Unconventional Reservoir Geomechanics: Shale Gas, Tight Oil, and Induced Seismicity

496 Pages·2019·99.057 MB·English

by  Mark D Zoback, Arjun H Kohli

Unconventional ReservoirGeomechanics
Since the beginning of the US shale gas revolution in 2005, the development of
unconventionaloilandgasresourceshasgatheredtremendouspacearoundtheworld.
This book provides a comprehensive overview of the key geologic, geophysical, and
engineering principles that govern the development of unconventional reservoirs.
The book begins with a detailed characterization of unconventional reservoir rocks:
theircompositionandmicrostructure,mechanicalproperties,andtheprocessescontrol-
lingfaultslipandfluidflow.Adiscussionofgeomechanicalprinciplesfollows,includ-
ing the state of stress, pore pressure, and the importance offractures and faults. After
reviewingthefundamentalsofhorizontaldrilling,multi-stagehydraulicfracturingand
stimulationofsliponpre-existingfaults,thekeyfactorsimpactinghydrocarbonproduc-
tionareexplored.Thefinalchapterscoverenvironmentalimpactsandhowtomitigate
hazardsassociatedwithinducedseismicity.Thistextprovidesanessentialoverviewfor
students,researchersandindustryprofessionalsinterestedinunconventionalreservoirs.
Dr. Mark D. Zoback is the Benjamin M. Page Professor of Geophysics at Stanford
University. He conducts research on in situ stress, fault mechanics, and reservoir
geomechanics with an emphasis on shale gas, tight gas and tight oil production. His
firstbook,ReservoirGeomechanics,publishedbyCambridgeUniversityPressin2007
is now in its 15th printing. His online course in reservoir geomechanics has been
completedbyapproximately10,000studentsaroundtheworld.Dr.Zobackhasreceived
a number of awards and honors, including election to the US National Academy of
Engineering.
Dr.ArjunH.KohliisaResearchScientistandLecturerintheDepartmentofGeophysics
atStanfordUniversity.Heconductsresearchonearthquakephysicswithanemphasison
plate boundary faults and induced seismicity in geologic reservoirs. He co-developed
twomassiveopenonlinecoursesonreservoirgeomechanics,whichfeatureinteractive
exercisesdesignedforstudentsrangingfromhighschooltoindustryprofessionals.

