Proposal for an initial development strategy for the Borinquen geothermal zone (Cañas Dulces, Costa Rica)

The uncertainty regarding the dimensions and exact location of the geothermal resource, along with the cost of drilling process of geothermal wells, are usually two factors that hinder the wider use of high enthalpy geothermal energy to generate electricity. In the first half of 2018, the Costa Rican Institute of Electricity (ICE) will begin to develop the Borinquen geothermal zone (drilling). In order to increase the probability of success in this phase, based on the experience acquired during the exploration and development of geothermal energy in Costa Rica, a methodology is proposed in which geospatial techniques are used to design an initial development strategy. This is achieved by combining available topographic, geological, geophysical and thermal gradient data, together with a conceptual model of the hydrothermal system. As a result, we obtain a suitability model that allows us to identify the most appropriate locations for drilling pads, zoning the high enthalpy geothermal resource, and to identify the areas to be used as production and reinjection poles of geothermal fluids. In addition, we use the USGS Heat in Place volumetric method and the Monte Carlo simulator to estimate the electrical energy that will be produced by the geothermal reservoir. The results obtained reveal that this zone has sufficient extractable energy potential to install a geothermal power unit with a capacity of 50 MWe for a period of useful life of 30 years, and we propose a preliminary viable development strategy as the basis for the sustainable exploitation of the Borinquen geothermal field.