Comprehensive Spectral and Thermal Characterization of Oil Shales

Abstract

The heterogeneous nature of oil shale resources associated to the depositional environments, lithology, and organic content make the reserve estimation complex and unpredictable. However, comprehensive laboratory studies on organic rich shale samples collected from different regions can increase the understanding about the organic content of oil shales, interaction of shale with organic matter and injected fluid used during enhanced oil recovery method. This study investigates the characterization of eight different Turkish and American oil shale samples with several spectral methods and a thermal analysis. The main purpose of this study is to characterize the oil shale samples to increase the understanding about the organic content and interaction of shale with organic matter. In this study, we used Thermal Gravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC) analysis to estimate organic content of each oil shale sample in air and nitrogen environments. X-Ray Diffraction (XRD) was used to define minerals in oil shale. Fourier Transform Infrared Spectroscopy (FTIR) was used to detect the mineral and kerogen in oil shale before and after the TGA/DSC analysis. Scanning Electron Microscope (SEM) was used to characterize the depositional environment of each oil shale samples. TGA/DSC results verified that oil shale samples have up to 50% of organic matter. XRD and FTIR results helped to identify the organic and inorganic compounds. Effects of minerals and ions were recognized by comparing TGA/DSC curves and FTIR spectra. It was recognized that the more carbonate ion in the oil shale the more increase in weight loss occurred. Diatoms identified from SEM results showed that depositional environments of the some oil shale samples are marine environments. This study provides insight for the reserve estimation of the eight different oil shale samples with comprehensive spectral and thermal characterization.

Characterization and Dynamics of Residual Organics in Oil Sands Fluid Fine Tailings

“…The mass loss (TG) thermograms are shown in Figure a where the y axis represents the percent of original (unheated) mass, while the curves of the first derivative of the TG thermograms (DTG) are presented in Figure b. From the DTG thermograms, the mass loss feature at 100 °C represents the loss of H 2 O; the features at 300 and 460 °C are from residual organics; the 550 °C feature is from the dehydroxylation of structural OH groups in the clay lattice; − and the high-temperature features at 650–800 °C are due to the loss of carbonates. − Of particular interest in this study are the mass loss features of the residual organics represented by the peaks centered around 300 and at 460 °C in Figure b and summarized in Table . The first mass loss feature corresponds to the volatilization mass loss (VML) of lower-molecular-mass organic substances. , The higher-temperature feature at 460 °C reflects the mass loss due to thermal cracking (TCL) of relatively higher-molecular-mass organic substances. − For both FFT-1 and FFT-2, maximum mass loss from organics is observed in the FFT samples before washing or polymeric treatment.…”