Inclusion of seismic refraction techniques in the characterization of the geological context for geothermal exploitation purposes

Abstract

Given the growing importance of geothermal energy in the decarbonization of the energy sector, the application of appropriate methodologies that contribute to a greater knowledge of the resource is considered convenient. In this sense, refraction seismic techniques have proven to be a potential tool to predict the thermal behavior of the subsoil in locations where it is intended to implement a shallow geothermal system. From thermal conductivity measurements on samples with different degrees of compaction and consolidation, and from the propagation speeds of the P waves, a correlation pattern is developed that in turn allows obtaining 2D sections of the average thermal conductivity distribution in depth. The methodology developed shows that it is possible to estimate the evolution of the thermal conductivity parameter of the ground and thus guarantee an adequate design of the well field and the future correct operation of the geothermal system (providing the correct drilling length which would be underestimated by 30% with the standard thermal conductivity values).