BIO: Pradeep Talwani,
Distinguished Professor Emeritus of Geophysics
The University of South Carolina.
Columbia, South Carolina
M.Sc. (Indian School of Mines, 1962)
Ph.D. (Stanford University, 1973)
Employed with the University of South Carolina from 1973 to present.
I have been involved in the study of Reservoir Induced Seismicity (RIS) since 1974, with an emphasis on understanding its mechanism. Besides a study of RIS at six locations in South Carolina, I have visited and/or studied RIS in Brazil, Canada, China, Egypt, India, Spain and Viet Nam. These studies have been complemented by a study of injection-induced seismicity. Another area of my research involves Intraplate Earthquakes.
BIO: William L. Ellsworth is a professor in the Department of Geophysics at Stanford University where he co-directs the Stanford Center for Induced and Triggered Seismcity. His research focuses on the seismological study of active faults, the earthquakes they generate and the physics of the earthquake source. He received B.S. in Physics and M.S. in Geophysics from Stanford University and his Ph.D. in Geophysics from MIT. He is a past President of the Seismological Society of America, a Fellow of the American Geophysical Union, and recipient of the Distinguished Service Award of the Department of the Interior.
16:00 – 17:30 POSTER SESSION – Castle Room
18:00 – 20:00 Icebreaker Reception sponsored by Western University & University of Southern California – ALPINE MEADOWS
07:00 – 08:30 – Breakfast Buffet – Glacier Salon
08:30 – 10:00
BIO: Yehuda Ben-Zion is a Professor of Geophysics at the University of Southern California. His research focuses on the physics of earthquakes and faults using a variety of theoretical frameworks and observational results. Ben-Zion received B.Sc. in physics and geology from the Hebrew University of Jerusalem in 1982 and Ph.D. in geophysics from the University of Southern California in 1990. He had visiting Professor positions in several institutions in Japan, Germany, Australia, France, Norway, China and the US. Ben-Zion is a fellow of the American Geophysical Union and received the Mercator fellowship from the German Research Society and the Humboldt Research Prize in geophysics.
This session will discuss basic processes leading to transitions from ongoing small failure events to large earthquakes, and how to track approaching large events with recorded data. The discussed material will include perspectives from laboratory experiments, analysis of in-situ data and well-instrumented field experiments.
BIO: Ilya Zaliapin‘s bio follows:
1999 PhD in Physics and Mathematics, Russian Academy of Science, MITPAN. Advisors: Vladilen Pisarenko, Vladimir Piterbarg
1995 MSc in Mathematics and Applied Mathematics (Probability and Statistics), Lomonosov Moscow State University, Department of Probability Theory, Advisor: Vladimir Piterbarg
Position: Professor, Director of Statistics and Data Science PhD program
Interests include: Self-similar trees, network transport; Aggregation (coagulation) processes; Delay Equations; Multiscale methods of time series analysis; Random sums of heavy-tailed variables; Statistical seismology, geo-statistics; Statistical consulting.
Natural and laboratory faults typically display characteristic structural patterns that evolve in space and time resulting in complex anastomosing networks of slip zones showing aspects of band-limited self-similarity across a broad range of spatial scales. Individual slip surfaces show varying roughness and are embedded in zones of distributed damage. Field studies and laboratory experiments suggest that structural heterogeneity and fault zone roughness may affect seismic characteristics such as earthquake magnitudes, recurrence intervals, b-values, radiated energy, and stress drops.
BIO: Georg Dresen is a Professor of Geology at the University of Potsdam and headed the Geomechanics and Rheology group at the GeoForschungsZentrum Potsdam from 1992-2017. He finished his PhD in Structural Geology at the University of Bonn in 1984 and his Habilitation in 1990. Between 1989 and 1993 he was a research scientist in the rock physics group at Department of Earth, Atmospheric and Planetary Sciences at MIT, Cambridge, Mass. His research interests comprise rock mechanics and geomechanics, wellbore stability problems, reservoir stimulation and induced seismicity, physics of earthquakes and faulting, scaling relations of geological processes, the macroscopic constitutive behaviour of rocks and rock transport properties. He is co-PI of an ICDP fault drilling project at the North Anatolian Fault (Turkey) and involved in several industry- and EU-funded projects focusing on geomechanics, unconventional reservoir rocks and geothermal energy is the co-founder of two start-up companies active in geomechanics and microseismics.
