Seismicity in Texas in Relation to Active Class I Underground Injection Control Wells: Preliminary Observations

Transcription

1 Seismicity in Texas in Relation to Active Class I Underground Injection Control Wells: Preliminary Observations David Murry Groundwater Protection Council UIC Conference Austin, Texas February 22, 2017 Texas Commission on Environmental Quality Office of Waste Radioactive Materials Division Underground Injection Control Permits Section

2 TCEQ Investigation Under its EPA-approved UIC program, TCEQ is responsible for administering the State s UIC program for Class I UIIC wells In May of 2016, TCEQ conducted a study to compare the locations of Class I UIC wells in Texas with recorded earthquake epicenters to identify any areas of the state in which there may be a spatial relationship This presentation is a summary of the preliminary observations gained from that study

3 Causes of Earthquakes Natural Tectonic Movement Magma Displacement Volcanic Eruption Induced Fluid Injection Explosives Reservoirs

4 Fault-related Earthquakes

5 Seismic Waves Body Waves P Waves S Waves Surface Waves Love Wave Rayleigh Wave (Website with video to illustrate ground movement for each type of wave)

6 Seismograph

7 US Seismic Hazard Map

8 1931 Valentine Earthquake Isoseismal Map

9 Fault of Concern A fault optimally oriented for movement and located in a critically stressed region Is of sufficient size, and possesses sufficient accumulated stress/strain, such that fault slip and movement has the potential to cause a significant earthquake (National UIC Technical Workgroup Final Product Minimizing and Managing Potential Impacts of Injection- Induced Seismicity from Class II Disposal Wells: Practical Approaches, Feb. 6, 2015)

10 Fault of Concern For subsurface injection to contribute to fault displacement by a reduction in pore pressure across a fault, three criteria must be met: The existence of a fault capable of undergoing displacement that would result in an earthquake; A pathway for pressure increases due to injection to be transmitted to the fault; and A sufficient pressure increase due to injection to contribute to fault displacement. (National UIC Technical Workgroup Final Product Minimizing and Managing Potential Impacts of Injection-Induced Seismicity from Class II Disposal Wells: Practical Approaches, Feb. 6, 2015)

11 Factors Considered Class I UIC Well Locations Presence of Seismic Activity Seismic Hazard identified by USGS Oil and Gas Production Class II UIC Well Locations

12 Class I UIC Wells In Texas

13 Active Texas Class I UIC Wells 172 Active Class I UIC Permits 103 Active Class I UIC Wells Gulf Coast 79 Panhandle 21 Eastern Shelf 2 East Texas Basin 1

14 ft ,000 ft generalized stratigraphic column for 84 active Class I permits in the Northern Gulf Coast, showing injection zones and lowermost USDWs ,200 ft ,400 ft Over 125 billion gallons of wastewater have been injected into the Northern Gulf Coast through Class I wells as of December 2014

15 ,300 ft ,200 ft generalized stratigraphic column for 43 active Class I permits in the Southern Gulf Coast, showing injection zones and lowermost USDWs ,300 ft Almost 70 billion gallons of wastewater have been injected into the Southern Gulf Coast through Class I wells as of December ,700 ft

16 ft generalized stratigraphic column for 31 active Class I permits in the Panhandle, showing injection zones and lowermost USDWs ,000 ft ,000 ft Over 44 billion gallons of wastewater have been injected into the Panhandle through Class I wells as of December ,500 ft

17 Seismic Areas Trans-Pecos Central Basin Platform Dallas-Ft. Worth Snyder Fashing Shelby-Panola Northern Panhandle

18 USGS Seismic Hazard Map

19 Oil and Gas Activity

20 Class II Injection Wells

21 Summary Table Areas Seismic Hazard Oil & Gas Activity Class II Wells in Area Class I Wells in Area Trans-Pecos Yes No No No Central Basin Platform Yes Yes Yes No Northern Panhandle Yes Yes Yes Yes Shelby-Panola No Yes Yes No Snyder No Yes Yes No Dallas-Ft. Worth No Yes Yes No Fashing No Yes Yes No

22 Texas Gulf Coast Area

23 Texas Growth Fault Systems

24 Texas Gulf Coast Growth Fault

25 Hardage et al. 1995

26 Growth Faults, Svalbard Archipelago

27

28 Ancestral Rocky Mountains

29 Palo DuroBasin Cross Section

30 Northern Panhandle Wells

31 Seismic Areas

32 Research University of Texas at Austin Bureau of Economic Geology Report of House Bill 2 ( ) Seismic Monitoring and Research in Texas December 1, Report-2016.pdf

33 BEG Report Dallas area is highest priority Panhandle area is lowest priority Plans to install and operate a state-wide network of seismometers

34 Uncertainties Locations of Earthquake Hypocenters and Epicenters Seismograph coverage is sparse EPA is unsure of the locations and depths of earthquakes in the Panhandle area Geologic Information Well control and seismic coverage is sparse due to lack of oil and gas accumulations in Palo Duro Basin Existence and locations of faults poorly understood Pathways for fluid migration not well-defined

35 Future Work TCEQ is continuing to evaluate seismicity concerns for Class I UIC wells in areas of known seismicity

36 Contact Information David Murry, P.G. Texas Commission on Environmental Quality Office of Waste Radioactive Materials Division Underground Injection Control Permits Section