Induced seismicity risk analysis of the hydraulic stimulation of a geothermal well on Geldinganes, Iceland

Abstract

Abstract. The rapid increase in energy demand in the city of Reykjavik has posed the need for an additional supply of deep geothermal energy. The deep-hydraulic (re-)stimulation of well RV-43 on the peninsula of Geldinganes (north of Reykjavik) is an essential component of the plan implemented by Reykjavik Energy to meet this energy target. Hydraulic stimulation is often associated with fluid-induced seismicity, most of which is not felt on the surface but which, in rare cases, can be a nuisance to the population and even damage the nearby building stock. This study presents a first-of-its-kind pre-drilling probabilistic induced seismic hazard and risk analysis for the site of interest. Specifically, we provide probabilistic estimates of peak ground acceleration, European microseismicity intensity, probability of light damage (damage risk), and individual risk. The results of the risk assessment indicate that the individual risk within a radius of 2 km around the injection point is below 0.1 micromorts, and damage risk is below 10−2, for the total duration of the project. However, these results are affected by several orders of magnitude of variability due to the deep uncertainties present at all levels of the analysis, indicating a critical need in updating this risk assessment with in situ data collected during the stimulation. Therefore, it is important to stress that this a priori study represents a baseline model and starting point to be updated and refined after the start of the project.

Induced Seismicity Completeness Analysis for Improved Data Mining

“…The term a fb is agnostic, while alternatives to poroelasticity exist (e.g., Mignan, 2016). A priori knowledge of the Gutenberg-Richter parameters is required in pre-stimulation risk assessment (e.g., Mignan et al, 2015;Broccardo et al, 2020), and the parameterization may be updated during stimulations via a dynamic traffic light system (e.g., Broccardo et al, 2017;Mignan et al, 2017). Note also that the maximum magnitude m mas relates directly to b (e.g., van der Elst et al, 2016;Broccardo et al, 2017).…”

Hydraulic stimulation strategies in enhanced geothermal systems (EGS): a review

“…Even though details of those hydraulic stimulations have not yet been published, the experience at this site illustrates the possibility of CSS to increase the reservoir permeability while mitigating seismic risks in EGS. Another hydraulic stimulation project has also been proposed, combining cyclic injection, TLS, and risk analysis system in a well RV-43 near Reykjavik, Iceland, at a depth from 1001 to 1750 m (Broccardo et al 2020). Furthermore, CSS hydraulic stimulation was also applied to an EGS project in Pohang, South Korea (Park et al 2020), which will be discussed in more detail in Sect.…”

A Strategy for Choosing Red‐Light Thresholds to Manage Hydraulic Fracturing Induced Seismicity in North America

“…One possibility is considering the level of individual risk exposure rather than a cumulative impact on the region. For example, individual risk exposure has been considered for induced earthquakes caused by gas extraction in the Netherlands (Bommer et al, 2017;Crowley et al, 2017;van Elk et al, 2017) and for geothermal projects in Iceland (Broccardo et al, 2020). Individual risk has the advantage that no individual person would exceed a personal level of risk and could be used as additional information to better inform the red-light thresholds for TLPs.…”