Abstract

In the extraction of the oil, it is mixed with water thus forming emulsions. The emulsions are found in almost all the stages of production and processing of the oil and in some cases is very difficult to be #x201C;broken#x201D;. The presence of emulsifiers agents is one of the responsible factors for the stability of emulsions. Certain fractions of high point of boiling, such as the asphaltenes and resins, can be emulsifier#xB4;s agents and to stabilize emulsions W/O. In some stages of refining, the oil suffers thermal treatments like the atmospheric distillation in order to separate the interest fractions. As the chemical composition of petroleum is much complex, it is interesting to evaluate the possible molecular transformations that can happen in those fractions asphaltenics. Temperature variations, pressure and chemical composition can cause some problems like the precipitation of the asphaltenes of the crude oil. In this work, the aim of is to evaluate if the effect of conditions as, for example, ambient temperature, presence of light and humidity can influence in the quantity of water and mainly in the structures of asphaltenes of two Brazilian oils, A and B, that were submitted for a period of stockage of two years in not inert atmosphere and the atmospheric pressure. Significant modifications had been observed in two oils principally in the amount of the asphaltenic fraction that can have the structural characteristics of the species contained in this fraction that can have action differentiated on emulsions water in oil.