Enhanced Oil Recovery (EOR) Water Treatment
Injection-water conditioning and produced-water de-oiling for polymer flooding, CO₂ injection and waterflooding.
Sector overview
EOR / IOR boosts recovery by maintaining reservoir pressure and improving sweep efficiency. Each method imposes a different water-quality duty, but a common theme runs through all of them: injection water — including recycled produced water — must meet strict oil, suspended-solids and particle-size limits to preserve injectivity and avoid formation damage.
Produced water from EOR is harder to treat: residual polymer and surfactant create viscous, stable emulsions. WFS leans on enhanced coalescence to grow oil droplets and lift separation efficiency, then fine filtration and (for waterflood) sulfate-removal nanofiltration to hit the injection spec.
Process overview and application parameters
Process steps
- 1Produced-water de-oilingSkim → flotation → coalescer → filtration removes oil and solids.
- 2Droplet-growth coalescenceElectrostatic / media coalescers enlarge droplets on stable emulsions.
- 3Fine filtrationMultimedia, cartridge or UF to the injectivity particle spec.
- 4Sulfate removal (waterflood)Nanofiltration strips sulfate to prevent souring and scale.
- 5Deaeration & dosingVacuum / gas-stripping deaerator plus biocide, scale and O₂-scavenger dosing.
Application parameters (feed water)
| Oil in produced water | 50 – 1,000 mg/L |
| Emulsion stability | High (chemical-stabilized) |
| TSS | 10 – 300 mg/L |
| Dissolved oxygen target | < 20 ppb |
| Sulfate (waterflood) | Reduce to control souring |
| Iron / hardness / bacteria | Controlled (polymer & souring risk) |
Modular treatment train
Modular Process-Train Schematic · Block flow
What makes this water hard — and how we solve it
Stable, chemically-laden EOR emulsions resist separation.
Electrostatic / media coalescence increases droplet size, raising flotation and filtration efficiency.
Injectivity loss from fine particles.
Fine media / UF filtration to <2–5 µm protects the formation.
Reservoir souring and sulfate scale (waterflood).
Sulfate-removal nanofiltration plus a managed biocide program.
Corrosion and scale under CO₂; polymer viscosity loss.
Inhibitors, resistant materials and deaeration; low-shear, deoxygenated handling for polymer.
Filtration approach & system required
Approach
Coalescence-led de-oiling to grow droplets, followed by multimedia / UF filtration to the injectivity spec.
Nanofiltration added for sulfate removal in waterflood / souring-prone reservoirs.
Filtration system / unit operations
- Induced / dissolved gas flotation (IGF / DGF)
- Electrostatic and oleophilic media coalescers
- Multimedia and cartridge filters; ultrafiltration
- Sulfate-removal nanofiltration (SRP) skid
- Vacuum / gas-stripping deaerator
- Chemical dosing (biocide, scale inhibitor, O₂ scavenger)
System specification, performance & layout
Indicative system specification
| Capacity | Per flood pattern and injection rate |
| Configuration | Tailored per EOR method (polymer / CO₂ / waterflood) |
| Membranes | Nanofiltration for sulfate removal; UF for solids |
| Materials | SS316 / duplex; CO₂-service corrosion-resistant alloys |
| Deaeration | Vacuum / gas-stripping to <20 ppb O₂ |
Performance parameters (guaranteed, tested)
| Oil in injection water | < 5 – 15 mg/L |
| TSS | < 2 – 10 mg/L |
| Particle size | < 2 – 5 µm |
| Dissolved oxygen | < 20 ppb |
| Sulfate (souring control) | Reduced (e.g. < 40 mg/L) |
Plant layout & general arrangement
- •Injection plant with coalescer / filter banks, nanofiltration and deaeration trains.
- •Chemical dosing skids and high-pressure injection pumps.
- •Arranged for the specific flood pattern and recycle ratio.
Project deliverables
- 1Water characterization & treatability study (design basis)
- 2Process selection, mass balance, P&ID and treatment-train design
- 3Pilot / trial skid where required to de-risk performance
- 4Detailed mechanical, civil, structural and E&I engineering
- 5Equipment design, fabrication and Factory Acceptance Test (FAT)
- 6Delivery, site construction and mechanical installation
- 7Electrical installation, instrumentation, controls & SCADA integration
- 8Commissioning, performance test to guaranteed spec & operator training
- 9Continuous Operations & Maintenance (O&M) and remote monitoring
Have a produced-water stream to characterize?
Water Filtration Solutions studies your water, custom-designs the treatment train, pilots it where needed, then fabricates, installs, automates and operates the plant — from characterization through continuous O&M.