Production-Injection at the Costa Rica Geothermal Fields 1994 – 2019: Dr. Alfredo Mainieri Protti (Formerly Miravalles) and Pailas

Abstract

The electricity capacity (from the geothermal resource) installed in Costa Rica is approximately 215 MWe in 2018, increased to 270 MWe with the Pailas II Unit by 2019. There are four steam units installed in Dr. Alfredo Mainieri Protti Geothermal Field (formerly Miravalles Geothermal Field): Unit 1 (55 MWe, although it can reach 60 MWe, 1994), Wellhead Unit (5 MWe, 1995), Unit 2 (55 MWe, although it can reach 60 MWe, 1998) and Unit 3 (29 MWe, 2000), and also a binary plant: Unit 5 (19 MWe, 2004). Pailas has a binary unit with a production of 42 MWe installed (2011). However, the commercial production of the second unit (Pailas II Unit, steam unit) begins in 2019, with a contribution of about 55 MWe. The Dr. Alfredo Mainieri Protti field has supplied the steam and brine needed to generate over twenty four years of exploitation (1994-2018), while Pailas field (Unit I) has approximately seven years of operation, with changes in the configuration of wells. The performance of the fields and changes in strategies, in terms of production-injection, are described in the following sections.