Evaluation of Water-in-Crude-Oil Emulsion Stability Using Critical Electric Field: Effect of Emulsion Preparation Procedure and Crude Oil Properties

Abstract

The critical electrical field has been used as a tool to probe water in crude emulsion stability to electrical fields in many previous studies. Given the increasing importance of this metric, this study investigates factors that are important to the reproducibility of the measurement and the effect of emulsion preparation variables on the critical electric field. It was observed that the emulsion preparation procedure has a strong effect on the measured critical electric field due to droplet size effects. Furthermore, the effect of crude oil properties on the critical electric field was investigated using emulsions from different oils but with the same average droplet diameter, where it was found that the measurement was dominated by crude oil viscosity.

Keywords:

• Critical electrical field
• crude oil
• electrocoalescence
• emulsion stability
• water-in-oil emulsion

Acknowledgements

R. C. C. C. wishes to thank Petrobras for giving us permission to publish this paper. M. N. wishes to thank to CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), FAPERJ (Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro), FINEP (Financiadora de Estudos e Projetos) and Petrobras for financial support.