EFFECT OF NACL AND MIBC KEROSENE ON BITUMEN DISPLACEMENT BY WATER ON A GLASS-SURFACE/

Experiments were conducted to study the effect of NaCl and MIBC/kerose ne surfactants on bitumen displacement by water on a glass surface. A thin coating of bitumen on a glass surface displaced spontaneously in the inward radial direction upon exposure to an aqueous environment co ntaining salt and surfactants. The initially circular bitumen disk too k the shape of a spherical droplet. The time variation of the dynamic contact angle and the static contact angle of bitumen on the glass sur face were measured and compared with the results available without sal t. The dynamic and static contact angles decreased above a certain NaC l concentration for a particular pH, e.g. 16 000 ppm of NaCl at pH 8.2 . For the same condition, the dynamic contact angle of bitumen decreas ed with increasing pH. Furthermore, the static contact angle is also d ecreased with increasing pH. When combined with a surfactant (MIBC/ker osene mixture is added in the presence of NaCl) the static contact ang le restored to a value close to that of a no-salt case. A previously p roposed mathematical model based on lubrication approximation for bitu men displacement is discussed. The dynamic contact angle predicted by the model is compared with experimental data for high salt and surfact ant concentrations at pH 8.2. The implication of the experimental resu lts to the Hot Water Bitumen Extraction Process is discussed. (C) 1998 Elsevier Science B.V.