High-Resolution Induced Earthquake Catalogs Reveal Non-Planar Faults Near Hydraulic Fracturing Wells in Canada and China
Description:
The development of portable nodal arrays in recent years greatly improved the seismic monitoring ability across multiple scales. The dense arrays also directly benefit microseismic monitoring, providing relatively low-cost surface recordings. In this study, we utilized a machine-learning based workflow to investigate the M<3 events during hydraulic-fracturing (HF) stimulations. Two datasets are analyzed: (1) 33-day recordings from 69 shallow-buried nodes within 5 km of an HF well in the Western Canada Sedimentary Basin (i.e., Toc2ME, 2016); (2) one-weak recordings from up to 85 surface nodes within 10 km of an HF well in the Sichuan Basin, China (i.e., WYC, 2021).
As a result, we detected ~20000 and ~3000 events from the two datasets with relative location errors constrained to meter scale. The event magnitudes range from -2 to 3 for both cases, consisting of both microseismicity and induced earthquakes. Correspondingly, our high-resolution catalogs reveal both the fractures and unmapped short fault segments (i.e., length < 1 km). The structures show strong heterogeneities and non-planar features. A large number of detected events in the high-resolution catalog also permit a detailed investigation of the statistical behavior of different clusters. As expected, we observed higher b-values and lower temporal Cv (coefficient of variance) from fracture-hosted microseismicity. Our comparisons revealed similar and distinctive features from the two HF sites. Aside from the results, we summarized our experience and provided recommendations for applying similar approaches to other local-scale, surface microseismic monitoring. The presented results will benefit induced seismicity regulation by filling the gap between microseismic monitoring and independent case studies of larger events.
Session: Understanding and Managing Induced Seismicity [Poster]
Type: Poster
Date: 4/19/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Ruijia Wang
Student Presenter: No
Invited Presentation:
Authors
Ruijia Wang Presenting Author Corresponding Author ruijia.wang@ualberta.ca Southern University of Science and Technology |
Fangxue Zhang fangxuezhang1998@gmail.com Zhejiang University |
Yunfeng Chen yunfeng_chen@zju.edu.cn Zhejiang University |
Dikun Yang yangdk@sustech.edu.cn Southern University of Science and Technology |
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High-Resolution Induced Earthquake Catalogs Reveal Non-Planar Faults Near Hydraulic Fracturing Wells in Canada and China
Category
Understanding and Managing Induced Seismicity