Abstract:
During waterflood operations in field development, attempts to reduce scale formation from produced formation waters are often negatively affected by short anti-scaling distance and environmental influences. To solve this problem, a new technique of scaling prevention by electrochemical induction was introduced, and laboratory and field tests were developed. To evaluate the new electrochemical induction scaling prevention technique in the laboratory, experimental apparatus were designed, and the mass concentrations of Ca2+ and Mg2+ were tested before and after the electrochemically induced scaling prevention. In addition, field site test units were also installed to assess the performance of this technique in the FM produced water treatment station, and the anion and cation contents were measured before and after the electrochemical induction. Parameters of anti-scaling by electrochemical induction such as electrode materials, polar plate spacing, cathode area and water flow pattern were optimized in laboratory tests. The results of field tests indicated that Ca2+ content in the produced water at the FM station decreased by 18.2%, HCO-3by 23.6%, and the theoretical water scaling content reduced by 43.4% after the electrochemically induced scaling prevention as estimated from Scalechem 3.1, a chemical scale analysis software. In summary, the results showed that using an electrochemical induction scaling prevention technique could efficiently remove the scaled ions from produced formation water, and result in good anti-scaling effects.