Paul C. Hackley, Ph.D.
Paul Hackley is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
As project chief of the Thermal Indices project I pursue research on thermal maturity, chemical composition and physical state of sedimentary organic matter. The Thermal Indices project is part of the Geology, Energy & Minerals (GEM) Science Center and is funded by the Energy Resources Program (ERP). The Thermal Indices project team develops and applies petrographic methods for the reliable identification of different types of sedimentary organic matter, and measures and interprets the response of organic matter to thermal stress in natural environments and in laboratory-based heating experiments. Improved understanding of the thermal evolution of sedimentary organic matter enables more accurate assessment of petroleum source rock maturation, thereby decreasing uncertainty in the determination of thermal histories, the timing of petroleum generation and the placement of resource assessment spatial boundaries. This leads to the overall goal of improving estimates of undiscovered petroleum resources, which is a central mission of the ERP.
My work focuses on four integrated research task areas which have petrographic approaches to thermal indices as their common denominator: 1) standardization and reproducibility of measurement, 2) utilization of hydrous pyrolysis for (artificial) thermal conversion of sedimentary organic matter, 3) petrographic innovation areas for thermal indices and organic evolution, and 4) petrographic laboratory support.
Thermal indices research is accomplished from the Organic Petrology and Hydrous Pyrolysis laboratories in Reston. The laboratories include facilities for sample preparation, hydrous pyrolysis, optical and fluorescence microscopy, and infrared spectroscopy. The Thermal Indices project team works with external collaborators from global academic, government and industry groups. All thermal indices research efforts reach toward the goal of improving fossil fuel resource assessments by generating new understanding of the processes occurring during thermal evolution of sedimentary organic matter and its conversion to petroleum.
Professional Experience
Unconventional petroleum systems
Conventional oil and gas assessment
Coalbed methane
Coal
Application of organic petrology techniques to fossil fuel resource assessment
Education and Certifications
Ph.D., George Mason University
M.S., George Washington University
B.A., Shippensburg State University
Affiliations and Memberships*
The Society for Organic Petrology (TSOP)
International Committee for Coal and Organic Petrology (ICCP)
American Association of Petroleum Geologists (AAPG)
American Society for Testing and Materials (ASTM)
Geological Society of America (GSA)
Science and Products
Data Release for Application of Raman spectroscopy as thermal maturity probe in shale petroleum systems: insights from natural and artificial maturation series (2018)
Reflectance, Raman band separation and Mean multivariant curve resolution (MCR) in organic matter in Boquillas Shale
Bitumen Reflectance Data from the Tattoo Well in the Horn River Basin, Sample E200205
Testing reproducibility of vitrinite and solid bitumen reflectance measurements in North American unconventional petroleum systems (2019)
Petroleum geology data from hydrous and anhydrous pyrolysis residues for coals and shales from the Cambrian through the Miocene (ver. 2.0, January 2023)
Photoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies
Nanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group Across a Natural Thermal Maturity Gradient
Oil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)
Data from Nanoscale Molecular Fractionation of Organic Matter within Unconventional Petroleum Source Beds (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
Mercury injection capillary pressure data in the U.S. Gulf Coast Tuscaloosa Group in Mississippi and Louisiana collected 2015 to 2017
An integrated geochemical, spectroscopic, and petrographic approach to examining the producibility of hydrocarbons from liquids-rich unconventional formations
Organo-facies and mineral effects on sorption capacity of low-maturity Permian Barakar shales from the Auranga Basin, Jharkhand, India
A review of spatially resolved techniques and applications of organic petrography in shale petroleum systems
Organic geochemistry and petrology of Devonian shale in eastern Ohio: Implications for petroleum systems assessment
Organic petrology and geochemistry of the Sunbury and Ohio Shales in eastern Kentucky and southeastern Ohio
Oil–source correlation studies in the shallow Berea Sandstone petroleum system, eastern Kentucky
Molecular and isotopic gas composition of the Devonian Berea Sandstone and implications for gas evolution, eastern Kentucky
Investigating the effects of broad ion beam milling to sedimentary organic matter: Surface flattening or heat-induced aromatization and condensation?
