Tese: Injectivity and stability of oil-in-water emulsions with lipophilic natural surfactants
Aluno(a) : Alandmara Rosa Dionizio LeoncioOrientador(a): Marcio Carvalho e Ranena Veronica Flores
Área de Concentração: Termociências
Data: 19/11/2019
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.47680
Resumo: Stable oil-in-water (O/W) and water-in-oil (W/O) emulsions are created in different processes of oil production due to the presence of natural crude oil surfactants, such as asphaltenes, resins, oil-soluble organic acids, solids, and waxes. An interfacial film is formed causing chemical interactions between the surfactants and other species in the water phase. This work aims to study the formation and stability of emulsions stabilized by a fatty acid as natural surfactant, under ambient and high-pressure conditions, and their flow behavior through injectivity tests in sandstones. To this end, study of emulsion stability and interfacial rheology analysis were performed by evaluating the droplet size distribution and interfacial viscoelastic modulus as a function of the surfactant concentration, aqueous composition, and flow conditions. In the rheological tests, results showed that the presence of the fatty acid in the oil phase promoted a reduction in the oil-water interfacial tension and elastic modulus larger than the viscous modulus, evidencing important surface activity. All emulsions formed with an alkaline solution without salts were stable under ambient conditions. During emulsion injection in single-phase flow, water mobility control was observed through the reduction of the absolute permeability as a strong function of emulsion drop size distribution and capillary number.V