Evaluation of the Effect of Addition Order on the Compatibility of Binary Crude Oil Blending

Compatibility issues that arise when crude oils are blended with different physical and chemical properties were examined. Incompatibility can lead to asphaltene precipitation, especially when low- and high-appreciation American Petroleum Institute (API) gravity crude oils are used. Binary blends of crude oils with a wide range of API gravities were prepared, and an experimental methodology was established to determine the impact of the crude oil blending orders on asphaltene precipitation. The tests included the analysis of API gravity, sulfur content, kinematic viscosity, S-value, spot test, and stability in a static column. The results indicated that the order of addition of crude oils influenced the stability of the blends. Unstable blends were found when heavy crude oil was added to light crude oil, while the opposite order generally resulted in more stable blends. More than 30 wt % of light crude negatively affected the stability of the blends, irrespective of the order of addition.