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Relative Permeability Display VersionRelative Permeability Display Version
RelativeRelative
PermeabilityPermeability
April...
Presentation OverviewPresentation Overview
 What is relative permeability & UsesWhat is relative permeability & Uses
 Fa...
Common Uses of RelativeCommon Uses of Relative
Permeability DataPermeability Data
 Evaluation of residual saturations and...
Absolute Permeability – is definedAbsolute Permeability – is defined
asas
 The Resistance to Fluid Flow Existing in aThe ...
Darcy’s Law for SINGLE PhaseDarcy’s Law for SINGLE Phase
Flow in Porous Media Can beFlow in Porous Media Can be
Expressed ...
Relative Permeability – is definedRelative Permeability – is defined
asas
 The Resistance to Fluid Flow Existing in aThe ...
Relative Permeability DefinitionRelative Permeability Definition
Kri = Ki(Si)
Kabs
Measured Permeability to a Specific
Pha...
ExampleExample
Absolute Permeability = 100 mD
Perm to Oil = 85 mD
Perm to water = 21 mD
Perm to gas = 14 mD
Kro = 85/100 =...
‘‘Normalized’ Relative PermeabilityNormalized’ Relative Permeability
1.0
0.0
0.0 1.0SATURATION
KRO @ Swi = 1.00
‘‘Absolute’ Relative Perm BasisAbsolute’ Relative Perm Basis
1.0
0.0
0.0 1.0SATURATION
KRO @ Swi = Ko
Kabs
Which Method of Representation isWhich Method of Representation is
the Bestthe Best
 Either method is accurate as long as...
Saturation ConceptsSaturation Concepts
Sinit Scrit Sirr SmaxSinitial
Initial Saturation (Swi)
Represents the initial water...
Major Factors Impacting RelativeMajor Factors Impacting Relative
PermeabilityPermeability
 Fluid SaturationsFluid Saturat...
Other Factors Which Also InfluenceOther Factors Which Also Influence
Relative PermeabilityRelative Permeability
 Overburd...
Saturation Effects on RelativeSaturation Effects on Relative
PermeabilityPermeability
Water Saturation Gas Saturation Liqu...
Saturation Effects on RelativeSaturation Effects on Relative
PermeabilityPermeability
 Strongly dependant function of sat...
Pore GeometryPore Geometry
 Relative permeability is strongly impactedRelative permeability is strongly impacted
by the s...
Example of Rel Perm Curves for aExample of Rel Perm Curves for a
System Dominated bySystem Dominated by
Macroporosity (e.g...
More Uniform Intergranular/MatrixMore Uniform Intergranular/Matrix
Type Porosity SystemType Porosity System
Macroporous Flow System WithMacroporous Flow System With
MicroporosityMicroporosity
Anisotropic FlowAnisotropic Flow
Flow Parallel to Bedding PlanesFlow Parallel to Bedding Planes
Flow Perpendicular to BeddingFlow Perpendicular to Bedding
PlanesPlanes
WettabilityWettability
The fluid that coats the rock pores
Also describes the wettability
Nature of that reservoir
Wettability TypesWettability Types
 Water WetWater Wet
 Oil WetOil Wet
 Neutral WetNeutral Wet
 Mixed WetMixed Wet
 S...
Relative PermeabilityRelative Permeability
Water Saturation - Fraction
RelativePermeability-Fraction
Swi 10%
Crossover 22%...
Typical RelativeTypical Relative
Permeability CurvePermeability Curve
Configurations for OtherConfigurations for Other
Wet...
Neutral Wet FormationsNeutral Wet Formations
Swi 10-20%
Crossover around 50%
Krw = 0.45
Mixed WettabilityMixed Wettability
 A fairly common wettability type in whichA fairly common wettability type in which
ti...
Typical Mixed Wettability RelativeTypical Mixed Wettability Relative
Permeability CurvesPermeability Curves
Swi = 40%
Cros...
Spotted/Dalmation WettabilitySpotted/Dalmation Wettability
Swi = 22%
Crossover = 59%
Krw = 0.28
Mobility &Mobility &
WaterfloodWaterflood
PerformancePerformance
Concept of ‘Mobility Ratio’Concept of ‘Mobility Ratio’
M = µο x Krw
µ w x K r o
Mobility Ratio
Viscosity of
Displaced Phas...
Factors Improving MobilityFactors Improving Mobility
M = µο x Krw
µ w x K r o
Low Oil ViscosityLow Krw/Krg Value
High Disp...
Example – Waterflood in aExample – Waterflood in a
Favorable Mobility System (M=0.5)Favorable Mobility System (M=0.5)
Example – Waterflood in aExample – Waterflood in a
Unfavorable Mobility SystemUnfavorable Mobility System
(M=20)(M=20)
Residual Oil Saturations inResidual Oil Saturations in
WaterfloodsWaterfloods
 BREAKTHROUGHBREAKTHROUGH SorSor
 ECONOMIC...
Breakthrough SorBreakthrough Sor
 Refers to residual oil saturation in theRefers to residual oil saturation in the
swept ...
Economic SorEconomic Sor
 Refers to residual oil saturation in theRefers to residual oil saturation in the
swept pattern ...
Ultimate (True) SorUltimate (True) Sor
 Refers to residual oil saturation in theRefers to residual oil saturation in the
...
Lab Measurements of SorLab Measurements of Sor
 Lab measurements of Sor generally give aLab measurements of Sor generally...
Waterflooding in DifferingWaterflooding in Differing
Wettability ReservoirsWettability Reservoirs
Cumulative Pore Volumes ...
Waterflooding in DifferingWaterflooding in Differing
Wettability ReservoirsWettability Reservoirs
Cumulative Pore Volumes ...
Waterflooding in DifferingWaterflooding in Differing
Wettability ReservoirsWettability Reservoirs
Cumulative Pore Volumes ...
Waterflooding in DifferingWaterflooding in Differing
Wettability ReservoirsWettability Reservoirs
Cumulative Pore Volumes ...
Relative Permeability HysteresisRelative Permeability Hysteresis
 Relative Permeability is not a uniqueRelative Permeabil...
Example – Primary Drainage –Example – Primary Drainage –
Initial Reservoir SaturationInitial Reservoir Saturation
Water Sa...
