New method for the onset point determination of the petroleum asphaltene aggregation

Work has been devoted to investigation of the process of asphaltenes aggregation in a model system asphaltene-toluene-heptane. The procedure of the onset point determination of the petroleum asphaltenes which is based on the method of photon correlation spectroscopy has been described. Two ways have been developed to determine the onset of asphaltenes aggregation by means of method of photon correlation spectroscopy. The first method allows defining the onset of asphaltenes aggregation of light scattering intensity depending on the quantity of n-alkane in the model system. The second method allows determining the onset point of asphaltenes aggregation parameter k depending on the quantity of n-alkane. A comparative evaluation of onset points, obtained in different ways has been given. The influence of the model system composition on the process of asphaltenes aggregation has been studied. The characteristic diffusion time of asphaltenes has been calculated.