Technology for Confecting Polymer Solution With Desalted Produced Water

摘要

Polymer flooding technology has been widely used in Daqing oilfield of China in recent years. To maintain the viscosity of polymer solution, fresh water was used to confect polymer solution instead of produced water. Then, a problem was generated that the produced water could not be injected into the stratum totally. The superfluous produced water must be treated to meet the requirement of discharge, which increased the cost of production. In this paper, we try to desalt the produced water using electrodialysis principle. A set of experimental equipments that could generate desalted produced water 300 m~3/d, was operated at a produced water treatment station of Daqing Oilfield. The experimental results indicated that the total salinity of desalted produced water less than 1000 mg/L. Comparing with fresh water, the polymer solution confected with desalted produced water has a sound character, its viscosity increases 63.5%, and the recovery ratio increases 4.5 percentage points. This experimental study has an important significance for the balance of oily water of production and injection in Daqing Oilfield. This produced water desalination technology would have a better application prospect in polymer flooding production.