Study of the phases composition influence on the physico-chemical properties of the water/oil interface and its impact on inversion point of crude oil emulsions

• Grant number: 19/21103-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2019
• End date: May 31, 2024
• Field of knowledge: Engineering - Mechanical Engineering
• Agreement: Equinor (former Statoil)
• Principal Investigator: Antonio Carlos Bannwart
• Grantee: Tatiana Marques Pessanha
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Mecânica (FEM)
• Associated research grant: 17/15736-3 - Engineering Research Centre in Reservoir and Production Management, AP.PCPE
• Associated scholarship(s): 22/05601-1 - Improvement of coalescence probability model based on dilational interfacial rheology: effect of formulation, composition and drop size dependence, BE.EP.PD

Abstract

The aim of this research project is to study crude oil emulsions, the process of droplet coalescence and the phase inversion point. For that, two kinds of studies will be performed: one based on the formulation of both phases composing the emulsion and other in microscopic scale focused on the coalescence of micro-droplets and interfacial phenomena related to emulsion stabilization. For the studies of phase inversion point of emulsions, it will be applied the HLD (hydrophilic/ lipophilic difference) theory, an extension of the research that has been developed in emulsion subject over the last years. This approach introduces new concepts in petroleum research area regarding the phase inversion phenomenon and the applicability of it in field. The HLD parameter is a thermodynamic property tightly associated to the partitioning of the surfactant species between both phases composing the emulsion system, affecting the physicochemical properties of the interfacial film and, consequently, the energetic barrier that separates both the isolated and the coalesced droplets thermodynamic states. Besides the process of emulsion inversion, the process of droplet coalescence will also be also investigate in micrometric scale. The impact of the interfacial film properties on the coalescence of micro-droplets (~50 mm) will be studied, looking for the macroscopic understanding of the coalescence phenomenon, phase inversion and water/ oil phase separation. Considering that both the composition, structure and, consequently, the physicochemical properties of the interfacial film are affected by the chemical composition of both phases, the variables to be experimentally explored are temperature, salinity, pH and viscosity of the oil phase. Even though most of the emulsion studies focus on model fluids, usually composed of mineral oils and additives that mimic chemical functions of natural components of the crude oil, such as asphaltenes and resins, this sort of fluids are not able to mimic the chemistry of them. Emulsion properties like kinetic stability, inversion point, interfacial film composition and its characteristics strongly rely on the composition of the whole system. By this way, the advances in the crude oil emulsions knowledge depends on the study of fluids with compositions more complex, closer to the crude composition. Thus, in this work it will be investigated the phase inversion and coalescence phenomena of emulsions produced with crude oil diluted with diesel to simulate the viscosity of the crude oil in the well conditions, evaluating the effect of the chemical composition of both phases (water and oil) and process variables (surfactant concentration, salinity and viscosity). (AU)