Publications
Filter Total Items: 858
Creating potentiometric surfaces from combined water well and oil well data in the midcontinent of the United States
For years, hydrologists have defined potentiometric surfaces using measured hydraulic-head values in water wells from aquifers. Down-dip, the oil and gas industry is also interested in the formation pressures of many of the same geologic formations for the purpose of hydrocarbon recovery. In oil and gas exploration, drillstem tests (DSTs) provide the formation pressure for a given depth interval i
Authors
Nicholas J. Gianoutsos, Philip H. Nelson
Multivariate analysis of ATR-FTIR spectra for assessment of oil shale organic geochemical properties
In this study, attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR) was coupled with partial least squares regression (PLSR) analysis to relate spectral data to parameters from total organic carbon (TOC) analysis and programmed pyrolysis to assess the feasibility of developing predictive models to estimate important organic geochemical parameters. The advantage of ATR-
Authors
Kathryn E. Washburn, Justin E. Birdwell
Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)
Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal
Authors
Michael M. McGlue, Andrew S. Cohen, Geoffrey S. Ellis, Andrew L. Kowler
Traces in the dark: sedimentary processes and facies gradients in the upper shale member of the Upper Devonian-Lower Mississippian Bakken Formation, Williston Basin, North Dakota, U.S.A.
Black, organic-rich rocks of the upper shale member of the Upper Devonian–Lower Mississippian Bakken Formation, a world-class petroleum source rock in the Williston Basin of the United States and Canada, contain a diverse suite of mudstone lithofacies that were deposited in distinct facies belts. The succession consists of three discrete facies associations (FAs). These comprise: 1) siliceous muds
Authors
Sven O. Egenhoff, Neil S. Fishman
Application of uniaxial confining-core clamp with hydrous pyrolysis in petrophysical and geochemical studies of source rocks at various thermal maturities
Understanding changes in petrophysical and geochemical parameters during source rock thermal maturation is a critical component in evaluating source-rock petroleum accumulations. Natural core data are preferred, but obtaining cores that represent the same facies of a source rock at different thermal maturities is seldom possible. An alternative approach is to induce thermal maturity changes by lab
Authors
Michael D. Lewan, Justin E. Birdwell
Changes in porosity and organic matter phase distribution monitored by NMR relaxometry following hydrous pyrolysis under uniaxial confinement
Artificial maturation methods are used to induce changes in source rock thermal maturity without the uncertainties that arise when comparing natural samples from a particular basin that often represent different levels of maturation and different lithofacies. A novel uniaxial confinement clamp was used on Woodford Shale cores in hydrous pyrolysis experiments to limit sample expansion by simulating
Authors
Kathryn E. Washburn, Justin E. Birdwell, Michael D. Lewan, Michael Miller
A new laboratory approach to shale analysis using NMR relaxometry
Low-field nuclear magnetic resonance (LF-NMR) relaxometry is a non-invasive technique commonly used to assess hydrogen-bearing fluids in petroleum reservoir rocks. Measurements made using LF-NMR provide information on rock porosity, pore-size distributions, and in some cases, fluid types and saturations (Timur, 1967; Kenyon et al., 1986; Straley et al., 1994; Brown, 2001; Jackson, 2001; Kleinberg,
Authors
Kathryn E. Washburn, Justin E. Birdwell
Characterizing tight-gas systems with production data: Wyoming, Utah, and Colorado
The study of produced fluids allows comparisons among tight-gas systems. This paper examines gas, oil, and water production data from vertical wells in 23 fields in five Rocky Mountain basins of the United States, mostly from wells completed before the year 2000. Average daily rates of gas, oil, and water production are determined two years and seven years after production begins in order to repre
Authors
Philip H. Nelson, Stephen L. Santus
Low-field nuclear magnetic resonance characterization of organic content in shales
Low-field nuclear magnetic resonance (LF-NMR) relaxometry is a non-invasive technique commonly used to assess hydrogen-bearing fluids in petroleum reservoir rocks. Longitudinal T1 and transverse T2 relaxation time measurements made using LF-NMR on conventional reservoir systems provides information on rock porosity, pore size distributions, and fluid types and saturations in some cases. Recent imp
Authors
Kathryn E. Washburn, Justin E. Birdwell, Joseph D. Seymour, Catherine Kirkland, Sarah J. Vogt
NMR measurement of oil shale magnetic relaxation at high magnetic field
Nuclear magnetic resonance (NMR) at low field is used extensively to provide porosity and
pore-size distributions in reservoir rocks. For unconventional resources, due to low porosity and
permeability of the samples, much of the signal exists at very short T2 relaxation times. In
addition, the organic content of many shales will also produce signal at short relaxation times.
Despite recent imp
Authors
Joseph D. Seymour, Kathryn E. Washburn, Catherine M. Kirkland, Sarah J. Vogt, Justin E. Birdwell, Sarah L. Codd
Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems
A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linea
Authors
Tongwei Zhang, Geoffrey S. Ellis, Stephen C. Ruppel, Kitty Milliken, Mike Lewan, Xun Sun