Predicting Residual Oil Saturation During Enhanced Oil Recovery


The main purpose of any enhanced oil recovery (EOR) scheme is to increase the amount of oil recovered from the reservoir typically following a secondary recovery scheme such as waterflooding.  Polymer flooding, as an EOR method, has been used to recover bypassed oil, thus increasing the oil recovery factor and reducing the residual oil (saturation, Sor) left in the reservoir. In recent times, a special type of polymer, viscoelastic polymers, have been used in polymer flooding. Viscoelastic polymers offer an advantage of improving the microscopic displacement efficiency of residual oil.  However, the value of predicted Sor with viscoelastic polymer flood schemes has not matched with conventional polymer prediction methods of Sor. This inaccurate prediction can cost the oil producer significant dollars in cost of the EOR scheme and less revenue than otherwise anticipated

University of Alberta inventors have developed a method to give a more accurate prediction of Sor in EOR, particularly those using viscoelastic polymer solutions. They have provided a new correlation that more accurately reflects the behaviour of the viscoelastic polymer flow in porous media and demonstrate the failure of capillary theory in defining the effectiveness of a potential chemical slugs injected into the reservoir.  Their new method provides a new analysis for determining properties of polymers which are used to select which polymer might be most effective in a reservoir EOR scheme and hence provide better financial forecasting of the EOR scheme.



  • Ability to select an optimal polymer before a polymer flood when conventional capillary number (Nc) of different viscoelastic polymers remain the same
  • More accurate prediction of residual oil saturation and thus economics of EOR
  • Allows polymer manufacturers to analyze/optimize polymer design

Protection Status

Patent Pending

Product Number


Contact Information

Monica Varga
Technology Management Group
TEC Edmonton – University of Alberta
Phone: 780-492-5744