T his paper reviews the impact of asphaltenes on wax crystallization and on the properties of crude oils, and the consequences thereof on the flow assurance of waxy crude oil. It initially includes studies of the crystallization of both pure n-alkanes as well as the mixtures thereof, because they have led to an understanding of how their precipitation occurs along with their transitions of crystalline phases, particularly, by studies of X-ray diffraction (XRD). This is followed by the studies and results of crystallization in crude oils and/or the fractions thereof and how their properties are affected in the presence of asphaltenes.The results on the influence of asphaltenes are inconclusive and sometimes contradictory: some confirm that their presence decreases pour point, others affirm that it increases it and yet others say there is no effect. Similar results have been reported for properties such as crystallization point, phase transition and rheological properties. The influence of the chemical structure of asphaltenes on the change in crude oil properties has not been generalized either. It has been inferred that is possibly due to the interaction between aliphatic chains of asphaltenes and waxes, and it has been established that there is synergy in coprecipitation due to evidence in the analysis of organic deposits. ABSTRACT REVISIÓN DE LOS ESTUDIOS SOBRE INTERACCIÓN ASFALTENOS Y PARAFÍNAS E INCIDENCIA EN SU CRISTALIZACIÓN 40É apresentada uma revisão do efeito que os asfaltenos têm na cristalização de parafinas, nas propriedades de crus parafínicos e nas consequências na garantia de escoamento. Inicialmente são incluídos os estudos de cristalização de n-alcanos puros e de suas misturas onde foi possível entender como ocorre sua precipitação e transições de fases cristalinas, especialmente, por estudos de difração de raios-X (DRX). São analisados os resultados de estudos de cristalização em crus e/ou suas frações e como a presença dos asfaltenos afeta suas propriedades.Sobre a influência dos asfaltenos, os resultados não são conclusivos e em ocasiões são contraditórios: alguns confirmam sua contribuição para diminuir o ponto de fluidez, outros que o aumenta e em alguns casos que não o afeta. Resultados semelhantes são relatados para o ponto de cristalização, a transição de fases e as propriedades reológicas. Também não é possível generalizar qual é a influência da estrutura química dos asfaltenos sobre as propriedades dos crus. Infere-se que possivelmente é devida à interação entre suas cadeias alifáticas com as parafinas e estabelece-se que existe sinergia na coprecipitação pela evidência nas análises dos depósitos orgânicos. Se presenta una revisión del efecto que tienen los asfaltenos en la cristalización de parafinas, en las propiedades de crudos parafínicos y las consecuencias en el aseguramiento de flujo. Inicialmente se incluyen los estudios de cristalización de n-alcanos puros y de sus mezclas donde se ha podido entender como ocurre su precipitación y transiciones de fases cristalinas, especialm...

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even chemical products with different chemical properties were evaluated as post-fracturing treatments to remove the polymer retained in the pore system of the fracture and adjacent rock after hydraulic fracturing. Three of those chemical products were used for the first time to degrade the polymer in fracturing fluids. All laboratory tests were conducted under the Unit K-1 Chichimene oil-field conditions -located in Eastern Colombia, and operated by Ecopetrol S.A.Fluid-fluid and fluid-rock compatibility tests were performed. In order to evaluate the capacity of the post-fracturing treatments to degrade the polymer in the fracturing fluid, a new methodology for polymer quantification was implemented. The chemical and thermal stability of the post-fracturing treatments was assessed trough coreflooding experiments. Finally, the evaluations of the effectiveness of the post-fracturing treatments were performed and assessed with coreflooding experiments using fractured rocks as porous media.The coreflooding results showed that the post-fracturing treatments evaluated promoted the recovery of about 40% of the total polymer retained in the porous system, and improved the retained permeability in values between 50 and 180%. The best obtained results came from the first-time usage of chemical products as post-fracturing treatments.