Investigation of the effect of crystallization conditions and "Difron-4201" depressant additive on the composition and properties of paraffin deposits

Abstract

For the first time in the laboratory, the physical and chemical characteristics of the model oil sample, the composition, and relative amounts of normal alkanes with carbon atoms from C8 to C60 were determined by high-temperature liquid-gas chromatography. When Difron-4201 is added to the model oil, seven carbon atoms are displaced in the direction of the lower molecular weight distribution of paraffin hydrocarbons in the sediment. The effect of the Difron-4201 additive on the group composition of model oil and oil sediments obtained at different temperatures of the "cold finger" was studied. It was found that with the addition of the additive and with a decrease in the temperature of model oil and "cold pipe", the number of paraffin hydrocarbons in the group composition of sediment increases and the amount of resin and asphaltenes decreases. Microanalysis of the structure of asphaltene–resin–paraffin sediments obtained after the addition of the additive showed that the model oil sediments, separated at 30/1500C and containing large amounts of high-molecular paraffin hydrocarbons, resin, and asphaltene components, have the highest proportion of amorphous structures. An increase in the share of dendritic modification of the crystalline structure is characteristic for paraffin hydrocarbons in sediments obtained with the addition of 900 g/t "Difron-4201" additive.