DEWATERING OF CRUDE-OIL EMULSIONS .1. RHEOLOGICAL BEHAVIOR OF THE CRUDE-OIL WATER INTERFACE

Rheological properties of Buchan crude oil-water interfaces have been determined using a biconical bob rheometer. The effects of temperature and the presence of surface-active demulsifiers on film characteristi cs have been evaluated. Free oscillation and creep modes have been use d, depending on the relative viscoelastic behaviour of the films. Film ageing is particularly significant, whilst temperature and the nature and concentration of any demulsification chemicals also contribute si gnificantly. Further detailed understanding of interfacial film rheolo gy is considered to be desirable for a complete appreciation of the st ability of water-in-crude oil emulsions.