Water injection
Treated water injected into a reservoir to maintain pressure and support oil production — reservoir flooding, not a treatment-for-discharge duty. Water quality here is set by reservoir compatibility, not a discharge or reuse standard.
| Parameter | Value |
|---|---|
| Typical capacity range | Field-dependent — from a few thousand to tens of thousands of m³/day, matched to reservoir voidage replacement requirements |
| Pre-treatment approach | Fine filtration and oxygen scavenging/deoxygenation, sized to the injection water source (produced water, seawater, or aquifer water) |
| Achievable performance | Suspended solids and oil-in-water reduced to levels compatible with the reservoir's formation permeability, set case by case rather than to a fixed target |
| Egyptian feed-water challenge | Produced-water reuse for injection carries residual oil and scaling ions (barium, strontium, sulfate) that filtration alone doesn't address |
| Design response | Scale-inhibitor dosing matched to the produced water's ion chemistry, with compatibility testing against the specific reservoir before the injection scheme is finalised |
Injection water quality is judged against the reservoir, not a discharge permit — a scheme that passes every standard water-quality test can still fail if its ion chemistry is incompatible with the formation water it's about to meet underground.