scholarly journals Influence of pore-pressure on the event-size distribution of induced earthquakes

2012 ◽  
Vol 39 (9) ◽  
pp. n/a-n/a ◽  
Author(s):  
C. E. Bachmann ◽  
S. Wiemer ◽  
B. P. Goertz-Allmann ◽  
J. Woessner
Keyword(s):  
Size Distribution ◽  
Pore Pressure ◽  
Induced Earthquakes

Comprehensive Characterization and Mitigation of Hydraulic Fracturing-Induced Seismicity in Fox Creek, Alberta

SPE Journal ◽  
2021 ◽  
pp. 1-12
Author(s):  
Gang Hui ◽  
Shengnan Chen ◽  
Zhangxin Chen ◽  
Fei Gu ◽  
Mathab Ghoroori ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Hydraulic Fracturing ◽  
Pore Pressure ◽  
Hydraulic Fracture ◽  
Induced Seismicity ◽  
Mitigation Strategy ◽  
Moment Magnitude ◽  
Induced Earthquakes ◽  
Data Set ◽  
Comprehensive Characterization

Summary The relationships among formation properties, fracturing operations, and induced earthquakes nucleated at distinctive moments and positions remain unclear. In this study, a complete data set on formations, seismicity, and fracturing treatments is collected in Fox Creek, Alberta, Canada. The data set is then used to characterize the induced seismicity and evaluate its susceptibility toward fracturing stimulations via integration of geology, geomechanics, and hydrology. Five mechanisms are identified to account for spatiotemporal activation of the nearby faults in Fox Creek, where all major events [with a moment magnitude (Mw) greater than 2.5] are caused by the increase in pore pressure and poroelastic stress during the fracturing operation. In addition, an integrated geological index (IGI) and a combined geomechanical index (CGI) are first proposed to indicate seismicity susceptibility, which is consistent with the spatial distribution of induced earthquakes. Finally, mitigation strategy results suggest that enlarging a hydraulic fracture-fault distance and decreasing a fracturing job size can reduce the risk of potential seismic activities.

scholarly journals Pore Pressure Analysis for Distinguishing Earthquakes Induced by CO2 Injection from Natural Earthquakes

2020 ◽  
Vol 12 (22) ◽  
pp. 9723
Author(s):  
Chanmaly Chhun ◽  
Takeshi Tsuji
Keyword(s):  
Pore Pressure ◽  
Co2 Storage ◽  
Carbon Capture And Storage ◽  
Co2 Injection ◽  
Storage Site ◽  
Seasonal Fluctuations ◽  
Induced Earthquakes ◽  
Seismogenic Fault ◽  
Seismogenic Faults ◽  
Natural Earthquakes

It is important to distinguish between natural earthquakes and those induced by CO2 injection at carbon capture and storage sites. For example, the 2004 Mw 6.8 Chuetsu earthquake occurred close to the Nagaoka CO2 storage site during gas injection, but we could not quantify whether the earthquake was due to CO2 injection or not. Here, changes in pore pressure during CO2 injection at the Nagaoka site were simulated and compared with estimated natural seasonal fluctuations in pore pressure due to rainfall and snowmelt, as well as estimated pore pressure increases related to remote earthquakes. Changes in pore pressure due to CO2 injection were clearly distinguished from those due to rainfall and snowmelt. The simulated local increase in pore pressure at the seismogenic fault area was much less than the seasonal fluctuations related to precipitation and increases caused by remote earthquakes, and the lateral extent of pore pressure increase was insufficient to influence seismogenic faults. We also demonstrated that pore pressure changes due to distant earthquakes are capable of triggering slip on seismogenic faults. The approach we developed could be used to distinguish natural from injection-induced earthquakes and will be useful for that purpose at other CO2 sequestration sites.

scholarly journals Preparation and Characterization of Latex Particles as Potential Physical Shale Stabilizer in Water-Based Drilling Fluids

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Junyi Liu ◽  
Zhengsong Qiu ◽  
Wei’an Huang ◽  
Dingding Song ◽  
Dan Bao
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Methyl Methacrylate ◽  
Size Distribution ◽  
Pore Pressure ◽  
Water Medium ◽  
Gravimetric Analysis ◽  
Latex Particles ◽  
Pressure Transmission ◽  
Ft Ir

The poly(styrene-methyl methacrylate) latex particles as potential physical shale stabilizer were successfully synthesized with potassium persulfate as an initiator in isopropanol-water medium. The synthesized latex particles were characterized by Fourier transform infrared spectroscopy (FT-IR), particle size distribution measurement (PSD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). FT-IR and TGA analysis confirmed that the latex particles were prepared by polymerization of styrene and methyl methacrylate and maintained good thermal stability. TEM and PSD analysis indicated that the spherical latex particles possessed unimodal distribution from 80 nm to 345 nm with the D90 value of 276 nm. The factors influencing particle size distribution (PSD) of latex particles were also discussed in detail. The interaction between latex particles and natural shale cores was investigated quantitatively via pore pressure transmission tests. The results indicated that the latex particles as potential physical shale stabilizer could be deformable to bridge and seal the nanopores and microfractures of shale to reduce the shale permeability and prevent pore pressure transmission. What is more, the latex particles as potential physical shale stabilizer work synergistically with chemical shale stabilizer to impart superior shale stability.

