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Potential Injection-Induced Seismicity Associated with Oil & Gas Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation Second Edition, 2017 Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation This report is developed by the StatesFirst Induced Seismicity by Injection Work Group (ISWG) members (the State agencies) with input and support from the ISWG technical advisors (subject matter experts from academia, industry, federal agencies, and environmental organizations) to help better inform all stakeholders and the public on technical and regulatory considerations associated with evaluation and response, seismic monitoring systems, information sharing, and the use of ground motion metrics. It also is intended to summarize the range of approaches that have been used or are currently being used by states to manage and mitigate the risks associated with seismicity that may be induced by injection. StatesFirst is an initiative of the Interstate Oil and Gas Compact Commission and the Ground Water Protection Council. Disclaimer This is an informational document, and is not intended to offer recommended rules or regulations. The ISWG recognizes that management and mitigation of the risks associated with induced seismicity are best considered at the state level with specific considerations at local, regional, or cross-state levels, due to significant variability in local geology and surface conditions (e.g., population, building conditions, infrastructure, critical facilities, seismic monitoring capabilities, etc.). Neither the Ground Water Protection Council, the Interstate Oil and Gas Compact Commission, the ISWG (collectively the Group) nor any person acting on their behalf makes any warranty, express or implied; or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or reliance on any information, apparatus, product, or process disclosed; or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favor by the Group nor any person acting on their behalf. The views and opinions of authors expressed herein do not necessarily state or reflect those of the Group. Recommended citation: Ground Water Protection Council and Interstate Oil and Gas Compact Commission. Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation. Second Edition, 2017, 181 pages Page 2 Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation Second Edition, 2017 Preface Although induced seismicity related to underground injection activities was first observed in the 1960s at the Rocky Mountain Arsenal near Denver, the dramatic increase in earthquake activity in the midcontinent since 2009 has focused attention on the potential hazard posed by earthquakes induced by injection. The science required to understand the process and predict its impacts is still undergoing significant change. This document is designed to provide state regulatory agencies with an overview of current technical and scientific information, along with considerations associated with evaluating seismic events, managing the risks of induced seismicity, and developing response strategies. It is not intended to offer specific regulatory recommendations to agencies but is intended to serve as a resource. Also, unlike prior studies by the National Research Council, U.S. Environmental Protection Agency, Stanford University, and others, this document is not intended to provide a broad literature review. This report was developed by StatesFirst, an initiative of the Interstate Oil and Gas Compact Commission (IOGCC) and the Ground Water Protection Council (GWPC). The effort was led by the Induced Seismicity by Injection Work Group (ISWG), composed of representatives of state oil and gas regulatory agencies and geological surveys with support from subject matter experts from academia, industry, federal agencies, and environmental organizations. The focus of this document is induced seismicity associated with underground disposal of oilfield-produced fluids in Class II wells. Appendix B provides background on Class II wells. Although far less likely to occur, the potential for felt induced seismicity related to hydraulic fracturing is discussed briefly in Chapter 1 and more extensively in Appendix I. Management and mitigation of the risks associated with induced seismicity are best considered at the state level, with specific considerations at local or regional levels. A one-size-fits-all approach is infeasible, due to significant variability in local geology and surface conditions, including such factors as population, building conditions, infrastructure, critical facilities, and seismic monitoring capabilities. Appendix C includes summaries of approaches that various states have taken to address risk management and mitigation. Although important, the issues of insurance and liability are not addressed in this report because each state has unique laws that render general consideration of these topics impractical. This report uses the term “earthquake” to refer to a seismic event other than a microseismic event and “induced seismicity” to refer to earthquakes triggered by human activity. The term “potentially induced seismicity” is used to refer to specific seismic events that may be related to human activity, but where such activity has not been established definitively as a contributing factor. Throughout this document moment magnitude (M) is used to denote the size of an earthquake unless otherwise noted. For a more complete description of moment magnitude and its relevance to the size of earthquakes, see Earthquake Magnitude in Appendix A. Page 3 Potential Injection-Induced Seismicity Associated with Oil & Gas Development: A Primer on Technical and Regulatory Considerations Informing Risk Management and Mitigation Second Edition, 2017 Table of Contents Preface .................................................................................................................................................. 3 Executive Summary ................................................................................................................................ 8 Introduction ................................................................................................................................................. 8 Understanding Induced Seismicity ............................................................................................................... 8 Assessing Potentially Injection-Induced Seismicity ...................................................................................... 9 Risk Management and Mitigation Strategies ............................................................................................. 10 Considerations for External Communication and Engagement.................................................................. 11 Key Message .............................................................................................................................................. 13 Chapter 1: Understanding Induced Seismicity ....................................................................................... 14 Chapter Highlights ..................................................................................................................................... 14 Introduction—Key Concepts and Earthquake Basics ................................................................................. 14 Magnitude and Depth of Induced Earthquakes ......................................................................................... 17 Hazards and Risks of Induced Seismicity .................................................................................................... 18 Ground-Motion Models for Induced Seismicity ......................................................................................... 19 Examples of Current Models ...................................................................................................................... 20 USGS Hazard Maps .................................................................................................................................... 21 Estimated Number of Induced Seismicity Locations .................................................................................. 23 How Fluid Injection May Induce Seismic Events ........................................................................................ 24 Potential for Seismicity Related to Hydraulic Fracturing ............................................................................ 25 Future Research ......................................................................................................................................... 26 Chapter 2: Assessing Potentially Injection-Induced Seismicity ..............................................................
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