Potential Injection-Induced Seismicity Associated With Oil & Gas Development

Transcription

1 Potential Injection-Induced Seismicity Associated With Oil & Gas Development A primer on technical & regulatory considerations informing risk management & mitigation Second Edition September, 2017 Induced Seismicity Work Group Sept. 29, 2017

2 Update Workgroup Rick Simmers, Chief, Division of Oil & Gas Resources, Ohio Department of Natural Resources (Chair) Bob Worstall, Deputy, Chief, Division of Oil & Gas Resources, Ohio Department of Natural Resources Hal Macartney, Geosciences Advisor, Pioneer Natural Resources Kris Nygaard, Senior Stimulation Consultant, ExxonMobil Upstream Research Company Ivan Wong, Principal Seismologist, Lettis Consultants International Ed Steele, Environment, Geosciences & Water Technology Manager, Baker Hughes (A GE Company)

3 Induced Seismicity in the News

4 Introduction StatesFirst: Collaborative partnership between the Ground Water Protection Council and the Interstate Oil & Gas Compact Commission StatesFirst Induced Seismicity Work Group ( ISWG ) originally chartered in 2014 and led by States The ISWG is focused on addressing public concerns associated with induced seismicity Work Group delivered: a Primer document to summarize and share knowledge in September 2015 Work Group began process of updating Primer in early 2017

5 ISWG Objectives Share science, research, technical understanding and experience Provide forum for stakeholder discussion and communication Identify potential approaches and decision making tools to manage and mitigate risks Update the Primer document that summarizes current knowledge and potential approaches for managing / mitigating risk and responding to anomalous seismicity

6 Primer Overview Primary emphasis on potential induced seismicity associated with Class II disposal wells and hydraulic fracturing Document is solely informational and is not intended to offer recommended rules or regulations

7 Primer Content 4 Chapters Understanding induced seismicity Assessing potentially induced seismicity Risk management & mitigation strategies External engagement & communication 9 Technical Appendices Relevant earthquake science Class II injection wells Induced seismicity case studies Design & installation of seismic monitoring networks NRC Report on induced seismicity potential in energy technologies Methods for estimating reservoir pressures changes associated with injection Tools for risk management and mitigation Data collection & interpretation Considerations for hydraulic fracturing

8 Primer Chapter 1 Understanding Induced Seismicity Primer Updates

9 Key Update Frequency of Earthquakes in Central USA The cumulative number of earthquakes M 3.0 and greater in the central United States, available at /states/top_states_maps.php. Source: USGS 2016

10 Key Update USGS Earthquake Hazards Program Model Figure 1.7. Short-term Induced Seismicity Models 2017 One-Year Model, Source: USGS Earthquake Hazards Program -

11 Key Updates Stanford Developed Fault Slip Potential Software used for probabilistic screening of faults near injection wells Estimates the chance of faults slipping when given stress, pore pressure, injection conditions, and fault geometry and geomechanical characteristics Found at Issued a report in 2015 on processes responsible for triggered earthquakes and principles for site characterization and risk assessment Found at

12 Key Updates Hydraulic Fracturing Felt-level seismicity occur infrequently with hydraulic fracturing but are becoming more frequent Typically have low magnitudes but some higher Recent occurrences ( ) Harrison County, Ohio (M 2.9) Pennsylvania (M 1.8-M 2.3) British Columbia, Canada (M 4.0) Alberta, Canada (M 4.0) Figure C.15 Simple map view of earthquakes (circles) located from 2013 to 2016 along with wells (lines) being stimulated at the time (blue = 2013, red = 2014, green =2015, and black = 2016). The horizontal width of the image is 6km across.

13 Key Updates California Implemented monitoring of California Integrated Seismic Network during and after hydraulic fracturing Suspension of HF activity if event greater than M 2.7 occurs within a specified area around the well Investigations by the DOGGR in consultation with the California Geologic Survey must determine there is no indication of a heightened risk of seismic activity form HF to continue

14 Key Updates Ohio Scheduled to deploy 14 additional seismic stations to its existing 39 station inventory. Published map of deep faults and basement faults in 2015 Investigated seismic events in Harrison County and Poland Township suggesting HF may have triggered faults Implemented permit conditions within certain areas of interest requiring seismic monitoring for fracturing operations within 3 miles of known faults or epicenter of a recorded seismic event Implemented response procedures based on magnitude of event

15 Key Updates Oklahoma M 5.0 event in Cushing, Oklahoma in 2016 Downward trend in seismicity tracked by the Oklahoma Geological Survey during 2016 Proposed a 3 year phased approach to upgrade current seismic network of 20 permanent seismometers to 72 permanent stations at a cost of $3.5 million and annual operating cost of $400,000 for 5 years In 2016 Oklahoma Corporation Commission (OCC) implements an area of interest and traffic light system to mitigate risk of HF operations triggering surface-felt seismicity OCC implemented a list of actions to be taken following anomalous seismic activity with 1.25 miles of HF operations

16 Key Updates Pennsylvania A sequence of seismic events (M 1.8-M 2.3) occurred in April 2016 Department of Environmental Protection (DEP) implemented permit conditions for operators to monitor and respond to seismic activity associated with Utica Shale gas wells in several Pennsylvania townships. Requires notification to DEP of events great than M 1.0 within a 6- mile radius of a wellbore path and M 2.0 or above within a 3-mile radius of a wellbore path and suspension of HF operations

17 Key Updates Texas Between 2008 and 2016, the rate of earthquakes with a magnitude greater than M 3.0 increased to about per year on average (The Academy of Medicine, Engineering and Science of Texas 2017) In December, 2016 the state legislature provide $4.471 million to the University of Texas at Austin, Bureau of Economic Geology to develop and manage a new earthquake monitoring system in Texas and to conduct research into seismicity across the state. Design and implement the TexNet Seismic Network Understand why earthquakes, both natural and potentially human-induced are occurring TexNet Technical Advisory Committee appointed in March, 2016 to review research strategies and tactics, and discuss network implementation State funding to provide TexNet system with 22 additional permanent stations and 36 temporary stations

18 In Conclusion Induced seismicity is a very complex issue where the base of knowledge is changing rapidly. The relationship between HF and potentially induced seismicity is becoming clearer State regulatory agencies are dealing with potential injection induced seismicity by using tools, knowledge, and expertise, many of which are offered in this document, to prepare for and respond to occurrences of induced seismicity. Risk management, risk mitigation, and response strategies are most effective when developed considering specific local conditions and situations

19 Questions?