Example – Primary Imbitition –Example – Primary Imbitition –
(Waterflood)(Waterflood)
Water Saturation – Fraction of Pore ...
Example – Primary Imbitition –Example – Primary Imbitition –
(Waterflood)(Waterflood)
Water Saturation – Fraction of Pore ...
Example –Secondary Drainage –Example –Secondary Drainage –
(ie Gas flood)(ie Gas flood)
Water Saturation – Fraction of Por...
Effect of Confining (Overburden)Effect of Confining (Overburden)
Pressure on Relative PermeabilityPressure on Relative Per...
Effect of Temperature on RelativeEffect of Temperature on Relative
PermeabilityPermeability
 Modifies WettabilityModifies...
Effect of Interfacial Tension (IFT)Effect of Interfacial Tension (IFT)
 IFT is aIFT is a very strong factorvery strong fa...
IFT EffectsIFT Effects
 The level of the IFT controls both theThe level of the IFT controls both the
magnitude of the res...
Effect of IFT on Rel Perm and SorEffect of IFT on Rel Perm and Sor
 Is highly dependant on wettability, poreIs highly dep...
‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative
PermeabilityPermeability
Gas or Water Saturation - Frac...
‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative
PermeabilityPermeability
Gas or Water Saturation - Frac...
‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative
PermeabilityPermeability
Gas or Water Saturation - Frac...
Using Proper IFTUsing Proper IFT
 Avoid treated fluidsAvoid treated fluids
 Avoid surfactants and de-emulsifiersAvoid su...
Viscosity IssuesViscosity Issues
Viscosity IssuesViscosity Issues
Viscosity EffectsViscosity Effects
 Considerably controversy in the pastConsiderably controversy in the past
 Classicall...
Favorable Viscosity Ratio (Favorable Viscosity Ratio (µµdd
>>>>µµinsitu)insitu)RelativePermeability
Water Saturation
Unit Viscosity Ratio (Unit Viscosity Ratio (µµd =d = µµinsitu)insitu)RelativePermeability
Water Saturation
Unfavorable Viscosity Ratio (Unfavorable Viscosity Ratio (µµdd
<<<<µµinsitu)insitu)RelativePermeability
Water Saturation
Initial SaturationsInitial Saturations
 Proper level of initial water saturation inProper level of initial water saturati...
Example – Effect of Swi on Ko/KgExample – Effect of Swi on Ko/KgRelativePermeability
Water Saturation
Example – Effect of Swi on RelExample – Effect of Swi on Rel
Perm Curve ConfigurationPerm Curve ConfigurationRelativePerme...
Presence of a Mobile or ImmobilePresence of a Mobile or Immobile
Third PhaseThird Phase
 Generally free or trapped gas in...
Example – Presence of TrappedExample – Presence of Trapped
Initial Gas SaturationInitial Gas SaturationRelativePermeabilit...
Example – Presence of TrappedExample – Presence of Trapped
Initial Gas SaturationInitial Gas SaturationRelativePermeabilit...
Example – Presence of TrappedExample – Presence of Trapped
Initial Gas SaturationInitial Gas SaturationRelativePermeabilit...
Capillary End EffectsCapillary End Effects
 Caused by a discontinuity in capillaryCaused by a discontinuity in capillary
...
Consequences of an End EffectConsequences of an End Effect
Commence Water
Injection
Delayed Production of Water
& Dp due t...
Consequences of an End EffectConsequences of an End Effect
 Delayed water breakthrough timesDelayed water breakthrough ti...
Mitigation of End EffectsMitigation of End Effects
 High rates and delta PHigh rates and delta P
 Long coresLong cores
...
Measurement ofMeasurement of
RelativeRelative
Permeability DataPermeability Data
Common Determination MethodsCommon Determination Methods
 Steady StateSteady State
 Unsteady StateUnsteady State
 Centr...
Sample SelectionSample Selection
 Rock typing and classificationRock typing and classification
 Single plug vs. composit...
Steady StateSteady State
MethodMethod
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
The Steady State DeterminationThe Steady State Determination
Method for Relative Permeability (2Method for Relative Permea...
Advantages of the Steady StateAdvantages of the Steady State
MethodMethod
 Computationally very simpleComputationally ver...
Disadvantages of the Steady StateDisadvantages of the Steady State
MethodMethod
 Complex and expensive method, very timeC...
Typical Steady State ApparatusTypical Steady State Apparatus
Capillary Contact Paper
Inlet Section Outlet Section
Typical Steady State ApparatusTypical Steady State Apparatus
Pressure Taps
External Core Sleeve
Flow Head Flow Head
Steady State ApparatusSteady State Apparatus
Water Inj Pump
Oil Inj Pump
Injection Pumps
Coreholder
In-Situ Saturation
Mon...
Common In-situ SaturationCommon In-situ Saturation
Determination MethodsDetermination Methods
 GravimetricGravimetric
 E...
X-Ray SaturationX-Ray Saturation
Mannville Samples 13A, 14B, 16, 19, 24A
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 5...
Typical Steady State LabTypical Steady State Lab
ApparatusApparatus
Displacement PumpsDisplacement Pumps
UnsteadyUnsteady
State MethodState Method
Unsteady State Method for RelativeUnsteady State Method for Relative
Permeability (2 Phase)Permeability (2 Phase)
Relative...
Unsteady Steady State Method forUnsteady Steady State Method for
Relative Permeability (2 Phase)Relative Permeability (2 P...
Unsteady Steady State Method forUnsteady Steady State Method for
Relative Permeability (2 Phase)Relative Permeability (2 P...
Transient Pressure and ProductionTransient Pressure and Production
HistoryHistory
DifferentialPressure
Cumulative Run Time...
Transient Pressure and ProductionTransient Pressure and Production
HistoryHistory
ProductionRate
Cumulative Run Time
Break...
Transient Pressure and ProductionTransient Pressure and Production
HistoryHistory
ProductionVolume
Cumulative Run Time
Bre...
The Unsteady State DeterminationThe Unsteady State Determination
Method for Relative Permeability (2Method for Relative Pe...
