Paul C Hackley, Ph.D.
Paul Hackley is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Biography
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.
Education
- Ph.D., George Mason University
- M.S., George Washington University
- B.A., Shippensburg State University
Work Experience
- Unconventional petroleum systems
- Conventional oil and gas assessment
- Coalbed methane
- Coal
- Application of organic petrology techniques to fossil fuel resource assessment
Professional Affiliations
- 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
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.
Vitrinite Reflectance Service
Vitrinite reflectance is regarded as the gold standard thermal maturity parameter and vitrinite reflectance data is needed for energy resource assessment and other types of basin analysis studies. This effort provides vitrinite reflectance and qualitative organic petrography of shale, mudrock, coal and other unconventional reservoir samples as a routine in-house service, from the Organic...
Thermal Indices Innovation
Thermal indices innovation utilizes correlative microscopy techniques for innovative approaches to thermal indices development, including confocal laser scanning microscopy (CLSM), AFM-IR (combined atomic force and infrared microscopy), atomic force microscopy (AFM), and SEM of Argon ion-milled sample surfaces combined with traditional organic petrography. The innovation task also is testing...
Hydrous Pyrolysis and Kerogen Conversion
This work is directed at understanding the kinetics of vitrinite and solid bitumen maturation through hydrous pyrolysis experiments, potentially enabling a direct methodology to detect ‘vitrinite reflectance suppression,’ a commonly reported problem in the early- to mid-oil window. This task also examines the molecular chemistry of kerogen conversion to petroleum via in situ chemical probing...
Standardization of Petrographic Measurements
Advent of the ‘shale revolution’ since about 2005 has caused increased demand for reliable petrographic measurements of thermal maturity in shale via vitrinite reflectance, long considered the ‘gold standard’ approach. A standardized methodology for organic reflectance measurement in shale first became available in 2011 (ASTM D7708), based on prior work by task members. However,...
Petroleum geology data from hydrous and anhydrous pyrolysis residues for coals and shales from the Cambrian through the Miocene
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.
Nanoscale 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
Investigating 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 at
Fluorescence spectroscopy of ancient sedimentary organic matter via confocal laser scanning microscopy (CLSM)
Fluorescence spectroscopy via confocal laser scanning microscopy (CLSM) was used to analyze ancient sedimentary organic matter, including Tasmanites microfossils in Devonian shale and Gloecapsomorpha prisca (G. prisca) in Ordovician kukersite from North American basins. We examined fluorescence emission as a function of excitation laser wavelength, sample orientation, and with respe
ATR data from interaction of kerogen with brine-saturated supercritical carbon dioxide (CO2) and its implications to geologic carbon sequestration and enhanced oil/gas recovery (2018)
The dataset covers Attenuated Total Reflectance (ATR) measurements taken from altered kerogen in shales from the Woodford formation. The ATR measurements were taken after the samples were run through supercritical CO2 alteration experiments in a brine solution.
