Absorption and scattering signature of fluid- injected, hydrocarbon, and low-to-medium enthalpy geothermal reservoirs

The High Agri Valley (HAV, Southern Italy) comprises the largest onshore oil field in Europe and has both significant geothermal extraction potential and one of the highest seismic hazards in Italy. However, seismic imaging and geological mapping have so far produced insufficient evidence regarding the location of fluid reservoirs and human-induced migration pathways within the HAV’s tectonic structures. Here, a 3D scattering and absorption tomography detects hydrocarbons and potential geothermal resources within the Apulian Platform. Seismic scattering differentiates the low-scattering Irpinia tectonic mélange, which deepens in the center of the valley, from the fractured high-scattering carbonates of the Apulian Platform. Seismic absorption identifies regions of fluid reinjection and reveals the preferred pathways for fluids that induce seismicity due to seasonal variations in the water level of the Pertusillo artificial lake. Scattering and absorption imaging provide a powerful tool for both seismic hazard assessment and the exploration of sustainable energy resources.