Paul C. Hackley, et al., report on a new microscopic technique for imaging and identifying sedimentary organic matter in geologic materials that combines inverted fluorescence microscopy with scanning electron microscopy and allows for sequential imaging of the same region of interest without transferring the sample between instruments. This integrated correlative light and electron microscopy technique is demonstrated with observations from an immature lacustrine oil shale from the Eocene Green River Mahogany Zone and mid-oil window paralic shale from the Upper Cretaceous Tuscaloosa Group.
This technique has the potential to allow for identification and characterization of organic matter in shale hydrocarbon reservoirs that is not possible using either light or electron microscopy alone, and may be applied to understanding the organic matter type and thermal regime in which organic nanoporosity forms, thereby reducing uncertainty in the estimation of undiscovered hydrocarbon resources.
We have described an application of iCLEM to geological materials by sequentially imaging sedimentary organic matter in shale via fluorescence and SEM. The results show that iCLEM can be used to identify and characterize organic matter types based on their fluorescence response (most prevalent at lower thermal maturities of up to about 1.0–1.1% VRo) with simultaneous resolution of submicron features via SEM. Because higher magnifications are available via SEM, this technique also allows sequential imaging at scales ranging from hundreds of microns to nanometres, enabling identification of organic matter types via fluorescence microscopy at low resolu-
tion followed by high-resolution SEM evaluation of nanoscale structures such as organic porosity. Future work using iCLEM should investigate alternative instrument configurations and begin systematic evaluation of the thermal regime and organic matter types in which organic porosity develops, including 382 shale samples of peak oil (VRo ~0.9 %) and higher maturities, and artificial maturation sequences created through hydrous pyrolysis experiments.
Managed & Built by I2M Consulting, LLC | © 2010-
