Incompatibility Determination of Crude Oil Blends from Experimental Viscosity and Density Data

In this work, a study to determine the incompatibility phenomenon in blends of crude oils mixed with a liquid hydrocarbon from experimental viscosity and density information is presented. The effect of the temperature and composition on asphaltene aggregates and asphaltene precipitation onset was investigated for two crude oil blends mixed with a refinery stream liquid hydrocarbon containing high isopentane and n-pentane concentrations. Dynamic viscosities of the system (crude oil containing asphaltenes and toluene) + n-heptane were measured to assess the changes of aggregation occurring in a crude oil under the influence of the temperature to determine the incompatible asphaltenes in the oil fraction of the liquid hydrocarbon. The method to detect the incompatibility of crude oil blends was based on experimental observations of an increase in the viscosity and density of the crude oil blends mixed with a liquid hydrocarbon, in which asphaltene particle aggregation occurs. From experimental determination of viscosities and densities, it was possible to determine an incompatibility region for the crude oil blends.