Investigating stress transfer via fluids in a hydraulic fracturing environment using seismic, geodetic, and hydrological observations coupled with poroelastic modeling techniques
Final Report Abstract
The Western Canadian Sedimentary Basin has experienced a drastic increase in the number of earthquakes thought to be induced by fluid injection during unconventional oil and gas extraction in the last 10 years. The occurrence of magnitude 4+ earthquakes associated with hydraulic fracturing operations in northeast British Columbia and Alberta commonly lead to temporarily production shut-downs and cause safety concerns among local communities. Because the detailed source process and triggering threshold of injection induced earthquakes remains a critical challenge to seismic hazard assessment and mitigation, we proposed to incorporate innovative geophysical and hydrogeological monitoring techniques and numerical tools to study induced seismicity source processes in close proximity to hydraulic fracturing wells in high resolution in the Kiskatinaw area of British Columbia. We installed a dense array of broadband seismometers, and used operational parameters from well-completion reports, geodetic and water well data, modeling, and artificial intelligence approaches to identify temporal variations related to fluid injection, including potential earthquake precursory signals. The multi-faceted analysis performed in this work provides a detailed investigation of the anomalously high seismic response to the stress-perturbations accompanying hydraulic-fracturing activity in the Kiskatinaw area. It also provides an interpretation of the physical processes that led and continue to lead to the high number of induced earthquakes in the study area. Specifically, the findings demonstrate compelling evidence that the stress changes caused by industrial activity in the study region play a key role in the (re-)activation of the geologically younger system of strikeslip faults at shallower depths (comparable to injection depths) that are optimally oriented for failure in the ambient stress field. The magnitudes of stress changes caused by industrial activity are small (e.g., on the order of tidal stress fluctuations, or smaller), suggesting that fluid interaction with geological structures, as opposed to pore pressure or poroelastic stress changes alone, may also play a role in inducing earthquakes. Furthermore, industrial activity may also be consistent with the (re-)activation of more deeply seated normal faults that were emplaced during past episodes of graben formation and have been reactivated in a reverse sense of slip. Our work suggests that the less frequent reverse-sense faults are also consistent with being optimally oriented in the ambient stress field, may occur at depths close to the basement, and are often host earthquakes of larger magnitude relative to shallower layers.
Publications
-
Velocity-structure imaging based on seismological observations close to hydraulic fracturing sites near Dawson Creek, northeastern British Columbia (parts of NTS 093P, 094A); in Geoscience BC Summary of Activities 2019: Energy and Water, Geoscience BC, Report 2020-02, p. 33–40.
Roth, M.P.; Harrington, R.M. & Liu, Y.
-
High-Resolution Imaging of Hydraulic-Fracturing-Induced Earthquake Clusters in the Dawson-Septimus Area, Northeast British Columbia, Canada. Seismological Research Letters, 91(5), 2744-2756.
Roth, Marco P.; Verdecchia, Alessandro; Harrington, Rebecca M. & Liu, Yajing
-
Preliminary results of source parameter inversion of earthquake sequences induced by hydraulic fracturing in the Kiskatinaw area, northeastern British Columbia (parts of NTS 093P, 094A); in Geoscience BC Summary of Activities 2020: Energy and Water, Geoscience BC, Report 2021-02, p. 67–80.
Roth, M.P.; Kemna, K.B.; Harrington, R.M. & Liu, Y.
-
Stress Chatter via Fluid Flow and Fault Slip in a Hydraulic Fracturing‐Induced Earthquake Sequence in the Montney Formation, British Columbia. Geophysical Research Letters, 47(14).
Peña, Castro A. F.; Roth, M. P.; Verdecchia, A.; Onwuemeka, J.; Liu, Y.; Harrington, R. M.; Zhang, Y. & Kao, H.
-
Small Magnitude Events Highlight the Correlation Between Hydraulic Fracturing Injection Parameters, Geological Factors, and Earthquake Occurrence. Geophysical Research Letters, 49(21).
Kemna, Kilian B.; Roth, Marco P.; Wache, Ricarda M.; Harrington, Rebecca M. & Liu, Yajing
-
Source Properties of Hydraulic‐Fracturing‐Induced Earthquakes in the Kiskatinaw Area, British Columbia, Canada. Journal of Geophysical Research: Solid Earth, 127(3).
Roth, M. P.; Kemna, K. B.; Harrington, R. M. & Liu, Y.