Advantages of the Unsteady StateAdvantages of the Unsteady State
MethodMethod
 RapidRapid
 Relatively inexpensive, even ...
Disadvantages of the UnsteadyDisadvantages of the Unsteady
State MethodState Method
 Unstable flow possibleUnstable flow ...
Typical Unsteady State ApparatusTypical Unsteady State Apparatus
Injection Pump
Coreholder
Three Phase
Separator
BPR
Pisto...
Typical Unsteady State ApparatusTypical Unsteady State Apparatus
Centrifuge MethodsCentrifuge Methods
 Use transient production vs. capillary pressureUse transient production vs. capilla...
What is the Best Method to Use?What is the Best Method to Use?
What is the Best Method to UseWhat is the Best Method to Use
 Many of the limitations of the unsteadyMany of the limitati...
Requirement for Two Phase FlowRequirement for Two Phase Flow
Fw
Average Sw
Water Saturation
RelativePermeability
Results i...
Requirement for Two Phase FlowRequirement for Two Phase Flow
Fw
Average Sw
Water Saturation
RelativePermeability
Requirement for Two Phase FlowRequirement for Two Phase Flow
Fw
Average Sw
Water Saturation
RelativePermeability
Results i...
Requirement for Two Phase FlowRequirement for Two Phase Flow
Fw
Average Sw
Water Saturation
RelativePermeability
Common Techniques Used in theCommon Techniques Used in the
Past to Disperse FlowPast to Disperse Flow
 Viscous refines oi...
Overcoming TheseOvercoming These
Deficiencies UsingDeficiencies Using
Modern SimulationModern Simulation
MethodsMethods
Simulation or ‘History Matching’Simulation or ‘History Matching’
Generation of Rel Perm DataGeneration of Rel Perm Data
 ...
History Matching TechniqueHistory Matching Technique
 In a normal simulation we know the relIn a normal simulation we kno...
Typical History Match ModelTypical History Match Model
Input Physical Parameters (L, A, Kabs, Porosity, Pore Volume, # Blo...
The HistoryThe History
MatchingMatching
ProcessProcess
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Step 1 – Pick Functional Form
For Rel ...
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
History Matching ProcessHistory Matching Process
 Continue the iterative process until theContinue the iterative process ...
Time Time Saturation
CumulativeProduction
DifferentialPressure
RelativePermeability
Conventional Relative PermeabilityConventional Relative Permeability
TestsTests
 Only provide data in the range of mobile...
Specialty Rel Perm ExperimentsSpecialty Rel Perm Experiments
 Critical condensate floodsCritical condensate floods
 Cons...
Critical condensate floodsCritical condensate floods
 Rich gas condensatesRich gas condensates
 Produced below dew point...
Typical critical condensateTypical critical condensate
apparatusapparatus
Constant IFT FloodsConstant IFT Floods
 Create high IFT injection gas & oilCreate high IFT injection gas & oil
ie models...
Vaporizing MiscibilityVaporizing Miscibility
Fluid PreparationFluid Preparation
Rich Gas
Lean Gas
Low IFT
Oil
High IFT
Oil...
Condensing MiscibilityCondensing Miscibility
Fluid PreparationFluid Preparation
Leaner GasRich Gas
High IFT
Oil
Low IFT
Oi...
Constant IFT FloodConstant IFT Flood
Reservoir Dominated byReservoir Dominated by IFTIFT
Gas Saturation - Fraction
Relativ...
Constant IFT FloodConstant IFT Flood
Reservoir Dominated byReservoir Dominated by MobilityMobility
Gas Saturation - Fracti...
ConclusionsConclusions
 Many controls / influences on relativeMany controls / influences on relative
permeabilitypermeabi...
Thank you!Thank you!
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Relative permeability presentation

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Relative permeability presentation

  1. 1. Relative Permeability Display VersionRelative Permeability Display Version RelativeRelative PermeabilityPermeability April 2005April 2005
  2. 2. Presentation OverviewPresentation Overview  What is relative permeability & UsesWhat is relative permeability & Uses  Factors that affect relative permeabilityFactors that affect relative permeability  How does relative permeability impactHow does relative permeability impact reservoir performance?reservoir performance?  Proper design and interpretation of relativeProper design and interpretation of relative permeability testspermeability tests  Optimizing reservoir performance byOptimizing reservoir performance by understanding relative permeability issuesunderstanding relative permeability issues  Summary and conclusionsSummary and conclusions
  3. 3. Common Uses of RelativeCommon Uses of Relative Permeability DataPermeability Data  Evaluation of residual saturations andEvaluation of residual saturations and displacement efficiency for waterflood, gasflooddisplacement efficiency for waterflood, gasflood and various EOR processesand various EOR processes  Evaluation of flow characteristics in multiphaseEvaluation of flow characteristics in multiphase reservoir situationsreservoir situations  Prediction of reservoir performance andPrediction of reservoir performance and recoverable reservesrecoverable reserves  Reservoir optimization for primary, secondaryReservoir optimization for primary, secondary and tertiary depletion operationsand tertiary depletion operations
  4. 4. Absolute Permeability – is definedAbsolute Permeability – is defined asas  The Resistance to Fluid Flow Existing in aThe Resistance to Fluid Flow Existing in a Porous Media When it is the Only PhasePorous Media When it is the Only Phase PresentPresent
  5. 5. Darcy’s Law for SINGLE PhaseDarcy’s Law for SINGLE Phase Flow in Porous Media Can beFlow in Porous Media Can be Expressed asExpressed as K = Q x L x u A x DP
  6. 6. Relative Permeability – is definedRelative Permeability – is defined asas  The Resistance to Fluid Flow Existing in aThe Resistance to Fluid Flow Existing in a Porous Media When it is in the presencePorous Media When it is in the presence of other mobile or immobile, immiscibleof other mobile or immobile, immiscible fluidsfluids
