WATER-IN-CRUDE-OIL EMULSIONS FROM THE NORWEGIAN CONTINENTAL-SHELF .9.A DIELECTRIC SPECTROSCOPIC CHARACTERIZATION OF AUTHENTIC AS WELL AS MODEL SYSTEMS

Properties of water-in-crude oil emulsions and model systems stabilize d by interfacially active crude oil fractions or tetraoxyethylene nony lphenyl ether were analyzed using time domain dielectric spectroscopy. The amount of dispersed aqueous phase containing 5% NaCl varied from 10 to 50% by volume. The dielectric spectra were fitted to a Debye fun ction. It was found that models based on heterogeneous mixture models could not explain the static permittivities found without a slight flo cculation. In order to interpret the whole dielectric spectrum the Bon ed-Peyrelasse equation was numerically solved for 80 frequencies betwe en 20 MHz and 5 GHz. A Debye function was fitted to these theoretical spectra and corresponding relaxation times were solved. The shape fact ors (A) obtained show the necessity of a flocculation (axial ratios 1: 10) at lower water concentrations while other more symmetrical structu res occur at higher water contents. (C) 1994 Academic Press, Inc.