Examination of inertinite within immature Eagle Ford Shale at the nanometer-scale using atomic force microscopy-based infrared spectroscopy
Photoluminescence imaging of whole zircon grains on a petrographic microscope—An underused aide for geochronologic studies
The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge
Characterization of the unconventional Tuscaloosa marine shale reservoir in southwestern Mississippi, USA: Insights from optical and SEM petrography
Nanoscale molecular composition of solid bitumen from the Eagle Ford Group across a natural thermal maturity gradient
Science and Products
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Filter Total Items: 40
Data Release for Application of Raman spectroscopy as thermal maturity probe in shale petroleum systems: insights from natural and artificial maturation series (2018)
Raman spectroscopy was studied as a thermal maturity probe in a series of Upper Devonian Ohio Shale samples from the Appalachian Basin spanning from immature to dry gas conditions. Raman spectroscopy also was applied to samples spanning a similar thermal range created from 72-hour hydrous pyrolysis (HP) experiments of the Ohio Shale at temperatures from 300 to 360 Celcius and isothermal HP experimReflectance, Raman band separation and Mean multivariant curve resolution (MCR) in organic matter in Boquillas Shale
The molecular composition of petroliferous organic matter and its composition evolution throughout thermal advance are key to understanding and insight into petroleum generation. This information is critical for comprehending hydrocarbon resources in unconventional reservoirs, as source rock organic matter is highly dispersed, in contact with the surrounding mineral matrix, and may be present as mBitumen Reflectance Data from the Tattoo Well in the Horn River Basin, Sample E200205
Bitumen reflectance data from a sample collected from the vertical EOG TATTOO D129 A28-F/094-O-10 ("Tattoo") well in the Horn River Basin, as part of the collection of a high-resolution geochemical data set.Testing reproducibility of vitrinite and solid bitumen reflectance measurements in North American unconventional petroleum systems (2019)
To test reproducibility of vitrinite and solid bitumen reflectance measurements in mudrocks, an interlaboratory study (ILS) was conducted using six samples from United States unconventional petroleum systems. Samples selected from the Marcellus, Haynesville, Eagle Ford, Barnett, Bakken and Woodford are representative of resource plays currently under exploitation in North America. All samples arePetroleum geology data from hydrous and anhydrous pyrolysis residues for coals and shales from the Cambrian through the Miocene (ver. 2.0, January 2023)
This data release contains programmed pyrolysis, organic petrographic (reflectance), and semiquantitative X-ray diffraction mineralogy data for subsurface coal and shale samples from around the world. Samples were subjected to hydrous or anhydrous pyrolysis experiments at varying temperatures and the resulting residues were analyzed via programmed pyrolysis and reflectance to document changes in tPhotoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies
The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most geNanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group Across a Natural Thermal Maturity Gradient
Solid bitumen is a petrographically-defined secondary organic matter residue produced during petroleum generation and subsequent oil transformation. The presence of solid bitumen impacts many shale reservoir properties including porosity, permeability, and hydrocarbon generation and storage, amongst others. Furthermore, solid bitumen reflectance is an important parameter for assessing the thermalOil-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 wData from Nanoscale Molecular Fractionation of Organic Matter within Unconventional Petroleum Source Beds (2019)
Fractionation of petroleum during migration through sedimentary rock matrices has been observed across lengths of meters to kilometers. Selective adsorption of specific chemical moieties at mineral surfaces and/or the phase behavior of petroleum during pressure changes are typically invoked to explain this behavior. Given the current emphasis on unconventional (continuous) resources, there is a neUSGS 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 apMercury injection capillary pressure data in the U.S. Gulf Coast Tuscaloosa Group in Mississippi and Louisiana collected 2015 to 2017
This data release contains mercury injection capillary pressure (MICP), pseudo-wetting saturation, and carbon dioxide (CO2) column height data for subsurface Tuscaloosa Group samples from Mississippi and Louisiana. - Publications
Filter Total Items: 139
An integrated geochemical, spectroscopic, and petrographic approach to examining the producibility of hydrocarbons from liquids-rich unconventional formations
