Industry Shared Practices Anomalous Induced Seismicity due to Hydraulic Fracturing April 2019 2019-0026 The Canadian Association of Petroleum Producers (CAPP) represents companies, large and small, that explore for, develop and produce natural gas and oil throughout Canada. CAPP’s member companies produce about 80 per cent of Canada’s natural gas and oil. CAPP's associate members provide a wide range of services that support the upstream oil and natural gas industry. Together CAPP's members and associate members are an important part of a national industry with revenues from oil and natural gas production of about $101 billion a year. CAPP’s mission, on behalf of the Canadian upstream oil and natural gas industry, is to advocate for and enable economic competitiveness and safe, environmentally and socially responsible performance. DISCLAIMER This publication was prepared for the Canadian Association of Petroleum Producers (CAPP) «andcompanyname(s)»by «CompanyName(s)». While it is believed that the information contained herein is reliable under the conditions and subject to the limitations set out, CAPP and «CompanyName(s)» do not guarantee its accuracy. The use of this report or any information contained will be at the user’s sole risk, regardless of any fault or negligence of «CompanyName», CAPP or its co-funders. 2100, 350 – 7 Avenue S.W. 1000, 275 Slater Street 1004, 235 Water Street Unit 202, 1110 Government St. Calgary, Alberta Ottawa, Ontario St. John’s, Newfoundland and Labrador Victoria, British Columbia Canada T2P 3N9 Canada K1P 5H9 Canada A1C 1B6 Canada V8W 1Y2 Tel 403-267-1100 Tel 613-288-2126 Tel 709-724-4200 Tel 778-265-3819 Fax 403-261-4622 Fax 613- 236-4280 Fax 709-724-4225 Fax 403-261-4622 Overview As prudent and responsible operators active in the development and production of unconventional resources, it is important to gain a better understanding of types and sources of seismic activity. By supporting research at universities, partnering with federal and provincial agencies, and conducting our own on-site research, we are contributing to a better understanding of seismicity and the potential impacts of our operations on each unique geological setting. Evidence suggests that any induced seismicity caused to date by hydraulic fracturing in the Western Canadian Sedimentary Basin (WCSB), while occasionally felt, is generally deep, near the reservoir interval and poses no risk to health, safety or the environment. CAPP and its member companies encourage approaches to managing potential seismic risk that are based on science, taking into account the local public exposure of such as felt events, operational factors, geological setting and historical baseline seismicity levels. We also support reasonable and prudent considerations of engineering standards and codes related to seismicity and structural integrity. We take a diligent risk- management approach toward studying and limiting the potential for anomalous induced seismicity caused by hydraulic fracturing in our operations. Seismicity is a normal part of hydraulic fracturing. Typically, these seismic events are small (microseismic events), too small to be felt at the surface. In rare cases, estimated to be 0.15 per cent1 of hydraulic fracturing stages completed in the Montney for example, seismic events can be large enough to be felt at the surface. These have not posed a threat to safety, structures or the environment in the WCSB. Seismic events felt at the surface and linked to human activities are often referred to as anomalous induced seismicity. This is the case in some areas in Alberta and northeast British Columbia where incidents of felt seismic events associated with hydraulic fracturing have been reported. 1 Source: BC OGC, Investigation of Observed Seismicity in the Montney Trend, December 2014 Contents Contents .......................................................................................................................................... iv 1 Purpose ............................................................................................................................ 1-1 2 Risk Appraisal and Risk Mitigation ................................................................................... 2-1 2.1 Pre-Completions Risk Assessment for Anomalous Induced Seismicity Due to Hydraulic Fracturing ............................................................................................. 2-1 2.1.1 Historical Seismicity ................................................................................. 2-3 2.1.2 In situ Stresses ......................................................................................... 2-3 2.1.3 Geological Fault Mapping ........................................................................ 2-4 2.1.4 Operational Risk Factors .......................................................................... 2-4 2.1.5 Consequence ............................................................................................ 2-5 2.1.6 Final Risk Assessment .............................................................................. 2-7 2.1.7 Pre-Completions Operations Risk Review ............................................... 2-8 2.2 Seismic Monitoring and Response during Hydraulic Fracturing Operations ....... 2-8 2.2.1 Monitoring System ................................................................................... 2-8 2.2.2 Operational Response: Roles/Responsibilities/Communications ........... 2-9 2.2.3 Example Operational Response System ................................................ 2-10 3 Areas of Active Research ............................................................................................... 3-11 4 Industry and Regulator Interactions .............................................................................. 4-12 4.1 Industry/Regulator Interface ............................................................................. 4-12 4.2 Industry/Industry Interface ................................................................................ 4-13 Figures Figure 1 Risk Matrix ........................................................................................................ 2-2 Figure 2 Gutenberg-Richter plot normalized for a single M=4.0 event .......................... 2-2 Figure 3: Observed horizontal-component ground motions (symbols) for induced events of M4.0 to 4.5 (converted to B/C site conditions) in Oklahoma and Alberta, (Atkinson, 2017, https://www.inducedseismicity.ca/wp-content/uploads/Atkinson2017-FACETS.pdf ..................................... 2-7 Tables Table 1 Description of the levels of Modified Mercalli Intensity (source USGS). ........... 2-5 Table 2: Relationship between PGA, PGV, Damage potential and Intensity .................. 2-6 Table 3: Example Operational Responses to Observed Seismicity based on AER’s Subsurface Order No.2 in High to Moderate Risk Areas .............................................. 2-10 1 Purpose Operators in CAPP’s seismicity committees have shared their experiences and knowledge to produce this document. It is designed to serve as a guide and describes current recommended practices for hydraulic fracturing induced seismicity risk appraisal, risk mitigation approaches, and key research and activities. Operators are encouraged to follow these recommended practices voluntarily. These shared practices reflect the current state of knowledge and take into account areas of ongoing research to improve understanding. This document is therefore described as a “shared” rather than “best” practice. Any recommendations herein are superseded by regulatory requirements that exist in specific areas of operations. The document provides information of use to operators in addressing the risk of induced seismicity. The shared practices are general in nature. Operators will need to adapt the shared practices to their specific situation. It is the responsibility of each operator to conduct their operations safely and in accordance with the circumstances of the particular operation 2 Risk Appraisal and Risk Mitigation The key planning activities that guide the design and implementation of hydraulic fracturing operations where induced seismicity is a potential should be influenced by a comprehensive risk assessment and a corresponding monitoring and response plan suited to the specific location. What follows is a discussion that will help lead to a substantiated and logical Pre- Completion Risk Assessment, and a presentation of recommendations for monitoring and appropriate operational responses. 2.1 Pre-Completions Risk Assessment for Anomalous Induced Seismicity Due to Hydraulic Fracturing While most hydraulic fracturing operations do not trigger anomalous induced seismicity, it has occurred under certain conditions. This section highlights some of the factors that should be considered when designing and assessing hydraulic fracturing operations. As with all aspects of oil and gas operations, risks exist and should be evaluated to manage and mitigate the hazards. A hazard is any source of potential damage or harm to people or property. The risk associated with a hazard is understood to be the product of the likelihood of the hazard to occur and its consequence as presented in Figure 1. That is: Risk = Likelihood x Consequence The consequence of a hazard is a measure of its impact. For ground motion associated with seismicity, this is primarily governed by the magnitude2, the resultant ground motion generated at various epicentral distances and the effects