Speaker: Ze’ev Reches – Authors: F. Kolawole, C. S. Johnston, C. B. Morgan, J. C. Chang, K. Marfurt, D. A. Lockner, B. M. Carpenter
Affiliations: School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma, USA. Oklahoma Geological Survey, Norman, Oklahoma; Currently: US Geological Survey, Menlo Park, CA, USA.
BIO: Professional Preparation of Ze’ev Reches
Hebrew University, Jerusalem, Israel, Geology, 1967-1970 B.Sc.; Hebrew University, Jerusalem, Israel, Geology, 1970-1972 M.Sc.; Stanford University., California, Geology, 1973-1977 Ph.D.
Appointments of Ze’ev Reches: 2016 to present University of Oklahoma, Norman, OK Geol./Geoph Professor Emeritus; 2002-2015 University of Oklahoma, Norman, OK Geol./Geoph Anadarko Centennial Professor; 1989-2002 Hebrew University, Jerusalem Geology Kozenitsky-Rosenbach Prof.
09:45 – 10:00 Q&A with Panel
10:00 – 10:30 Coffee Break and POSTER SESSION – Castle Room
10:30 – 12:45 Hazard and Mitigation with Chair, Dr. Gail Atkinson, Western University
Hazards to infrastructure and their mitigation are explored from several perspectives. These include hindcasting of induced-seismicity hazard based on observations (such as 1-year hazard maps) and developments in forecasting models based on operational parameters and geological susceptibility, including machine-learning approaches. Improvements to hazard models to better account for spatial and temporal clustering behaviours are also explored.
The 2018 one‐year probabilistic seismic hazard forecast for the central and eastern United States from induced and natural earthquakes is developed using the same probabilistic seismicity‐based methodology as applied in the two previous forecasts. Rates of earthquakes across the U.S. have steadily declined over the past 3 years, especially in areas of Oklahoma and southern Kansas where fluid injection has decreased. The seismicity pattern in 2017 was complex with earthquakes more spatially dispersed than in the previous years. Some areas of west‐central Oklahoma experienced increased activity rates where industrial activity increased. Earthquake rates continue to be higher than historical levels. Almost all earthquakes occurred within the highest hazard regions of the 2017 forecast. Fine details and variability between the 2016–2018 forecasts are obscured by significant uncertainties in the input model. These short‐term hazard levels are similar to active regions in California.
Co-Authors: Charles Mueller, USGS & Morgan Moschetti, USGS
BIO: Dr. Mark D. Petersen is a regional coordinator for the U.S. Geological Survey’s (USGS) Earthquake Program and chief of the U.S. National Seismic Hazard Project. Dr. Petersen led the development of the 1996 (California Geological Survey) and 2002 (USGS) versions of the California Seismic hazard maps and 2008, 2014, and 2018 versions of the U.S. National Seismic Hazard Models that are applied in building codes, risk assessments, and public policy. He developed 3 one-year USGS forecasts for the Central and Eastern U.S. for induced and natural earthquakes.
Feature importance suggests that proximity to basement, in situ stress, proximity to fossil reef margins, lithium concentration, and rate of natural seismicity are among the strongest model predictors. Our derived seismogenic potential map faithfully reproduces the current distribution of induced seismicity and is suggestive of other regions which may be prone to induced earthquakes. The refinement of induced seismicity geological susceptibility may become an important technique to identify significant underlying geological features and address induced seismic hazard forecasting issues.
Co-Authors are Ryan Schultz, Steven Pawley , Tiffany Playter, Hilary Corlett , Todd Shipman, Steven Lyster, and Tyler Hauck.
BIO: Ryan Schultz has been a seismologist at the Alberta Geological Survey in Edmonton, Alberta for close to seven years.