The geochemical and petrophysical complexity of source-rock reservoirs in liquids-rich unconventional (LRU) plays necessitates the implementation of a more expansive analytical protocol for initial play assessment. In this study, original samples from selected source-rock reservoirs in the USA and the UK were analyzed by 22 MHz nuclear magnetic resonance (HF-NMR) T1-T2 mapping, followed by hydrousAuthorsThomas Gentzis, Humberto Carvajal-Ortiz, Z. Harry Xie, Paul C. Hackley, Hallie FowlerOrgano-facies and mineral effects on sorption capacity of low-maturity Permian Barakar shales from the Auranga Basin, Jharkhand, India
Shales associated with the Lower Permian (Barakar Formation) sediments of the Auranga Coalfield, India, occur in the immature–early mature stage. The sorption capacity of Barakar shale samples has been studied through high-pressure methane (CH4) adsorption and low-pressure N2 gas adsorption (LPN2GA) methods, supported with proximate analyses, programmed pyrolysis, optical petrography, and with eneAuthorsDivya Kumari Mishra, Atul Kumar Varma, Vinod Atmaram Mendhe, Shailesh Agrawal, Bhagwan Das Singh, Paul C. HackleyA 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 geochemistry and petrology of Devonian shale in eastern Ohio: Implications for petroleum systems assessment
Recent production of light sweet oil has prompted reevaluation of Devonian petroleum systems in the central Appalachian Basin. Upper Devonian Ohio Shale (lower Huron Member) and Middle Devonian Marcellus Shale organic-rich source rocks from eastern Ohio and nearby areas were examined using organic petrography and geochemical analysis of solvent extracts to test ideas related to organic matter sourAuthorsPaul C. Hackley, Robert T. RyderOrganic petrology and geochemistry of the Sunbury and Ohio Shales in eastern Kentucky and southeastern Ohio
As part of a study to determine the origin of oil and gas in the Berea Sandstone in northeastern Kentucky and southeastern Ohio, 158 samples of organic-rich shale from the Upper Devonian Olentangy and Ohio Shales and the Lower Mississippian Sunbury Shale, collectively referred to as the “black shale,” were collected and analyzed from 12 cores. The samples were analyzed for total organic carbon (TOAuthorsCortland F. Eble, Paul C. Hackley, Thomas M. Parris, Stephen F. GrebOil–source correlation studies in the shallow Berea Sandstone petroleum system, eastern Kentucky
Shallow production of sweet high-gravity oil from the Upper Devonian Berea Sandstone in northeastern Kentucky has caused the region to become the leading oil producer in the state. Potential nearby source rocks, namely, the overlying Mississippian Sunbury Shale and underlying Ohio Shale, are immature for commercial oil generation according to vitrinite reflectance and programmed pyrolysis analysesAuthorsPaul C. Hackley, T.M. Parris, C. F. Eble, S. F. Greb, D.C. HarrisMolecular and isotopic gas composition of the Devonian Berea Sandstone and implications for gas evolution, eastern Kentucky
Since 2011, the Devonian Berea Sandstone in northeastern Kentucky has produced oil where thermal maturity studies indicate that likely source rocks, namely, the Devonian Ohio Shale and Mississippian Sunbury Shale, are thermally immature. Downdip, where source rocks are mature for oil, the Berea Sandstone and Ohio Shale primarily produce gas. To investigate this thermal maturity discordancy, the moAuthorsT. M. Parris, Paul C. Hackley, S. F. Greb, C. F. EbleInvestigating 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. PodrazkyExamination of inertinite within immature Eagle Ford Shale at the nanometer-scale using atomic force microscopy-based infrared spectroscopy
The nanoscale molecular composition of sedimentary organic matter is challenging to characterize in situ given the limited tools available that can adequately interrogate its complex chemical structure. This is a particularly relevant issue in source rocks, as kerogen composition will strongly impact its reactivity and so is critical to understanding petroleum generation processes during catagenesAuthorsAaron M. Jubb, Paul C. Hackley, Justin E. Birdwell, Javin J. Hatcherian, Jing QuPhotoluminescence imaging of whole zircon grains on a petrographic microscope—An underused aide for geochronologic studies
The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge
AuthorsRyan J. McAleer, Aaron M. Jubb, Paul C. Hackley, Gregory J. Walsh, Arthur J. Merschat, Sean P. Regan, William C. Burton, Jorge A. VazquezCharacterization 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. DulongNanoscale molecular composition of solid bitumen from the Eagle Ford Group across a natural thermal maturity gradient
Microscopic solid bitumen is a petrographically defined secondary organic matter residue produced during petroleum generation and subsequent oil transformation. The presence of solid bitumen impacts many reservoir properties including porosity, permeability, and hydrocarbon generation and storage, among others. Furthermore, solid bitumen reflectance is an important parameter for assessing the therAuthorsAaron M. Jubb, Justin E. Birdwell, Paul C. Hackley, Javin J. Hatcherian, Jing Qu - Web Tools
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government