Desenvolvimento de nanofluidos para aplicação em recuperação avançada de petróleo à base de nanocompósitos de materiais inorgânicos e poliméricos

Abstract

The growing demand for energy and the natural decline in reservoir pressure have driven the development of Enhanced Oil Recovery (EOR) techniques, highlighting the application of nanomaterials to improve extraction efficiency. This thesis investigated the development of nanocomposites based on graphene oxide (GO) and magnetite nanoparticles (NMag), functionalized with hyperbranched polyglycerol (HPG), focusing on their application as additives in EOR processes. The synthesis, characterization, and evaluation of these materials were explored in terms of wettability alteration, interfacial tension reduction, and performance in unconsolidated porous media. Zeta potential and particle size measurements were employed to assess the influence of the oxidation degree on GO stability, as well as the impact of surfactants and HPG coatings on the stability of GO- and NMag-based nanomaterials. The results showed that GO, with its bidimensional structure and high hydrophilicity, demonstrated excellent capacity to alter the wettability of rock surfaces. On the other hand, NMag, with its spheroidal structure and magnetic properties, stood out as an efficient surfactant carrier, reducing surfactant retention in porous media and optimizing oil displacement. HPG played a crucial role in increasing the stability ofnanofluids under saline conditions, preventing aggregation, and improving dispersibility, which are critical factors for applications in real reservoirs. Atomic force microscopy (AFM) and Raman spectroscopy measurements enabled the elucidation of the mechanism of action of the proposed EOR agents. Nanocomposites based on GO and NMag functionalized with HPG proved to be promising for EOR, offering specific advantages in their structural and functional properties. HPG was key to the stability and efficiency of the systems, emerging as a transformative component in the oil sector. Both systems achieved significant tertiary recovery under controlled laboratory conditions, with recovery rates of up to 22%. However, challenges such as scalability, production costs, and environmental impact need to be addressed to enable large-scale application. The developed nanocomposites demonstrated high potential as EOR additives, being capable of altering rock wettability to water-wet and/or acting as surfactant carriers, evidencing their efficiency in increasing the oil recovery factor.