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Hydraulicfracturingandits
rela1onshiptoinduced
seismicityin1meandspace
DaveEaton
DepartmentofGeoscience
KeyPoints
§ IntheCrookedLakearea,steeplydippingfaultsare
ac=vatedby:
- elevatedpore-pressure(àpersistentseismicity,=mescale~months)
- poroelas=cstresschange(àtransientseismicity,mainlyconfinedto
treatmentinterval)
§ Marcellus:focalmechanismsforcompositeevents
§ NorthernMontney:EmpiricalHazardMatrix
§ FiniteElementfaultsimula=ons:
- roleofcohesionforwellhealed(inac=ve)faults
- largesurfacedisplacementforshallowreversefaults
§ Somecurrentac=vi=es
0 30 60 90
2
1
3
5
4
6
Days after 2015/01/01
− − − −117˚30' 117˚24' 117˚18' 117˚12'
54˚24'
54˚30'
injection well
Crooked
Lk
Longitude
La
titu
de
km0 5
MW<2
2 <3≤MW
M ≥w 3
Σ=-2.7
Σ=-1.7
Σ=-1.5
Σ=-1.5
CrookedLakeArea:W2015
BaoandEaton,SSA2016
MP
a
MW
0
3
6
10
m4
3
M(m
ax)1
−1012345
65
70
75
Dec 14 Jan 15 Feb 15 Mar 15− − − −
S1 S2 S3
Seismicityvs.Injec1onData
• Largesteventduringflowback−butunusuallylowfluidrecovery
• EpisodicseismicitypersiststhroughoutW2015(S1,S2,S3)butnottypical
aUershocksequence
• Maximummagnitude(MW3.9)compa=ble(barely)withMcGarrformula
BaoandEaton,SSA2016
Dec 14 Jan 15 Feb 15 Mar 15− − − −
0
2
4
10
m4
3
6
−1012345
70
75
80
Dec 14 Jan 15 Feb 15 Mar 15− − − −
M(m
ax)
MP
a
MW
5
MP
a
MW
0
3
6
10
m4
3
M(m
ax)1
−1012345
65
70
75
Dec 14 Jan 15 Feb 15 Mar 15− − − −
S1 S2 S3
S2: τ ≈4days
r=9.2±2.0km
RemoteTriggeringofS2?
BaoandEaton,SSA2016
−0.2 0 0.2 0.4 0.6 0.8 1 1.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4
4.1
4.2
Distance East (km)
Depth
(km
)
east s
trand
west s
trand
hz wells
crystalline basement MW 3.9
Duvernay shale
de
pth
(km
)
distance east (km)
Mul1plestrands–varyingresponse
East:transient
West:persistent
CrossSec=onW E
Migra=on
BaoandEaton,SSA2016
MarcellusExperiment(2014)
10portablebroadbandsta=onsinstalledtorecord11-welltreatment
SeeposterbyZhangandEaton
Focalmechanismofcompositeevents
DepthSec=on
Sh/Pra=o
FocalMechanism
-jackknifetest
SeeposterbyZhangandEaton
Finite-ElementModelling
ModifiedfromSaDariandEaton,Tectonophysics,inreview
• 2-DFEsimula=onyields
realis=cscaling,
includingslip/area,
stressdrop,shapefactor
anddynamicovershoot
• Predictssimplemodel
forco-seismicstress
droptensor
• Unlikeac=vefault
systems,cohesionmay
exertasignificant
controlonfaultrheology
Opera=onalFactor
e.g.Cumula=veInjectedVolume
Ac=vityLevel
e.g.MaximumPriorMagnitude
Hit
Constructa“hitmap”asfollows.
1.Foreachrecordedevent,assignan
opera=onalfactor(e.g.cumula=ve
volume)andac=vitylevel(e.g.
maximumprioreventwithina
specified=mewindow).
2.Testfor“hit”–occurrenceofa
subsequenteventthatmeetscriteria
(e.g.magnitude,=mewindow).
3.Ifhit,addzeros,onestomapas
shown.
EmpiricalHazardMatrix
HitMap:M≥1innext4days
NorthernMontneyEHMs
Datasource:Mahanietal.,BSSA,inpress
TippingPoint?
CourtesyM.Rempel,BScseniorthesisproject
HitMap:M≥2.5innext21days
Tradeoff?
Datasource:Mahanietal.,BSSA,inpress
NorthernMontneyEHMs
CourtesyM.Rempel,BScseniorthesisproject
AUershocks
Foreshocks
CurrentAc1vi1es
• DevelopingaPython-
basedworkflowfor
matched-filtering
analysis
• Applyingthisapproach
toW2016seismicity,
usingRV,DS(NMX/UC)
andothernetworks
SeeposterbyVragovandEaton
CurrentAc1vi1es
• Ongoingfracprogram
(startedthisweek)
• Dualmonitoring:
inducedseismicityand
microseismic
• 6broadbandsta=ons+
accelerometerinstalled
forUCbyNMX
• Holdbackondatarelease
ImagecourtesyofMichaelLaporte,Nanometrics
Acknowledgements
• TransAlta,NanometricsandNSERC(InducedSeismicityProcessesCRD)
• Repsol,NanometricsandCanadianDiscoveryLtd.(dataforSciencepaper)
• NobleEnergyandSpectraseis(MarcellusSurfaceMicroseismic
Experiment)
• Chevron,ConocoPhillips,AquaTerra,Nanometrics(IRC)
• AliMahani(preprintofnorthernMontneyBSSApaper)