Coalescence of Water-in-Shale Oil Emulsions

Abstract The coalescence and interfacial behavior of water-in-shale oil emulsions in the presence of chemical additives was studied using photomicrographic analysis. Both the coalescence and flocculation rate constants were determined as a function of the demulsifier concentration. The coalescence rates increased and the interfacial viscosity decreased with an increase in the temperature. These changes are due to the decrease in bulk and interfacial viscosities with increase in temperature, higher temperatures facilitating better film drainage and hence better coalescence rates. The overall coalescence rate goes through a maximum as the speed of agitation is increased. This maximum may be explained by the mechanism of flocculation and redispersion. The presence of solids was seen to significantly increase the stability of these emulsions.