MULTIPHASE FLOW IN PERMEABLE MEDIA A Pore-Scale Perspective Hydrocarbonproduction,gasrecoveryfromshale,CO storageandwatermanage- 2 ment have a common scientific underpinning: multiphase flow in porous media. This book provides a fundamental description of multiphase flow through porous rock, with emphasis on the understanding of displacement processes at the pore, ormicron, scale.Fundamentalequationsandthe principal conceptsusingenergy, momentumandmassbalancearedeveloped.Thelatestadvancesinhigh-resolution three-dimensional imaging and associated modelling are explored. The treatment ispedagogical,developingsoundphysicalprinciplestopredictflowandrecovery through complex rock structures while providing a review of the recent litera- ture. This systematic approach makes it an excellent reference for those who are newtothe field. It providesthe scientific backgroundnecessaryfor a quantitative assessmentofmultiphasesubsurfaceflowprocesses,andisidealforhydrologyand environmental engineering students, as well as professionals in the hydrocarbon, waterandcarbonstorageindustries. MARTIN J. BLUNT is professor of Petroleum Engineering at Imperial College London,visitingprofessoratPolitecnicodiMilanoandeditor-in-chiefofthejour- nalTransportinPorousMedia.Hepublisheswidelyonmultiphaseflowinporous media applied to oil recovery, groundwater flows and carbon dioxide storage. He is a distinguished member of the Society of Petroleum Engineers (SPE), having won the 2011 SPE Lester C. Uren Award, and the 2012 Darcy Medal for lifetime achievement from the Society of Core Analysts. The book is inspired by recent research and based on courses taught to thousands of students and professionals fromaroundtheworld. MULTIPHASE FLOW IN PERMEABLE MEDIA A Pore-Scale Perspective MARTIN J. BLUNT ImperialCollegeLondon UniversityPrintingHouse,CambridgeCB28BS,UnitedKingdom OneLibertyPlaza,20thFloor,NewYork,NY10006,USA 477WilliamstownRoad,PortMelbourne,VIC3207,Australia 4843/24,2ndFloor,AnsariRoad,Daryaganj,Delhi–110002,India 79AnsonRoad,#06–04/06,Singapore079906 CambridgeUniversityPressispartoftheUniversityofCambridge. ItfurtherstheUniversity’smissionbydisseminatingknowledgeinthepursuitof education,learning,andresearchatthehighestinternationallevelsofexcellence. www.cambridge.org Informationonthistitle:www.cambridge.org/9781107093461 DOI:10.1017/9781316145098 (cid:2)c MartinJ.Blunt2017 Thispublicationisincopyright.Subjecttostatutoryexception andtotheprovisionsofrelevantcollectivelicensingagreements, noreproductionofanypartmaytakeplacewithoutthewritten permissionofCambridgeUniversityPress. Firstpublished2017 PrintedintheUnitedKingdombyTJInternationalLtd,Padstow,Cornwall AcataloguerecordforthispublicationisavailablefromtheBritishLibrary. LibraryofCongressCataloging-in-PublicationData Names:Blunt,MartinJ. Title:Multiphaseflowinpermeablemedia:apore-scaleperspective/MartinJ.Blunt, ImperialCollegeLondon Description:Cambridge:CambridgeUniversityPress,2017. Identifiers:LCCN2016026616 | ISBN9781316145098 Subjects:LCSH:Multiphaseflow. | Fluiddynamics. | Porousmaterials. Classification:LCCTA357.5.M84B582017 | DDC532/.56–dc23 LCrecordavailableathttps://lccn.loc.gov/2016026616 ISBN978-1-107-09346-1Hardback CambridgeUniversityPresshasnoresponsibilityforthepersistenceoraccuracy ofURLsforexternalorthird-partyInternetWebsitesreferredtointhispublication anddoesnotguaranteethatanycontentonsuchWebsitesis,orwillremain, accurateorappropriate. Thisworkisdedicatedtomyfamily,andparticularlytoCatherine,whois nolongerheretoreadit.Iamsorrythatthisisfarlessthanyoucouldhave achieved,butitisthebestIcanmanage. Contents Preface pagexiii Acknowledgements xvi ListofSymbols xvii 1 InterfacialCurvatureandContactAngle 1 1.1 InterfacialTension 1 1.2 Young-LaplaceEquation 4 1.3 TheYoungEquationandContactAngle 7 1.3.1 TheYoungEquationasanEnergyBalance 10 1.3.2 InterfacialTension,RoughnessandWettability 11 1.3.3 CapillaryRise 