Interfacial properties of asphaltene-brine systems and analysis of adsorption kinetics: effects of ion and water injection for EOR

Asphaltenes are the heaviest crude oil components and active agents on the oil-water interface. Understanding the key parameters related to interfaces phenomenon, such as the adsorption kinetics, allows for the more efficient development of new E&P technologies. Therefore, this work aimed to study fluid-fluid interactions between a Brazilian Pre-salt asphaltene and customized water for enhanced oil recovery (EOR) purposes. The crude oil was characterized by SARA analysis, the total number of acids (TAN), the total number of basic (TBN), and density. The asphaltenes were characterized by FTIR and particle size. The dynamic interfacial tension (IFT) measurements through the pendant drop method were performed at 60 degrees C using a Drop Shape Analyser (DSA). The experimental IFT curves were modeled using the Ward-Tordai and Gibbs-Duhem diffusion equations to obtain the equilibrium IFT of asphaltene solutions and the interfacial diffusion coefficient. The results of characterization showed many active compounds in the asphaltenes structure, such as OH, NH, C = O. The interfacial activity of the system indicated that customized brine is more efficient than NaCl or MgCl2 solutions in reducing the IFT of asphaltene-brine systems confirming that these ions act together on the interface. Furthermore, the customized brine containing NaCl CaCl2, MgCl2, KCl, SrCl2, NaHCO3, and Na2CO3 (brine #2) presented higher diffusion coefficient patterns. This system contains high content of divalent ions, pH adjusted, and specific ions are the main ones responsible for the highest IFT reduction rate and diffusion coefficient. [GRAPHICS] .