  7. 7. Relative Permeability DefinitionRelative Permeability Definition Kri = Ki(Si) Kabs Measured Permeability to a Specific Phase at a Given Saturation of that Phase Absolute (single phase) Permeability of the Porous Media Under Consideration Relative Permeability to A Given Phase at Saturation Level ‘I’ Value of That Phase
  8. 8. ExampleExample Absolute Permeability = 100 mD Perm to Oil = 85 mD Perm to water = 21 mD Perm to gas = 14 mD Kro = 85/100 = 0.85 Krw = 21/100 = 0.21 Krg = 14/100 = 0.14
  9. 9. ‘‘Normalized’ Relative PermeabilityNormalized’ Relative Permeability 1.0 0.0 0.0 1.0SATURATION KRO @ Swi = 1.00
  10. 10. ‘‘Absolute’ Relative Perm BasisAbsolute’ Relative Perm Basis 1.0 0.0 0.0 1.0SATURATION KRO @ Swi = Ko Kabs
  11. 11. Which Method of Representation isWhich Method of Representation is the Bestthe Best  Either method is accurate as long as theEither method is accurate as long as the correct value of the reference ‘initial’correct value of the reference ‘initial’ permeability is usedpermeability is used  Normalized basis is useful in many casesNormalized basis is useful in many cases where ‘absolute’ permeability is unknownwhere ‘absolute’ permeability is unknown (e.g. – preserved state core material)(e.g. – preserved state core material)
  12. 12. Saturation ConceptsSaturation Concepts Sinit Scrit Sirr SmaxSinitial Initial Saturation (Swi) Represents the initial water Saturation present in the Reservoir before any man induced External influences Critical (Swcrit) Saturation refers To the water saturation at Which the water phase first Is able to move – note in many Reservoirs than Swi is NOT the Same as Swcrit (dehydrated Or undersaturated reservoir) The maximum saturation (Swmax) is the Maximum water saturation present under Floodout conditions (a residual oil or trapped Gas saturation would comprise the Remainder of the pore system) The Irreducible or Trapped water saturation (Swirr) represents the water saturation Present after the saturation has been increased Beyond the critical value and then Subsequently reduced – it is often (almost Always) greater than Scrit
  13. 13. Major Factors Impacting RelativeMajor Factors Impacting Relative PermeabilityPermeability  Fluid SaturationsFluid Saturations  Rock PropertiesRock Properties  WettabilityWettability  Saturation HistorySaturation History
  14. 14. Other Factors Which Also InfluenceOther Factors Which Also Influence Relative PermeabilityRelative Permeability  Overburden PressureOverburden Pressure  In-Situ Stresses and HydrationIn-Situ Stresses and Hydration  TemperatureTemperature  IFTIFT  ViscosityViscosity  Initial Fluid SaturationsInitial Fluid Saturations  Immobile PhasesImmobile Phases  Displacement RatesDisplacement Rates  Core handling and PreservationCore handling and Preservation
  15. 15. Saturation Effects on RelativeSaturation Effects on Relative PermeabilityPermeability Water Saturation Gas Saturation Liquid Saturation
  16. 16. Saturation Effects on RelativeSaturation Effects on Relative PermeabilityPermeability  Strongly dependant function of saturationStrongly dependant function of saturation  Rel perm is always expressed as aRel perm is always expressed as a saturation functionsaturation function
  17. 17. Pore GeometryPore Geometry  Relative permeability is strongly impactedRelative permeability is strongly impacted by the specific geometry/tortuosity of theby the specific geometry/tortuosity of the pore system under considerationpore system under consideration Grain sizeGrain size Pore sizePore size Aspect ratioAspect ratio Presence of vugs/natural fracturesPresence of vugs/natural fractures WormholesWormholes Horizontal laminationsHorizontal laminations
  18. 18. Example of Rel Perm Curves for aExample of Rel Perm Curves for a System Dominated bySystem Dominated by Macroporosity (e.g. – fractures)Macroporosity (e.g. – fractures)
  19. 19. More Uniform Intergranular/MatrixMore Uniform Intergranular/Matrix Type Porosity SystemType Porosity System
  20. 20. Macroporous Flow System WithMacroporous Flow System With MicroporosityMicroporosity
  21. 21. Anisotropic FlowAnisotropic Flow
  22. 22. Flow Parallel to Bedding PlanesFlow Parallel to Bedding Planes
  23. 23. Flow Perpendicular to BeddingFlow Perpendicular to Bedding PlanesPlanes
  24. 24. WettabilityWettability The fluid that coats the rock pores Also describes the wettability Nature of that reservoir
  25. 25. Wettability TypesWettability Types  Water WetWater Wet  Oil WetOil Wet  Neutral WetNeutral Wet  Mixed WetMixed Wet  Spotted/Dalmation WetSpotted/Dalmation Wet
  26. 26. Relative PermeabilityRelative Permeability Water Saturation - Fraction RelativePermeability-Fraction Swi 10% Crossover 22% Sw Krw = 0.88 Swi approx 25% Crossover approx 68% Krw = 0.08
  27. 27. Typical RelativeTypical Relative Permeability CurvePermeability Curve Configurations for OtherConfigurations for Other Wettability TypesWettability Types
  28. 28. Neutral Wet FormationsNeutral Wet Formations Swi 10-20% Crossover around 50% Krw = 0.45
  29. 29. Mixed WettabilityMixed Wettability  A fairly common wettability type in whichA fairly common wettability type in which tight microporosity is water saturated andtight microporosity is water saturated and water wet, while oil saturated macroporeswater wet, while oil saturated macropores are oil wetare oil wet
  30. 30. Typical Mixed Wettability RelativeTypical Mixed Wettability Relative Permeability CurvesPermeability Curves Swi = 40% Crossover approx 55% Krw = 0.70
  31. 31. Spotted/Dalmation WettabilitySpotted/Dalmation Wettability Swi = 22% Crossover = 59% Krw = 0.28
  32. 32. Mobility &Mobility & WaterfloodWaterflood PerformancePerformance
  33. 33. Concept of ‘Mobility Ratio’Concept of ‘Mobility Ratio’ M = µο x Krw µ w x K r o Mobility Ratio Viscosity of Displaced Phase Rel Perm of Displacing Phase Viscosity of Displacing Phase Rel Perm of Displaced Phase
  34. 34. Factors Improving MobilityFactors Improving Mobility M = µο x Krw µ w x K r o Low Oil ViscosityLow Krw/Krg Value High Displacing Phase Viscosity High Kro Value
