Asphaltene Stability in Crude Oils

摘要

The influence of different factors on the asphaltene stability inrncrude oils was evaluated. Compositional studies and structuralrncharacterization of resins and asphaltenes were carried out inrnorder to study a possible relationship between these propertiesrnand the asphaltene deposition behavior. Asphaltenes werernobtained by precipitation with n-heptane and characterized byrnelemental analysis and spectroscopic techniques. Lowrnhydrogen to carbon ratios, high aromaticities and highrncondensation of aromatic rings were the main characteristicsrnof the asphaltenes from unstable crude oils. According to thesernresults, the stability behavior of the asphaltenes was stronglyrninfluenced by their structural characteristics. However, it wasrnalso found that stabilization by means of a commercialrninhibitor was affected by the composition of the crude oil. Inrnparticular, a high content of basic functionalities in the crudernoil can be related to the decrease of the inhibitor’srneffectiveness (dodecylbenzene sulphonic acid). Based on thesernfindings, some useful suggestions applicable to the oilfieldrnoperations are made.