Performance assessment of the induced seismicity traffic light protocol for northeastern British Columbia and western Alberta

2018 ◽  
Vol 37 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Honn Kao ◽  
Ryan Visser ◽  
Brindley Smith ◽  
Stuart Venables
Keyword(s):  
British Columbia ◽  
Performance Assessment ◽  
Induced Seismicity ◽  
Traffic Light

Performance Evaluation of the Regional Seismograph Network in Northeast British Columbia, Canada, for Monitoring of Induced Seismicity

2016 ◽  
Vol 87 (3) ◽  
pp. 648-660 ◽  
Author(s):  
Alireza Babaie Mahani ◽  
Honn Kao ◽  
Dan Walker ◽  
Jeff Johnson ◽  
Carlos Salas
Keyword(s):  
British Columbia ◽  
Performance Evaluation ◽  
Induced Seismicity ◽  
Seismograph Network

Well-Log-Based Velocity and Density Models for the Montney Unconventional Resource Play in Northeast British Columbia, Canada, Applicable to Induced Seismicity Monitoring and Research

2020 ◽  
Author(s):  
Alireza Babaie Mahani ◽  
Dmytro Malytskyy ◽  
Ryan Visser ◽  
Mark Hayes ◽  
Michelle Gaucher ◽  
...  
Keyword(s):  
British Columbia ◽  
Hydraulic Fracturing ◽  
Cross Sections ◽  
Induced Seismicity ◽  
Focal Depth ◽  
Depth Resolution ◽  
Velocity Model ◽  
The North ◽  
Seismicity Monitoring ◽  
Unconventional Resource

Abstract We present detailed velocity and density models for the Montney unconventional resource play in northeast British Columbia, Canada. The new models are specifically essential for robust hypocenter determination in the areas undergoing multistage hydraulic-fracturing operations and for detailed analysis of induced seismicity processes in the region. For the upper 4 km of the sedimentary structure, we review hundreds of well logs and select sonic and density logs from 19 locations to build the representative models. For depths below 4 km, we extend our models using data from the southern Alberta refraction experiment (Clowes et al., 2002). We provide one set of models for the entire Montney play along with two separated sets for the southern and northern areas. Specifically, the models for the southern and northern Montney play are based on logs located in and around the Kiskatinaw Seismic Monitoring and Mitigation Area and the North Peace Ground Motion Monitoring area, respectively. To demonstrate the usefulness of our detailed velocity model, we compare the hypocenter location of earthquakes that occurred within the Montney play as determined with our model and the simple two-layered model (CN01) routinely used by Natural Resources Canada. Locations obtained by our velocity model cluster more tightly with the majority of events having root mean square residual of <0.2  s compared with that of <0.4  s when the CN01 model is used. Cross sections of seismicity versus depth across the area also show significant improvements in the determination of focal depths. Our model results in a reasonable median focal depth of ∼2  km for events in this area, which is consistent with the completion depths of hydraulic-fracturing operations. In comparison, most solutions determined with the CN01 model have fixed focal depths (0 km) due to the lack of depth resolution.

scholarly journals Application of focal-time analysis for improved induced seismicity depth control: A case study from the Montney Formation, British Columbia, Canada

Geophysics ◽  
2020 ◽  
Vol 85 (6) ◽  
pp. KS185-KS196 ◽  
Author(s):  
Naimeh Riazi ◽  
David W. Eaton ◽  
Alemayehu Aklilu ◽  
Andrew Poulin
Keyword(s):  
British Columbia ◽  
Seismic Data ◽  
Induced Seismicity ◽  
Search Algorithm ◽  
Focal Depth ◽  
Global Search ◽  
3D Seismic ◽  
Global Search Algorithm ◽  
Montney Formation ◽  
3D Seismic Data

Characterization of induced seismicity and associated microseismicity is an important challenge for enhanced oil recovery and development of tight hydrocarbon reservoirs. In particular, accurately correlating hypocenters of induced events to stratigraphic layers plays an important role in understanding the mechanisms of fault activation. Existing methods for estimating focal depth, however, are prone to a high degree of uncertainty. A comprehensive analysis of inferred focal depths is applied to induced events that occurred during completions of horizontal wells targeting the Montney Formation in British Columbia, Canada. Our workflow includes a probabilistic, nonlinear global-search algorithm (NonLinLoc), a hierarchical clustering algorithm for relative relocation (GrowClust), and depth refinement using the recently developed focal-time method. The focal-time method leverages stratigraphic correlations between P-P and P-S reflections to eliminate the need for an explicit velocity model developed specifically for hypocenter depth estimation. We find that this approach is robust in the presence of noisy picks and location errors from epicenters obtained using a global-search algorithm, but it is limited to areas where multicomponent 3D seismic data are available. We have developed a novel method to determine statics corrections to ensure that the passive seismic observations and 3D seismic data share a common datum in areas of moderate to high topography. Our results highlight the importance of transverse faults, which appear to provide permeable pathways for activation of other faults at distances of up to 2 km from hydraulic fracturing operations.