  35. 35. Example – Waterflood in aExample – Waterflood in a Favorable Mobility System (M=0.5)Favorable Mobility System (M=0.5)
  36. 36. Example – Waterflood in aExample – Waterflood in a Unfavorable Mobility SystemUnfavorable Mobility System (M=20)(M=20)
  37. 37. Residual Oil Saturations inResidual Oil Saturations in WaterfloodsWaterfloods  BREAKTHROUGHBREAKTHROUGH SorSor  ECONOMICECONOMIC SorSor  ULTIMATEULTIMATE SorSor
  38. 38. Breakthrough SorBreakthrough Sor  Refers to residual oil saturation in theRefers to residual oil saturation in the swept pattern at the time ofswept pattern at the time of firstfirst waterwater productionproduction INJ PROD
  39. 39. Economic SorEconomic Sor  Refers to residual oil saturation in theRefers to residual oil saturation in the swept pattern at the time ofswept pattern at the time of MaximumMaximum EconomicEconomic water cutwater cut INJ PROD
  40. 40. Ultimate (True) SorUltimate (True) Sor  Refers to residual oil saturation in theRefers to residual oil saturation in the swept pattern if a nearswept pattern if a near InfiniteInfinite volume ofvolume of water were displaced to near zero oil cutwater were displaced to near zero oil cut INJ PROD
  41. 41. Lab Measurements of SorLab Measurements of Sor  Lab measurements of Sor generally give aLab measurements of Sor generally give a reasonable approximation of thereasonable approximation of the ULTIMATE Sor since usually a very largeULTIMATE Sor since usually a very large number of pore volumes of displacementnumber of pore volumes of displacement are conducted (10-100 typical)are conducted (10-100 typical)
  42. 42. Waterflooding in DifferingWaterflooding in Differing Wettability ReservoirsWettability Reservoirs Cumulative Pore Volumes of Injection PercentRecoveryOOIP Breakthrough Sor Economic Sor Ultimate Sor
  43. 43. Waterflooding in DifferingWaterflooding in Differing Wettability ReservoirsWettability Reservoirs Cumulative Pore Volumes of Injection PercentRecoveryOOIP
  44. 44. Waterflooding in DifferingWaterflooding in Differing Wettability ReservoirsWettability Reservoirs Cumulative Pore Volumes of Injection PercentRecoveryOOIP
  45. 45. Waterflooding in DifferingWaterflooding in Differing Wettability ReservoirsWettability Reservoirs Cumulative Pore Volumes of Injection PercentRecoveryOOIP
  46. 46. Relative Permeability HysteresisRelative Permeability Hysteresis  Relative Permeability is not a uniqueRelative Permeability is not a unique function of saturationfunction of saturation  The relative permeability value dependsThe relative permeability value depends on the direction of saturation changeon the direction of saturation change
  47. 47. Example – Primary Drainage –Example – Primary Drainage – Initial Reservoir SaturationInitial Reservoir Saturation Water Saturation – Fraction of Pore Space RelativePermeability 0 1.0 0 1.0 WATER OIL
  48. 48. Example – Primary Imbitition –Example – Primary Imbitition – (Waterflood)(Waterflood) Water Saturation – Fraction of Pore Space RelativePermeability 0 1.0 0 1.0 WATER OIL
  49. 49. Example – Primary Imbitition –Example – Primary Imbitition – (Waterflood)(Waterflood) Water Saturation – Fraction of Pore Space RelativePermeability 0 1.0 0 1.0 WATER OIL
  50. 50. Example –Secondary Drainage –Example –Secondary Drainage – (ie Gas flood)(ie Gas flood) Water Saturation – Fraction of Pore Space RelativePermeability 0 1.0 0 1.0 WATER OIL
  51. 51. Effect of Confining (Overburden)Effect of Confining (Overburden) Pressure on Relative PermeabilityPressure on Relative Permeability  Increased overburden pressure causesIncreased overburden pressure causes compaction andcompaction and a reductiona reduction in absolutein absolute permeabilitypermeability  Changes inChanges in pore geometrypore geometry may also affectmay also affect relative permeabilityrelative permeability  Proper net overburden pressure should beProper net overburden pressure should be used in all determinationsused in all determinations
  52. 52. Effect of Temperature on RelativeEffect of Temperature on Relative PermeabilityPermeability  Modifies WettabilityModifies Wettability  Changes Viscosity RatioChanges Viscosity Ratio  Changes IFTChanges IFT  May Alter Rel PermMay Alter Rel Perm  Tests Should be Run At Temp Of InterestTests Should be Run At Temp Of Interest
  53. 53. Effect of Interfacial Tension (IFT)Effect of Interfacial Tension (IFT)  IFT is aIFT is a very strong factorvery strong factor in controllingin controlling residual saturations and relativeresidual saturations and relative permeability curve endpoints andpermeability curve endpoints and configurationsconfigurations  Proper IFT conditions are essential to aProper IFT conditions are essential to a proper relative permeability determinationproper relative permeability determination
  54. 54. IFT EffectsIFT Effects  The level of the IFT controls both theThe level of the IFT controls both the magnitude of the residual saturations inmagnitude of the residual saturations in accessible pore spaceaccessible pore space and the degree ofand the degree of ‘interference’ between phases‘interference’ between phases  Residual saturation is controlled byResidual saturation is controlled by capillary pressure, the lower the IFT, thecapillary pressure, the lower the IFT, the lower the capillary pressurelower the capillary pressure
  55. 55. Effect of IFT on Rel Perm and SorEffect of IFT on Rel Perm and Sor  Is highly dependant on wettability, poreIs highly dependant on wettability, pore geometry and pore system accessibilitygeometry and pore system accessibility  Not all low/zero IFT systems give highNot all low/zero IFT systems give high recoveryrecovery  Concept of IFT vs. Mobility dominatedConcept of IFT vs. Mobility dominated displacements in porous mediadisplacements in porous media
  56. 56. ‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative PermeabilityPermeability Gas or Water Saturation - Fraction RelativePermeability
