## Mitigating Injection-Induced Seismicity Bill Bates Office of Ground Water and Drinking Water, Prevention Branch – Underground Injection Control Program

28/03/2016 1 U.S. Environmental Protection Agency

## Disclaimer These slides and the information contained in them have been prepared by EPA staff for informational purposes only. They should not be relied on for regulatory compliance purposes and do not necessarily reflect EPA’s official policy and legal positions.

28/03/2016 2 U.S. Environmental Protection Agency

## Increase	in	Seismic	Events

28/03/2016 U.S. Environmental Protection Agency 3 USGS, http://earthquake.usgs.gov/research/induced/

## Cri2cal	Components Pressure Buildup
• An increase in the formation pore pressure from disposal activities Faults of Concern
• Optimally oriented for movement, and under critical stress. • Sufficient size for movement to potentially cause a significant earthquake • May be a single fault or a zone of multiple faults and fractures. Pathway
• A permeable avenue (matrix or fracture permeability) allowing the pore pressure increase to reach the fault

28/03/2016 U.S. Environmental Protection Agency 428/03/2016 U.S. Environmental Protection Agency 5 USGS, http://earthquake.usgs.gov/research/induced/modeling.php 

## Cri2cal	ComponentsPressure Buildup
• An increase in the formation pore pressure from disposal activities Faults of Concern
• Optimally oriented for movement, and under critical stress. • Sufficient size for movement to potentially cause a significant earthquake • May be a single fault or a zone of multiple faults and fractures. Pathway
• A permeable avenue (matrix or fracture permeability) allowing the pore pressure increase to reach the fault

28/03/2016 U.S. Environmental Protection Agency 6



## Cri2cal	Components28/03/2016 U.S. Environmental Protection Agency 7 USGS, http://earthquake.usgs.gov/research/induced/modeling.php 

## Cri2cal	ComponentsPressure Buildup
• An increase in the formation pore pressure from disposal activities Faults of Concern
• Optimally oriented for movement, and under critical stress. • Sufficient size for movement to potentially cause a significant earthquake • May be a single fault or a zone of multiple faults and fractures. Pathway
• A permeable avenue (matrix or fracture permeability) allowing the pore pressure increase to reach the fault

28/03/2016 U.S. Environmental Protection Agency 8



## Cri2cal	Components28/03/2016 U.S. Environmental Protection Agency 9 USGS, http://earthquake.usgs.gov/research/induced/modeling.php 

## Cri2cal	Components

## Classic	Example

28/03/2016 10 U.S. Environmental Protection Agency Evans, The Mountain Geologist, v3, 1966

## Minimizing	and	Managing	the	Poten/al	for Injec/on	Induced	Seismicity	Associated	with Class	II	Disposal	Wells:	A	Prac/cal	Approach

28/03/2016 U.S. Environmental Protection Agency 11

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 12

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 13

## Study	Approach

• Literature	review	and	compila/on • Peer	reviewed	material	only • Comprehensive,	but	moving	target

28/03/2016 U.S. Environmental Protection Agency 14

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 15

## Study	Approach

28/03/2016 U.S. Environmental Protection Agency 16

## Study	Approach

• Analysis	of	four	case	examples • Geologic	site	summary • History	of	seismicity • State	ac/ons • Applica/on	of	reservoir	engineering	methods • Lessons	learned

28/03/2016 U.S. Environmental Protection Agency 18

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 19

## Study	Approach

• Development	of	decision	model • Received	much	input	throughout	process • Comprehensive	thought	process	-	not	specific • Founded	on	Director	Discre/onary	Authority

28/03/2016 U.S. Environmental Protection Agency 2020 

## Decision Thought Process

No Permit Existing Class II New Class II

UIC Process UIC Process Seismicity Concerns? Site Assessment (Faults, Pressure Buildup, Pathway) Remaining Seismicity Concerns?

