Geothermal reservoir characterization and monitoring through Seismic (ambient noise) and Geodetic (InSAR) Imaging applied to Torfajökull volcano and Reykjanes peninsula, Iceland.

Activity: Talk or presentationTalk or presentation at a conference

Description

In this study, we investigate and discuss the potential of two economic geophysical measurement techniques for geothermal reservoir characterization and monitoring: Passive seismic interferometry for better subsurface characterization through seismic imaging (static model) and satellite-based radar interferometry for geodetic imaging (dynamic model). Seismic imaging using passive seismic techniques allows for subsurface characterization via Ambient Noise Tomography, and supports the assessment of geothermal resources without requiring the use of shooting, reducing the cost compared to active seismics. Geodetic imaging, by measuring the surface displacements during and after production, allows for the monitoring of the effects of production and constrains reservoir modelling, and can be achieved through the use of (freely available) satellite imagery. We discuss the results of both techniques over two high enthalpy geothermal sites in Iceland: Reykjanes Peninsula and Torfajökull volcano. While the Reykjanes Peninsula has geothermal fields that have been producing for decades, Torfajökull’s geothermal field, despite being the largest in Iceland, is not producing. For the subsurface characterization, we use S-wave velocity tomographic images derived from ambient noise seismic interferometry over the two geothermal sites. Within the tomographic images, low- and high-velocity anomalies are used to characterize subsurface structures, which complement, with information at greater depths, current geological models. From the monitoring point of view, radar satellite deformation measurements over both areas show displacements (subsidence) due to production (Reykjanes) and due to natural phenomena (Torfajökull). Finally, we summarize the lessons learnt and discuss outcomes on each technique.
Period13 Mar 2020
Event titleNAC 2020: Nederlands Aardwetenschappelijk Congres
Event typeConference
LocationUtrecht, Netherlands
Degree of RecognitionInternational

Keywords

  • InSAR
  • Subsidence
  • seismic interferometry
  • imaging, inversion, nonlinear, reciprocity, full-waveform inversion
  • Geothermal
  • monitoring