| Title | Reactivation of a Clogged Reinjection Well by Opening and Putting into Production. Stabilization of Reinjection and Mitigation of the Generation Drop at the Pailas Geothermal Field |
|---|---|
| Authors | Federico Nietzen |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | reinjection capacity decline, well collapse, cooling of production zone, generation jeopardy / power output reduction, Pailas Geothermal Field |
| Abstract | The Pailas I Generating Unit of the Pailas Geothermal Field (Costa Rica) began commercial production in May 2011, with a net output of 35 MW (binary fluids technology). Over time, a decline in the reinjection capacity of one of the main wells (PGP-25) is observed, necessitating the transfer of unused fluids to another area of the field. This action causes cooling in the Pailas II production zone, jeopardizing the generation of the entire complex. To remedy this impact, it is proposed to reduce the reinjection rate, decreasing production from the producing wells and, consequently, generation at Pailas I (by approximately 10 MW). However, the main reinjection well, PGP-25, collapsed in July 2022, making the situation critical. It was then decided to open and put PGP-25 into production, achieving the objective. Once the well was stabilized and the lagoon was at its limit, the well was shut in and reinjection was immediately integrated. Extraordinary reinjection results were obtained, achieving acceptances exceeding 150 l/s at low pressures. These successful reinjection recovery operations in the PGP-25 Pailas well reduced the contribution to the problem zone and thus mitigated the risk of cooling in Pailas II. At the same time, the generation rate in Pailas I was maintained and even increased slightly in the first quarter of 2023. |