With the combination of an increase in world energy demand and the decline of conventional oils, heavy crude oils have been presented as a relevant hydrocarbons resource for use in the future. Hydrocarbon resources are very important given that they account for approximately 65% of the world's overall energy resources. Currently, there are three general approaches for transportation of heavy and extra heavy oil: viscosity reduction, drag minimization and in-situ oil upgrading. This book introduces Another promising pipeline technique is the transport of viscous crudes as concentrated oil-in-water (O/W) emulsions.