Unconventional Reservoir
Geomechanics
Shale Gas, Tight Oil, and Induced Seismicity
MARK D. ZOBACK AND ARJUN H. KOHLI
StanfordUniversity,California
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www.cambridge.org
Informationonthistitle:www.cambridge.org/9781107087071
DOI:10.1017/9781316091869
©MarkD.ZobackandArjunH.Kohli2019
Thispublicationisincopyright.Subjecttostatutoryexception
andtotheprovisionsofrelevantcollectivelicensingagreements,
noreproductionofanypartmaytakeplacewithoutthewritten
permissionofCambridgeUniversityPress.
Firstpublished2019
PrintedandboundinGreatBritainbyClaysLtd,ElcografS.p.A.2019
AcatalogrecordforthispublicationisavailablefromtheBritishLibrary.
LibraryofCongressCataloging-in-PublicationData
Names:Zoback,MarkD.,author.|Kohli,ArjunH.,author.
Title:Unconventionalreservoirgeomechanics:shalegas,tightoilandinducedseismicity/Mark
D.Zoback,StanfordUniversity,California,ArjunH.Kohli,SLACNationalAcceleratorLaboratory.
Description:Cambridge,UnitedKingdom;NewYork,NY,USA:CambridgeUniversityPress,2019.|
Includesbibliographicalreferencesandindex.
Identifiers:LCCN2018044699|ISBN9781107087071
Subjects:LCSH:Hydrocarbonreservoirs–Technologicalinnovations.|Energydevelopment–
Environmentalaspects.
Classification:LCCTN870.57.Z642019|DDC553.2/8–dc23
LCrecordavailableathttps://lccn.loc.gov/2018044699
ISBN978-1-107-08707-1Hardback
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Contents
Preface pageix
PartI PhysicalPropertiesofUnconventionalReservoirs 1
1 Introduction 3
UnconventionalResources 6
TypesofUnconventionalReservoirs 9
RecoveryFactorsandProductionRates 17
HorizontalDrillingandMulti-StageHydraulicFracturing 21
2 Composition,Fabric,ElasticPropertiesandAnisotropy 31
CompositionandFabric 31
ElasticProperties 41
ElasticAnisotropy 50
Poroelasticity 53
EstimatingElasticPropertiesfromGeophysicalData 56
3 StrengthandDuctility 65
RockStrength 65
Time-DependentDeformation(Creep) 69
StressandStrainPartitioning 73
ModelingTime-DependentDeformation 76
EstimatingInSituDifferentialStressfromViscoelasticProperties 80
BrittlenessandStressMagnitudes 84
4 FrictionalProperties 91
FaultStrengthandStressMagnitudes 92
RockFriction 95
FrictionalStrengthandStability 101
ImplicationsforInducedShearSlipduringHydraulicStimulation 111
vi Contents
5 PoreNetworksandPoreFluids 115
MatrixPorosity 115
MatrixPoreNetworks 132
InSituPoreFluids 138
6 FlowandSorption 149
MatrixFlow 150
Permeability 154
Sorption 168
7 Stress,PorePressure,FracturesandFaults 181
StateofStressinUSUnconventionalReservoirs 182
MeasuringStressOrientationandMagnitude 191
PorePressureinUnconventionalReservoirs 204
FracturesandFaultsinUnconventionalReservoirs 211
Utilizing3DSeismicDatatoMapFaultzonesandFractures 225
PartII StimulatingProductionfromUnconventionalReservoirs 231
8 HorizontalDrillingandMulti-StageHydraulicFracturing 233
HorizontalDrilling 233
Multi-StageHydraulicFracturing 238
FracturingFluidsandProppants 254
9 ReservoirSeismology 263
MicroseismicMonitoringduringReservoirStimulation 263
SeismicWaveRadiation 270
EarthquakeSourceParametersandScalingRelationships 282
EarthquakeStatistics 287
LocatingMicroearthquakes 289
10 InducedShearSlipduringHydraulicFracturing 301
ShearStimulationandProduction 301
CoulombFaultingandSliponPoorlyOrientedFractureandFaultPlanes 304
ShearSlipandPermeability 315
11 GeomechanicsandStimulationOptimization 322
LandingZones 323
OptimizingCompletionsI:FieldTestsandReservoirSimulation 328
VerticalHydraulicFractureGrowth 332
Contents vii
OptimizingCompletionsII:ReservoirSimulationand3DGeomechanics 334
ViscoplasticStressRelaxationandVaryingStressMagnitudeswithDepth 339
TargetingGeomechanicalSweetSpots:Fractures,FaultsandPorePressure 344
12 ProductionandDepletion 345
ProductionDeclineCurvesandOne-DimensionalFlow 346
UsingMicroseismicitytoEstimateTotalFractureArea 349
EvolutionofaShearFractureNetwork 353
MatrixDamageandPermeabilityEnhancement 358
SeismicandAseismicFaultSlip 359
DepletionofUltra-LowPermeabilityFormationswithHighPermeability
Fractures 360
TheFracHitPhenomenonandWell-to-WellCommunication 362
ModelingPoroelasticStressChanges 370
PartIII EnvironmentalImpactsandInducedSeismicity 375
13 EnvironmentalImpactsandInducedSeismicity 377
OverviewofEnvironmentalIssues 378
InducedSeismicity 389
14 ManagingtheRiskofInjection-InducedSeismicity 406
AvoidingInjectionNearPotentiallyActiveFaults 406
EstimationofFaultSlipPotentialinthePermianandFortWorthBasins 415
RiskManagementandTrafficLightSystems 422
UtilizingSeismogenicIndexModelstoManageProducedWaterInjection 426
SiteCharacterizationRiskFrameworks 434
References 442
Index 479