Recent technological advances are making the exploitation of heavy crude oil reserves increasingly profitable. This paper describes the use of nozzle-type disc-stack centrifuges for dehydration of heavy oil.
The nature and composition of heavy oil leads to a number of undesirable properties, such as its tendency to form stable emulsions in the presence of asphaltenes, particles and other emulsifiers occurring naturally in the oil. This, combined with a high viscosity and a relatively high content of solids, makes dehydration a challenging task that introduces new concerns when compared to light crude oil.
As the density of the heavy oil increases and approaches that of water, conventional static and gravity-based separation systems become unacceptably large and require excessive heating and chemical addition to produce pipeline specification oil. Hence, the disc-stack centrifuge is proposed as an efficient solution in a compact size, enabling breakdown of stable emulsions and removal of dispersed water droplets and solid contaminants from heavy and viscous crudes, in both onshore and offshore installations.