John Brodylo, Jean-Yves Chatellier,Guillaume Matton & Michel Rheault

The Stability Of Fault Systems

In The South Shore Of The

St. Lawrence Lowlands Of Québec

Implications For Shale Gas Development

Copyright 2011, Society of Petroleum Engineers 1

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Outline • Majority of Québec Utica shale gas exploration in south

shore area of St. Lawrence Lowlands

• Natural and man-made earthquakes in south shore

• Tectonic domains, in-situ stress and fault styles

• Fracture stimulation containment within shale gas target

• Hydrofracturing Utica very unlikely to damage surface structures or shallow aquifers

Ottawa-Bonnechere

Graben

St. Lawrence

Graben

St. Lawrence

Lowlands

Study Area Montréal

Québec

City

Study Area

Québec

3

Earthquake

• A sudden release of energy in the earth's crust or upper mantle as a result of fault slip

• Destructive at magnitudes of 5 and above

• Minor earthquakes magnitude 2 to 5

• Micro-earthquake is a very low intensity earthquake generally magnitude 2 or less

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Perspective

1 kg TNT

Stick of

Dynamite

2 X Hiroshima

Atomic Bomb

-3 -2 -1 0 3 4 5 2 1

Earthquake (Nuttli) Magnitude

-4 6

Micro-earthquakes

Imperceptible

by man

Minor-earthquakes

rarely felt felt

Light

shaking Moderate

damage

Limit

of measurement

Small

Firecracker

Impact of

Brick

Falling from

1 meter

Utica Shale

Gas Frac

Microseismic

event

30 tons TNT

Average Québec

Earthquake

Earthquake Magnitude Comparison

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Southern Québec Earthquakes

Major

Basement Faults

Québec City

Montréal

Most Active Earthquake

Regions of Southern Québec

Charlevoix Impact Crator

South Shore

Shale Gas

Exploration

Areas

US Border

Southern Québec Earthquakes

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Comparison of Induced Seismic Events

Mag

nit

ud

e

-3

-2

-1

0

3

5

2

1

-4

6

4

9

8

7

10

Event

Geothermal Various

countries.

Barnett Shale

Fracs. TX.

Mine Collapse, NY. 1994

Manic 3 Dam, Qc.

1975

Dams Various Global

Micro-seismic event Utica Shale Fracs.

Québec, 2008-2010

Waste Water inj., TX. 2010

US Army. Co. Fluid Inj., 1962

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St. Lawrence

Lowlands

Induced Seismic in Québec

SM3 Reservoir Impoundment

Induced - unspecified

Blasting

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Risk?

The Earth Sciences Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory has studied induced seismicity relating to oil and gas activity and to date hydraulic fracturing has resulted in no known surface earthquakes felt by man

Update: Blackpool U.K. 2.3 M earthquake attributed to fluid

injection following hydraulic fracturing. Felt at surface because of shallow focal depth, very unusual circumstances, no damage to building or aquifers

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Stratigraphy

Queenston/Lorraine

Sandstone, siltstone and shale

Utica Shale Gas target

Quartz/carbonate organic shale

Potsdam

Regional seismic reflector

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Image Modified from: TRIANGLE ZONES IN ACCRETIONARY WEDGES: EXAMPLES FROM THE QUÉBEC APPALACHIANS AND PHYSICAL MODELING

Konstantinovskaya et al, AAPG Poster, 2010

Autochthonous Domain Passive margin Sediments

Cambro-Ordovician Shale gas target

Grenville Basement Granite & Metasediments

Disturbed Domain Convergent margin Sediments

U Ordovician Lorraine and Queenstown

3 Major Tectonic Domains

South Shore Utica Shale Gas Fairway

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Borehole Breakouts, Fractures and In-situ Stresses

