Hydrocyclones as a Technology for Separating Oil, Water, and Solids

by Dr. Franklin Foster, 2006
[note: this article made possible by support and funding from the Petroleum Society of CIM, Lloydminster Section]

     The Heavy Oil industry in the Lloydminster area sometimes seems to have been one long struggle to separate oil from water and solids.  Recent processes emphasize producing the mixture, then treating it to separate the constituents.  The mixture has been shaken, heated, treated with chemicals, etc., etc. 
Now, along comes another technology - the hydrocyclone

    One immediate advantage of the hydrocyclone is that it has no moving parts.  Rather, it is based on the characteristics of fluids and solids under centrifugal pressure.  The hydrocyclone optimizes a spinning motion of the mixture and the heavier materials are thrown to the outside of the spin while the lighter material rises up through the vortex of the mini-tornado.

[See diagram to the right:
courtesy Husky Energy]

     Among the current applications of hydrocyclones are obtaining concentrated crude oil from the slop oil of skim tanks at a treater, and producing a stream of clean water from refinery effluent or a desalter.  Field tests have produced water with fewer than 100 ppm of solids from this application.

     Currently experimentation is ongoing to improve the results.  One promising direction is to use two or more hydrocyclones in combination to achieve even better results.  Temperature and pressure adjustments can effect results, as does the diameter of the vessel(s) in which the hydrocyclone action takes place.