Authors: N. Abrahamson and C. Hale
Abstract: The effect of induced seismicity on the seismic risk of the earth dams is evaluated using a simplified approach to estimating seismic deformation of embankment dams combined with a probabilistic hazard analyses for induced earthquakes and for naturally occurring earthquakes. Hale (2018) developed a simplified model of the impulse response of the sliding mass based on an equivalent linear approach. The Abrahamson et al (2014) GMPE is modified to be applicable for induced earthquakes. Specifically, the short-period ground motion at distances less than 20 km is significantly increased compared to the Abrahamson et al (2014) GMPE for crustal earthquakes. The deformation is estimated by combining spectrum-compatible time histories for the input motion with the impulse response of the sliding mass and then computing a Newmark displacement. Although simplified, this approach allows the full frequency range of the input motion to be considered in the estimation of the deformation rather than using a single ground motion parameter such as PGA or PGV. This is important for induced earthquakes due to the enriched high-frequency content of induced earthquakes compared to current GMPEs for crustal earthquakes. Deformations from deterministic scenarios for a range of magnitudes, distances, and yield accelerations are computed for dam heights from 25 ft to 150 ft. Comparing these deformation with the available freeboard allows for setbacks to be selected. In addition, an example of a probabilistic analysis of the deformation hazard is shown which shows the increase in the deformation hazard due to the addition of the induced seismicity.
BIO: Dr. Abrahamson is an engineering seismologist with expertise in ground-motion models, seismic hazard, and seismic risk. This year, he retired from PG&E after 22 years as the technical manager for PG&E seismic research program on the seismic studies for application to PG&Es nuclear power plants, dams, office buildings, gas pipelines, and electric grid. He is currently an adjunct professor in the civil engineering departments at UC Berkeley and UC Davis. He also serves as a consultant for seismic hazard and seismic risk studies for nuclear power plants, dams, and bridges around the world.
BIO: Gail Atkinson conducts research at the engineering-seismology interface. She has authored over 200 research articles on earthquake ground motions and seismic hazards and has also been active in the development of seismic design regulations for buildings, dams and nuclear power plants. Professor Atkinson has served as President of both the Seismological Society of America and the Canadian Geophysical Union, is a member of the U.S. National Earthquake Prediction Evaluation Council, and a Fellow of Royal Society of Canada. She currently holds the NSERC/TransAlta/Nanometrics Industrial Research Chair in Hazards from Induced Seismicity.
11:55 – 12:30 Q&A with Panel
12:30 – 13:30 Lunch Break in the Glacier Salon and POSTER SESSION – Castle Room
14:00 – 15:30 High-quality datasets: Hits and Misses. An interactive session with shorter talks focusing on possible uses of presented datasets with Chair, Dr. David Eaton, University of Calgary
Acquisition of high-quality datasets has provided insights into underlying processes, ground-motion relationships and traffic light protocols for induced seismicity. The advent of large-N geophone arrays, in particular, offers new opportunities to characterize source-processes and wave fields. There are some challenges, however, that hinder high-quality data acquisition, including lack of access to sufficient proprietary data and suitable field locations. This session will cover recent successes as well as a retrospective look at remaining challenges.
BIO: Honn Kao obtained his BSc in Geophysics from the National Central University, Taiwan, in 1985, MSc and Ph.D. in Geophysics from the University of Illinois at Urbana-Champaign in 1991 and 1993, respectively. He was recruited by the Institute of Earth Sciences (IES), Academia Sinica, Taiwan, as an Assistant Research Fellow immediately after finishing his Ph.D. study. During his initial years in IES, he was in charge of establishing the Broadband Array in Taiwan for Seismology (BATS). He was promoted to Associate Research Fellow in 1996 and then Research Fellow in 2000. He was awarded the Outstanding Research Award of the National Research Council twice (1999 and 2001). In 2001, he was awarded the Distinguished Youth Medal of the Republic of China. He joined the Geological Survey of Canada in 2002 as a research scientist working on earthquake source characteristics and seismogenic structures. In 2006, he was appointed by the School of Earth and Ocean Sciences, University of Victoria, as an Adjunct Professor. He has served as an Associate Editor of the Journal of Geophysical Research between 2011 and 2017. He was also a member of the Editorial Board of the International Journal of Geophysics between 2012 and 2017. Currently, he is the leader of the Induced Seismicity Research Project of Natural Resources Canada.
