Geophysical Reservoir Characterization of Berlin Geothermal Field, El Salvador

Summary The purpose of this report is to present the geophysical characterization of the Berlin geothermal field reservoir, based on results of different methodologies carried out in different moment, such us: MT, passive seismic and gravity. From MT results, the reservoir corresponds to a resistivity range of 50–90 Ohm- m inside the resistive dome. Its estimated thickness varies from 600 to 800 m. From the 9 years seismic data collected, a seismic tomography modelling was built, this model shows that production zone has good correlation to a seismic waves speed ratio (Vp/Vs) lower than 1.7. The area of this anomaly correlates very well with that suggested by the MT method. Finally the gravity survey result suggests that the Berlin producer reservoir is associated to a high positive gravimetric anomaly which it extends toward the south and southwest of the actual production zone, beyond to the Berlin town.