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 integrated correlative light and electron microscopy (iCLEM) to simultaneously probe scales ranging from tens of microns to several nanometers in the same instrument. This effort may provide new understanding of the development of organic porosity with thermal maturity in tight (shale) oil and gas systems, e.g., Eagle Ford, Marcellus and Bakken shales, where organic porosity may serve a primary hydrocarbon migration and storage function. Work in this task partners with many external organizations, including CLSM at the BGR and Univ. of Maryland, AFM-IR with the Univ. of Delaware, AFM with Hitachi, among others.
Objective
Use correlative light and SEM techniques to document the development of organic porosity in different thermal regimes, organic matter types, and at a range of scales. Innovate new applications of specialized microscopes to chemical characterization of organic matter across a range of thermal maturities in the North American shale plays.
Listed below are other science projects associated with this project.
Photomicrograph Atlas
Vitrinite Reflectance Service
Standardization of Petrographic Measurements
Hydrous Pyrolysis and Kerogen Conversion
Listed below are data products associated with this project.
Strain induced molecular heterogeneity in ancient sedimentary organic matter mapped at nanoscales using optical photothermal infrared spectroscopy
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
Nanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group Across a Natural Thermal Maturity Gradient
Data from Nanoscale Molecular Fractionation of Organic Matter within Unconventional Petroleum Source Beds (2019)
High Microscale Variability in Raman Thermal Maturity Estimates from Shale Organic Matter - Data Release
Listed below are publications associated with this project.
Relating systematic compositional variability to the textural occurrence of solid bitumen in shales
Hydrous pyrolysis of New Albany Shale: A study examining maturation changes and porosity development
Examination of inertinite within immature Eagle Ford Shale at the nanometer-scale using atomic force microscopy-based infrared spectroscopy
Nanoscale molecular composition of solid bitumen from the Eagle Ford Group across a natural thermal maturity gradient
Fluorescence spectroscopy of ancient sedimentary organic matter via confocal laser scanning microscopy (CLSM)
Applications of correlative light and electron microscopy (CLEM) to organic matter in the North American shale petroleum systems
A chemo-mechanical snapshot of in-situ conversion of kerogen to petroleum
Nanoscale molecular fractionation of organic matter within unconventional petroleum source beds
Quantitative evaluation of vitrinite reflectance in shale using Raman spectroscopy and multivariate analysis
Understanding organic matter heterogeneity and maturation rate by Raman spectroscopy
Development of Raman spectroscopy as a thermal maturity proxy in unconventional resource assessment
Analysis of artificially matured shales with confocal laser scanning raman microscopy: Applications to organic matter characterization
- Overview
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 integrated correlative light and electron microscopy (iCLEM) to simultaneously probe scales ranging from tens of microns to several nanometers in the same instrument. This effort may provide new understanding of the development of organic porosity with thermal maturity in tight (shale) oil and gas systems, e.g., Eagle Ford, Marcellus and Bakken shales, where organic porosity may serve a primary hydrocarbon migration and storage function. Work in this task partners with many external organizations, including CLSM at the BGR and Univ. of Maryland, AFM-IR with the Univ. of Delaware, AFM with Hitachi, among others.
ObjectiveUse correlative light and SEM techniques to document the development of organic porosity in different thermal regimes, organic matter types, and at a range of scales. Innovate new applications of specialized microscopes to chemical characterization of organic matter across a range of thermal maturities in the North American shale plays.
- Science
Listed below are other science projects associated with this project.
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 Petrology...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, interlaboratory...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 by... - Data
Listed below are data products associated with this project.
Strain induced molecular heterogeneity in ancient sedimentary organic matter mapped at nanoscales using optical photothermal infrared spectroscopy
Here we report ultra-high resolution infrared mapping of organic matter functional group distribution in Tasmanites (algal microfossils) from the Upper Devonian Ohio Shale using optical photothermal infrared spectroscopy (O-PTIR). O-PTIR is capable of rapidly measuring the vibrational response of samples in situ with ~500-nm spatial resolution, well below the infrared diffraction limit. Our resultTextural 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), 14.0Organic 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 electrNanoscale 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 thermalData 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 neHigh Microscale Variability in Raman Thermal Maturity Estimates from Shale Organic Matter - Data Release
Here the spatial variation in Raman estimates of thermal maturity within individual organic domains from several shale geologic reference materials originating from the Boquillas, Marcellus, Niobrara, and Woodford Formations are assessed from the respective Raman response. We show that for all four shales the thermal maturity parameters extracted from Raman spectra by iterative peak fitting can va - Publications
Listed below are publications associated with this project.
Filter Total Items: 16Relating 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 sampleHydrous 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 pyExamination 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 catagenesNanoscale 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 therFluorescence 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 respect to locationApplications of correlative light and electron microscopy (CLEM) to organic matter in the North American shale petroleum systems
Scanning electron microscopy (SEM) has revolutionized our understanding of shale petroleum systems through microstructural characterization of dispersed organic matter (OM). However, due to the low atomic weight of carbon, all OM appears black in SEM (BSE image) regardless of differences in thermal maturity or OM type (kerogen types or solid bitumen). Traditional petrographic identification of OMA chemo-mechanical snapshot of in-situ conversion of kerogen to petroleum
Organic matter (OM) from various biogenic origins converts to solid bitumen in-situ when it undergoes thermal maturation. It is well documented that during this process, the ratios of both hydrogen and oxygen to carbon will decrease, resulting in an increase in OM aromaticity and molecular chemo-mechanical homogeneity. Although there have been extensive efforts to reveal molecular alteration occurNanoscale molecular fractionation of organic matter within unconventional petroleum source beds
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 typically are invoked to explain this behavior. Such phenomena are of interest as they impact both the quality and recoverabilityQuantitative evaluation of vitrinite reflectance in shale using Raman spectroscopy and multivariate analysis
The current research builds upon a previously published study that demonstrated the combination of Raman spectroscopy coupled with multivariate analysis (MVA) for the prediction of thermal maturity in coal by evaluating the efficacy of this method for the prediction of thermal maturity in shale. MVA techniques eliminate analyst bias in peak-fitting methods by using the full Raman spectrum, and theUnderstanding organic matter heterogeneity and maturation rate by Raman spectroscopy
Solid organic matter (OM) in sedimentary rocks produces petroleum and solid bitumen when it undergoes thermal maturation. The solid OM is a ‘geomacromolecule’, usually representing a mixture of various organisms with distinct biogenic origins, and can have high heterogeneity in composition. Programmed pyrolysis is a common method to reveal bulk geochemical characteristics of the dominant OM, whileDevelopment of Raman spectroscopy as a thermal maturity proxy in unconventional resource assessment
The objective of this study was to correlate shale hydrous pyrolysis with thermal maturity measurements based on solid bitumen reflectance (BRo) at the U.S. Geological Survey (USGS) and Raman microscopy (RM) at WellDog. In semi-blind Phase I, BRo values of the initial set of 8 samples were withheld prior to RM analysis. As reported previously, a strong correlation was observed between BRo and RamaAnalysis of artificially matured shales with confocal laser scanning raman microscopy: Applications to organic matter characterization
Raman spectroscopy has been suggested as a method for characterizing the thermal maturity of rocks. The literature contains many empirical correlations between thermal maturity proxies, such as vitrinite reflectance (VRo) and pyrolysis-Tmax, with spectral metrics such as Raman peak-widths, peak-center positions, peak-areas and all manner of differences and ratios of these parameters. However, whil