气候变化领域集成服务门户(CCPortal): Injection-driven fracture instability in granite: Mechanism and implications

CCPortal

DOI	10.1016/j.tecto.2020.228572
	Injection-driven fracture instability in granite: Mechanism and implications
	Ji Y.; Wu W.
发表日期	2020
ISSN	00401951
卷号	791
英文摘要	An unprecedented increase in earthquakes associated with hydraulic stimulation has been recognized as a major barrier to the development of enhanced geothermal systems. However, the mechanism of injection-induced seismicity remains enigmatic. Here we simulate the critical stress states of sawcut and natural fractures, and examine the fracture instabilities due to fluid injection. We shed light on fluid pressure heterogeneity, injection-induced fracture instability, acoustic emission characteristics and fracture surface evolution. We find that injection-induced fracture instability is strongly dependent on fluid pressure heterogeneity and fracture surface heterogeneity. High injection rates can induce a high fluid overpressure ratio in the sawcut fracture, promoting the rupture of fracture extending into the unpressurized area. The instability of the natural fracture is due to the near-uniform reduction in effective normal stress associated with a low fluid overpressure ratio. Our data indicate that maintaining a low fluid overpressure ratio during injection activities could confine the rupture of fracture within the pressurized area. A turning point of the total moment release may be used as a reference to optimize the fluid injection strategy. The seismic response of rock fracture could be modified by changing fluid pathways between the injection borehole and the fracture and by evolving surface roughness of the fracture within the stimulated volume. © 2020 Elsevier B.V.
关键词	Injection-induced seismicity Laboratory experiments Rock fractures Seismic moment release
英文关键词	Fracture; Geothermal fields; Induced Seismicity; Stability; Surface roughness; Acoustic emission characteristics; Effective normal stress; Enhanced geothermal systems; Fluid overpressure; Fracture instability; Fracture surfaces; Hydraulic stimulations; Uniform reduction; Acoustic emission testing; enhanced geothermal system; fluid injection; fracture flow; granite; hydraulic fracturing; instability; seismic response; seismicity
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207781
作者单位	School of Civil and Environmental Engineering, Nanyang Technological University639798, Singapore
推荐引用方式 GB/T 7714	Ji Y.,Wu W.. Injection-driven fracture instability in granite: Mechanism and implications[J],2020,791.
APA	Ji Y.,&Wu W..(2020).Injection-driven fracture instability in granite: Mechanism and implications.Tectonophysics,791.
MLA	Ji Y.,et al."Injection-driven fracture instability in granite: Mechanism and implications".Tectonophysics 791(2020).