A continuous corrosion-inhibitor treat rate is set in parts per million (ppm). To order chemical, size an injection pump, and budget, you need that as litres per day. The conversion has two steps — work out the total produced fluid from the oil rate and water cut, then take the ppm of it — and one thing to confirm first: whether your target ppm is measured against the total produced fluid (oil plus water) or against the water alone. This page uses the total-fluid basis and covers continuous injection; batch treatment is sized differently.
A continuous treat rate is a ppm, and the usual basis is the total produced fluid passing the injection point. Some programs instead quote it against the produced-water fraction alone — and on a high-water-cut line the two give very different volumes, so confirm which basis your number is on before you size anything. This page works on the total-produced-fluid basis. It also covers continuous injection only: batch or slug treatment is sized as a volume to fill a length of line or a well annulus, not as a ppm of flow.
Water cut is the fraction of the produced liquid that is water. If you produce oil at a known rate and the water cut is WC(as a decimal), the total produced fluid is the oil rate divided by (1 − WC):
Example: 10,000 bbl/d of oil at 80% water cut → 10,000 ÷ (1 − 0.80) = 50,000 bbl/d of total fluid (that is 10,000 bbl oil + 40,000 bbl water). On this basis the inhibitor is dosed on all 50,000.
On a high-water-cut field the total fluid is several times the oil rate, so a treat rate quoted on total fluid but sized against the oil alone would badly under-dose the line.
Convert the fluid to litres, then take the ppm:
Continuing the example: 50,000 bbl/d × 158.99 = 7,949,500 L/day of fluid. At a treat rate of 25 ppm: 7,949,500 × 25 ÷ 1,000,000 = ≈ 199 litres/day of neat inhibitor.
This assumes the ppm refers to neat (undiluted) product. If the inhibitor is injected pre-diluted, scale the volume up by the dilution factor.
Total fluid, 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 | Total fluid | Treat rate | Inhibitor / day | Inhibitor / month |
|---|---|---|---|---|---|
| 2,000 bbl/d | 70% | 6,667 bbl/d | 15 ppm | ≈ 16 L/d | ≈ 0.48 m³ (~2–3 drums) |
| 2,000 bbl/d | 70% | 6,667 bbl/d | 30 ppm | ≈ 32 L/d | ≈ 0.95 m³ (~5 drums) |
| 10,000 bbl/d | 80% | 50,000 bbl/d | 25 ppm | ≈ 199 L/d | ≈ 6.0 m³ (~30 drums) |
| 10,000 bbl/d | 80% | 50,000 bbl/d | 40 ppm | ≈ 318 L/d | ≈ 9.5 m³ (~48 drums) |
| 20,000 bbl/d | 90% | 200,000 bbl/d | 25 ppm | ≈ 795 L/d | ≈ 23.8 m³ (~119 drums) |
Drum counts use a 200-litre drum. Water cut, not oil rate, drives the volume: the 20,000 bbl/d field at 90% water cut makes four times the fluid of the 10,000 bbl/d field at 80%.
Once you have litres per day, multiply by the order period for the volume and divide by the drum or tote size for the count. Corrosion inhibitor is an operating cost that runs for the life of the line, so the number that matters is not the price per litre but the treat rate that holds the corrosion rate at target: a product that protects at 15 ppm where another needs 30 ppm costs, at the same unit price, half as much to run — and the only way to know which does is field monitoring, not the label.
The treat rate itself is set by the line’s corrosivity 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.