  57. 57. ‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative PermeabilityPermeability Gas or Water Saturation - Fraction RelativePermeability
  58. 58. ‘‘Classic’ IFT Effects on RelativeClassic’ IFT Effects on Relative PermeabilityPermeability Gas or Water Saturation - Fraction RelativePermeability
  59. 59. Using Proper IFTUsing Proper IFT  Avoid treated fluidsAvoid treated fluids  Avoid surfactants and de-emulsifiersAvoid surfactants and de-emulsifiers  Live reservoir fluids should be usedLive reservoir fluids should be used
  60. 60. Viscosity IssuesViscosity Issues
  61. 61. Viscosity IssuesViscosity Issues
  62. 62. Viscosity EffectsViscosity Effects  Considerably controversy in the pastConsiderably controversy in the past  Classically rel perm considered to beClassically rel perm considered to be purely a rock functionpurely a rock function  Research has indicated that viscosity ratioResearch has indicated that viscosity ratio can strongly affect rel perm curvecan strongly affect rel perm curve configuration and location of endpointsconfiguration and location of endpoints  Use of proper live reservoir fluids isUse of proper live reservoir fluids is required to mimic proper viscosity ratiorequired to mimic proper viscosity ratio
  63. 63. Favorable Viscosity Ratio (Favorable Viscosity Ratio (µµdd >>>>µµinsitu)insitu)RelativePermeability Water Saturation
  64. 64. Unit Viscosity Ratio (Unit Viscosity Ratio (µµd =d = µµinsitu)insitu)RelativePermeability Water Saturation
  65. 65. Unfavorable Viscosity Ratio (Unfavorable Viscosity Ratio (µµdd <<<<µµinsitu)insitu)RelativePermeability Water Saturation
  66. 66. Initial SaturationsInitial Saturations  Proper level of initial water saturation inProper level of initial water saturation in the matrix for testing is essential forthe matrix for testing is essential for accurate relative permeabilityaccurate relative permeability measurementsmeasurements  Value of Swi can strongly effect originalValue of Swi can strongly effect original Ko or Kg endpoint permeabilityKo or Kg endpoint permeability  Incorrect values of Swi can have aIncorrect values of Swi can have a laterally shifting effect on the entirelaterally shifting effect on the entire relative permeability curverelative permeability curve
  67. 67. Example – Effect of Swi on Ko/KgExample – Effect of Swi on Ko/KgRelativePermeability Water Saturation
  68. 68. Example – Effect of Swi on RelExample – Effect of Swi on Rel Perm Curve ConfigurationPerm Curve ConfigurationRelativePermeability Water Saturation
  69. 69. Presence of a Mobile or ImmobilePresence of a Mobile or Immobile Third PhaseThird Phase  Generally free or trapped gas in a water-Generally free or trapped gas in a water- oil situationoil situation  Trapped oil saturation may exist in someTrapped oil saturation may exist in some water-gas systemswater-gas systems  Trapped saturations generally reduceTrapped saturations generally reduce perm to both phasesperm to both phases  Mobile third saturations may selectivelyMobile third saturations may selectively reduce perm more to one phase thanreduce perm more to one phase than anotheranother
  70. 70. Example – Presence of TrappedExample – Presence of Trapped Initial Gas SaturationInitial Gas SaturationRelativePermeability Water Saturation
  71. 71. Example – Presence of TrappedExample – Presence of Trapped Initial Gas SaturationInitial Gas SaturationRelativePermeability Water Saturation
  72. 72. Example – Presence of TrappedExample – Presence of Trapped Initial Gas SaturationInitial Gas SaturationRelativePermeability Water Saturation
  73. 73. Capillary End EffectsCapillary End Effects  Caused by a discontinuity in capillaryCaused by a discontinuity in capillary pressure at the outlet face of the corepressure at the outlet face of the core samplesample
  74. 74. Consequences of an End EffectConsequences of an End Effect Commence Water Injection Delayed Production of Water & Dp due to End Effect
  75. 75. Consequences of an End EffectConsequences of an End Effect  Delayed water breakthrough timesDelayed water breakthrough times  Zone of ‘Stagnant’ fluid at end of sampleZone of ‘Stagnant’ fluid at end of sample  Reduced apparent perm to water at lowerReduced apparent perm to water at lower displacement ratesdisplacement rates
  76. 76. Mitigation of End EffectsMitigation of End Effects  High rates and delta PHigh rates and delta P  Long coresLong cores  Pressure tapped coresPressure tapped cores  Semi permeable membranesSemi permeable membranes  Numerical simulation methodsNumerical simulation methods  ‘‘Bump’ floodsBump’ floods
  77. 77. Measurement ofMeasurement of RelativeRelative Permeability DataPermeability Data
  78. 78. Common Determination MethodsCommon Determination Methods  Steady StateSteady State  Unsteady StateUnsteady State  CentrifugeCentrifuge  Ambient vs. Reservoir Condition TestingAmbient vs. Reservoir Condition Testing
  79. 79. Sample SelectionSample Selection  Rock typing and classificationRock typing and classification  Single plug vs. composite stacksSingle plug vs. composite stacks  Plug vs. full diameter testingPlug vs. full diameter testing  Vertical vs. horizontal flooding methodsVertical vs. horizontal flooding methods
  80. 80. Steady StateSteady State MethodMethod
  81. 81. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Sample at Initial Conditions of Water (Irreducible) and Oil (Maximum) Saturation
  82. 82. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 100% Oil at Swi, Measure Ko at Swi
  83. 83. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 90% Oil and 10% water, Measure Ko And Kw at New Stabilized Higher Sw
  84. 84. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 70% Oil and 30% water, Measure Ko And Kw at New Stabilized Higher Sw
  85. 85. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 30% Oil and 70% water, Measure Ko And Kw at New Stabilized Higher Sw
