Sistemas microemulsionados na remoção de dano orgânico em meio poroso arenítico

Abstract

As a consequence of oil composition and conditions which are subjected during flow into reservoir, heavier components may segregate and eventually precipitate in reservoir`s pores causing a permeability reduction, restricting the production or injection of fluids. This reduction of natural permeability in the region near wellbore is known as formation damage by organic deposition or organic damage. Near wellbore permeability reduction reduces the well production performance impacting in companies’ revenue. The emphasis in this work is the use of microemulsion systems, known for their high solubilization capacity, in the treatment of organic deposition formation damage, in special caused by asphaltenes precipitation. This work was divided in two main stages, being: Characterization of the fluids used and efficiency evaluation in injection tests in porous medium. As damaging precursors were used Fazenda Belém oil/n-heptane (FZBHEP) mixtures. To formulate the treatment systems were used, the ALKONAT L90 and ULTRANEX NP 100 surfactants, n-butanol as cosurfactant and kerosene as oil phase. The characterization results showed that the Fazenda Belém oil is a heavy, viscous and significant asphaltenes content oil. Silica is the main constituent of Botucatu sandstone used during the experiments. The results of the injection tests showed that the FZBHEP blend was able to cause an average of 15% of damage and the microemulsion systems used got 85% efficiency in damage the removal, similar to the xylene efficiency, thus showing be an alternative to aromatic solvents using, with the advantage of being more operationally and environmentally acceptable.