Brett J. Valentine
Brett Valentine is a Physical Scientist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Since joining the USGS in 2009, Brett has devoted his career to studying organic petrology and specializes in electron microscopy techniques. He is currently the manager of the Reston Electron Microbeam Laboratory at USGS National Center in Reston, VA. Presently, his research focuses on developing electron microscopy methods and applications to improve our understanding of the micro-to-nanoscale changes that occur to coals and organic-rich shales as they thermally mature.
Professional Experience
Physical Scientist, USGS Geology, Energy & Minerals Science Center, 2009-Present
Assistant County Soil Scientist, Fauquier County, VA, 2004-2009
Education and Certifications
B.S. Forestry and Environmental Science, Virginia Tech
Science and Products
Photomicrograph Atlas
Thermal Indices Innovation
Screening geochemistry, gas chromatography, and solid bitumen reflectance data in the Bakken petroleum system, Williston Basin, USA
Thirty-two organic-rich samples from the lower and upper shale members of the Devonian–Mississippian Bakken Formation were collected from eight cores across the Williston Basin, USA, at depths (~7,575–11,330 ft) representing immature through post peak oil/early condensate thermal maturity conditions. Reflectance results were correlated to programmed temperature pyrolysis parameters [hydrogen index
SEM-CL investigation of sedimentary organic matter samples
Evaluation of pore-like features in sedimentary organic matter
Textural occurrence and organic porosity of solid bitumen in shales
Organic petrology of Cretaceous Mowry and Niobrara source-rock reservoirs, Powder River Basin, Wyoming, USA
TOC, Reflectance and Raman Data from Eocene Green River Mahogany Zone
Reflectance and confocal laser scanning fluorescence spectroscopy of bituminite in Kimmeridge Clay
Investigating the effects of broad ion beam milling to sedimentary organic matter
Organic petrographic evaluation of carbonaceous material in sediments of the Kinnickinnic River, Milwaukee, WI, U.S.A.
Oil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)
USGS Gulf Coast Petroleum Systems and National and Global Oil and Gas Assessment Projects-Louisiana-Mississippi Salt Basins and Western Gulf Provinces, Upper Cretaceous Tuscaloosa Marine Shale Assessment Unit Boundaries and Assessment Input Data Forms
Petroleum geology data from Cenozoic rock samples in the eastern U.S. Gulf Coast collected 2014 to 2016
Scanning electron microscopic evaluation of broad ion beam milling effects to sedimentary organic matter: Sputter-induced artifacts or naturally occurring porosity?
Interlaboratory study: Testing reproducibility of solid biofuels component identification using reflected light microscopy
Pore systems and organic petrology of cretaceous Mowry and Niobrara source-rock reservoirs, Powder River Basin, Wyoming, USA
Relating systematic compositional variability to the textural occurrence of solid bitumen in shales
Evaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
Identification of thermal maturity-relevant organic matter in Shale Working Group Report 2021
Characterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy
Hydrous pyrolysis of New Albany Shale: A study examining maturation changes and porosity development
A review of spatially resolved techniques and applications of organic petrography in shale petroleum systems
Organic petrographic evaluation of carbonaceous material in sediments of the Kinnickinnic River, Milwaukee, WI, U.S.A.
Investigating the effects of broad ion beam milling to sedimentary organic matter: Surface flattening or heat-induced aromatization and condensation?
Characterization of the unconventional Tuscaloosa marine shale reservoir in southwestern Mississippi, USA: Insights from optical and SEM petrography
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.
