| Title | Case Study: Use of Highly Thermally Stable Calcite Inhibitor to Prevent Scale Formation in Orzunil Production Well |
|---|---|
| Authors | Davide Parravicini, Alessandro Guidetti, Jeremy Rodefer, Adam Johnson, Megan Midkiff |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Chemical treatment for preventing scale formation is now widely used in the geothermal industry. The high temperatures involved in geothermal processes constitute one of the major challenges for most of the standard chemistries currently applied as they may undergo a degradation which cancels their inhibition effect and, in some cases, may generate additional deposition due to by-product formation. In this paper, the use of a novel, highly thermally stable, chemical inhibitor is presented. Lab work has shown a superior performance against calcite at high temperature and it has been decided to confirm lab outcomes during a field trial. Orzunil plant, a 20 MW binary plant located in Guatemala, was the site selected for the trial. It is characterized by high reservoir temperature (220°C) and the brine contains up to 18-22ppm of Calcium . The combination of these two elements leads to significant calcite risk in the production well. Over the three months trial, 8ppm of inhibitor, diluted with condensed steam, have been dosed while calcium content in the brine and production well flow rates have been monitored to assess performance. Trial results suggested an almost complete inhibition of calcite precipitation while no corrosion or deposition in the chemical injection line have been observed. As additional benefit, the dose rate used was about the half of the previously used technology, leading to a significant reduction of the cost of the treatment and confirming that this new technology represents a unique cost-effective solution for geothermal plants affected by calcite risk. |