BIO: Elizabeth Cochran is a geophysicist with the US Geological Survey in Pasadena, California. As an observational seismologist, her research ranges from studying the detailed behaviour of fault slip to developing new techniques to densely observe earthquakes.
Dr. Cochran conducts detailed studies of aftershock behaviour, fault zone properties, and deep seismic slip (tremor). After a large earthquake, large numbers of seismic stations are installed in near the mainshock to record the hundreds to thousands of aftershocks that will occur over the subsequent months. These data are then used to image fault structure and study the small-scale details of fault complexity and damage zones around faults. The work has shown that fault structures can exhibit highly complex slip behaviour. And, faults tend to localize on zones that are 100m – 1 km wide and severely damaged compared to surrounding, intact rock.
She is also currently investigating new techniques to densely monitor strong ground motions in urban areas. The Quake-Catcher Network is a collaborative research effort that uses low-cost MEMS sensors connected to personal computers or other devices in homes, offices, and schools. The data collected by these sensors may be used to augment the existing seismic networks to aid in the study of earthquake rupture processes, block-by-block variations in ground motion, and may even provide useful data for earthquake early warning systems currently being developed for California and the Pacific Northwest.
The result from any analysis is directly controlled by the quality of the data inputs. When it comes to induced seismic risk management and mitigation, accurate and complete seismic catalogs generated in near real-time are critical to the utility and practicality of seismicity attribute forecasts. In this study we demonstrate the importance of catalog quality for successful seismic risk assessment and mitigation. We also discuss different published seismicity forecasting models and evaluate their performance for number of datasets.
To understand the sensitivity and reliability of forecasting models to the data quality, we compared observed and forecasted seismicity for local and regional arrays. We also assessed the estimated seismicity with and without applying advanced event detection and location techniques on the local arrays. The results show that a fine-tuned enriched catalog is the most important requirement to drive a reliable risk management application.
In the next step, we evaluated published seismicity forecasting models by playing back 30+ datasets generated from hydraulic fracturing monitoring. Three prediction models are used to estimate maximum magnitude and one for evaluation of number of events larger than a threshold magnitude. Our findings show that in general maximum magnitude estimates from different models are nearly identical and in a good agreement with the observed seismicity. We also discussed the limitation of the models where for few cases the seismicity forecasts were not very successful. Our investigation in the effect of the injection volume on seismicity and maximum magnitude estimations reveals that as the seismogenic index and seismicity statistics are estimated in every time step, the forecasts lost their sensitivity to the injection volume over time.
In order to improve the practicality of seismicity forecasts, all observations and estimations are presented in a dashboard environment with the objective of providing effective real-time operational risk mitigation feedback.
BIO: With over 10 years experience in engineering seismology applications, Emrah Yenier specializes in ground motion modelling and seismic hazard analysis. He is the Engineering Seismology Lead with Nanometrics Inc., in Ottawa, Canada, where he is responsible for the management and development of models for earthquake source, attenuation and site processes for use in engineering practices. He has co-authored over 15 scientific papers and has participated in several collaborative research projects, including the Turkish National Strong Motion Project, Seismic Harmonization in Europe, and the Next Generation Attenuation–East. Emrah received BSc. and MSc. degrees in Civil Engineering from Middle East Technical University, Turkey and holds a Ph.D. degree in Geophysics from Western University, Canada.
