Comprehensive Review of Demulsifiers based on Magnetic Nanoparticles for Oil-water and Water-oil Separation

Oil-water emulsion causes a wide range of problems, one of which is the emergence of significant decreases in pressure in flow lines resulting in higher pumping and transportation costs. The most widely developed trend among oil/water separation technologies is using demulsifiers based on magnetic nanoparticles (MNPs). MNPs have specific chemical and mechanical properties, providing unique opportunities to solve oil production issues. The key features of such magnetic nanoparticles for their sustainable application are their reusability and stability; the opportunity of remote manipulation using external magnetic fields gives them a singular benefit in transport operations. The main objective of the study is the systematization of MNPs researches for effective oil and water emulsion separation. This review provides MNP demulsifier characteristics, Oil-water emulsions (OWE) separation mechanism, and factors influencing oil-water emulsions efficiency disruption by MNP demulsifier. The relevance of this study is that oil-water emulsions are often encountered in practice during field development. To solve this problem, the use of demulsifiers based on magnetic nanoparticles is proposed. The novelty of the work lies in the fact that the work collects several factors affecting demulsification at once and describes the impact of each factor. Among these factors, the most influential are: emulsion characteristics, water salinity, pH, reservoir temperature, addition of chemical surfactants, time and magnetic field. The mechanism of formation of oil-water emulsions of various types is also described, and negative consequences of emulsion formation are discussed. The results showed that the magnetic nanoparticles need a protective layer and the demulsifier should have good wettability by the continuous phase of the emulsion.