Heavy Oil and Bitumen Dehydration—A Comparison Between Disc-Stack Centrifuges and Conventional Separation Technology

Abstract

Summary Recent technological advances are making the exploitation of heavy crude oil reserves increasingly profitable. This paper compares nozzle-type disc-stack centrifuges to conventional separation technology for dehydration of heavy oil and bitumen. 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 solids content, makes dehydration a challenging task that introduces new concerns when compared to dehydrating 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 a compact and efficient solution, 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.