Journal of Petroleum Science and Engineering 32 (2001) 217 – 230 www.elsevier.com/locate/jpetscieng

Asphaltene flocculation and collapse from petroleum fluids
Valter Antonio M. Branco a, G. Ali Mansoori b,*, Luiza Cristina De Almeida Xavier a, Sang J. Park b, Hussain Manafi b a Petroleo Brasilerio S.A., Petrobras/CENPES/DIGER, Cidade Universitaria, Quadra 7, Ilma Fundao, Rio de Janeiro, RJ, 21910, Brazil b Thermodynamics Research Laboratory, Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton Street, Chicago, IL 60607-7000, USA

Abstract Deposition of complex and heavy organic compounds, which exist in petroleum crude and heavy oil, can cause a number of severe problems. To prevent deposition …ver más…

In addition, it is a proven fact that the flocculation of asphaltene is generally followed by its deposition resulting with precipitates which are insoluble in petroleum fluids and containing other heavy organics and mineral deposits (Cole and Jessen, 1960; Hunt, 1962; Lhioreau et al., 1967; Shock et al., 1955; Sanchez and Mansoori, 1998). Over the last six decades, a number of investigators have researched the nature of heavy organics and mechanisms of organics deposition. There has been good progress made in the past several years in the formulation of accurate vapor – liquid phase behavior prediction of complex petroleum fluids (Manafi et al., 1999), statistical mechanics of polydisperse polymer solutions (Scott and Magat, 1945) and kinetic theory of aggregation and precipitation (Smoluchowski, 1916). Because of the complexity of the nature of heavy organic substances, the phenomena of the organic

deposition are not well understood. In addition, in view of the complexity of the petroleum fluids, study and understanding of the in situ precipitation of organic substances seems to be a challenging and timely task. Such an understanding will help to design a more profitable route for petroleum production and transportation projects. The difficulty of dealing with organic deposits is proven to be proportional to the amount and nature of asphaltene present in such systems. A number of investigators have