Friday, February 14, 2020

Science & Technology: Researchers Determine Potential for Occurrence of M > 2.0 Seismicity for Geothermal Operations in Sandstone Target Formations in the Netherlands is Low

Review of induced seismicity in geothermal systems worldwide and implications for geothermal systems in the Netherlands (Cambridge Core)

Here we review the occurrence (or the lack) of felt seismic events in geothermal systems worldwide and identify key factors influencing the occurrence and magnitude of these events. 

Based on this review, we project the findings for seismicity in geothermal systems to typical geothermal formations and future geothermal developments in the Netherlands. 

The case study review shows that doublets that circulate fluids through relatively shallow, porous, sedimentary aquifers far from the crystalline basement are unlikely to generate felt seismic events. On the other hand, stimulations or circulations in or near competent, fractured, basement rocks and production and reinjection operations in high-temperature geothermal fields are more prone to induce felt events, occasionally with magnitudes of M > 5.0. 

Many of these operations are situated in tectonically active areas, and stress and temperature changes may be large. The presence of large, optimally oriented and critically stressed faults increases the potential for induced seismicity. 

The insights from the case study review suggest that the potential for the occurrence of M > 2.0 seismicity for geothermal operations in several of the sandstone target formations in the Netherlands is low, especially if faults can be avoided. The potential for induced seismicity may be moderate for operations in faulted carbonate rocks. 

Induced seismicity always remains a complex and site-specific process with large unknowns, and can never be excluded entirely. However, assessing the potential for inducing felt seismic events can be improved by considering the relevant (site-specific) geological and operational key factors discussed in this article.

Read More..........

Review of induced seismicity in geothermal systems worldwide and implications for geothermal systems in the Netherlands by Loes Buijze, Lonneke van Bijsterveldt, Holger Cremer, Bob Paap, Hans Veldkamp, Brecht B.T. Wassing, Jan-Diederik van Wees, Guido C.N. van Yperen, Jan H. ter Heege. Part of: Netherlands Journal of Geosciences, Volume 98 - Geothermal Energy. Published online by Cambridge University Press: 12 February 2020, e13.

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