Evaluation of Water Content and Average Droplet Size in Water-in-Crude Oil Emulsions by Means of Near-Infrared Spectroscopy

Abstract

The main objective of this work is evaluating the influence of water content and average droplet size upon the near-infrared (NIR) spectra collected during water-in-crude oil emulsions synthesis and observing whether NIR spectroscopy may be used for predicting these properties simultaneously. It is shown that NIR spectra are sensitive to changes of the water content and average droplet size and that standard empirical models [partial least-squares (PLS)] may be built to correlate these properties and total absorbance at the NIR region properly. Finally, it is shown that these models, built with off-line experiments, allow for the online evaluation of average droplet size and water content in water-in-crude oil emulsions with NIR spectroscopy when low water content (<5 wt %) is involved.

The application of a multi-scale approach to the manufacture of concentrated and highly concentrated emulsions

“…This will shift the spectra toward areas of higher absorbance for the emulsion with greater average droplet size. Araujo et al (2008) observed similar changes in the NIR spectra of water-in-crude oil emulsions due to changes in the average droplet size and concentration of water. However, the trends of the different spectra were opposite to those reported previously (Aske et al, 2002;Sjöblom et al, 2003).…”

Stability Proxies for Water-in-Oil Emulsions and Implications in Aqueous-based Enhanced Oil Recovery

“…According to this theory, the intensity of a beam of light is exponentially attenuated while traversing a distance L through a particular medium. If multiple scattering is negligible, attenuation can be calculated by the following equation [75]:…”

“…Mathematical calculations have been performed by Rayleigh, Mie and Frauhhofer among others [76]. According to Rayleigh scattering, scatter intensity is a strong function of the droplets radius and the wavelength as described by the following equation [75]:…”

“…Water droplets radii can be extracted indirectly in NIR spectroscopy. It turns out that larger droplets scatter light more effectively than smaller ones with consequent decrease in absorbance, which can be seen in the shift in the baseline of the spectra [75].…”

Soft Measurement of Water Content in Oil-Water Two-Phase Flow Based on RS-SVM Classifier and GA-NN Predictor

“…So far, many efforts have been made to develop several typical instrumental techniques, such as capacitance method [3][4], microwave technique [5][6] and near-infrared spectroscopy [7][8]. The capacitance sensor depends on the significant difference in the dielectric permittivity of water and oil, changing the capacitance proportionally with the varying permittivity of the oil/water mixture.…”