Theory of viscosity as a criterion for detection of onset of asphaltene flocculation
- Univ. of Illinois, Chicago, IL (United States)
Recently, the authors proposed a new technique for the determination of the onset of asphaltene flocculation. This method is based on viscosity measurements of a crude oil being diluted with a precipitating solvent (i.e., n-pentane, n-heptane, etc.). The onset of asphaltene flocculation is detected by a sharp increase in the relative viscosity of the suspension in which asphaltene particle aggregation occurs. The key point in this development is the changes which occur in the relative viscosity of the mixture and its relationship to the phenomenon of flocculation of asphaltene particles induced by the addition of a low-molecular-weight n-paraffin to crude oil. In this paper, they present a theoretical analysis of the proposed new technique for the onset of asphaltene flocculation and to estimate the background viscosity of the crude oil-precipitating solvent mixture. This in turn has allowed them to perform analyses of the trends of specific and relative viscosities as a function of precipitating solvent concentration, and hence particle concentration. These analyses have provided them information regarding the effect of the suspended asphaltene particles on the viscosity of the mixture. This effect becomes remarkable at a point which coincides with the previously predicted onset of asphaltene flocculation. The increase in the specific (or relative) viscosity after this point is very rapid.
- OSTI ID:
- 397987
- Report Number(s):
- CONF-941048--
- Country of Publication:
- United States
- Language:
- English
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