Advent of the shale revolution since about 2005 caused increased demand for reliable petrographic measurements of thermal maturity in shale via vitrinite reflectance, which has long been considered the gold standard approach. The first standardized methodology for vitrinite reflectance measurement in shale became available in 2011. Subsequent interlaboratory studies demonstrated that significant work remains to be done to improve measurement precision and further advances in the standardization and reliability of petrographic measurements of thermal maturity. Standardization efforts of this research task were recognized by bestowment of the 2019 Organic Petrology Award from the International Committee for Coal and Organic Petrology (ICCP).
Objective:
The overall objective of this research is to improve the standardization and reliability of petrographic measurements of thermal maturity, including reflectance and fluorescence of sedimentary organic matter.
Methodology:
One research goal is to develop a standard test method for quantitative spectroscopic measurement of fluorescence in sedimentary organic matter (SOM). This thermal maturity parameter is used on sedimentary organic matter (SOM) in the early- to mid-oil window. Absence of a standardized approach has resulted in poor interlaboratory agreement. Development of a standard test method will improve reporting and understanding of spectral fluorescence in SOM as well as improve the accuracy of the placement of continuous undiscovered oil and gas resource assessment boundaries, which may, in some cases, use the beginning of the oil window for spatial delineation.
Another research goal is to improve understanding of the effects of broad ion beam (BIB) milling on SOM. BIB milling is a common approach for sample preparation in scanning electron microscopy petrography. Poor understanding of BIB milling effects on SOM has prevented its adoption as a standardized preparation technique.
The third research goal is to develop improved classification schemes for environmental applications of organic petrology. The absence of uniform terminology and nomenclature in environmental applications results in multiple identifying terms for the same material, which interferes with scientific communication.
Listed below are other science projects or tasks associated with this project.
Petrographic Thermal Indices Research
Vitrinite Reflectance Service
Thermal Indices Innovation
Hydrous Pyrolysis and Kerogen Conversion
Listed below are data products associated with this project.
Reflectance and confocal laser scanning fluorescence spectroscopy of bituminite in Kimmeridge Clay
Investigating the effects of broad ion beam milling to sedimentary organic matter
Listed below are publications associated with this project.
Finalization of the Confocal Laser Scanning Microscopy (CLSM) working group
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
The Confocal Laser Scanning Microscopy Working Group of the ICCP: Final report 2021
A review of spatially resolved techniques and applications of organic petrography in shale petroleum systems
Investigating the effects of broad ion beam milling to sedimentary organic matter: Surface flattening or heat-induced aromatization and condensation?
Sample mounting for organic petrology: No thermal effects from transient exposure to elevated temperatures
Testing reproducibility of vitrinite and solid bitumen reflectance measurements in North American unconventional source-rock reservoir petroleum systems
Reflectance increase from broad beam ion milling of coals and organic-rich shales due to increased surface flatness
Listed below are online interactive applications associated with this project.
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.
- Overview
Advent of the shale revolution since about 2005 caused increased demand for reliable petrographic measurements of thermal maturity in shale via vitrinite reflectance, which has long been considered the gold standard approach. The first standardized methodology for vitrinite reflectance measurement in shale became available in 2011. Subsequent interlaboratory studies demonstrated that significant work remains to be done to improve measurement precision and further advances in the standardization and reliability of petrographic measurements of thermal maturity. Standardization efforts of this research task were recognized by bestowment of the 2019 Organic Petrology Award from the International Committee for Coal and Organic Petrology (ICCP).
Objective:
The overall objective of this research is to improve the standardization and reliability of petrographic measurements of thermal maturity, including reflectance and fluorescence of sedimentary organic matter.
Methodology:
One research goal is to develop a standard test method for quantitative spectroscopic measurement of fluorescence in sedimentary organic matter (SOM). This thermal maturity parameter is used on sedimentary organic matter (SOM) in the early- to mid-oil window. Absence of a standardized approach has resulted in poor interlaboratory agreement. Development of a standard test method will improve reporting and understanding of spectral fluorescence in SOM as well as improve the accuracy of the placement of continuous undiscovered oil and gas resource assessment boundaries, which may, in some cases, use the beginning of the oil window for spatial delineation.
Another research goal is to improve understanding of the effects of broad ion beam (BIB) milling on SOM. BIB milling is a common approach for sample preparation in scanning electron microscopy petrography. Poor understanding of BIB milling effects on SOM has prevented its adoption as a standardized preparation technique.
The third research goal is to develop improved classification schemes for environmental applications of organic petrology. The absence of uniform terminology and nomenclature in environmental applications results in multiple identifying terms for the same material, which interferes with scientific communication.
- Science
Listed below are other science projects or tasks associated with this project.
