Effects of amphiphiles on the association state of the asphaltene and the viscosity of heavy oil

The effects of two types of amphiphiles on the association state of the asphaltene and the viscosity of heavy oil are systematically studied by testing the characteristics of viscosity and temperature, the centrifugal stability, and the conductivity. Experimental results show dodecylbenzene sulfonic acid (DDBSA) can enhance the stability of centrifugation of the asphaltene, increase the viscosity of the heavy oil, and improve the conductivity of the systems of heavy oil, amphiphile, and n-heptane. But the results obtained by the addition of dodecylamine (DA) are opposite to those of DDBSA. Due to the loose structure of the association body of the asphaltene, DDBSA causes a big association body to split into large number of small association bodies which influence more light weight compounds and increase the viscosity of the heavy oil; DA can compress the solvation layer and weaken the effect of solvation to decrease the viscosity of the heavy oil. The conclusions can provide certain guidance for the development of a new type of viscosity reducer with high efficiency.