Banca de DEFESA: CAMILA LOUYSE OLIVEIRA DA ROCHA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CAMILA LOUYSE OLIVEIRA DA ROCHA
DATE: 24/02/2026
TIME: 08:30
LOCAL: Auditorio do LIME
TITLE:

DEVELOPMENT AND EVALUATION OF ALUMINA NANOFLUIDS FOR ADVANCED OIL RECOVERY IN SANDY RESERVOIRS

KEY WORDS:

enhanced oil recovery; g-Al2O3; coprecipitation; nanofluid; stability.

PAGES: 85
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

Enhanced Oil Recovery (EOR) comprises a set of techniques aimed at increasing oil production from reservoirs with limited primary and secondary recovery. Among the strategies employed, nanofluids have gained prominence, as they combine a base fluid, additives, and nanoparticles capable of modifying critical reservoir properties such as wettability, oil viscosity, and interfacial tension, thereby contributing to an increase in the recovery factor. Among the nanomaterials applied in EOR, aluminum oxide (Al₂O₃) stands out due to its high stability, large specific surface area, and chemical versatility, which favor its interaction with fluids and rock surfaces. Coprecipitation is a widely used synthesis method for this material because it yields homogeneous particles with high purity; however, the tendency toward agglomeration in liquid media still limits its performance. To overcome this limitation, the use of anionic polymers, such as sodium polyacrylate (PAS), has proven effective by enhancing electrosteric repulsion between particles and, consequently, improving colloidal stability. This study aimed to synthesize γ-Al₂O₃ nanoparticles via coprecipitation, stabilize them through the addition of PAS, and evaluate the performance of the resulting nanofluids in enhanced oil recovery processes in sandstone reservoirs. The nanoparticles were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FEG-SEM), and Brunauer–Emmett–Teller (BET) surface area analysis, while the nanofluids were analyzed in terms of rheological behavior, zeta potential, sedimentation, UV–Vis spectroscopy, dynamic light scattering (DLS), interfacial tension, and wettability. Enhanced oil recovery experiments were conducted by initial brine injection, followed by the injection of nanofluids formulated with γ-Al₂O₃ nanoparticles and a polymer additive, as well as an additional test using only the polymer solution, all performed at a flow rate of 1 mL/min; the recovered oil volume was determined from the collected effluent samples. The results indicated the initial formation of fibrillar pseudoboehmite with low crystallinity and a high degree of hydration, subsequently converted into high-purity nanometric γ-Al₂O₃ with crystallite sizes of approximately 3 nm, spherical morphology, and a specific surface area of 250–270 m²/g. The nanofluids exhibited pseudoplastic behavior, and the addition of PAS promoted increased colloidal stability, bimodal particle size distribution, and inversion of surface charge. Wettability and interfacial tension tests demonstrated that the combination of γ-Al₂O₃ and PAS reduced interfacial tension and altered the rock surface from oil-wet to strongly water-wet, particularly at higher alumina concentrations, evidencing a synergistic effect between the polymer and the nanoparticles. In the EOR experiments, polymer solution injection resulted in a moderate increase in the recovery factor compared to the reference brine, whereas PAS-stabilized nanofluids promoted progressive and concentration-dependent increases, achieving the highest advanced recovery factors; this performance is associated with enhanced colloidal stability, reduced sedimentation, and more efficient nanoparticle action in the porous medium, demonstrating the high potential of PAS-stabilized γ-Al₂O₃ nanofluids for enhanced oil recovery applications. 

COMMITTEE MEMBERS:
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Interno - 1300987 - CARLOS ALBERTO PASKOCIMAS
Externa à Instituição - ANNELISE KOPP ALVES - UFRGS
Externo à Instituição - GREGORY VINICIUS BEZERRA DE OLIVEIRA