Petrographic Thermal Indices Research
A petrographic thermal index is typically an organic matter indicator in sedimentary rocks that allows for estimations of burial temperature. Petrographic thermal indices include the commonly used proxy vitrinite reflectance as well as other approaches such as solid bitumen reflectance, fluorescence, micro-Raman, and micro-Fourier transform infrared (FTIR) spectroscopies. Measurements from these...Vitrinite Reflectance Service
Vitrinite is a maceral group that is derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. A maceral group is a set of organic matter types with similar properties and appearance. Vitrinite reflectance measures the percentage of incident light that is reflected from the surface of vitrinite as calibrated to a...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...Hydrous Pyrolysis and Kerogen Conversion
Hydrous pyrolysis (HP) experimentation is a laboratory method used to thermally mature organic-rich sedimentary rocks. It simulates petroleum generation in the closest available analogue to that of a natural system. Artificial maturation of sedimentary organic matter (SOM) to petroleum allows for the examination of its molecular chemistry to address the issue of anomalous reflection measurement... - Data
Listed below are data products associated with this project.
Reflectance 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 micr - Publications
Listed below are publications associated with this project.
Finalization of the Confocal Laser Scanning Microscopy (CLSM) working group
A working group in Commission II to investigate applications of confocal laser scanning microscopy (CLSM) for organic petrology investigations has finalized with publication of the manuscript “Characterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy” in the International Journal of Coal Geology. The manuscript is available via Open Access from https:AuthorsPaul C. Hackley, Jolanta KusIdentification 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. HatcherianThe Confocal Laser Scanning Microscopy Working Group of the ICCP: Final report 2021
This report summarizes the activities and results of the Confocal Laser Scanning Microscopy (CLSM) working group (WG) of the International Committee for Coal and Organic Petrology (ICCP), from its inception in September, 2015, to the present day (September, 2021). The purpose of this report is to document the history of the working group and to compile and evaluate its results. The CLSM WG examineAuthorsPaul C. Hackley, Jolanta Kus, João Graciano Mendonça Filho, Andrew D. Czaja, Angeles Borrego, Dragana ŽivotićA 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. BirdwellInvestigating 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. PodrazkySample mounting for organic petrology: No thermal effects from transient exposure to elevated temperatures
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 thermoplastic (e.g., 180 °C, used by U.S. Geological Survey, USGS). Previous workers have suggested a systematic huminite/vitrinite reflectance (VRo) increase was associated with the thermoplastic preparation process, relative to epoxy moAuthorsPaul C. Hackley, Brian J. CardottTesting reproducibility of vitrinite and solid bitumen reflectance measurements in North American unconventional source-rock reservoir petroleum systems
An interlaboratory study (ILS) was conducted to test reproducibility of vitrinite and solid bitumen reflectance measurements in six mudrock samples from United States unconventional source-rock reservoir 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. AlAuthorsPaul C. Hackley, Carla V. Araujo, Angeles G. Borrego, Antonis Bouzinos, Brian J. Cardott, H. Carvajal-Ortiz, Martha Rocio Lopez Cely, Vongani Chabalala, Peter J. Crosdale, Thomas D. Demchuk, Cortland F. Eble, Deolinda Flores, Agnieszka Furmann, Thomas Gentzis, Paula Goncalves, Carsten Guvad, M. Hamor-Vido, Iwona Jelonek, M. Johnston, Tatiana Juliao-Lemus, Stavros Kalaitzidis, Wayne Knowles, Jolanta Kus, Zhongsheng Li, Gordon Macleod, Maria Mastalerz, Taissa Rego Menezes, Seare Ocubalidet, Richard Orban, Walter Pickel, Paddy Ranasinghe, Joana Ribeiro, Olga Patricia Gomez Rojas, Ricardo Ruiz-Monroy, Jaques Schmidt, Abbas Seyedolali, Georgios Siavalas, Isabel Suarez-Ruiz, Carlos Vargas Vargas, Brett J. Valentine, Nicola Wagner, Bree Wrolson, Julian Esteban Jaramillo ZapataReflectance increase from broad beam ion milling of coals and organic-rich shales due to increased surface flatness
Broad ion beam (BIB) milling is useful in organic petrology because it can yield flat sample surfaces and avert the ‘smearing’ of organic matter (OM) that results from traditional mechanical polishing. This potentially makes BIB especially useful in the study of nano-porosity, where even minor mechanical disruption of the sample surface distorts the sample characteristic of interest—the pore struAuthorsBrett J. Valentine, Paul C. Hackley, Javin J. Hatcherian, Jing-Jiang Yu - Web Tools
Listed below are online interactive applications associated with this project.
Photomicrograph Atlas
A database of images related to the characterization of fossil fuel resources in the United States and the world.