MSc defence by Mayra Raquel Hernández Cabrera

Mayra Raquel Hernández Cabrera from El Salvador, MSc Fellow in Geophysics at University of Iceland will present her MSc project on Thursday 16th of May at 13:30-13:42 at University of Iceland, Askja building, conference room (room 132).  The presentation will be a part of the UI series "Open seminar at Masters-day of Natural Sciences".  

The title of the project is:
3D-density model using gravity data and a Play Fairway Analysis to evaluate the most favorable drilling targets in Berlin Geothermal Field, El Salvador

Mayra's supervisors are:
Gylfi Páll Hersir, geophysicist and independent researcher
Thorbjörg Ágústsdóttir, geophysicist, ÍSOR

Her external examiner is Thorsteinn Egilson, geophysicist, ÍSOR

Abstract
The Berlín Geothermal Field is a high-temperature geothermal system located in the southern flank of the Central Graben and the northwest sector of the Berlín-Tecapa volcanic complex in Usulután, El Salvador. The geothermal system is one of the main geothermal resources in El Salvador, with an installed capacity of 109.2 MWe, composed of three condensing units: two units of 28.1 MWe since 2000, one of 44 MWe operating since 2007, and one binary unit of 9 MWe since 2009. In the area, there are 45 wells, of which 15 are producers, 24 are injection wells, and one well is used for monitoring the reservoir pressure. The rest of the wells are either on standby or abandoned. By 2023, the geothermal power plant delivered approximately 11.08% of the total energy generation in the country. Due to its great importance as a renewable resource, it is deemed of big value to understand the geothermal system better since physical properties (density, electrical resistivity, temperature) permit validating geophysical models for further utilization of the resource. This work aims to evaluate the Berlín Geothermal resource through a 3D model "a conceptual model”, which includes different geoscientific data, and another model called the "Weighted Model", using the Play Fairway Analysis method to identify the most favorable areas to drill new production and reinjection. We used the Geosoft Oasis Montaj and Leapfrog Geothermal programs to build the 3D-density and 3D-weighted models, respectively. This study builds on previous works. The 3D density model, the seismic velocity tomography made in 2022, and the static temperature profile are used to update the conceptual model from 2019 (LAGEO, 2019) as well as, the weighted model made in 2021 (Hernández et al., 2023). The updated conceptual model shows the flow path of deep hot fluids towards platform TR-4, TR-18, and TR-17, which confirms the upflow zones in BGF. Besides, the steam cap of the area which has been identified in boreholes TR-18A and TR-18B and extends towards borehole TR-17A. To summarize, the caprock is confirmed between 1.7 to 2.0 g/cc , the reservoir between 2.3 and 2.6 g/cc and the basement between 2.65 and 3.0 g/cc . The updated Favorability Index model suggests five potential geothermal areas where the best parameters are converging from all models, indicating a favorability equal to or higher than 75%.