Conventional Block Oilfield Reinjection Water Treatment Process
Process Flow
Process Introduction
The process is centered around the CDFU (Continuous Deoiling and Filtration Unit) as the core equipment, combining filters with different filtration precision to meet the treatment requirements of formations with different permeabilities. The produced fluid undergoes preliminary separation of oil, gas, and water through a three-phase separator. The oil-containing wastewater enters the CDFU for deep deoiling, and the CDFU discharges oil (already subjected to microbubble demulsification, allowing for rapid oil-water separation). The effluent then re-enters the three-phase separator to achieve oil-water separation. The produced water goes through corresponding filters for deep purification before being conveyed to the reinjection system.
Technical Comparison
| NO. | Large tank sedimentation + chemicals + two-stage filtration (traditional technology) | Two-stage CDFU+ filter (SINOKLE patented technology) |
| Process effect | Unstable effluent water and can only meet A3 or even C1 standards. | Stable effluent and reach A1 standard (5.1,1) |
| Chemicals | Add demulsifiers, water purifiers and other chemicals | Pure physics, no chemical separation, environmentally friendly |
| Stability | Low equipment reliability and automation, poor quality fluctuation adaptability and impact resistance, poor system stability | Fully automatic operation, automatic real-time monitoring of multiple indicators, good adaptability and impact resistance, and good system stability |
| Land area | Large tank settlement and traditional filters occupy a large area and are difficult to transport and install. | Efficient and fast processing equipment, compact equipment, small footprint, skid-mounted design, convenient transportation and installation |
| Safety and environmental protection | Large dosage of chemicals and amount of sludge (hazardous waste), not closed operation, and the exhaust gas leaks out, causing secondary pollution and posing great safety and environmental risks. | Fully enclosed and pressurized operation, zero leakage, friendly on-site environment, no hidden dangers, safe and environmentally friendly |
| Commissioning period and footprint | The settlement of large tanks requires a large area, long construction and installation cycles, and many factors affecting construction (weather, labor, etc.) | Skid-mounted equipment, small footprint, short construction, installation and debugging cycle (skid-mounted design, factory pre-assembly and debugging) |
Process Characteristics
·The process is short, the efficiency is high, the impact resistance is strong, and the water output is stable and meets water quality requirements;
·No chemicals, pure physical demulsification and separation technology, good and stable demulsification effect, no oily sludge (hazardous waste) is produced;
·Using two-stage cyclonic dissolved air flotation for pre-treatment, it has strong impact resistance and ensures stable and reliable operation of subsequent processes;·Active filter, with high filtration accuracy, good effect, strong impact resistance and long filter life;
·Skid-mounted, small footprint, suitable for occasions with high space requirements such as offshore platforms;
· Fully automated, information-based operation, remote monitoring, less labor, convenient operation and maintenance, and low cost.
Process Index
| Process | Effluent Water Index | ||
| Oil Content (ppm) | SS (mg/L) | Particle Diameter (μm) | |
| Solution 1 | ≤10 | ≤5 | ≤3 |
| Solution 2 | ≤6 | ≤2 | ≤1.5 |
| Solution 3 | ≤5 | ≤1 | ≤1 |
Application Case
① Skid for back-injection water treatment at a certain joint station of PetroChina
② Raw water- One-stage CDFU- Two-stage CDFU- Filtration
