Hydraulic Fracturing‐Induced Seismicity

Abstract

Hydraulic fracturing (HF) is a technique that is used for extracting petroleum resources from impermeable host rocks. In this process, fluid injected under high pressure causes fractures to propagate. This technique has been transformative for the hydrocarbon industry, unlocking otherwise stranded resources; however, environmental concerns make HF controversial. One concern is HF‐induced seismicity, since fluids driven under high pressure also have the potential to reactivate faults. Controversy has inevitably followed these HF‐induced earthquakes, with economic and human losses from ground shaking at one extreme and moratoriums on resource development at the other. Here, we review the state of knowledge of this category of induced seismicity. We first cover essential background information on HF along with an overview of published induced earthquake cases to date. Expanding on this, we synthesize the common themes and interpret the origin of these commonalities, which include recurrent earthquake swarms, proximity to well bore, rapid response to stimulation, and a paucity of reported cases. Next, we discuss the unanswered questions that naturally arise from these commonalities, leading to potential research themes: consistent recognition of cases, proposed triggering mechanisms, geologically susceptible conditions, identification of operational controls, effective mitigation efforts, and science‐informed regulatory management. HF‐induced seismicity provides a unique opportunity to better understand and manage earthquake rupture processes; overall, understanding HF‐induced earthquakes is important in order to avoid extreme reactions in either direction.

Green, yellow, red, or out of the blue? An assessment of Traffic Light Schemes to mitigate the impact of hydraulic fracturing-induced seismicity

“…Hydraulic fracturing-induced seismicity (HF-IS) has become a significant concern for the unconventional gas industry (e.g. Schultz et al, 2020a). The seismicity response has been highly variable between different basins and regions.…”

Well Proximity Governing Stress Drop Variation and Seismic Attenuation Associated With Hydraulic Fracturing Induced Earthquakes

“…Since the start of hydraulic fracturing (HF) activities in 2008, it has experienced a drastic increase of local seismicity, including three significant (M4.5+) earthquakes (International Seismological Centre, 2019). While the large injected volumes of wastewater disposal (WD) are generally ascribed to M4+ induced events in the central and eastern United States (Ellsworth, 2013), it remains to be fully understood why the relatively low fluid injection volumes associated with HF in western Canada (e.g., Schultz et al, 2016;Wang et al, 2020), in Sichuan Basin, China (e.g., Lei et al, 2019) and recently in south Texas (e.g., Fasola et al, 2019) can lead to earthquakes of similar magnitude (e.g., Schultz et al, 2020;van der Elst et al, 2016). With intense injection operations and high levels of local seismicity, the Montney Play provides a natural laboratory to study the causal relation between HF and injection-induced earthquakes (IIEs) in detail (Mahani et al, 2017;Wang et al, 2020).…”

Statistical Modeling and Characterization of Induced Seismicity Within the Western Canada Sedimentary Basin

“…We focus our study on these four clusters, as their seismicity is sufficiently rich for analysis. New clusters continue to emerge, such as those in the area near Red Deer, Alberta (e.g., Schultz et al, 2020).…”