Recover free oil before it becomes a downstream treatment problem.
The DHI Centurion™ is a large atmospheric separation and reaction vessel for produced-water service. It provides hydraulic retention time, controlled rotational flow and dedicated oil recovery ahead of DAF systems, filtration or chemical treatment.
Built for Produced-Water Pretreatment
Use the Centurion where free oil needs to be separated early, recovered, and kept out of downstream treatment equipment.
Oil Recovery
Free oil accumulates as a top layer and overflows into a raised annular skim cup, then exits through a dedicated oil recovery pipe.
DAF Load Reduction
By removing readily separable oil upstream, the Centurion can reduce oil loading, chemical demand and sludge generation at flotation equipment.
Deployment Flexibility
Operate as a single unit or in series where additional retention time is required for higher oil concentration or more variable water.
Separation Process
The Centurion uses tank volume, gentle rotation and gravity separation to recover free and readily separable oil.
Recommended Operating Window
A practical single-tank range is typically 20,000–30,000 BPD for produced-water pretreatment. Lower rates increase retention time and are preferred for maximum oil recovery.
| Operating Mode | Typical Flow Range | Use Case / Notes |
|---|---|---|
| High-retention oil recovery | 10,000–20,000 BPD | Best for high oil concentration, variable water, smaller oil droplets or when maximum oil recovery is desired. |
| Normal produced-water pretreatment | 20,000–30,000 BPD | Practical single-tank operating range for reducing free-oil load ahead of DAF / chemistry. |
| High-rate service | 30,000–40,000 BPD | May be suitable when oil is mostly free oil with larger droplets. |
| Beyond normal range | Above 40,000 BPD | Use with caution; evaluate oil droplet size, inlet turbulence, interface control and downstream treatment. |
Expected Separation Performance
Performance depends on droplet size distribution, emulsification, chemical history, turbulence, temperature, density difference and tank level stability. The Centurion is intended for free and readily separable oil, not as a substitute for DAF or chemical treatment where oil is emulsified.
| Influent Condition | Expected Primary Result |
|---|---|
| Mostly free oil, larger droplets (>50 micron) | High free-oil recovery and significant reduction in oil loading to downstream DAF. |
| Moderate droplet size, approximately 40–60 micron | Good primary recovery if retention and interface control are stable. |
| Fine or emulsified oil | Partial removal only; downstream chemistry / DAF likely required. |
| High solids, iron or paraffin | May require upstream screening, periodic cleaning and downstream coagulation / flocculation. |
Hydraulic Capacity & Retention Time
Retention time below uses a 300-barrel normal operating volume for liquid operating level, interface setpoint and internal displacement.
Formula: retention time = 300 bbl ÷ daily barrels × 1,440 minutes/day.
| Throughput (BPD) | Influent Flow (GPM) | Residence Time (min) | Cross-Sectional Loading (gpm/ft²) |
|---|---|---|---|
| 10,000 | 292 | 43.2 | 2.6 |
| 15,000 | 438 | 28.8 | 3.9 |
| 20,000 | 583 | 21.6 | 5.2 |
| 25,000 | 729 | 17.3 | 6.4 |
| 30,000 | 875 | 14.4 | 7.7 |
| 40,000 | 1,167 | 10.8 | 10.3 |
Key Features & Options
Core Features
- Large atmospheric separation volume.
- Tangential upward inlet to reduce short-circuiting.
- Raised annular oil skim cup around the standpipe.
- Separate oil and water discharge paths.
- Vented inverted-U water standpipe to prevent siphon behavior.
Operating Options
- Oil/water interface monitoring.
- Oil layer / skim level indication.
- Inlet / outlet pressure or level checks.
- Influent, mid-tank, water outlet and oil outlet sample ports.
- Sight glass and external level indication.
Vapor & Maintenance
- Vent can incorporate a flame arrester when required.
- Option to tie vent into vapor recovery.
- Optional VOC capture using activated carbon media.
- Cleanout and drain connections for solids removal.
- Quality liners for long service life.
Applications
Temporary Production
Gun barrel / wash tank service where temporary separation and treatment capacity needs to be deployed quickly.
Flowback Oil Recovery
Recover sellable oil at the well site before produced water moves into the next treatment stage.
Chemical Pretreatment
Use ahead of reaction tanks, DAF systems or filtration to reduce oil load and improve downstream treatment economics.
Need to size a Centurion train?
Provide BPD, oil concentration, droplet size estimate, solids/iron/paraffin loading and downstream treatment targets.