A continuous scale-inhibitor treat rate is set in parts per million. Because scale forms in the water, that ppm is usually measured against the produced water — not the total fluid — so the first thing to confirm is which basis your number is on. This page uses the produced-water basis, shows the two-step conversion to litres per day, and notes how a squeeze treatment is sized differently.
Scale forms in the water, so a continuous scale-inhibitor treat rate is usually a ppm of the produced water. Some programs quote it against total produced fluid instead — on a high-water-cut line the two are close, but on a low-water-cut line they differ a lot — so confirm which basis your number is on before you size anything. This page works on the produced-water basis, and covers continuous injection only.
Total produced fluid is the oil rate divided by (1 − WC); the produced water is that total times the water cut:
Example: 10,000 bbl/d of oil at 80% water cut → total 50,000 bbl/d, of which 40,000 bbl/d is water. On this basis the inhibitor is dosed on the 40,000 bbl/d of water.
Convert the water to litres, then take the ppm:
Continuing the example: 40,000 bbl/d × 158.99 = 6,359,600 L/day of water. At a treat rate of 20 ppm: 6,359,600 × 20 ÷ 1,000,000 = ≈ 127 litres/day of neat inhibitor.
This assumes the ppm refers to neat product. If the inhibitor is injected pre-diluted, scale the volume up by the dilution factor.
Produced water, then neat inhibitor at the treat rate, across three field sizes. Barrels converted at 158.99 L/bbl; monthly figure at 30 days.
| Oil rate | Water cut | Produced water | Treat rate | Inhibitor / day | Inhibitor / month |
|---|---|---|---|---|---|
| 2,000 bbl/d | 70% | 4,667 bbl/d | 15 ppm | ≈ 11 L/d | ≈ 0.33 m³ (~2 drums) |
| 10,000 bbl/d | 80% | 40,000 bbl/d | 20 ppm | ≈ 127 L/d | ≈ 3.8 m³ (~19 drums) |
| 20,000 bbl/d | 90% | 180,000 bbl/d | 15 ppm | ≈ 429 L/d | ≈ 12.9 m³ (~64 drums) |
Drum counts use a 200-litre drum. Because the dose is on the water, water cut drives the volume even harder than for a chemical dosed on total fluid.
A squeeze is not a ppm of flow. It is a batch of inhibitor pumped into the formation, sized by a squeeze design — how much inhibitor the rock will retain, the target return concentration, and how long you want the squeeze to last before the returning concentration falls below the minimum effective level. That is a reservoir-and-chemistry calculation, not the topside arithmetic on this page; talk it through with the technical desk.
The treat rate itself is set by the water’s scaling tendency and confirmed by monitoring — this page turns a chosen ppm into volumes, it does not set the rate. Figures are rounded; confirm against your metered rates and your program’s dose basis.