Abstract
In this paper we present a literature review on the role of surface-active components in emulsions and foams. Models are presently unable to accurately predict scenarios involving multiphase flows with complex chemistry, and this is a major obstacle for many petroleum production/transport systems. This paper highlights some of the most important physical phenomena that are relevant for understanding and ultimately predicting the flow behaviour of complex fluid systems. Some of the main topics addressed are fluid interfaces with surfactants, droplet coalescence and breakup, emulsions, and foams.