Polyvinyl alcohol (PVA) as an emulsifying agent for viscosity reduction of heavy and extra-heavy oils

Heavy and extra-heavy oils represent important energy resources and have contributed significantly to the world energy supply. Emulsification technology (specifically, formation of oil-in-water emulsion) has been considered an innovative approach to reduce the high viscosity of heavy oil and subsequently cut production and transportation costs. However, resolution of emulsion remains a costly task. A promising solution to this problem is the use of polyvinyl alcohol (PVA) in dispersing heavy oil particle in aqueous solution to form emulsion which is easy to resolve thereby nullifying the need for expensive demulsification process. Although PVA has been used in many industrial applications due to its excellent properties, applications in heavy oil recovery and transportation have not received adequate attentions. In this article, the basic technical aspects of emulsification technology in reducing viscosity and improving flow property of heavy oil are presented. Moreover, properties of PVA and few research efforts on its suitability as an emulsifying agent in heavy and extra-heavy oil emulsification are reviewed. This is with the aim of creating further awareness on the use of the chemical to solve heavy oil flow problems.