Ultrafiltration of Produced Water from Polymer Flooding with Hydrophilized Polyvinylidene Fluoride Membrane for Reuse

To meet the oilfield reinjection water quality for low and ultra-low permeability reservoirs in China, a hydrophilized polyvinylidene fluoride membrane manufactured by our laboratory was used for ultrafiltration of the produced water from polymer flooding in Daqing Oilfield. The results showed that a temperature of 37 degrees C, volume reduction factor (VRF) of 4, TMP of 0.20 MPa and crossflow velocity of 4.5 m/s were the feasible operation conditions for the membrane, and the average flux could reach 75 L/(m(2)h). In the permeate, the total suspension substance was consistently below detection limits (2.5 mg/L) and medium grain size was undetectable, and the content of hydrolyzed polyacrylamide, crude oil and turbidity were respectively lower than 50 mg/L, 1 mg/L and 1 NTU, all of which reached the highest oilfield reinjection water quality in China and demonstrated the membrane had a good anti-fouling characteristics.