With the structural modification of quartz sand filter in Daqing oil field, and using the suspended sludge filtration in treating oilfield wastewater, the good experimental results are obtained.

Different methods are described to measure sludge sedimentation and filtration properties, by use of sedimentation indices, initial sedimentation velocity and capillary suction time.

The investigation reviewed the influence of flocculants to sludge with oil and the factor influenced the sludge flocculation filtration. The best running condition is confirmed through experiment.