  86. 86. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 10% Oil and 90% water, Measure Ko And Kw at New Stabilized Higher Sw
  87. 87. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation Commence Injection of 0% Oil and 100% water, Measure Kw at Sorw
  88. 88. The Steady State DeterminationThe Steady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation
  89. 89. Advantages of the Steady StateAdvantages of the Steady State MethodMethod  Computationally very simpleComputationally very simple  Inherently stable (no viscous effects)Inherently stable (no viscous effects)  Test modifications can reduce or eliminateTest modifications can reduce or eliminate impact of capillary end effectsimpact of capillary end effects  ‘‘Classic’ method of relative permeabilityClassic’ method of relative permeability determinationdetermination
  90. 90. Disadvantages of the Steady StateDisadvantages of the Steady State MethodMethod  Complex and expensive method, very timeComplex and expensive method, very time consumingconsuming  Difficult and expensive for full reservoirDifficult and expensive for full reservoir conditionsconditions  Large volumes of reservoir fluids requiredLarge volumes of reservoir fluids required  In-situ saturation monitoring essential forIn-situ saturation monitoring essential for accuracyaccuracy  More of a research method in many casesMore of a research method in many cases than a viable commercial techniquethan a viable commercial technique
  91. 91. Typical Steady State ApparatusTypical Steady State Apparatus Capillary Contact Paper Inlet Section Outlet Section
  92. 92. Typical Steady State ApparatusTypical Steady State Apparatus Pressure Taps External Core Sleeve Flow Head Flow Head
  93. 93. Steady State ApparatusSteady State Apparatus Water Inj Pump Oil Inj Pump Injection Pumps Coreholder In-Situ Saturation Monitoring Three Phase Separator BPR Piston Cylinders Pressure Transducers Core Sample OVEN
  94. 94. Common In-situ SaturationCommon In-situ Saturation Determination MethodsDetermination Methods  GravimetricGravimetric  Electrical resistivityElectrical resistivity  X-rayX-ray  MRIMRI  Gamma rayGamma ray  Microwave attenuationMicrowave attenuation
  95. 95. X-Ray SaturationX-Ray Saturation Mannville Samples 13A, 14B, 16, 19, 24A 2000 3000 4000 5000 6000 7000 8000 9000 10000 0 50 100 150 200 250 300 350 Distance, mm X-Raycounts
  96. 96. Typical Steady State LabTypical Steady State Lab ApparatusApparatus
  97. 97. Displacement PumpsDisplacement Pumps
  98. 98. UnsteadyUnsteady State MethodState Method
  99. 99. Unsteady State Method for RelativeUnsteady State Method for Relative Permeability (2 Phase)Permeability (2 Phase) RelativePermeability Water Saturation Sample at Initial Conditions of Water (Irreducible) and Oil (Maximum) Saturation
  100. 100. Unsteady Steady State Method forUnsteady Steady State Method for Relative Permeability (2 Phase)Relative Permeability (2 Phase) RelativePermeability Water Saturation Commence Injection of 100% Oil at Swi, Measure Ko at Swi
  101. 101. Unsteady Steady State Method forUnsteady Steady State Method for Relative Permeability (2 Phase)Relative Permeability (2 Phase) RelativePermeability Water Saturation Switch to Injection of 100% Water at Swi, Measure Transient Pressure and Production History
  102. 102. Transient Pressure and ProductionTransient Pressure and Production HistoryHistory DifferentialPressure Cumulative Run Time Breakthrough Point
  103. 103. Transient Pressure and ProductionTransient Pressure and Production HistoryHistory ProductionRate Cumulative Run Time Breakthrough Point
  104. 104. Transient Pressure and ProductionTransient Pressure and Production HistoryHistory ProductionVolume Cumulative Run Time Breakthrough Point
  105. 105. The Unsteady State DeterminationThe Unsteady State Determination Method for Relative Permeability (2Method for Relative Permeability (2 Phase)Phase) RelativePermeability Water Saturation
  106. 106. Advantages of the Unsteady StateAdvantages of the Unsteady State MethodMethod  RapidRapid  Relatively inexpensive, even for fullRelatively inexpensive, even for full reservoir condition HTHP testsreservoir condition HTHP tests  Limited reservoir fluid requirementsLimited reservoir fluid requirements  Easy to run at full reservoir conditionsEasy to run at full reservoir conditions  Simpler equipment and procedures thanSimpler equipment and procedures than steady statesteady state
  107. 107. Disadvantages of the UnsteadyDisadvantages of the Unsteady State MethodState Method  Unstable flow possibleUnstable flow possible  Capillary end effects possibleCapillary end effects possible  More complex data reduction proceduresMore complex data reduction procedures  Data may be poorly conditionedData may be poorly conditioned depending on computational method useddepending on computational method used to regress transient lab resultsto regress transient lab results
  108. 108. Typical Unsteady State ApparatusTypical Unsteady State Apparatus Injection Pump Coreholder Three Phase Separator BPR Piston Cylinders Pressure Transducers Core Sample OVEN
  109. 109. Typical Unsteady State ApparatusTypical Unsteady State Apparatus
  110. 110. Centrifuge MethodsCentrifuge Methods  Use transient production vs. capillary pressureUse transient production vs. capillary pressure history to generate psuedo rel perm curvehistory to generate psuedo rel perm curve  Limited to very small samples and higher permLimited to very small samples and higher perm mediamedia  Reservoir condition tests can not be easilyReservoir condition tests can not be easily conductedconducted  Common requirement to augment SS or USS relCommon requirement to augment SS or USS rel perm experiments for evaluation of near Sor &perm experiments for evaluation of near Sor & Swir rel perm effects – always history matchedSwir rel perm effects – always history matched for integration of the two methodsfor integration of the two methods
  111. 111. What is the Best Method to Use?What is the Best Method to Use?
