Oilfield produced water reinjection treatment process
Process Overview
Process Introduction
This process uses CDFU as the core equipment, combined with filters of different filtration precision to meet the treatment requirements of formations with varying permeability. The produced fluid is initially separated into oil, gas, and water by a three-phase separator; the oily wastewater then enters the CDFU for deep oil removal. The oil discharged from the CDFU (already demulsified by micro-bubbles, enabling rapid oil-water separation) re-enters the three-phase separator for oil-water separation. The produced water is then deeply purified by the corresponding filters before being delivered to the water injection system.
Two-stage CDFU cyclone dissolved-air flotation + fine filtration — purely physical separation, chemical-free, skid-mounted design, fully automated operation, with stable effluent meeting A1 standard.
| Process Scheme | Oil Content in Water(mg/L) | Suspended Solids (mg/L) | Median Particle Size (um) |
|---|---|---|---|
| Scheme 1 | ≤10 | ≤5 | ≤3 |
| Scheme 2 | ≤6 | ≤2 | ≤1.5 |
| Scheme 3 | ≤5 | ≤1 | ≤1 |
Oilfield produced water reinjection treatment process Flow
Technological Advantages
Technological Advantage
Short process flow, high efficiency, strong shock resistance, stable effluent consistently meeting water quality requirements
Purely physical demulsification and separation technology, effective and stable demulsification, no oily sludge (hazardous waste) generated
Two-stage cyclone dissolved-air flotation for pre-treatment, strong shock resistance, ensuring stable and reliable downstream process operation
High filtration precision, excellent performance, strong shock resistance, long filter media service life
Small footprint, suitable for space-constrained applications such as offshore platforms
Fully automated and digitalized operation with remote monitoring capability, minimal manpower required, convenient and cost-effective operation and maintenance
Technical Comparison
Technical Comparison
| Comparison Item | Large Tank Sedimentation + Chemicals + Two-Stage Filtration | Two-Stage CDFU + Filtration (Sinokle) |
|---|---|---|
| Treatment Effectiveness | Unstable effluent, can only reach A3 or even C1 standard | Stable effluent, capable of reaching A1 standard |
| Chemicals | Requires addition of demulsifiers, flocculants and other chemicals | Purely physical, chemical-free separation, environmentally friendly |
| Stability | Low equipment reliability and automation level, poor adaptability to water quality fluctuations and shock resistance | Fully automated operation, real-time multi-parameter monitoring, excellent adaptability and shock resistance |
| Footprint | Large tank sedimentation and conventional filters require large footprint, difficult to transport and install | Compact equipment, small footprint, skid-mounted design, convenient transportation and installation |
| Safety & Environment | High chemical consumption, large sludge volume, non-enclosed operation, exhaust gas leakage, high risk of secondary pollution | Fully enclosed pressurized operation, zero leakage, site-friendly, safe and environmentally compliant |
| Commissioning Period | Large footprint, long construction and installation cycle, many factors affecting the build schedule | Skid-mounted equipment, small footprint, short construction, installation and commissioning period |
Application Cases
Application Case
Oilfield produced water Treatment Project at Congo
