Mechanisms, performance optimization and new developments in demulsification processes for oil and gas applications.

The present review discusses new developments and optimization of demulsification processes in oil and gas applications, and highlights the critical parameters. Discussed are the primary mechanisms of demulsification, as well as the strategies for developing optimum demulsifiers. Demulsification mechanisms are presented in the context of emulsion stability principles which are equally applicable to the destabilization of crude oil-water emulsions. The present paper is a concise overview of the various surfactant classes and their structure-activity relationship. It correlates demulsification optimization with surfactant properties and their applications. These classes include, but are not limited to pluronic block co-polymers, as well as amine- and siloxane based nonionic surfactants. The emphasis is on providing some strategies for achieving optimum crude oil-water separation efficiency by tuning the demulsifier to the intended application and crude oil properties. A brief overview of unconventional analytical techniques, which reach beyond the standard demulsifier evaluation methods, i.e., Near Infrared Spectroscopy (NIR), and in particular, low resolution NMR relaxometry, highlights their role in monitoring demulsification processes.