Spot Experimental Study on Reuse Process for Oil Recovery Wastewater from Polymer Flooding

Abstract

Oil recovery wastewater from polymer flooding (ORWFP) is a new type industrial wastewater, which contains high molecular weight polyacrylimide. Large amount of ORWFP was discharged and ecological environment of oilfields was polluted. A reuse process with fabric filtration, O3/H2O2/UV oxidation and membrane filtration was used to treat ORWFP. Spot experimental results show that more than 70% oil and 80% SS are eliminated in fabric filtration unit. O3/H2O2/UV oxidation unit shows evident treatment effect on oil and PAM. COD removal in O3/H2O2/UV oxidation unit is relatively low, which indicates that most parts of PAM may be changed into low molecular weight ones and only a few are mineralized. Membrane filtration unit is effective for removals of oil, SS and particles. But the retention of PAM by the membrane is only 13.08%, which also indicates that most parts of PAM may be changed into low molecular weight ones. The water quality of ORWFP treated by the reuse process is improved evidently, which can live up to the requirement of oil recovery production.