Pilot Study on Ultrafiltration of Produced Water from Polymer Flooding for Reuse
Produced water from polymer flooding (PWfPF) in oilfield is high contents of crude oil, total suspension substance (TSS), hydrolyzed polyacrylamide and salinity. Most existing traditional processes in China are incapable to treat PWfPF to meet the reinjection water quality for low and ultra-low permeability reservoirs. In the present paper, a hydrophilized tubular polyvinylidene fluoride (PVDF) membrane with a total active area of 110 m2 manufactured by our laboratory was used for ultrafiltration of the PWfPF. The temperature and volume reduction factor (VRF) of the PWfPF were fixed at 37 °C and 4, respectively. The influences of transmembrane pressure (TMP) and crossflow velocity on the membrane flux were investigated. The experimental results showed that a TMP of 0.20 MPa and crossflow velocity of 4.5 m/s were the optimum operation conditions. Under the above conditions, long-term filtration experiments were conducted for 12 months to evaluate the effectiveness of the membrane. The obtained results revealed that the membrane average flux could reach 75 L/(m2•h) and the flux recovery was more than 95%. In the permeate, the content of crude oil and turbidity were respectively lower than 1 mg/L and 1 NTU, while the TSS was consistently below detection limits (2.5 mg/L), all of which reached the highest reinjection criteria for oilfield in China and demonstrated that the membrane has a good anti-fouling characteristics to PWfPF.
Zhenyu Du and X.B Sun
J. Xu et al., "Pilot Study on Ultrafiltration of Produced Water from Polymer Flooding for Reuse", Advanced Materials Research, Vols. 113-116, pp. 1266-1269, 2010