Characterisation of the Basel 1 enhanced geothermal system

Häring, Markus; Schanz, Ulrich; Ladner, Florentin; Dyer, B.

doi:10.1016/j.geothermics.2008.06.002

Cited by 587 publications

(589 citation statements)

References 15 publications

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“…Consistent with observations at Cooper Basin and Soultz, post-injection seismicity at Basel occurs at the outer boundary of the zone of previous seismic activity (Häring et al, 2008). The field Kaiser Effect (Baisch and Harjes, 2003; absence of seismicity until the stress level of previous stimulations is exceeded) is a characteristic feature of geothermal sites located in hot granitic rock masses.…”

Section: Discussionsupporting

confidence: 75%

“…All of these sites have been investigated within the framework of the European Union project GEISER. In Europe, locations include the Lower Rhine Graben site in Soultz-sous-Forêts, France (Evans et al, 2005), the Upper Rhine Graben site in Basel, Switzerland (Häring et al, 2008), Icelandic geothermal test sites , Latera (Italy) and Groß Schönebeck in the North German Basin (Kwiatek et al, 2010). Non-European sites investigated include Berlin, El Salvador (Bommer et al, 2006;Kwiatek et al, 2014), The Geysers in California, USA (Oppenheimer, 1986;Majer et al, 2007), Cooper Basin (Asanuma et al, 2005;Baisch et al, 2006) and Paralana (Hasting et al, 2011;Albaric et al, 2014), both in Australia and Bouillante in Guadeloupe (Sanjuan et al, 2010;Calcagno et al, 2012).…”

Section: Seismic Response To Fluid Injection: Network Design Velocitmentioning

confidence: 99%

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Analysis of induced seismicity in geothermal reservoirs – An overview

et al. 2014

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In this overview we report results of analysing induced seismicity in geothermal reservoirs in various tectonic settings within the framework of the European Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs (GEISER) project. In the reconnaissance phase of a field, the subsurface fault mapping, in situ stress and the seismic network are of primary interest in order to help assess the geothermal resource. The hypocentres of the observed seismic events (seismic cloud) are dependent on the design of the installed network, the used velocity model and the applied location technique. During the stimulation phase, the attention is turned to reservoir hydraulics (e.g., fluid pressure, injection volume) and its relation to larger magnitude seismic events, their source characteristics and occurrence in space and time. A change in isotropic components of the full waveform moment tensor is observed for events close to the injection well (tensile character) as compared to events further away from the injection well (shear character). Tensile events coincide with high Gutenberg-Richter -values and low Brune stress drop values. The stress regime in the reservoir controls the direction of the fracture growth at depth, as indicated by the extent of the seismic cloud detected. Stress magnitudes are important in multiple stimulation of wells, where little or no seismicity is observed until the previous maximum stress level is exceeded (Kaiser Effect). Prior to drilling, obtaining a 3D -wave ( ) and -wave velocity ( ) model down to reservoir depth is recommended. In the stimulation phase, we recommend to monitor and to locate seismicity with high precision (decametre) in real-time and to perform local 4D tomography for velocity ratio ( / ). During exploitation, one should use observed and model induced seismicity to forward estimate seismic hazard so that field operators are in a position to adjust well hydraulics (rate and volume of the fluid injected) when induced events start to occur far away from the boundary of the seismic cloud.

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Section: Discussionsupporting

confidence: 75%

Section: Seismic Response To Fluid Injection: Network Design Velocitmentioning

confidence: 99%

Analysis of induced seismicity in geothermal reservoirs – An overview

et al. 2014

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“…At the same time, it is crucial not to induce or trigger LME, which may not only cause damage at the surface, e.g. Basel EGS (Häring et al 2008), but also lower the efficiency of the geothermal system by the creation of 'hyper-permeable' pathways. If a LME occurs, it may create a master pathway for fluids that can shortcut the reservoir, preventing heat exchange from being efficient.…”

Section: Characterization Of Large Magnitude Events (Lme)mentioning

confidence: 99%

Overview of Geothermal Energy Projects in Europe and the GEISER Project on Induced Seismicity

Yoon

Bruhn²,

Zang³

2013

Journal of Korean Society For Rock Mechanics

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This article provides an overview on the geothermal energy research in Europe and one of the EU funded projects 'GEISER (Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs)' in which the authors were involved. More details are given for description of GEISER, in particular, about aims and discussions and how the project was managed. Emphasis is given to one of the work packages 'Induced Seismicity and Large Magnitude Events (LME)' and results of this work package are summarized. This article intends to summarize the lessons learned in the GEISER project and give recommendations to future geothermal projects by creating Enhanced Geothermal Systems hydraulic stimulation where induced seismicity issues are expected to be a major issue and obstacle.

