Improve Waterflood Efficiency by Film Treatment Technology

In the process of reservoir water-flooding development, the injected water of sodium sulfate type and calcium, barium and strontium ion in high salinity formation water combine to form slightly-soluble sulfate scale, result in low efficiency of water injection system and reduction of water-flooding swept volume. In view of above problems, nanofiltration (NF) will be a main driver in injection water treatment. It removes SO4 2- in injected water, reduces scale ion content from the source, achieves the purpose of scale inhibition and control, and increases water-flooding efficiency. Lab and field trials indicate that the NF treatment has a favorable result. The removal rate of SO4 2- reaches 85.0%, scale inhibition efficiency is 80.2% and the injection profile of injected well increases 1.95m. The study creates a new way for preventing and treating sulfate scale (especially strontium sulfates scaling), increasing waterflood sweep efficiency and improving injection system efficiency.