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 hot water from 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 cause nuisance to the population and even damage to 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 a-priory risk assessment with in-situ data collected during the stimulation.

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.…”

Preventing Instabilities and Inducing Controlled, Slow‐Slip in Frictionally Unstable Systems

“…Numerous laboratory and field experiments focused on determining factors influencing the transition from seismic to a‐seismic slip during fluid injections (see Cappa et al., 2019; Guglielmi et al., 2015; Scuderi & Collettini, 2018; Tinti et al., 2016; Tzortzopoulos et al., 2021, among others). Seismic traffic‐light systems have been also proposed for minimizing seismicity and risks to acceptable levels (see Baisch et al., 2019; Bommer et al., 2006; Bommer et al., 2015; Bosman et al., 2016; Broccardo et al., 2020; Häring et al., 2008; Kwiatek et al., 2019; Verdon & Bommer, 2021; Walters et al., 2015). More recently, “cyclic stimulation” (Hofmann et al., 2018, 2019; Zang et al., 2019) and “fracture caging” (Frash et al., 2021) were proposed for limiting induced seismic events in geothermal energy projects.…”

Induced Earthquake Hazard by Geothermal Power Plants: Statistical Evaluation and Probabilistic Modeling

“…Cheng and Chen (2018) performed a statistical analysis on the distance of observed seismic events induced by the Salton Sea GPP operation, and found that the magnitude of events located outside the defined ring of a GPP (radius of 2−5 km) is five times less than the ones located near the power plant. Broccardo et al (2020) estimated the seismic risk of the Geldinganes GPP in Iceland. Their study emphasized the need for reevaluation of the risk by using updated data throughout a power plant's activity.…”