Stress Transfer Outpaces Injection-Induced Aseismic Slip and Triggers Seismicity

Abstract

As concerns rise over damaging earthquakes related to industrial activities such as hydraulic fracturing, geothermal energy extraction and wastewater disposal, it is essential to understand how subsurface fluid injection triggers seismicity even in distant regions where pore pressure diffusion cannot reach. Previous studies suggested long-range poroelastic stressing and aseismic slip as potential triggering mechanisms. In this study, we show that significant stress transfer originating from injection-induced aseismic slip can travel at much higher speeds and is a viable mechanism for distant earthquake triggering. It could also explain microseismicity migration that is much faster than aseismic slip front propagation. We demonstrate the application of these concepts with seismicity triggered by hydraulic fracturing operations in Weiyuan Shale Gas Field, China. The speed of stress transfer is dependent on the background stress level and injection rate, and can be almost an order of magnitude higher than that of the aseismic slip front.

Seismological Evidence for the Existence of Long‐Distance Hydrological Channel and Its Implication for Fluid Overpressure in Southern Sichuan, China

“…Fluid injection operations can propagate pore pressure and stress through fluid pressure diffusion, different types of sliding, and pore‐elastic effect (Eyre et al., 2019; Gori et al., 2021). Researches have shown that fluid pressure diffusion typically occurs within a few kilometers from the injection point (Shapiro et al., 1997; Sheng et al., 2022; F. Zhang, Wang, et al., 2022), while significant stress transfer resulting from injection‐induced aseismic slip can propagate at higher speeds and more easily trigger distant earthquakes (Cebry et al., 2022; Guglielmi et al., 2015; Y. Yang et al., 2023). Before the Ms 4.7 event, the well g 048 is in the hydraulic fracturing operation cycle (between June and October 2021 inferred from satellite imagery, see Text S3 in Supporting Information for details), and frequent seismicity was observed in the reservoir below the well.…”

“…Studies on the seismicity migration (Lei et al., 2020; Meng et al., 2018), focal mechanism (Chu & Sheng, 2023; Dai et al., 2023; Liu & Zahradník, 2020; Sheng et al., 2020; Yi et al., 2020), Coulomb stress changes (Lei et al., 2017), finite fault models (S. Wang et al., 2022), statistical analysis (e.g., b ‐values and ETAS models, etc.) (Sheng et al., 2022; Tan et al., 2023), and numerical simulation (H. Yang et al., 2024; Y. Yang et al., 2023) in southern Sichuan suggested that industrial activities could alter the subsurface fluid state, affect the local crustal stress, accelerate the fracturing of tectonic formations, and finally induce earthquakes. On one hand, the direct penetration of fluid into pre‐existing faults increases the pore pressure within faults, thereby facilitating fault slip (Bao & Eaton, 2016; Goebel & Brodsky, 2018; Igonin et al., 2021; Schultz et al., 2017; Yu et al., 2019).…”