Science and Products
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Photomicrograph Atlas
The Photomicrograph Atlas provides a basic tutorial in the nomenclature of organic materials as they occur in sedimentary rocks such as coal and shale, information on the taxonomies used by various groups and organizations, and a database of images related to the characterization of fossil fuel resources in the United States and the world.Thermal Indices Innovation
Thermal indices innovation focuses on the utilization of correlative microscopy and spectroscopy techniques for innovative approaches to advance the understanding of thermal indices development. These techniques include correlative light and electron microscopy (CLEM), confocal laser scanning microscopy (CLSM), and atomic force microscopy and infrared microscopy (AFM-IR), among others. Use of... - Data
Filter Total Items: 14
Screening geochemistry, gas chromatography, and solid bitumen reflectance data in the Bakken petroleum system, Williston Basin, USA
Thirty-two organic-rich samples from the lower and upper shale members of the Devonian–Mississippian Bakken Formation were collected from eight cores across the Williston Basin, USA, at depths (~7,575–11,330 ft) representing immature through post peak oil/early condensate thermal maturity conditions. Reflectance results were correlated to programmed temperature pyrolysis parameters [hydrogen index
SEM-CL investigation of sedimentary organic matter samples
High-resolution scanning electron microscopy (SEM) visualization of sedimentary organic matter (SOM) is widely utilized in the geosciences for evaluation of microscale rock properties relevant to depositional environment, diagenesis, and the processes of fluid generation, transport, and storage. However, despite thousands of studies which have incorporated SEM approaches, the inability of SEM to dEvaluation of pore-like features in sedimentary organic matter
Research examining organic-matter hosted porosity has significantly increased during the last ten years 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 flaTextural occurrence and organic porosity of solid bitumen in shales
This study presents Raman spectroscopic data paired with scanning electron microscopy (SEM) to assess solid bitumen composition and porosity development as a function of solid bitumen texture and association with minerals. A series of hydrous pyrolysis experiments (1-103 days, 300-370°C) using a low maturity (0.25% solid bitumen reflectance, BRo), high total organic carbon [(TOC), 14.0 wt. %] NewOrganic petrology of Cretaceous Mowry and Niobrara source-rock reservoirs, Powder River Basin, Wyoming, USA
Imaging of Niobrara Formation and Mowry Shale samples from a range of thermal maturities provided observations and data on pore systems, organic matter (OM) types and associations with mineralogy and fabric, wettability, and microporosity associated with both diagenetic and detrital clays. Imaging techniques included scanning electron microscopy, organic petrography and correlative scanning electrTOC, Reflectance and Raman Data from Eocene Green River Mahogany Zone
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of exchangeable hydrogen from water, organic-rich (22 wt. percent total organic carbon, TOC) mudrock sampleReflectance and confocal laser scanning fluorescence spectroscopy of bituminite in Kimmeridge Clay
This work investigates the characterization of bituminite (amorphous sedimentary organic matter) in Kimmeridge Clay source rock via confocal laser canning microscopy (CLSM) and atomic force microscopy (AFM). As part of an International Committee for Coal and Organic Petrology working group, an immature (0.42% vitrinite reflectance), organic-rich (44.1 wt.% total organic carbon content) sample of KInvestigating the effects of broad ion beam milling to sedimentary organic matter
To test if reflectance increases to sedimentary organic matter (vitrinite) caused by broad ion beam (BIB) milling were related to molecular aromatization and condensation, we used Raman and Fourier transform infrared (FTIR) spectroscopies to evaluate potential compositional changes in the same vitrinite locations pre- and post-BIB milling. The same locations also were examined by atomic force micrOrganic petrographic evaluation of carbonaceous material in sediments of the Kinnickinnic River, Milwaukee, WI, U.S.A.