• Bore hole break outs in the direction of Shmin = 315 degrees

• Drilling induced fractures in direction of SHmax = 45 degrees

sHMAX

shmin

principal stresses, s1 > s3

Azimuth of Borehole breakouts

Azimuth of Natural, Drilling Induced,

and Hydraulic Fractures

borehole

N

Shmin

Breakout SHmax

Present day in-situ Stress

Drill Induced

Fracture

Borehole Breakouts, Fractures and In-situ Stresses

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sv = s1

sHMAX = s2

shmin = s3

s3 = shmin

s2 = sHmax

In Situ Stresses

s1=sv

sV>sHmax>shmin

Old Healed Fractures From Rift Phase

Strike Direction

of Fractures

Autochthonous Domain

• Tensional passive margin Normal faulting

• Result of opening of the Iapetus Sea

• Hydraulic fractures propagate vertically

• 488.3–443.7 million years old

• Fractures in direction of SHmax = 38 degrees

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s1 = shMAX

s2 = shmin

In Situ Stresses

s3=sv

sHmax>shmin>sV

Open Fractures From

Compressional Phase

Strike Direction

of Fractures

Disturbed Domain

• Compressional thrusting

• Hydraulic fractures in direction of SHmax = 325 degrees

shmin = s2

sHMAX = s1

sv = s3

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s3 = shmin

s1 = sHmax

In Situ Stresses

s2=sv

sHmax>sV>shmin

Shmin

Breakout SHmax

Present day in-situ Stress

Drill Induced

Fracture

• Bore hole break outs in direction of Shmin = 315 degrees

• Drilling induced fractures in direction of SHmax = 53 degrees

Wrenching

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Wrenching

shmin = s3

sv = s2

sHMAX = s1

sn

sn

Coulomb Stress = tb + m(sn + P)

tb = shear stress

m = coefficient of friction sn = normal stress

P = pore pressure

Fault Slip

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20 40 60 80 100 MPa

Pore

Pressure

shmin

sHMAX

sv

sHmax > shmin > sv

Wrench Regime

Pre-completion stress state More vertical fracturing

sHmax > sV > shmin

Thrust Regime

Hydraulic fracturing stress state More horizontal fracturing

Stress Affects on Completions

Utica

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• Contrasts in fracture toughness form barriers

• High Young’s modulus

(Y)=Brittle=low toughness • Low Young’s modulus=Ductile=high

toughness • Frac target a brittle zone with low

toughness between ductile zones

• High toughness ductile zones are barriers

• Thrust fault are barriers

Hydraulic Fracture Height Containment

Lorraine

Utica Shale

Gas Target

Trenton

GR Y Hi Low

Ductile

Ductile

Brittle

Brittle

Schematic

Thrust

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Micro-seismic

Microseismic events confined

to +/- 50 m of wellbore

Aquifer

Utica

Horizontal Shale Gas Well with Micro-seismic Events

•Minimal vertical height growth

•Formations above and below zone likely acting as barriers

•No communication or propagation to shallow aquifers.

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There are a total of 14 minor >

M2.5 earthquakes recorded

in the South Shore Shale Gas

exploration Area

Surface Lineament Analysis

Matton and Rheault 2011

South Shore

Shale Gas

Exploration

Area

(Study Area)

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Inset Map

St. Lawrence

Lowlands

Shale Gas

Fairway

Québec City Cap-Rouge Earthquake

Neuville Fault Trace

at Potsdam Level

18 3.6

Focal Depth kilometers Earthquake magnitude

Earthquake < M2.5

Seismic Line 78-824

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Summary • South shore shale gas exploration region is in stress relaxed

state and less prone to fault reactivation

• No correspondance between natural and man-made earthquakes and shallow faults in study area

• In- situ stress, rock toughness, and thrust faults all act as

barriers to vertical propagation of fractures and faults

• Fracture stimulations are contained within shale gas target • Hydrofracturing is very unlikely to cause damage to shallow

aquifers or surface structures

Michael Binnion Questerre Energy Corporation

Marianne Molgat Talisman Energy Inc

Geoff Rait, - IEX Structural Geologist, Talisman Energy

Scott McLellan, - IEX Geophysicist, Talisman Energy

Heather Davey Exploration Specialist Geology

Acknowledgements

Questions?

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