Türkiye is among the world’s leading countries in terms of geothermal resource potential, and geothermal energy is used in many areas, from electricity generation to greenhouse and residential heating. However, with its high temperature and dissolved minerals, geothermal fluid creates a harsh environment for plant equipment. In this environment the two greatest enemies are scaling and corrosion.
Why does scaling occur?
Minerals dissolved underground under high pressure begin to precipitate as the fluid rises to the surface and pressure and temperature change. Calcite (calcium carbonate) deposits form particularly in the zone of the well where pressure drops and carbon dioxide is released, while silica deposits are seen in surface equipment and reinjection lines where the fluid cools.
Consequences of scaling:
- Lower well flow and production losses,
- Reduced heat transfer efficiency in heat exchangers,
- Unplanned shutdowns for mechanical cleaning,
- Clogging of reinjection wells.
Corrosion risk
Dissolved carbon dioxide (CO2), hydrogen sulphide (H2S) and chlorides in geothermal fluids, combined with high temperature, can cause rapid corrosion of carbon steel pipes and equipment. When corrosion products combine with scale, the problem becomes even more complex.
How does chemical treatment work?
Scale inhibitors prevent crystal formation and growth so that minerals stay in solution. They are usually dosed continuously into the well through a capillary tube below the depth where scaling begins. Corrosion inhibitors form a protective film on the metal surface.
Our BiyoGeo series for the geothermal sector focuses on three needs:
- BiyoGeo CS: Prevention of calcite and silica scaling,
- BiyoGeo CI: Corrosion control in CO2 and H2S environments,
- BiyoGeo HX: Treatment for heat exchangers and district heating circuits.
For a successful programme
- Know your fluid: Chemical analysis and the temperature and pressure profile are the basis of product selection.
- Verify thermal stability: The chemical used must not decompose under well conditions.
- Optimise the dosage: Too little gives no protection; too much is an unnecessary cost.
- Monitor: Track programme effectiveness regularly with corrosion coupons, scale measurements and fluid analyses.
Not only geothermal
The same principles apply to cooling towers (BiyoScale), steam boilers (BiyoBoiler), reverse osmosis systems (BiyoRO) and wastewater treatment (BiyoFloc).
Frequently asked questions
How is a scale inhibitor dosed into a well?
In geothermal production wells, the scale inhibitor is usually injected continuously through a capillary tube below the depth where scaling begins. Determining the dosing point correctly requires evaluating the well’s temperature and pressure profile together with the fluid analysis.
Can a scale inhibitor and a corrosion inhibitor be used together?
Yes, but the two products must be compatible with each other and with the fluid. Incompatible products can form precipitates or reduce each other’s effectiveness. Compatibility tests should therefore be carried out before the programme is commissioned.
How do I know the programme is working?
Wellhead pressure and flow, heat exchanger temperature differences, corrosion coupon results and fluid analyses should be monitored regularly. Trends in these data show whether the dosage and product choice are correct.
Conclusion
In geothermal plants, scale and corrosion control is not a cost item but a guarantee of production continuity. We can design a treatment programme specific to your fluid together.
Related products: Water Treatment Chemicals
Let us choose the right product together. For a solution, sample and technical data sheet suited to your plant or project, contact us.