Tese: Microscale Analysis of Foam Formation and Surfactant-Alternating-Gas Injection in Porous Media Micromodels
Aluno(a) : Nicolle Miranda de LimaOrientador(a): Márcio Carvalho
Área de Concentração: Termociências
Data: 27/10/2021
Link para tese/dissertação: https://doi.org/10.17771/PUCRio.acad.57011
Resumo: Foam is widely used in oil recovery operations to improve sweep efficiency, in gas storage and acidization operations, and to solve problems caused by either a thief zone or gravity override. Foam, which can be preformed and injected into the reservoir or produced in-situ through the pore space, fills the high permeability areas known as thief zones and diverts the displacing fluid into the direction of trapped oil, reducing the relative permeability of gas and leading to a more stable displacement front. The efficiency of these processes largely depends on the generation and stability of the foam films (lamellae) residing in the pores. The mobility of the injected gas is reduced when foam is formed; this reduction is attributed to the reduction of the gas phase relative permeability. The lamellae formed create resistance against the gas flow, impeding its free motion inside the porous media. The lamellae population that composes the foam is direct related to surfactant concentration, and their flow and mobility are functions of the pore geometry and foam properties. However, the dynamics of foam formation in porous media is not fully understood due to its complexity. The goal of the first part of this research is to understand the dynamic process of gas invading a two-dimensional porous media glass model occupied by a surfactant solution and forming foam. The second part focus on foam formation and its impact on oil displacement during SAG (surfactant-alternating-gas) injection. A microfluidic setup composed of a glass micromodel, syringe pump, pressure transducer and microscope, was used to visualize the pore-scale displacement and correlate the evolution of lamellae formation during the injection process with pressure difference for different flow conditions through image processing. The dynamics of lamellae formation is reported and related to macroscopic flow behavior.