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This research article proposes the use of a novel variant of the HS algorithm (harmony search), i.e. SFHS (self-regulated fret width harmony search algorithm), for calculating and predicting fugacity and activity coefficients in binary mixtures. Parameter selection was carried out based on preliminary results with different standard test functions. Different previously reported systems were selected, at 25 ° C and 40 ° C, and at low and moderate pressure levels. Moreover, two solutes were selected: carbon dioxide and ethane. Different solvents, both polar and nonpolar, were selected with comparative purposes. Activity and fugacity coefficients were calculated using the Redlich-Kwong state equation and Lewis rule, along with the sfhs algorithm, assuming both solutes in vapor phase. Consistency of the activity coefficients was analyzed by the Redlich-Kister strategy. Results were very close to those found experimentally by other authors, and most of them did not differ in more than one percentage unit.

The purpose of this study was to determine the feasibility of using electric fields as a method for to inhibit the formation of paraffin deposits in the production and transport of paraffinic crude oils. a capillary viscometer was designed and constructed, and then adapted to an electric field generator. This experimental setup allowed generating electric fields of different amplitudes. Capillaries tubes of different diameters were used in order to obtain different exposures times of the oil to the electric field. The variables used to quantify the effect of the electric field on the oil were the mass flow, viscosity, cloud point, and pour point. The experimental data shows that the application of the electric field to oil from Colorado 67 and Colorado 36 wells resulted in an increase of viscosity, cloud point, and pour point. These results suggest that exposure of oil to the electric field accelerates the precipitation process of organics and therefore it is not recommended for implementation in the studied wells.