Authors: David Eaton and the ToC2ME working group
The Tony Creek Dual Microseismic Experiment (ToC2ME) is a field program that employed a diverse set of sensors to record a hydraulic-fracturing program within a region of known susceptibility to induced seismicity west of Fox Creek, Alberta. The acquisition systems consisted of a 68-station shallow borehole array, six broadband seismometers and one strong-motion accelerometer. Analysis of the dataset is ongoing; to date, 20,000 events (M-1 to M3.2) have been detected over a 5-week period, including 530 high-quality moment tensors. The largest events have strike-slip mechanisms and are located several hundred metres above the treatment zone (~ 3.2 km depth) along a series of well defined N-S lineaments. Integration of regional stress information with stress inversion results using moment tensors indicates that activated faults required a ~11-17 MPa pore-pressure increase in order to induce slip. A coincident 3-D multicomponent seismic survey provides a rare opportunity for detailed correlations between induced seismicity and pre-existing faults. Despite being nearly parallel to activated faults and proximal to the injection, fault strands that are most conspicuous in the 3D seismic data were not activated. There is evidence, however, that seismogenic faults have a local stress signature that is distinct from stable (cemented?) pre-existing faults.
BIO: Professor David Eaton holds the NSERC/Chevron Industrial Research Chair in Microseismic System Dynamics in the Department of Geoscience at the University of Calgary. Together with graduate students and postdoctoral fellows, his work focuses primarily on the advancement of research, education and technological innovations in microseismic methods and their practical applications for resource development, with a secondary focus on the deep lithospheric structure of continents. In 2007, he rejoined the University of Calgary as Head of the Department of Geoscience, after an 11-year academic career at the University of Western Ontario. His postdoctoral research experience included work at Arco’s Research and Technical Services (Plano, Texas) and the Geological Survey of Canada (Ottawa). He has over 140 publications in peer-reviewed journals and books, including articles in Nature and Science, as well as a recently published textbook on Passive Seismic Monitoring of Induced Seismicity.
15:00 – 15:30 Q&A with Panel
15:30 – 17:00 Refreshment Break and POSTER SESSION – Castle Room
07:00 – 08:30 – Breakfast Buffet – Glacier Salon
08:30 – 10:00 Regulatory and Policy Approaches with Chairs, Shawn Maxwell, Itasca-Image and Dan Allan, Canadian Society for Unconventional Resources
Regulators, policy-setters, and operators from various jurisdictions will compare and discuss regulations regarding objectives, technical assumptions and practical application. Regulations are typically based on traffic light protocols although the details of implementation, including magnitude thresholds and responses, vary significantly in different locations.
Dan Allan, President and CEO
Canadian Society for Unconventional Resources
Mr. Allan is a registered professional geologist with 40 years of diverse industry experience working in both Canada and the United States. He is a graduate of McGill University with an honours degree in Geological Sciences. Mr. Allan has held executive management positions in numerous oil and gas companies over the last twenty years. These have included both large and smaller organizations, including being the President and CEO of several publically listed energy firms.
Mr. Allan has extensive experience in unconventional resource exploration and development having worked on projects throughout North America. Mr. Allan is the former chairman of the board for CSUR, is a member of the Canadian Society of Petroleum Geologists, the American Association of Petroleum Geologists and is a registered Professional Geologist in both the province of Alberta and the state of Wyoming.
Shawn Maxwell is Geophysical and Geomechanical advisor for Newfield Resources, based in The Woodlands. Previously he was President and Chief Technology Officer for Itasca IMaGE, Chief Geophysicist and Microseismic Advisor for Schlumberger, led microseismic development at Pinnacle Technologies (Halliburton) and ESG, and served as a Lecturer at Keele University in England. Shawn was awarded a Ph.D. specializing in microseismology from Queen’s University in Kingston, Canada.
Induced seismic events from deep well fluid disposal or well completion operations, although rare, do occur. Regulatory programs must be able to monitor and evaluate data in real-time and be prepared to make informed regulatory decisions on short notice. The regulated community may realize adverse economic impacts from these actions. There may be a safety or functional issues that delay cessation of operations that could have induced seismic events.
The public expects the regulator to protect human health and safety, and the environment and may expect or demand quick regulatory action.
What data is necessary to make such decisions? What legal authority does the regulatory agency have? What is an appropriate regulatory action for the induced seismic event? What data could the company provide to assist the regulator in the review? What precautions have the company initiated to minimalize the risk? Is the seismic monitoring network adequate to effectively evaluate the cause?
