation at wet-gas thermal maturity conditions

Petroleum within unconventional source-rock reservoirs is hosted in organic matter and mineral pore space as well as in voids and microfractures. Recent work has shown that for source-rock reservoirs in the dry gas window, significant portions of methane (CH4), the main component of petroleum at elevated maturities, can be stored within fine (<5 nm) organic matter porosity. However, within reservo
Authors
Aaron M. Jubb, Leslie F. Ruppert, Tristan G. A. Youngs, Tom Headen, Justin E. Birdwell, Michael Cheshire, Martha (Rebecca) Stokes

A residual oil zone (ROZ) assessment methodology with application to the central basin platform (Permian Basin, USA) for enhanced oil recovery (EOR) and long-term geologic CO2 storage

Residual oil zones (ROZ) form due to various geologic conditions and are located below the oil/water contact (OWC) of main pay zones (MPZ). Since ROZs usually contain immobile oil, they have not typically been considered commercially attractive for development by conventional primary recovery methods used in the initial phases of oil production. However, during the last decade some operators of th
Authors
C. Özgen Karacan, Sean T. Brennan, Marc L. Buursink, Philip A. Freeman, Celeste D. Lohr, Matthew D. Merrill, Ricardo A. Olea, Peter D. Warwick

Geology and assessment of coal resources for the Cherokee coal bed in the Fort Union Formation, south-central Wyoming

The Cherokee coal bed is a locally thick and laterally continuous coal bed in the Overland Member of the Paleocene Fort Union Formation in south-central Wyoming. It represents a significant resource that is easily accessible and may be extractable through both surface and underground mining methods. A database of more than 600 data points, comprising coalbed methane wells, coal exploration drill h
Authors
Brian N. Shaffer, Ricardo A. Olea

Assessment of continuous oil and gas resources in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast, 2022

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 0.8 billion barrels of oil and 16 trillion cubic feet of gas in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast region.
Authors
Katherine J. Whidden, Justin E. Birdwell, Rand D. Gardner, Scott A. Kinney, Stanley T. Paxton, Janet K. Pitman, Christopher J. Schenk

Merging machine learning and geostatistical approaches for spatial modeling of geoenergy resources

Geostatistics is the most commonly used probabilistic approach for modeling earth systems, including quality parameters of various geoenergy resources. In geostatistics, estimates, either on a point or block support, are generated as a spatially-weighted average of surrounding samples. The optimal weights are determined through the stationary variogram model which accounts for the spatial structur
Authors
Gamze Erdogan Erten, Oktay Erten, C. Özgen Karacan, Jeff Boisvert, Clayton V. Deutsch

Assessment of undiscovered conventional oil and gas resources in the offshore Salt Basin area of Morocco, 2021

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 3.8 billion barrels of oil and 20.7 trillion cubic feet of gas offshore of Morocco.
Authors
Christopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Phuong A. Le, Andrea D. Cicero, Ronald M. Drake, Geoffrey S. Ellis, Thomas M. Finn, Michael H. Gardner, Sarah E. Gelman, Jane S. Hearon, Benjamin G. Johnson, Jenny H. Lagesse, Heidi M. Leathers-Miller, Kristen R. Marra, Kira K. Timm, Scott S. Young

Assessment of coalbed gas resources in the Raton Basin-Sierra Grande Uplift Province, Colorado and New Mexico, 2022

Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 5.2 trillion cubic feet of coalbed gas in the Vermejo Formation and Raton Formation of the Raton Basin-Sierra Grande Uplift Province.
Authors
Christopher J. Schenk, Thomas M. Finn, Tracey J. Mercier, Cheryl A. Woodall, Phuong A. Le, Andrea D. Cicero, Ronald M. Drake, Geoffrey S. Ellis, Michael H. Gardner, Sarah E. Gelman, Jane S. Hearon, Benjamin G. Johnson, Jenny H. Lagesse, Heidi M. Leathers-Miller, Kristen R. Marra, Kira K. Timm, Scott S. Young

U.S. Geological Survey Rocky Mountain Region 2022 science exchange, showcasing interdisciplinary and state-of-the-art USGS science

IntroductionThe Rocky Mountains and the Colorado River Basin in the Western United States represent complex, interconnected systems that sustain a number of species, including tens of millions of humans. These systems face several challenges, including worsening drought, altered wildfire regimes, climate change, and the spread of invasive species. These factors can exacerbate one another, further
Authors
Dana E. Peterson, Katherine L. French, Jeannette H. Oden, Patrick J. Anderson, Timothy N. Titus, Katharine G. Dahm, Jessica M. Driscoll, William J. Andrews

Modeling the maturation history of the stacked petroleum systems of the Williston Basin, USA

A three-dimensional petroleum systems model was built to support U.S. Geological Survey assessments of undiscovered oil and gas resources in the Williston Basin of North Dakota, Montana, and South Dakota. Numerous Paleozoic source rocks have been proven or postulated in the basin, of which five were the focus of maturation and migration modeling: the Ordovician Icebox Formation, the kukersite beds
Authors
Sarah E. Gelman

Mapping abandoned uranium mine features using Worldview-3 imagery in portions of Karnes, Atascosa and Live Oak Counties, Texas

Worldview-3 (WV3) 16-band multispectral data were used to map exposed bedrock and mine waste piles associated with legacy open-pit mining of sandstone-hosted roll-front uranium deposits along the South Texas Coastal Plain. We used the “spectral hourglass” approach to extract spectral endmembers representative of these features from the image. This approach first requires calibrating the imagery to
Authors
Bernard E. Hubbard, Tanya J. Gallegos, Victoria G. Stengel

Reconnaissance survey for potential energy storage and carbon dioxide storage resources of petroleum reservoirs in western Europe

Energy producers and utilities use oil and gas reservoirs for gas storage to meet peak seasonal demand or to supplement intermittent energy production. These reservoirs are also suitable for the long-term storage of carbon dioxide (CO2), a greenhouse gas. This study reports on a reconnaissance analysis of the potential magnitude of storage resources in 9424 known oil and gas reservoirs from 24 cou
Authors
Emil D. Attanasi, Philip A. Freeman