Banca de QUALIFICAÇÃO: CAMILA LOUYSE OLIVEIRA DA ROCHA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : CAMILA LOUYSE OLIVEIRA DA ROCHA
DATE: 18/12/2025
TIME: 14:00
LOCAL: Auditorio do LIME
TITLE:

Development of alumina nanofluids for enhanced oil recovery: synthesis, stabilization and evaluation in sandstone reservoirs

KEY WORDS:

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

PAGES: 71
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 extraction from mature reservoirs and is essential in the context of rising energy demand and the need to optimize low-productivity fields. Among the emerging strategies, nanofluids stand out as systems composed of a base fluid, additives, and nanoparticles capable of modifying critical reservoir properties, such as wettability, oil viscosity, and interfacial tensio, thereby improving the recovery factor. Among the nanomaterials applied in EOR, aluminum oxide (Al₂O₃) is noteworthy due to its high stability, large surface area, and chemical versatility, characteristics that enhance its interaction with fluids and rock surfaces. Coprecipitation is widely employed for its synthesis because it produces homogeneous and high-purity particles, although the tendency of nanoparticle agglomeration in liquid media still limits performance. To address this issue, the use of anionic polymers such as sodium polyacrylate (PAS) has proven effective by strengthening electrosteric repulsion among 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 XRD, XRF, FTIR, FE-SEM, and BET, while the nanofluids were evaluated in terms of rheology, zeta potential, sedimentation, UV–Vis spectroscopy, DLS, interfacial tension, and wettability. The results indicated the initial formation of fibrillar pseudoboehmite with low crystallinity and a high degree of hydration, later converted into high-purity nanometric γ-Al₂O₃ with an average crystallite size of approximately 3.43 nm, spherical morphology, and a specific surface area of 262.68 m²/g. The nanofluids exhibited pseudoplastic behavior, and the addition of PAS reduced viscosity, enhanced colloidal stability, promoted a bimodal particle-size distribution, and reversed the surface charge. Wettability and interfacial tension tests demonstrated that the combination of γ-Al₂O₃ and PAS decreased interfacial tension and shifted the rock surface from oleophilic to strongly hydrophilic, especially at higher alumina concentrations, highlighting a synergistic effect between the polymer and nanoparticles. Overall, the PAS-stabilized γ-Al₂O₃ nanofluids exhibited favorable physicochemical and rheological properties, good stability, and effective wettability alteration, underscoring their potential for enhanced oil recovery applications.

 

COMMITTEE MEMBERS:
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Interno - 1300987 - CARLOS ALBERTO PASKOCIMAS
Externo ao Programa - 1754344 - MARCOS ALLYSON FELIPE RODRIGUES - UFRNExterno à Instituição - GREGORY VINICIUS BEZERRA DE OLIVEIRA