These are but a few of the questions a regulator must consider. The regulated community should be prepared to respond to an induced seismic event with sound data and an appropriate mitigation plan. It is in everyone’s best interest to be prepared before any action is necessary.
BIO: Rick Simmers is Chief of the Ohio Department of Natural Resources’ Division of Oil and Gas Resources Management. He is responsible for enforcing Ohio’s laws related to oil and gas drilling, production, plugging, orphan wells, solution mining, enhanced recovery, gas storage and underground injection control operations.
An ODNR career employee, Simmers began working for the Oil and Gas Program in 1985. Over the years he has served as a staff geologist, groundwater investigator, acting chief and statewide field enforcement administrator.
Simmers earned both a Master of Science degree and Bachelor’s degree in geology from the University of Akron. He also holds a Bachelor’s degree in biology from the University of Akron.
He is currently serving as Ohio’s representative to the Interstate Oil and Gas Compact Commission and has also served on the Ground Water Protection Council.
SESSION on the BC MONTNEY
BIO: Stuart (Stu) Venables grew up in Ottawa, Ontario. He obtained a B.Sc. in Geology from Acadia University graduating in 1999. Upon graduation, Mr. Venables moved to Calgary, Alberta where he worked for a variety of E&P and M&A firms from small 5 person operations to large, multinational corporations and banking firms. In 2010, he left Calgary and moved to Victoria, British Columbia where he accepted a position with the BC Oil & Gas Commission (Commission). Since 2010, Stu has worked for the Commission as a Senior Petroleum Geologist and taken on a variety of issues including the launch and on-going oversight of fracfocus.ca and implementing the first fracture fluid disclosure regulations in Canada. Currently, his primary focus is the regulatory approach, oversight and mitigation of induced seismicity. Stu Venables is a registered Professional Geologist with APEGBC.
BIO: Lindsay Miller, BSc., joined Progress Energy in 2013 to work with conventional and unconventional assets within Western Canada. Lindsay works with the asset team to deliver operational geophysical support; including, seismic interpretation to aid the drilling and completions team with well programs and geo-hazard assessments. Previously she worked on conventional international exploration at Talisman Energy, her work involved regional interpretation for oil and gas exploration. Lindsay is an active member of CSEG, SEG, AAPG, and, on behalf of Progress Energy, sits on the CAPP B.C. Induced Seismicity Working Group committee. Lindsay graduated with a Bachelor of Science in Geophysics from the University of Calgary in 2007. Outside of work, Lindsay can be found playing hockey, skiing, and rodeoing with her horses in the summer.
10:00 – 10:15 Q&A with Panel
10:15 – 10:45 Coffee Break and POSTER SESSION – Castle Room
SESSION on the DUVERNAY
The Alberta Energy Regulator is unique in the world as being the home of a world-class geological survey – the Alberta Geological Survey (AGS). Because the AGS is embedded in the energy regulator, applied science and knowledge can flow into regulatory response and design in real time when a subsurface event unfolds. In a similar way, resources and direction can flow into the AGS from the AER in real time as well to direct geologists and geophysicists to immediately turn their applied research programs and expertise to areas of immediate provincial priority. This is exemplified by the rapid growth of AGS’ applied research into Alberta seismicity from one experimental seismometer and no full-time seismology staff in 2008 to running a regional monitoring network of over 52 stations, including `14 AGS own seismic stations today with a team of three applied seismologists supporting AER real-time response to induced seismicity while producing research published in the highest quality scientific journals today. This success story built on the experience of AGS in building and running the Turtle Mountain-Frank Slide active landslide-monitoring system starting in 2003, going from no monitoring at all then to a world-renowned landslide observatory and real-time monitoring system that operates to this day.
BIO: Carol Crowfoot has been monitoring energy markets since 1981 and has been with the Alberta Energy Regulatory (AER) since 2007. Ms. Crowfoot is the AER’s executive vice president of the Strategy and Regulatory Division. She is responsible for leading the organization to the successful execution of its strategy, ensuring organization standards are developed and followed when designing risked-based regulatory requirements, and delivering energy information, independent analysis, and supply-and-demand forecasts for Alberta commodities to all stakeholders.
