a study on structure and property of special sulfonated petroleum as a complicated anionic surfactant

Alkaline/surfactant/polymer (asp) flooding has been extensively applied to enhancing oil recovery. as an oil displacement agent, pe1troleum sulfonate (ps) is widely used in asp pilot experiments. it is very important to find a petroleum sulfonate with a high interfacial activity and low adsorption loss. anionic surfactant petroleum sulfonate is synthesized in a single-tube film sulfonation reactor. ps is separated into fractions with different average molecular weights, and the structure of the fractions is characterized. it has been found out that the interfacial chemistry property of ps is closely related to the molecular structure. the adsorption reaches the maximum value near the critical micellar concentration. furthermore, there are significantly different interfacial activity and adsorptive property for each fraction. as the lab test result shows, the oil-displacement efficiency for each fraction is changed. the interfacial tension between crude oil and water is declined, and the oil-displacement efficiency of the system is greatly increased as ps or its fraction is used with electrolytes.