Seismic b-value within the Montney Play of Northeast British Columbia, Canada

2021 ◽  
Author(s):  
Alireza Babaie Mahani
Keyword(s):  
British Columbia ◽  
Hydraulic Fracturing ◽  
Induced Seismicity ◽  
B Value ◽  
Systematic Difference ◽  
Magnitude Distribution ◽  
Seismicity Rate ◽  
Northern Area ◽  
Seismicity Rates ◽  
Frequency Magnitude Distribution

Critical analysis of induced earthquake occurrences requires comprehensive datasets obtained by dense seismographic networks. In this study, using such datasets, I take a detailed investigation into induced seismicity that occurred in the Montney play of northeast British Columbia, mostly caused by hydraulic fracturing. The frequency-magnitude distribution (FMD) of earthquakes in several temporal and spatial clusters, show fundamental discrepancies between seismicity in the southern Montney play (2014-2018) and the northern area (2014-2016). In both regions, FMDs follow the linear Gutenberg-Richter (G-R) relationship for magnitudes up to 2-3. While in the southern Montney, within the Fort St. John graben complex, the number of earthquakes at larger magnitudes falls off rapidly below the G-R line, within the northern area with a dominant compressional regime, the number of events increases above the G-R line. This systematic difference may have important implications with regard to seismic hazard assessments from induced seismicity in the two regions, although caution in the interpretation is warranted due to local variabilities. While for most clusters within the southern Montney area, the linear or truncated G-R relationship provide reliable seismicity rates for events below magnitude 4, the G-R relationship underestimates the seismicity rate for magnitudes above 3 in northern Montney. Using a well-located dataset of earthquakes in southern Montney, one can observe generally that 1) seismic productivity correlates well with the injected volume during hydraulic fracturing and 2) there is a clear depth dependence for the G-R b-value; clusters with deeper median depths show lower b-values than those with shallower depths.

Characteristics of induced seismicity during hydraulic stimulations

2020 ◽  
Author(s):  
Georg Dresen ◽  
Stephan Bentz ◽  
Grzegorz Kwiatek ◽  
Patricia Martínez-Garzón ◽  
Marco Bohnhoff
Keyword(s):  
Real Time ◽  
Seismic Moment ◽  
Induced Seismicity ◽  
Fluid Volume ◽  
Physical Models ◽  
Traffic Light ◽  
Induced Earthquakes ◽  
Induced Earthquake ◽  
Energy Pumping ◽  
Good Agreement

<p>Near-realtime seismic monitoring of fluid injection allowed control of induced earthquakes during the stimulation of a 6.1 km deep geothermal well near Helsinki, Finland. The stimulation was monitored in near-real time using a deep seismic borehole array and series of borehole stations. Earthquakes were processed within a few minutes and results informed a Traffic Light System (TLS). Using near-realtime information on induced-earthquake rates, locations, magnitudes, and evolution of seismic and hydraulic energy, pumping was either stopped or varied. This procedure avoided the nucleation of a project-stopping red alert at magnitude M2.1 induced earthquake, a limit set by the TLS and local authorities. Our recent studies show that the majority of EGS stimulation campaigns investigated reveal a clear linear relation between injected fluid volume, hydraulic energy and cumulative seismic moments suggesting extended time-spans during which induced seismicity evolution is pressure-controlled. For most projects studied, the observations are in good agreement with existing physical models that predict a relation between injected fluid volume and maximum seismic moment of induced events. Some EGS stimulations however reveal unbound increase in seismic moment suggesting that for these cases evolution of seismicity is mainly controlled by stress field, the size of tectonic faults and fault connectivity. Transition between the two states may occur at any time during injection, or not at all. Monitoring and traffic-light systems used during stimulations need to account for the possibility of unstable rupture propagation from the very beginning of injection by observing the entire seismicity evolution in near-real-time and at high resolution could possibly provide a successful physics-based approach in reducing seismic hazard from stimulation-induced seismicity in geothermal projects.</p>

Experiences and learnings from induced seismicity regulation in Alberta

2018 ◽  
Vol 6 (2) ◽  
pp. SE15-SE21 ◽  
Author(s):  
Todd Shipman ◽  
Ron MacDonald ◽  
Tom Byrnes
Keyword(s):  
Hydraulic Fracturing ◽  
Induced Seismicity ◽  
Red Light ◽  
Seismic Hazard Assessment ◽  
Traffic Light ◽  
Regulatory Requirements ◽  
Current State ◽  
New Information ◽  
Response Plan ◽  
The Town

We have examined the experiences and learnings acquired through the implementation of the Alberta Energy Regulator’s (AER) subsurface order no. 2 (sub or no. 2) traffic light protocol (TLP). On 22 January 2015, a 4.4 [Formula: see text] seismic event occurred near a hydraulic fracturing operation in west-central Alberta and was felt by residents of the town of Fox Creek. On 19 February 2015, the AER issued sub or no. 2 to help manage induced seismicity, as related to hydraulic fracturing of the Duvernay zone in a prescribed area around Fox Creek. Sub or no. 2 requires operators affected by the order to conduct a seismic hazard assessment; prepare a monitoring, mitigation, and response plan; conduct seismic monitoring; and adhere to a TLP. Since sub or no. 2 was issued, two “red light” events (i.e., [Formula: see text]) have occurred in the area. Review and analysis of data and information collected under sub or no. 2 facilitate an improved understanding of the key geologic and operational controls on induced seismicity and allow for an assessment of the efficacy of industry practices and regulatory requirements. We still support the use of local magnitude [Formula: see text] for our TLP based on the purpose and outcomes provided by sub or no. 2. Conversations with operators have suggested that [Formula: see text] orientation should inform the wells’ trajectory with respect to critically stressed faults. The requirement of a response plan was part of the learning process developed under sub or no. 2. Through this exercise, the AER has developed a better understanding of the goals of the response plans, which were better defined through conversations with operators. Sub or no. 2 is consistent with the current state of the evolving science of induced seismicity and has the capacity to change as new information is obtained.

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