Application of Optical-electron Correlative Microscopy for Characterization of Organic Matter
Loading...
Date
2024
Authors
Journal Title
Journal of the Geological Society of India
Journal ISSN
Volume Title
Publisher
Geological Society of India
Abstract
Application of coal petrology is known to play significant role in several industrial sectors viz. thermal industries, steel industries, unconventional oil and gas fields. One important aspect of organic matter characterization, especially for unconventional oil and gas fields is the development of organic matter hosted porosity, and commonly Scanning Electron Microscopy (SEM) is used to study the same. While, SEM helps in understanding the nature of porosity developed in coals and shales, one significant limitation is that under SEM the different organic matter types can�t be distinguished, as all organic matter appears dark due to their lower atomic mass. Optical-electron correlative microscopy has recently gained importance for making advancement in addressing the above-mentioned scientific gap. While this method has been found some usage for characterizing the dispersed organic matter in shales, only one work globally exists where the technique has been used for studying coals. In this work, possibly, for the first time, this technique is applied for characterizing three Indian coals from Korba basin, India, with the main objective of establishing necessary protocols for reliable imaging of different organic matter types under SEM. Our results establish that imaging under SEM using Backscattered electron (BSE) detector, the macerals and mineral matter were clearly discernible at 15 kV accelerating voltage. Further, this exercise also indicates that identification of vitrinite macerals under SEM, without correlative technique can be challenging, while some inertinites with their distinctive structures can be identified under stand-alone SEM. Sporinites too, due to their distinctive morphology, were easily identifiable under SEM. � 2024 Geological Society of India, Bengaluru, India.
Description
Keywords
Coal petrology, macerals, Optical-Electron correlative microscopy, Scanning Electron Microscope