14 1.3.4 HistoricalInterlude:ThomasYoungandtheMarquis deLaplace 16 2 PorousMediaandFluidDisplacement 17 2.1 Pore-SpaceImages 17 2.1.1 StatisticalandProcess-BasedPore-SpaceReconstruction 22 2.1.2 Definition of a Porous Medium, Representative Volumes,PorosityandSaturation 29 2.2 Pore-ScaleNetworksandTopologicalDescription 32 2.2.1 TransportNetworks 33 2.2.2 NetworkConstruction 35 2.2.3 GeneralizedNetworkModels 45 2.2.4 TopologicalDescriptorsofthePoreSpace 50 2.3 WettabilityandDisplacement 56 2.3.1 ThermodynamicDescriptionofDisplacementProcesses 56 2.3.2 DisplacementSequences 59 2.3.3 WettabilityandWettabilityChange 60 2.3.4 SurfaceRoughnessandContactAngleHysteresis 65 2.3.5 EffectiveContactAngleandCurvature 69 vii viii Contents 3 PrimaryDrainage 73 3.1 EntryPressuresandFluidConfigurations 74 3.1.1 WettingLayers 79 3.1.2 EntryPressuresforIrregularThroats 82 3.2 MacroscopicCapillaryPressureinDrainage 85 3.3 BundleofTubesModelandtheThroatSizeDistribution 89 3.3.1 PredictionofCapillaryPressurefromImages 92 3.4 InvasionPercolation 95 3.4.1 ScalingRelationsinInvasionPercolation 99 3.4.2 DisplacementunderGravityandGradientPercolation 105 3.4.3 InvasionPercolation,NormalPercolationandFlow 109 3.5 FinalSaturationandMaximumCapillaryPressure 110 4 ImbibitionandTrapping 115 4.1 LayerFlow,SwellingandSnap-Off 116 4.1.1 RoofSnap-OffduringDrainage 122 4.2 Piston-LikeAdvanceandPoreFilling 126 4.2.1 Piston-LikeThroatFilling 126 4.2.2 CooperativePoreFilling 128 4.2.3 CompetitionbetweenSnap-OffandCooperativePore Filling 132 4.2.4 FrequencyofDifferentFillingEvents 135 4.2.5 DynamicsofFilling 141 4.2.6 DisplacementasaSeriesofMetastableStates 144 4.3 DisplacementPatternsinImbibition 145 4.3.1 PercolationwithTrapping 145 4.3.2 InvasionPercolationwithTrapping 147 4.3.3 FrontalAdvance 148 4.3.4 ClusterGrowth 149 4.3.5 PhaseDiagramsforCapillary-ControlledDisplacement 149 4.3.6 InfiltrationorUnstableImbibitionunderGravity 157 4.4 MacroscopicCapillaryPressure 161 4.5 InterfacialArea 165 4.6 CapillaryTrappingandResidualSaturation 168 4.6.1 DirectImagingofTrappedClustersand PercolationTheory 168 4.6.2 EffectofInitialSaturation 176 5 WettabilityandDisplacementPaths 188 5.1 DefinitionsandCapillaryPressureCycles 188 Contents ix 5.2 OilandWaterLayers 194 5.2.1 PinnedWaterLayersandForcedSnap-Off 194 5.2.2 ForcedWaterInjectionandOilLayerFormation 196 5.2.3 RecapofDisplacementProcesses 200 5.3 CapillaryPressuresandWettabilityIndices 201 5.3.1 WettabilityTrendsandRelationshipsbetweenIndices 204 5.3.2 DisplacementStatisticsinMixed-WetSystems 208 5.4 TrappinginMixed-WetandOil-WetMedia 211 5.4.1 Layer Connectivity as a Function of Initial Water Saturation 213 5.4.2 Pore-Scale Observation of Trapping in Mixed-WetSystems 216 6 Navier-StokesEquations,Darcy’sLawandMultiphaseFlow 219 6.1 Navier-StokesEquationsandConservationofMass 219 6.1.1 FlowinaPipe 221 6.1.2 TheWashburnEquation 225 6.1.3 FlowinWettingLayers 228 6.1.4 ReynoldsNumberandtheStokesEquation 233 6.2 Darcy’sLawandPermeability 236 6.2.1 PermeabilityofaBundleofCapillaryTubes 238 6.2.2 TypicalPermeabilityValues 239 6.2.3 TheLeverettJFunction 243 6.2.4 ComputingFlowFieldsonPore-SpaceImages 247 6.3 TheMultiphaseDarcyLawandRelativePermeability 254 6.3.1 HistoricalInterlude:Muskat,LeverettandBuckingham 254 6.3.2 AssumptionsInherentintheMultiphaseDarcyLaw 255 6.4 CapillaryNumberandPore-ScaleDynamics 257 6.4.1 MacroscopicFlowPatternsforImbibition 257 6.4.2 Capillary Number and the Perturbative Effect of FlowRate 263 6.4.3 LayerConductanceandViscousEffects 265 6.4.4 CorrelationLengthsforPercolation-LikeDisplacement 270 6.4.5 CorrelationLengthandResidualSaturation 273 6.4.6 MobilizationofTrappedGanglia 275 6.4.7 GanglionDynamics,ConnectivityandFlowRegimes 279 6.4.8 ViscousandCapillaryForcesasanEnergyBalance 285 6.4.9 DirectComputationofMultiphaseFlow 288 6.5 ExtensionstotheMultiphaseDarcyLaw 298 6.5.1 InfiltrationandPhaseFieldModels 298