NEAR-INFRARED DIFFUSE REFLECTANCE ANALYSIS OF ATHABASCA OIL SAND

The application of near-infrared diffuse reflectance analysis for the determination of bitumen content in samples of Athabasca oil sand is described. Quantitative analysis is performed using calibrations based on linear correlation between spectral features at selected wavelengths and compositional data for a series of known samples. The anhydrous bitumen content of oil sand within a length of core was obtained from spectra recorded at 1-cm sampling Intervals. Analyses by a micro Soxhlet extraction procedure provided reference assay data for correlating sample composition and spectral response. The training set included representative samples of oil sand, indurated clay, coal, and interbedded regions. A model based on the first derivative of absorbance spectra provided the best relationship between spectral features and hydrocarbon concentration over a wide range of oil sand grades. This model was used to predict the bitumen content of samples along the entire length of the test core section, thus providing a high-resolution profile of grade variability as a function of depth. © 1990, American Chemical Society. All rights reserved.