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Seismological Methods for Geothermal Exploration in Magmatic Settings - Lessons Learned from Hengill Volcano, Iceland
Vala HJÖRLEIFSDÓTTIR, Ásdis BENEDIKTSDOTTIR, Bettina GOERTZ-ALLMAN, Ortensia AMOROSO, Fernando NAPOLITANO, Þorbjörg ÁGÚSTSDOTTIR, Anne OBERMANN
[Reykjavik Energy, Iceland]
While active seismic exploration methods are a staple of oil-and-gas resource estimation, they are rarely used in geothermal exploration in magmatic rift settings. In these settings the lithological units are composed of highly scattering material and interleaved in complex ways. This is in contrast to uniform layers observed in sedimentary settings, with sharp, reflective boundaries between them, making them ideally suited for controlled seismic reflection methods. Furthermore, in magmatic rift geothermal systems the resource does not necessarily follow lithological units, and geothermal fluid-rock interaction may have altered the rock, affecting both porosity and/or permeability. While active seismic methods may not be considered suitable for geothermal settings, other seismological methods and sensing techniques may generate better results. In recent years, several projects (DEEPEN, Carbfix2, S4CE, COSEISMIQ, SUCCEED) have focused on applying various passive seismological methods to the Hengill volcano, and its associated geothermal and carbon mineralization fields. In this study, we will review the results from these experiments, compare them with other datasets from Hengill, and comment on the value of information provided by each method.
Topic: Geophysics