GRSG Members, Rosa Elvira Correa Pabón and Carlos Roberto deSouza Filho who both work at the Institute of Geosciences at the University of Campinas (UNICAMP) have published a paper in Fuel, the journal dedicated to the science of fuel and energy.
Now, until December 9th 2018, their paper; ‘Crude oil spectral signatures and empirical models to derive API gravity’ is free to download.
The Abstract of the paper reads:
Infrared spectroscopy is presented as a quick alternative method for establishing crude oil properties such as density (°API gravity) and content of saturates, aromatics, resins and asphaltenes (SARA). Here, thirty seven (37) samples of crude oils with different °API gravities and SARA fractions were measured in the visible, near infrared and short wave infrared (VIS – NIR – SWIR/350–2500 nm), and in the middle and longwave infrared (MWIR – LWIR/3000–15,000 nm) ranges.
Main CH absorption bands and optimal intervals for the discrimination among oil types were identified in all spectral regions. Based on diffuse reflectance spectroscopy and equivalent wavelet spectra, Principal Component Analysis allowed distinguishing between three major groups of crude oils with varied densities. Partial Least Squares Regression analysis yielded sixteen predictive models tailored to estimate the °API of crude oils based on their spectral signatures in the NIR – SWIR – MWIR – LWIR intervals.
These data and methods are swift and nondestructive ways to estimate the °API of crude oils, with latent applications in several chains of the petroleum industry, particularly to assess and manage the environmental impact caused by oil discharge, leakage and spill events.
Additionally, considering that airborne and orbital sensor systems currently in operation can sense some of the crude oil absorption bands highlighted in this study, the oil signatures revealed here could be potentially used to map oil contamination in diverse settings and globally using remote sensing.