This study describes the application of organic petrology techniques to quantify the amount of coal and carbonaceous combustion by-products (i.e., coke, coal tar/pitch, cenospheres) in sediments taken from the Kinnickinnic River adjacent to the former site of the Milwaukee Solvay Coke and Gas Company. The site produced metallurgical coke and coal-gasification by-products from 1902-1983 and was assOil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)
The U.S. Geological Survey assessed undiscovered unconventional hydrocarbon resources reservoired in the Upper Cretaceous Tuscaloosa marine shale (TMS) of southern Mississippi and adjacent Louisiana in 2018. As part of the assessment, oil- source rock correlations were examined in the study area where operators produce light (38-45 degrees API), sweet oil from horizontal, hydraulically-fractured wUSGS Gulf Coast Petroleum Systems and National and Global Oil and Gas Assessment Projects-Louisiana-Mississippi Salt Basins and Western Gulf Provinces, Upper Cretaceous Tuscaloosa Marine Shale Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered gas hydrate resources on the north slope of Alaska. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System.Petroleum geology data from Cenozoic rock samples in the eastern U.S. Gulf Coast collected 2014 to 2016
The U.S. Geological Survey assessed undiscovered petroleum resources in the downdip Paleogene formations of the U.S. Gulf Coast in 2018. During the assessment new data and information were collected to evaluate thermal maturity, source rock character, and unconventional reservoir rock prospectivity for the Cenozoic-aged section in south Louisiana. Samples were analyzed using multiple analytical ap - Multimedia
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Filter Total Items: 51
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 gAuthorsBrett J. Valentine, Paul C. HackleyInterlaboratory study: Testing reproducibility of solid biofuels component identification using reflected light microscopy
Considering global market trends and concerns about climate change and sustainability, increased biomass use for energy is expected to continue. As more diverse materials are being utilized to manufacture solid biomass fuels, it is critical to implement quality assessment methods to analyze these fuels thoroughly. One such method is reflected light microscopy (RLM), which has the potential to compAuthorsAgnieszka Drobniak, Maria Mastalerz, Zbigniew Jelonek, Iwona Jelonek, Tushar Adsul, Neža Malenšek Andolšek, Omid Haeri Ardakani, Tara Congo, Batbold Demberelsuren, Bryon S. Donohoe, Ashley Douds, Deolinda Flores, Ranjin Ganzorig, Santanu Ghosh, Andrew Gize, Paula Alexandra Goncalves, Paul C. Hackley, Javin J. Hatcherian, James C. Hower, Stavros Kalaitzidis, Sławomir Kędzior, Wayne Knowles, Jolanta Kus, Kacper Lis, Grzegorz Lis, Bei Liu, Qingyong Luo, Meili Du, Divya Mishra, Magdalena Misz-Kennan, Theophile Mugerwa, Jennifer Nedzweckas, Jennifer M. K. O'Keefe, Jackie Park, Richard Pearson, Henrik I. Petersen, Julito Reyes, Joana Ribeiro, Genaro de la Rosa-Rodriguez, Piotr Sosnowski, Brett J. Valentine, Atul Kumar Varma, Małgorzata Wojtaszek-Kalaitzidi, Zhanjie Xu, Alexander Zdravkov, Konrad ZiemianinPore systems and organic petrology of cretaceous Mowry and Niobrara source-rock reservoirs, Powder River Basin, Wyoming, USA
The Powder River Basin (PRB) is a world-class oil province, in large part thanks to contributions from premier source rocks, Cretaceous Mowry and Niobrara shales. Both formations are also unconventional reservoirs. A critical aspect of evaluating production potential and finding sweet spots is the nature of the pore systems in these fine-grained source-rock reservoirs. Variation by stratigraphic iAuthorsTerri Olson, Brad Michalchuk, Paul C. Hackley, Brett J. Valentine, Jason Parker, Ricardo San MartinRelating systematic compositional variability to the textural occurrence of solid bitumen in shales
This study presents Raman spectroscopic data paired with scanning electron microscopy (SEM) images to assess solid bitumen composition as a function of solid bitumen texture and association with minerals. A series of hydrous pyrolysis experiments (1–103 days, 300–370 °C) using a low maturity (0.25% solid bitumen reflectance, BRo), high total organic carbon [(TOC), 14.0 wt%] New Albany Shale sampleAuthorsMartha (Rebecca) Stokes, Brett J. Valentine, Aaron M. Jubb, Paul C. HackleyEvaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of hydrogen from water, organic-rich (22 wt% total organic carbon, TOC) mudrock samples from the Eocene lacAuthorsPaul C. Hackley, Aaron M. Jubb, Patrick L. Smith, Ryan J. McAleer, Brett J. Valentine, Javin J. Hatcherian, Palma J. Botterell, Justin E. BirdwellIdentification of thermal maturity-relevant organic matter in Shale Working Group Report 2021