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“…However, in the past decades, the accompanying induced seismicity became a problem not only at geothermal reservoirs but also in connection with other types of underground mining activities such as hydrocarbon exploitation, as well as potash and coal mining (Evans et al 2012;Majer et al 2007Majer et al , 2012Grünthal 2013;Suckale 2009Suckale , 2010. In particular, in Europe, the induced events at the geothermal site in Basel (Switzerland) related to fluid stimulation ( 3.2 in 2006; Häring et al 2008;Deichmann and Ernst 2009;Deichmann and Giardini 2009) and in Landau (Germany) due to a shut-in in the production phase ( 2.6 in 2009;Grünthal 2013) were the nucleus of an intense and ongoing discussion since both sites are situated in the suburb of the respective cities. For the Basel geothermal site, the induced event even resulted in the termination of the whole project.…”

Section: Introductionmentioning

confidence: 99%

“…This approach was also tested during the hydraulic fracturing at the geothermal site in Basel. However, it was not successful; the fluid injection was halted after the monitoring of 2.6 event followed by a substantial increase in the seismicity rate in general, but a few hours after this shut-in, the 3.2 event occurred (Häring et al 2008;Deichmann and Giardini 2009). Furthermore, from a practical point of view, the traffic light system cannot give recommendations on how to plan the fluid injection strategy once the threshold of seismicity rate and/or peak ground acceleration is reached.…”

Section: Introductionmentioning

confidence: 99%

Forward induced seismic hazard assessment: application to a synthetic seismicity catalogue from hydraulic stimulation modelling

et al. 2014

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The 3.2-induced seismic event in 2006 due to fluid injection at the Basel geothermal site in Switzerland was the starting point for an ongoing discussion in Europe on the potential risk of hydraulic stimulation in general. In particular, further development of mitigation strategies of induced seismic events of economic concern became a hot topic in geosciences and geoengineering.Here, we present a workflow to assess the hazard of induced seismicity in terms of occurrence rate of induced seismic events. The workflow is called Forward Induced Seismic Hazard Assessment (FISHA) as it combines the results of for-ward hydromechanical-numerical models with methods of time-dependent probabilistic seismic hazard assessment. To exemplify FISHA, we use simulations of four different fluid injection types with various injection parameters, i.e. injection rate, duration and style of injection. The hydromechanical-numerical model applied in this study represents a geothermal reservoir with pre-existing fractures where a routine of viscous fluid flow in porous media is implemented from which flow and pressure driven failures of rock matrix and preexisting fractures are simulated, and corresponding seismic moment magnitudes are computed. The resulting synthetic catalogues of induced seismicity, including event location, occurrence time and magnitude, are used to calibrate the magnitude completeness and the parameters a and b of the frequency-magnitude relation. These are used to estimate the time-dependent occurrence rate of induced seismic events for each fluid injection scenario. In contrast to other mitigation strategies that rely on real-time data or already obtained catalogues, we can perform various synthetic experiments with the same initial conditions. Thus, the advantage of FISHA is that it can quantify hazard from numerical experiments and recommend a priori a stimulation type that lowers the occurrence rate of induced seismic events. The FISHA workflow is rather general and not limited to the hydromechanical-numerical model used in this study and can therefore be applied to other fluid injection models.

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Characterisation of the Basel 1 enhanced geothermal system

Cited by 587 publications

References 15 publications

Analysis of induced seismicity in geothermal reservoirs – An overview

Analysis of induced seismicity in geothermal reservoirs – An overview

Overview of Geothermal Energy Projects in Europe and the GEISER Project on Induced Seismicity

Forward induced seismic hazard assessment: application to a synthetic seismicity catalogue from hydraulic stimulation modelling

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