Investigation of the influence of the compositions of the water / oil phases on the coalescence phenomenon and the impact of the salinity of the aqueous phase on the corrosion of the transport / production lines

Abstract

This research project aims to investigate the influence of the composition of the aqueous and oil phases on the phenomenon of coalescence of water/oil (W/O) emulsions types. Still, the influence of the composition of the salinity in aqueous phase on corrosion process in metallic alloys used in pipelines and instrumentation.The physical-chemical characteristics of the interfacial films can affect both the point of inversion of continuous phase of W/O emulsions and the type of emulsion formed (oil/water - O/W or water/oil - W/O). This study in molecular scale intends to understand the phenomenon of coalescence, inversion point and phase separation of water/oil emulsions in macroscale.Also, in the specific case of W/O emulsions, the dispersed phase salinity can promote corrosion processes in the pipelines, due to the combination of oxygen and salts in the system. However, the oil phase can significantly change the corrosion behavior, which makes it interesting to study the impact of the aqueous phase on the corrosion process of metal alloys.The proposal is a continuation of the research line that has been developed in the emulsion area in the research group in EQUINOR/FAPESP/UNICAMP Research Center, recently inaugurated at CEPETRO. The present approach focuses on understanding the phenomenon of coalescence of droplets as a function of the chemical and mechanical characteristics (elasticity and viscosity) of the formed interfacial film. Even how the composition of the phases influences the corrosion process.In this work, the phenomenon of microscopic droplet coalescence (~ 50 ¼m) will be investigated and how the physical-chemical characteristics of the interfacial film of molecular dimension affects the coalescence process. Since the composition and structure of the interfacial film are affected by the chemical composition of both phases (oil and water), the variables to be explored will be temperature, salinity, pH and viscosity of the oil phase. These variables are represented by HLD (Hydrophilic/Lipophilic Difference), defined by the relative solubility of the surfactant in both phases as a thermodynamic parameter. A correlation will be established between HLD, interface characteristic and the coalescence time between two drops. In addition, it will be studied how both phases and their chemical composition (oil and type of electrolytes), salinity and temperature lead to the corrosion process of metal alloys. (AU)