Ms. Crowfoot started her career at GLJ Petroleum Consultants. Through this work, she was responsible for monitoring and understanding the fundamentals of supply, demand, and transportation issues in energy markets. She also provided commentary regarding market trends and participated in regulatory hearings and civil proceeding as an expert witness. In addition to her duties with GLJ Petroleum Consultants, in 2002 Ms. Crowfoot was named the president of GLJ Energy Publications Inc., a firm specializing in market information and analysis of the North American natural gas industry.
Throughout her career, Ms. Crowfoot has been a frequent presenter to industry conferences including the Canadian Energy Research Institute Natural Gas Conference, numerous Canadian Institute conferences, the Economics Society of Calgary technical seminars, Canadian Society of Petroleum Geologists conventions, and Petroleum Society technical luncheons.
BIO: Todd Shipman, PhD., Landscape and Geological Hazards Manager with the Alberta Geological Survey has a Masters degree in Geology from Northern Arizona University 1999 and a Ph.D. from the University of Arizona in Geoscience 2004. Todd worked at the Arizona Geological Survey until 2009, where he developed the first earth fissure monitoring program for the State of Arizona. In 2010, he started work at the Alberta Geological Survey, where he became manager of the Landscapes and Geohazards Group. Todd was one of the authors of Subsurface Order #2 and currently manages the group that operates the RAVEN seismic network.
Chevron Canada Limited has been an active operator in the Kaybob Duvernay play since the early exploration days of the late 2000’s. Chevron has worked extensively with the regulator, other operators and academia to collaborate and accelerate the advancement of our knowledge on seismicity related to hydraulic fracturing operations in the Duvernay. Our monitoring and mitigation protocols to manage the risk have adapted over time as knowledge has accumulated. A significant focus has been to provide key early recognition of risk features and trends and to provide a more detailed characterization of anomalous seismicity.
BIO: John Evans is a Senior Staff Geophysicist in the Kaybob Duvernay asset team at Chevron Canada. During his 30+ year career with Chevron, John has worked on many different exploration and development subsurface teams in several locations including Calgary, St. John’s and Houston. For the last 10 years, his work has focused on exploration and development of unconventional heavy oil and shale assets.
12:05 – 12:20 Q&A with Panel
12:30 – 13:30 Lunch Break in the Glacier Salon and POSTER SESSION – Castle Room
13:30 – 15:00 Data Mining With Novel Analysis Techniques
Chair: Yehuda Ben-Zion, University of Southern California and David Eaton, University of Calgary
The rapid increase in the quantity and quality of recorded seismic data sets and the development of data mining techniques increase significantly the ability to extract robust information on the occurrence and properties of small earthquakes. Discussed techniques and applications include advanced use of templates and machine learning to develop detailed seismic catalogues and derive source properties of small events.
Microseismicity often conveys the most direct information about active processes in the earth’s subsurface. However, routine network processing typically leaves most earthquakes uncharacterized. These “sub-catalogue” events can provide critical clues to ongoing processes in the source region. To address this issue, we have developed waveform-based processing that leverages the existing catalogue of earthquakes to detect and characterize events absent in routine catalogues. Using large-scale waveform cross-correlation between cataloged events with the continuous data stream, we 1) identify events with similar waveform signatures in the continuous data across multiple stations, 2) precisely measure relative time lags across these stations for both P- and S-waves, and 3) estimate the relative polarity between events by the sign of the peak absolute value correlations and its height above the secondary peak. This final step facilitates robust focal mechanism estimation for large populations of tiny earthquakes, addressing a common shortcoming in microseismicity analyses (Shelly et al., JGR, 2016). Depending on the application, we can characterize 2-10 times as many events as included in the initial catalogue. Application to a 2014 swarm in Long Valley Caldera, California, illuminates complex patterns of faulting that would have otherwise remained obscured. Together, these patterns imply strong interactions between fluid diffusion and faulting processes in the crust.