scholarly journals Pore pressure studies initiated in area of reservoir-induced earthquakes in India

Eos ◽  
2000 ◽  
Vol 81 (14) ◽  
pp. 145 ◽  
Author(s):  
H. K. Gupta ◽  
I. Radhakrishna ◽  
R. K. Chadh ◽  
H.-J. Kümpel ◽  
G. Grecks
Keyword(s):  
Pore Pressure ◽  
Induced Earthquakes

scholarly journals Pore-pressure diffusion, enhanced by poroelastic stresses, controls induced seismicity in Oklahoma

2019 ◽  
Vol 116 (33) ◽  
pp. 16228-16233 ◽  
Author(s):  
Guang Zhai ◽  
Manoochehr Shirzaei ◽  
Michael Manga ◽  
Xiaowei Chen
Keyword(s):  
Pore Pressure ◽  
Induced Seismicity ◽  
Energy Demand ◽  
Regional Scale ◽  
Exceedance Probability ◽  
Resource Exploitation ◽  
Induced Earthquakes ◽  
Seismicity Rate ◽  
Pressure Diffusion ◽  
Stress Changes

Induced seismicity linked to geothermal resource exploitation, hydraulic fracturing, and wastewater disposal is evolving into a global issue because of the increasing energy demand. Moderate to large induced earthquakes, causing widespread hazards, are often related to fluid injection into deep permeable formations that are hydraulically connected to the underlying crystalline basement. Using injection data combined with a physics-based linear poroelastic model and rate-and-state friction law, we compute the changes in crustal stress and seismicity rate in Oklahoma. This model can be used to assess earthquake potential on specific fault segments. The regional magnitude–time distribution of the observed magnitude (M) 3+ earthquakes during 2008–2017 is reproducible and is the same for the 2 optimal, conjugate fault orientations suggested for Oklahoma. At the regional scale, the timing of predicted seismicity rate, as opposed to its pattern and amplitude, is insensitive to hydrogeological and nucleation parameters in Oklahoma. Poroelastic stress changes alone have a small effect on the seismic hazard. However, their addition to pore-pressure changes can increase the seismicity rate by 6-fold and 2-fold for central and western Oklahoma, respectively. The injection-rate reduction in 2016 mitigates the exceedance probability of M5.0 by 22% in western Oklahoma, while that of central Oklahoma remains unchanged. A hypothetical injection shut-in in April 2017 causes the earthquake probability to approach its background level by ∼2025. We conclude that stress perturbation on prestressed faults due to pore-pressure diffusion, enhanced by poroelastic effects, is the primary driver of the induced earthquakes in Oklahoma.

Statistical mechanics-based forecasting of induced seismicity within the Groningen gas field

2020 ◽  
Author(s):  
Stephen Bourne ◽  
Steve Oates
Keyword(s):  
Size Distribution ◽  
Induced Seismicity ◽  
Gas Production ◽  
Linear Functions ◽  
Fault System ◽  
Induced Earthquakes ◽  
Gas Field ◽  
Hazard And Risk ◽  
Stress Dependent ◽  
Groningen Gas Field

<p>Geological faults may fail and produce earthquakes due to external stresses induced by hydrocarbon recovery, geothermal extraction, CO<sub>2</sub> storage or subsurface energy storage. The associated hazard and risk critically depend on the spatiotemporal and size distribution of any induced seismicity. The observed statistics of induced seismicity within the Groningen gas field evolve as non-linear functions of the poroelastic stresses generated by pore pressure depletion since 1965. The rate of earthquake initiation per unit stress has systematically increased as an exponential-like function of cumulative incremental stress over at least the last 25 years of gas production. The expected size of these earthquakes also increased in a manner consistent with a stress-dependent tapering of the seismic moment power-law distribution. Aftershocks of these induced earthquakes are also observed, although evidence for any stress-dependent aftershock productivity or spatiotemporal clustering is inconclusive.</p><p>These observations are consistent with the reactivation of a mechanically disordered fault system characterized by a large, stochastic prestress distribution. If this prestress variability significantly exceeds the induced stress loads, as well as the earthquake stress drops, then the space-time-size distribution of induced earthquakes may be described by mean field theories within statistical fracture mechanics. A probabilistic seismological model based on these theories matches the history of induced seismicity within the Groningen region and correctly forecasts the seismicity response to reduced gas production rates designed to lower the associated seismic hazard and risk.</p>

Sign in / Sign up

Export Citation Format

Share Document