Abstract: Method of predicting paraffin deposition risks during hydrocarbon production and/or transport, applicable at an early reservoir characterization and production stage. It comprises forming a database characterizing the hydrocarbons in the formation, including density data acquired by well logging and data obtained by analysis of rock samples taken from the reservoir formation, an analytical representation of the hydrocarbons by a limited number of pseudo-components comprising each certain hydrocarbon classes with a definition of their respective mass fractions and application of data of said base to a thermodynamic model for determining one or more parameters indicative of the crystallization conditions such as, for example, the starting crystallization temperature, the solid fraction that precipitates when the temperatures falls below this starting crystallization temperature, etc. Applications: hydrocarbon production field valuation.

Abstract: Method of predicting paraffin deposition risks during hydrocarbon production and/or transport, applicable at an early reservoir characterization and production stage.

Abstract: Integrated analysis process and device for characterization of hydrocarbons in a petroleum product, in distillation fractions, by simulated distillation. The hydrocarbons of a petroleum sample are characterized without fractional distillation by coupling gas chromatography (GC) with liquid chromatography (LC) techniques. GC simulated distillation (SD) is carried out. The separation column is preceded by a precolumn of the same nature but shorter. At the outlet of the main column, retention means (CT, AC) allow to collect and to store one or more light fractions that are sent each to a GC analytical column (6) allowing detailed analysis of the hydrocarbons, and one or more middle fractions. The remaining heavy fraction is collected at the precolumn outlet. The middle and heavy fractions are characterized by a combined LC-GC chromatography unit. Several interfaces allowing GC-GC-LC-GC coupling are described.

Abstract: A thermodynamic model is formed which allows determination of the temperature at which waxes or paraffins appear in petroleum fluids, and notably in crudes, as well as the solid fraction that precipitates when the temperature of the petroleum fluid falls below this critical value. A differentiation is established between n-paraffins, iso-paraffins, naphthenes and aromatics. The model utilizes an analytical representation of the fluids by pseudo-components, the physico-chemical parameters of most of them being determined by combination of the corresponding parameters of a certain number of pure hydrocarbons gathered in a database. The model takes account of the non-ideality of the solid, liquid, and gas phases. Two of the pseudo-constituents including the heaviest fractions are represented by two ficticious molecules, each being defined by a molar distribution among various groups which constitute them, and a group contribution method is used to calculate the thermodynamic properties thereof.