The Identification of Thermal Maturity-Relevant Organic Matter in Shale Working Group of the ICCP was established in 2008 to provide guidelines for identifying and measuring the reflectance of the population of dispersed organic matter that is relevant to thermal maturity determination. Information products published by the working group include ASTM D7708 Standard Test Method for Microscopical DeAuthorsPaul C. Hackley, Javin J. Hatcherian, Jennifer L. Rivera, Margaret M. Sanders, Brett J. ValentineCharacterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy
This work investigates bituminite (amorphous sedimentary organic matter) in Upper Jurassic Kimmeridge Clay source rock via confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM). These petrographic tools were used to provide better understanding of the nature of bituminite, which has been historically difficult to identify and differentiate from similar organic matter types inAuthorsPaul C. Hackley, Jolanta Kus, João Graciano Mendonça Filho, Andrew D. Czaja, Angeles G. Borrego, Dragana Životić, Brett J. Valentine, Javin J. HatcherianHydrous pyrolysis of New Albany Shale: A study examining maturation changes and porosity development
The characterization of nanoscale organic structures has improved our understanding of porosity development within source-rock reservoirs, but research linking organic porosity evolution to thermal maturity has generated conflicting results. To better understand this connection, an immature (0.25% solid bitumen reflectance; BRo) sample of the New Albany Shale was used in four isothermal hydrous pyAuthorsBrett J. Valentine, Paul C. Hackley, Javin J. HatcherianA review of spatially resolved techniques and applications of organic petrography in shale petroleum systems
This review examines new techniques and applications of organic petrography in source-rock reservoir petroleum systems that have occurred along with development of the global ‘shale revolution’ in energy resources. The review is limited to techniques and instrumentation that provide spatially resolved information, typically at or below microscales, for dispersed organic matter occurring in situ inAuthorsPaul C. Hackley, Aaron M. Jubb, Ryan J. McAleer, Brett J. Valentine, Justin E. BirdwellOrganic petrographic evaluation of carbonaceous material in sediments of the Kinnickinnic River, Milwaukee, WI, U.S.A.
This study examines the use of organic petrology techniques to quantify the amount of coal and carbonaceous combustion by-products (i.e., coke, coal tar/pitch, cenospheres) in sediments taken from the Kinnickinnic River adjacent to the former site of the Milwaukee Solvay Coke and Gas Company. These materials are of concern as contaminants like polycyclic aromatic hydrocarbons (PAHs) are known to rAuthorsBrett J. Valentine, John H Krahling Jr, Stephen D. MuellerInvestigating the effects of broad ion beam milling to sedimentary organic matter: Surface flattening or heat-induced aromatization and condensation?
Previous work has proposed transfer of kinetic heat energy from low-energy broad ion beam (BIB) milling causes thermal alteration of sedimentary organic matter, resulting in increases of organic matter reflectance. Whereas, other studies have suggested the organic matter reflectance increase from BIB milling is due to decreased surface roughness. To test if reflectance increases to sedimentary orgAuthorsPaul C. Hackley, Aaron M. Jubb, Brett J. Valentine, Javin J. Hatcherian, Jing-Jiang Yu, William K. PodrazkyCharacterization of the unconventional Tuscaloosa marine shale reservoir in southwestern Mississippi, USA: Insights from optical and SEM petrography
This study presents new optical petrography and electron microscopy data, interpreted in the context of previously published petrophysical, geochemical, and mineralogical data, to further characterize the Tuscaloosa marine shale (TMS) as an unconventional reservoir in southwestern Mississippi. The basal high resistivity zone has a higher proportion of Type II sedimentary organic matter than the ovAuthorsCeleste D. Lohr, Brett J. Valentine, Paul C. Hackley, Frank T. Dulong - Web Tools
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.