Organic Petrography and Diagenesis of Leonardian Mudrocks and Carbonates, Midland Basin, Texas (2018)
As part of a larger study, organic petrographic features of Leonardian Wolfcamp A repetitive siliceous and calcareous mudrock and fine-grained carbonate lithofacies cycles occurring in the R. Ricker #1 core from Reagan County, Midland Basin, Texas were evaluated. The objectives of the petrographic investigation were to estimate thermal maturity, identify organic matter types and abundan
Sample mounting for organic petrology: no thermal effects from transient exposure to elevated temperatures (2019)
For sample mounting, organic petrology laboratories typically use cold-setting epoxy-resin (e.g., 40°C, used by Oklahoma Geological Survey, OGS) or heat-setting plastic (e.g., 180°C, used by U.S. Geological Survey, USGS). Previous workers have suggested a systematic vitrinite reflectance (VRo) increase was associated with the thermoplastic preparation process%2
Oil-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° API), sweet oil from horizontal, hydraulicall
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. A
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, ther
XRD data from study on the impact of thermal maturity on shale microstructures using hydrous pyrolysis (2018)
The dataset covers X-ray diffraction (XRD) applied for mineral determination in shales from the Utica, Excello, Niobrara, and Monterey formations. The XRD was performed prior to modified Rock-Eval pyrolysis, reflectance, organic petrology, and Fourier-transform infrared spectroscopy (FTIR) being employed to analyze geochemical properties; gas adsorption (CO2 and N2) was
Enhanced wildfire at the Frasnian-Famennian boundary and its implications for O2 level and F-F mass extinction: evidence from organic petrology and Os isotope stratigraphy
In this study, organic petrology and Osmium isotope (187Os/188Os) stratigraphy, major and trace element, and programmed pyrolysis analysis were performed on five outcrop samples from western New York, USA. Seawater Os isotope composition is controlled by radiogenic input from weathering of the ancient land and nonradiogenic input from extraterrestrial and hydrothermal sources (Peu
Relating Tmax and hydrogen index to vitrinite and solid bitumen reflectance in hydrous pyrolysis residues: Comparisons to natural thermal indices
Vitrinite reflectance (VRo; %) generally is considered the most reliable technique to determine the thermal maturity of sedimentary rocks. However, it is a time-consuming process to collect reflectance (Ro; %) measurements and is subjective to the interpretation of each trained technician, who must be able to discern between ...
Lohr, Celeste D.; Hackley, Paul C. A 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...
Hackley, Paul C.; Jubb, Aaron M.; McAleer, Ryan J.; Valentine, Brett J.; Birdwell, Justin E. Organic 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...
Hackley, Paul C.; Ryder, Robert T. Organic 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...
Eble, Cortland F.; Hackley, Paul C.; Parris, Thomas M.; Greb, Stephen F. Oil–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...
Hackley, Paul C.; Parris, T.M.; Eble, C. F.; Greb, S. F.; Harris, D.C. Molecular 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...
Parris, T. M.; Hackley, Paul C.; Greb, S. F.; Eble, C. F. Evidence of cosmic impact at Abu Hureyra, Syria at the Younger Dryas Onset (~12.8 ka): High-temperature melting at >2200 °C
At Abu Hureyra (AH), Syria, the 12,800-year-old Younger Dryas boundary layer (YDB) contains peak abundances in meltglass, nanodiamonds, microspherules, and charcoal. AH meltglass comprises 1.6 wt.% of bulk sediment, and crossed polarizers indicate that the meltglass is isotropic. High YDB concentrations of iridium, platinum, nickel, and cobalt...
Moore, Andrew M.T.; Kennett, James P.; Kennett, Douglas J.; Napier, William M.; Bunch, Ted E.; Weaver, James C.; LeCompte, Malcolm A.; Adedji, Victor; Hackley, Paul C.; Lowenstern, Jacob B.; Kletetschka, Gunther K.; Culleton, Brendan J.; Hermes, Robert E.; Wittke, James H.; Razink, Joshua J.; Gaultois, Michael; West, Allen Investigating 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....
Hackley, Paul C.; Jubb, Aaron M.; Valentine, Brett J.; Hatcherian, Javin J.; Yu, Jing-Jiang; Podrazky, William K. Examination 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...
Jubb, Aaron M.; Hackley, Paul C.; Birdwell, Justin E.; Hatcherian, Javin J.; Qu, Jing 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...
McAleer, Ryan J.; Jubb, Aaron M.; Hackley, Paul C.; Walsh, Gregory; Merschat, Arthur J.; Regan, Sean P.; Burton, William C.; Vazquez, Jorge A. Characterization 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...
Lohr, Celeste D.; Valentine, Brett J.; Hackley, Paul C.; Dulong, Frank T. Nanoscale 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...
Jubb, Aaron M.; Birdwell, Justin E.; Hackley, Paul C.; Hatcherian, Javin J.; Qu, Jing