摘要：Polymer flooding is a measure to increasecrude oil production by injecting polymer into thereservoir for flooding.On the one hand,the injectedpolymer increases the viscosity of the displacementfluid and reduces the mobility ratio between the dis-placement fluid and the displaced fluid,thereby ex-panding swept volume; On the other hand,due to theinherent viscoelasticity of the polymer,the oil filmor oil droplets are stretched during the flow process,which increases the carrying capacity and improvesthe oil washing efficiency .The polymer injected intothe formation can effectively improve the oil recov-ery,but a large amount of wastewater contains re-maining oil,var ious salts,suspended solids,and mi-croor ganisms,which brings great difficulties toSew-age treatment.Based on the example of the groundsewage produced after polymer injection in theChangqing Oilfield,the starch-cadmium iodidemethod,laser particle size analyzer,scanning elec-tron microscope,optical microscope,etc.are used tostudy polymer-containing sewage.The researchshows that after the filtration,the polymer concen-tration of the polymer-containing sewage drops sig-nificantly,and the polymer content on the sur face ofthe filter material is as high as 81 6mg/L,which ismuch higher than the polymer concentration in thefiltered polymer-containing sewage.The max imumparticle size of the suspended matter in the polymer-containing sewage after filtration is 62.63um,whichreflects that the filtration efficiency value is 18.82%.The overall filtration effect is checked,and the anal-ysis shows that the reason for the poor filtration ef-fect is that the polymer is more easily adsorbed onthe filter material than the oil droplets.The surfaceof the particles and the suspended particles are easilyadsorbed on the acute angles of the filter particlesand are intercepted,resulting in a poor filtering ef-fect on the oil in the polymer-containing sewage.
