Study of the effect of organic substances on the interphase surface tension of emulsions

The presented article investigates the stability of crude oil emulsions obtained from wells in two different fields with varying physico-chemical properties. Oil samples from the Muradkhanli and Balakhani fields, operated by the State Oil Company of Azerbaijan, served as the subjects of this study. The demulsification of both oil samples, which differ in their content of high-molecular-weight compounds, was analyzed over intervals of 2, 4, 6, 8, 10, and 12 hours using the static sedimentation method. The amount of residual water in the dispersed phase of the oil was determined. During the same time intervals, the oil samples were alternately treated with normal hexane and phenol at various concentrations. It was observed that increasing the concentration of normal hexane in the emulsion led to a transition to an aggregated and kinetically stable form. Experimental results indicated that the addition of phenol to the oil samples reduced the surface tension at the water-oil interface, thereby accelerating the demulsification process. The experiments revealed that the rate of demulsification varies depending on the composition and surface activity of the added organic substances. Particularly, when the oil contains a high concentration of high-molecular-weight compounds, the surface tension is elevated, complicating the separation of the water phase from the oil. The demulsification efficiency of the organic substances added to the Muradkhanli and Balakhani oil samples, as well as the A, B, and C compositions formulated from these substances, was studied in relation to surface tension.