Skid-mounted method for treating produced sewage in small centralized treatment station or water injection station

The invention discloses a skid-mounted method for treating produced sewage in a small centralized treatment station or a water injection station. The method includes the following steps: S1. conveyingthe produced sewage to a destabilising oil removal device through a lifting pump to carry out viscosity reduction, oil floating removal and sand removal pretreatment; S2. entering, by the pretreatedproduced sewage, an electrochemical reactor through the lifting pump for preoxidation flocculation, S3. performing, by a high-efficiency coagulation device which is a unit, coagulation sedimentation reaction on the sewage; S4. flowing, by an effluent of the high-efficiency coagulation device, into a secondary oil-removing nitrogen air floatation device by gravity flow; and S5. entering, by sewage-discharging oil-collecting floating residues of the destabilising oil removal device, the high-efficiency coagulation device, the secondary oil-removing nitrogen air flotation device and the like, into a conditioning tank, and