BIO: David R. Shelly is a research geophysicist in the Geologic Hazards Science Center, U.S. Geological Survey, Golden, Colorado. His research interests include earthquake swarms (and associated fluid-faulting interactions) and tectonic tremor. To gain insight into these processes, he has worked to develop new techniques for earthquake detection, source location, and focal mechanism determination, applicable to large populations of microseismicity.
With the volume of seismic data recorded around the world growing rapidly by the year, reliable automated techniques are becoming increasingly relied upon for extracting the usable scientific signal. Such automated methods, however, generally lag behind in performance compared with the capabilities of expert seismologists. Here, we develop a framework for generalized seismic phase detection using technology from artificial intelligence that learns directly from seismograms without the need for feature extraction. We utilize millions of manually determined phase picks to train deep neural networks to detect P and S body waves, localize onset times, and determine first-motion polarities. The networks are shown to perform as well, or better, than professional seismic analysts due to their ability to generalize entire waveform archives. This enables the trained models to be applied to data from completely different tectonic regimes or too large magnitude events without representation in the training set.
We separately develop a deep learning approach to seismic phase association, which is the task of linking together phase detections on different sensors that originate from a common earthquake. This fundamental task is challenging because the number of sources is unknown and events frequently overlap in time. We train recurrent neural networks to link phases together that share a common origin by examining tens of millions of synthetic example sequences. The method is simple to apply to any tectonic regime and can naturally incorporate errors in arrival time picks. Rather than tuning a set of ad hoc parameters to improve performance, the results are improved by adding examples of problematic cases to the training dataset for the network to learn from. The developed techniques are expected to significantly improve the resolution of seismicity catalogues, stabilize real-time seismic monitoring, and streamline the automated processing of large seismic datasets.
BIO: Zachary Ross is a Postdoctoral Scholar in Geophysics at the California Institute of Technology. He previously received a Ph.D. in Geophysics from the University of Southern California, and a B.S. in Physics from the University of California, Davis. His research interests are in detection and picking of seismic waves with artificial intelligence, high-resolution imaging of fault zones, relationships between earthquake rupture processes and properties of fault zones, and algorithms for improved automated analysis of large seismic datasets.
1. GFZ German Research Centre for Geosciences, Potsdam, Germany; 2. Free University, Berlin, Germany; 3. University of Southern California, Los Angeles, United States
We investigate theoretical limits on detection and reliable estimates of source characteristics of small induced and natural earthquakes using synthetic seismograms for shear/tensile dislocations on kinematic circular ruptures, observed seismic noise and properties of several acquisition systems typically used in industrial monitoring (instrument response, sampling rate). Simulated source time functions for shear/tensile dislocation events with different magnitudes, static stress drops and rupture velocities provide estimates for the amplitude and frequency content of P and S phases at various observation angles. The source time functions are convolved with a Green’s function for a homogeneous solid / 1D velocity model assuming given P-, S- wave velocities and attenuation coefficients and a given instrument response. The synthetic waveforms are superposed with average levels of the observed ambient seismic noise up to 1 kHz. The combined seismograms are used to calculate signal-to-noise ratios and expected frequency content of P and S phases at various locations.
The synthetic simulations of signal-to-noise ratio reproduce observed ratios extracted from several well-recorded datasets of induced seismicity (mining, geothermal stimulation, fracking) with magnitudes ranging from MW-3 to MW5. The results provide guidelines on detection of small seismic events in various geological environments, along with information relevant to reliable analyses of earthquake source properties, ground motion assessment and earthquake scaling relations.
BIO: Grzegorz Kwiatek is a Senior researcher at Section 4.2: Geomechanics and Rheology of the GFZ German Research Centre of Geosciences in Potsdam, and Free University in Berlin. His background is Environmental Geophysics, with a focus on physics of earthquake source, earthquake scaling relations, and geomechanics. His research covers seismo-mechanical studies in a broad range of earthquake scales from analysis of acoustic emission activity recorded in laboratory experiments on rock samples and in the in-situ geomechanical laboratories to seismicity induced by exploitation of geo-reservoirs.
14:45 – 15:00 Q&A with Panel
15:00 – 16:00 Refreshment Break and POSTER SESSION – Castle Room
16:00 – 17:00 Closing Panel Discussion