Influência da concentração ácida de sistemas microemulsionados e nanoemulsionados na recuperação avançada de petróleo

Abstract

One of the main reasons that leads to the development of technologies for the oil recovery is the high remaining oil percentage in the well after primary and secondary recovery, and these are no longer able to recover it. In this work, microemulsion systems and acid nanoemulsions will be used in advanced recovery processes. The systems present in its composition: surfactant, co-surfactant, kerosene and acid solution with different concentrations. The used surfactant is commercial and of noionic character. The acid, when reacting with the carbonated rock, tends to open the possible pores that still are closed for certain particles or until forming new canals, increasing the permeability of the rock. The used systems had differed only in the acid concentration in aqueous phase that contained 1.5% of HCl, 5%, 10% and 15%. The concentrations that compose the systems were chosen through the mounted ternary diagram, the systems contain 80% of aqueous phase, 2% of oil phase, 12% of surfactant and 6% of cosurfactant. After to have definitive this point, all the systems were characterized by its superficial tension, viscosity, corrosive capacity, c.m.c., diameter of the particle and speed of reaction between acid and rock. After the this, the efficiency of the recovery of each system in a simulator of the reservoir with controlled temperature and the pressure had been measured, them had presented the following recovered oil percentages: 28%, 39%, 44% and 48% for the systems with 1,5%, 5%, 10% and 15% of HCl, respectively. In this manner, was concluded that how much bigger the concentration of the acid one, plus it tends to increase the permeability of the rock and to increase the recovery efficiency. Finally, was made a nanoemulsion of the microemulsion system more efficient (system 4), it was characterized in the same way that too much systems, presenting 84% of recovered oil. It was concluded that acidic microemulsion and nanoemulsion are afficient systems when applied in the advanced recovery with the advantage of permeating the rock becoming a more homogeneous and reducting the corrosion of the equipaments in values up to 60%, constituting an alternative for application in the area.