UIC Process With Conditions Approaches (Monitoring, Operational, Management) Is There a Satisfactory Approach? 28/03/2016 U.S. Environmental Protection Agency

## Work	Flow	and	Ac2on	Plan

Collect Necessary Data GIS Mapping and Analysis Can the Potential be Mitigated Act in a Timely Fashion

28/03/2016 21 U.S. Environmental Protection Agency

## Mul2-Disciplinary	Site Assessment

28/03/2016 22 U.S. Environmental Protection Agency Information Needed Source Regional and Local Seismicity USGS or state agency catalog; event accuracy, seismometer spacing Detailed Well Information Permit and other Well Files, including daily disposal volumes and pressures Geologic Setting Maps, Cross-sections, Permit Application, Seismic Surveys, Publications Reservoir Characterization Core analysis, Well Tests, Well Logs, Hydraulic Fracture Results, Publications Reservoir Pressure Static Pressure: gauge or fluid level Flow Character Analysis or Modeling Pathway Analysis or Test Results Stress Direction Borehole Breakout, Production logs

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 24

## Study	Approach

• Fundamentals	of	induced	seismicity • Captures	a	broader	poten/al	audience • Provides	a	general	reference • Includes	geoscience	and	engineering	aspects

28/03/2016 U.S. Environmental Protection Agency 25

## Study	Approach

• Literature	review	and	compila/on • Analysis	of	four	case	examples • Development	of	decision	model • Fundamentals	of	induced	seismicity • Explore	petroleum	engineering	methods

28/03/2016 U.S. Environmental Protection Agency 26

## Engineering	Tools

• A	few	points. • Quality	of	data	is	crucial. • These	methods	are	an	interpre/ve	tool,	not	a	fix-all. • PE	tools	can	determine	if	fracture	flow	is predominant. • Fractured	reservoirs	can	transmit	pressure	buildup over	great	distances. • PE	tools	can	detect	reservoir	changes	at	distance, including	faults. • Correspondence	between	well	behavior	and seismicity	was	apparent	in	some	case	example	wells . 28/03/2016 U.S. Environmental Protection Agency 27

### • Two	fundamental	approaches • Well	tes/ng • Pressure	transient	or	falloff	tes/ng	can determine	if	a	reservoir	is	fractured,	as	well as	sta/c	forma/on	pressure. • Func/on	of	near	well	condi/ons. • Analysis	of	opera/onal	data • Hall	plots	using	opera/onal	data	(rates	and pressures)	indicate	changes	in	transmissivity (ease	of	injec/on)	at	distance. • Covers	both	near	wellbore	and	distance increasing	with	/me. 28/03/2016 U.S. Environmental Protection Agency 28 

## Engineering	Tools28/03/2016 U.S. Environmental Protection Agency 29 

## Engineering	Tools28/03/2016 29 U.S. Environmental Protection Agency 

## Engineering	Tools28/03/2016 U.S. Environmental Protection Agency 30 

## Engineering	Tools

## Summary	of	Findings

• Take	a	proac/ve	approach • Realis/c	analysis	instead	of	defini/ve	proof • Monitor	seismicity	trends	in	regional	area • Magnitude	and	frequency • Engage	operators	early • Addi/onal	site	geologic	data • Voluntary	ac/ons • Increased	opera/onal	data • Engage	external	exper/se	if	warranted • Modify	opera/ons	if	warranted

## Summary	of	Findings

• Perform	mul/-disciplinary	characteriza/on	of	site. (injec/on	reservoir	tes/ng,	analysis,	consulta/on, literature). • Case	examples	–	deep	fractured	reservoirs • Fractures	more	likely	to	communicate	pressure buildup	long	distances • Buildup	can	be	direc/onal	and	extend	miles • Fractured	reservoirs	can	result	in	communica/on with	basement	rocks,	lower	confining	strata	is important.

## Summary	of	Findings

• Assure	high	quality	opera/onal	data • PermiYng	con/ngencies	(green,	yellow,	red	lights) are	an	excellent	tool	to	address	site	uncertain/es • Increased	seismometers	beZer	define	seismic ac/vity.– Minimizing and Managing Potential Impacts of InjectionInduced Seismicity From Class II Disposal Wells: Practical Approaches : https://www.epa.gov/sites/production/files/2015-08/documents/ induced-seismicity-201502.pdf

– Scientific Principles Affecting Protocols for Sitecharacterization and Risk Assessment Related to the Potential for Seismicity Triggered by Saltwater Disposal and Hydraulic Fracturing : https://scits.stanford.edu/sites/default/files/ scitsguidelines_final_spring2015_0.pdf

– Potential Injection Induced Seismicity Associated With Oil & Gas Development: A Primer On Technical & Regulatory Considerations Informing Risk Management & Mitigation : http://www.gwpc.org/sites/default/files/finalprimerweb.pdf 28/03/2016 34 U.S. Environmental Protection Agency 

## Addi2onal	Resources