  112. 112. What is the Best Method to UseWhat is the Best Method to Use  Many of the limitations of the unsteadyMany of the limitations of the unsteady state method have been overcome instate method have been overcome in recent years by experimental andrecent years by experimental and numerical modificationsnumerical modifications  95% plus of all commercial rel perm95% plus of all commercial rel perm measurements are conducted usingmeasurements are conducted using variants of the unsteady state methodvariants of the unsteady state method
  113. 113. Requirement for Two Phase FlowRequirement for Two Phase Flow Fw Average Sw Water Saturation RelativePermeability Results in Highly Compressed Saturation Range
  114. 114. Requirement for Two Phase FlowRequirement for Two Phase Flow Fw Average Sw Water Saturation RelativePermeability
  115. 115. Requirement for Two Phase FlowRequirement for Two Phase Flow Fw Average Sw Water Saturation RelativePermeability Results in a More Dispersed Saturation Range
  116. 116. Requirement for Two Phase FlowRequirement for Two Phase Flow Fw Average Sw Water Saturation RelativePermeability
  117. 117. Common Techniques Used in theCommon Techniques Used in the Past to Disperse FlowPast to Disperse Flow  Viscous refines oils used instead ofViscous refines oils used instead of reservoir oil to ‘smear’ production profilereservoir oil to ‘smear’ production profile  Problem – wrong viscosity, IFT andProblem – wrong viscosity, IFT and possibly wettabilitypossibly wettability  High rate displacementsHigh rate displacements  Problem – unstable flowProblem – unstable flow
  118. 118. Overcoming TheseOvercoming These Deficiencies UsingDeficiencies Using Modern SimulationModern Simulation MethodsMethods
  119. 119. Simulation or ‘History Matching’Simulation or ‘History Matching’ Generation of Rel Perm DataGeneration of Rel Perm Data  Most common current techniqueMost common current technique  Basically a numerical simulation study inBasically a numerical simulation study in reversereverse
  120. 120. History Matching TechniqueHistory Matching Technique  In a normal simulation we know the relIn a normal simulation we know the rel perm curves and we use this, along withperm curves and we use this, along with other input data, to predict the reservoirother input data, to predict the reservoir pressure and production historypressure and production history  In the history matching method we knowIn the history matching method we know the pressure and production history fromthe pressure and production history from the lab tests, and we use this data in anthe lab tests, and we use this data in an iterative fashion to generate the rel permiterative fashion to generate the rel perm curvescurves
  121. 121. Typical History Match ModelTypical History Match Model Input Physical Parameters (L, A, Kabs, Porosity, Pore Volume, # Blocks Input Fluid Properties – Viscosity, Density, Rate, Initial Saturations Input Test Properties – Endpoint Perms and Saturations, Pressure History, Production History Input Cap Pressure and Outlet Boundary Cond- ition to Model Capillary Effects
  122. 122. The HistoryThe History MatchingMatching ProcessProcess
  123. 123. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability Step 1 – Pick Functional Form For Rel Perm Curve Step 2 – Pick Initial ‘Guess’ For Rel Perm Curve Configuration
  124. 124. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  125. 125. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  126. 126. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  127. 127. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  128. 128. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  129. 129. History Matching ProcessHistory Matching Process  Continue the iterative process until theContinue the iterative process until the error between the stimulated and actualerror between the stimulated and actual production and pressure data is as smallproduction and pressure data is as small as possibleas possible  The resulting set of rel perm curvesThe resulting set of rel perm curves represent the best fit to the lab generatedrepresent the best fit to the lab generated datadata  Algorithms to avoid localized or non-Algorithms to avoid localized or non- physical solutionsphysical solutions
  130. 130. Time Time Saturation CumulativeProduction DifferentialPressure RelativePermeability
  131. 131. Conventional Relative PermeabilityConventional Relative Permeability TestsTests  Only provide data in the range of mobileOnly provide data in the range of mobile fluid saturationsfluid saturations  Presence and effect of critical fluidPresence and effect of critical fluid saturations is essential in many processessaturations is essential in many processes  Special tests and procedures are requiredSpecial tests and procedures are required to precisely measure these saturationsto precisely measure these saturations and their effect on relative permeabilityand their effect on relative permeability
  132. 132. Specialty Rel Perm ExperimentsSpecialty Rel Perm Experiments  Critical condensate floodsCritical condensate floods  Constant IFT floodsConstant IFT floods  Above are two examples of super normalAbove are two examples of super normal relative permeability experimentsrelative permeability experiments
  133. 133. Critical condensate floodsCritical condensate floods  Rich gas condensatesRich gas condensates  Produced below dew point at near wellboreProduced below dew point at near wellbore  Two stage experimentTwo stage experiment  Stage 1: establish critical condensate satStage 1: establish critical condensate sat  Incremental pressure decrements in pore spacesIncremental pressure decrements in pore spaces  Flood with equilibrium gasFlood with equilibrium gas  Stop at first sign of condensate productionStop at first sign of condensate production  Stage 2: Steady state gas & condensate floodStage 2: Steady state gas & condensate flood  Equilibrium gas & condensateEquilibrium gas & condensate  Gas saturation decreasingGas saturation decreasing  Stop at trapped gas – residual gas saturationStop at trapped gas – residual gas saturation
  134. 134. Typical critical condensateTypical critical condensate apparatusapparatus
  135. 135. Constant IFT FloodsConstant IFT Floods  Create high IFT injection gas & oilCreate high IFT injection gas & oil ie models the near well bore for vaporizing driveie models the near well bore for vaporizing drive  Create low IFT injection gas & oilCreate low IFT injection gas & oil ie models deep reservoir for vaporizing driveie models deep reservoir for vaporizing drive  Run two floods on matched core stacksRun two floods on matched core stacks  Compare results to determine IFTCompare results to determine IFT domination versus other controls ofdomination versus other controls of incremental oil recoveryincremental oil recovery Ie mobility, pore geometry…Ie mobility, pore geometry…
  136. 136. Vaporizing MiscibilityVaporizing Miscibility Fluid PreparationFluid Preparation Rich Gas Lean Gas Low IFT Oil High IFT Oil Flood #1 Made From: Flood #2 Made From:
  137. 137. Condensing MiscibilityCondensing Miscibility Fluid PreparationFluid Preparation Leaner GasRich Gas High IFT Oil Low IFT Oil Flood #1 Made from: Flood #2 Made From:
  138. 138. Constant IFT FloodConstant IFT Flood Reservoir Dominated byReservoir Dominated by IFTIFT Gas Saturation - Fraction RelativePermeability
  139. 139. Constant IFT FloodConstant IFT Flood Reservoir Dominated byReservoir Dominated by MobilityMobility Gas Saturation - Fraction RelativePermeability
  140. 140. ConclusionsConclusions  Many controls / influences on relativeMany controls / influences on relative permeabilitypermeability  Live oil & reservoir conditions necessaryLive oil & reservoir conditions necessary  Specialty floods for extension of routineSpecialty floods for extension of routine relative permeability applicationsrelative permeability applications
  141. 141. Thank you!Thank you!

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