(78h) Effect of Nature of Brine Solution on the Water-in-Crude Oil Interface for Low and High Tan Oil

The efficiency of the breaking of water-in-crude oil emulsion depends on the characteristic of oil such as TAN (Total Acid Number) value, salt concentration, asphaltenes composition and the interfacial properties. Here, we demonstrate how the interfacial tension is an influence in the presence of cations in brine namely Ca and Na ions for both low as well as high TAN crude oil. Spinning drop tensiometer (SDT) was used to estimate the interfacial tension of the crude oil-water system. In case of high TAN crudes, the presence of Ca ions in brine leads to an appreciable increase in the interfacial properties with time, being most significant because of the formation of skin around the oil droplet. Addition of demulsifier is found to compete with naphthenic acids, thereby leading to a considerable reduction in the interfacial tension. These findings should be useful in understanding as well as controlling electro-desalter performance.