Ageing of interfacially active components and its effect on emulsion stability as studied by means of high voltage dielectric spectroscopy measurements

Interfacially active components (asphaltenes and resins) have been extracted from North Sea crude oils and aged at 50 degrees C. Model water-in-oil emulsions have been stabilized by these compounds in different amounts and ratios, The stability of these emulsions has been established by means of critical electric fields measured by time domain dielectric spectroscopy in the presence of an external electric field. It is found that the stability depends mainly on the amount of asphaltenes, the degree of aging of asphaltenes and resins and the ratio between asphaltenes and resins. (C) 1997 Elsevier Science B.V.