Searching correlations of composition and stability data by tailoring the analytical methods for the quantification of the components of petroleum and fractions(Abstract)

摘要

It is well-known that the instability of petroleum asphaltenes may lead to the formation of deposited solid phases in the operations of petroleum production, transportation, storage and refining. Though the physico-chemical variables responsible for the deposition in each of these cases are not the same, the phenomenon can always be described as the loss of capacity of the oil medium to keep the asphaltenes in the colloidal suspension state, in which they were in the reservoir. To access the capacity of peptization of crude oils and distillation fractions, specially residua, some instability indices can be found in the literature, which we split into two categories: titrimetric and compositional. The titrimetric indices employ the titration with an alkane. Because asphaltenes can be precipitated by alkanes, the higher the quantity of an alkane added to the oil before the onset of precipitation, the more stable the oil is. Besides having the added volume of the alkane itself as an index, some physico-chemical calculations can be done if several concentrations of the oil are used.