Síntese de nanopartículas de alumina e sua influência nas propriedades rocha-fluido em reservatórios de óleo

Abstract

The adsorption and retention of heavier oil fractions on the rock surface over time as a result of oil aging and exposure poses a challenge for the oil industry in terms of extraction efficiency. Conventional methods exhibit limited sweep efficiency, leaving part of the oil trapped in the microporous regions of the rock. The use of alumina nanoparticles (Al2O3) has proven to be attractive for Enhanced Oil Recovery (EOR) processes due to their properties such as reducing interfacial tension (IFT) and oil viscosity, in addition to the possibility of reversing the wettability of the rock. Alumina can be obtained by various chemical routes, with the hydrothermal route standing out due to better control of parameters such as temperature, time, and pressure, which influence the characteristics of nanomaterials. This study focuses on the synthesis of γ-Al2O3 nanoparticles by thermal treatment of boehmite (AlOOH), obtained via hydrothermal synthesis, and investigates the impact of these nanoparticles on IFT and rock wettability. Material characterization was performed using XRD, FTIR, SEM-FEG, and BET techniques. Nanofluids with different concentrations of Al2O3 were also produced and tested for their interaction with medium (°API = 22,36) and heavy oils (°API = 26,68). The results showed the production of Al2O3 nanoparticles with nanoplace like morphology and low agglomeration. A greater influence on IFT modification was observed in nanofluids with lower concentrations for medium oil and higher concentrations for heavy oil. Alumina also demonstrated potential for wettability inversion in sandstone reservoirs, emphasizing its viability as an EOR technique.