Chet Goerzen

Topic

Analyzing induced seismicity using the techniques of observational seismology: A case study of a hydraulic fracturing operation in northeast British Columbia

School of Earth and Ocean Sciences

Date & location

• Wednesday, July 3, 2024
• 1:30 P.M.
• Clearihue Building, Room B017

Examining Committee

Supervisory Committee

• Dr. Stan Dosso, School of Earth and Ocean Sciences, University of Victoria (Co-Supervisor)
• Dr. Honn Kao, School of Earth and Ocean Sciences, UVic (Co-Supervisor)
• Dr. Blake Dyer, School of Earth and Ocean Sciences, UVic (Member)

External Examiner

• Dr. Rebecca Swinscoe, Geological Survey of Canada, Natural Resources Canada

Chair of Oral Examination

• Dr. Barbara Hawkins, Department of Biology, UVic

Abstract

This thesis uses techniques of observational seismology to investigate induced seismicity related to a hydraulic fracturing operation. The hydraulic fracturing operation targeted the Montney formation in the Western Canada Sedimentary Basin. This study is unique due to its unprecedented resolution in both seismic data and injection information. An initial earthquake catalog is developed, with 3377 high quality events detected from 2021-01-26 to 2021-06-06. Joint high precision double difference earthquake relocation and tomography are performed. The majority of earthquakes in the catalog were associated with the Tower Lake hydraulic fracturing operation. The study area is located near Taylor, British Columbia, and the hydraulic fracturing operation was targeting the Montney formation for the extraction of oil and gas resources. It is found that the cumulative injected fluid volume is the injection parameter with the most influence on seismicity. Injection pressure and rate have less of an effect. This is consistent with the observations that most earthquakes are likely triggered by pore pressure diffusion, rather than the poroelastic effect. Double couple focal mechanisms are also calculated for select earthquakes. The calculated focal mechanisms are generally consistent with the maximum horizontal shear stress in the area. Some small-scale faults are identified using earthquake locations and focal mechanisms. Foreshock sequences are observed along two of the identified faults, demonstrating that fault characterization may be used to help guide injection operations to avoid induced seismicity.