Understanding Hydrocarbon Fluid Properties and Behavior

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Understanding HydrocarbonFluid Properties and
Behavior
Djamel Eddine Ouzzane
Reservoir Engineer Sonatrach-bp
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Outline

• Application of Fluid Properties
• Volumetric Relationships used by Reservoir
  Engineers
• Different Sources to Obtain Fluid Properties
• PVT Analysis and Fluid Compositions
• Aspects of Sampling

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Application of Fluid Analysis Properties
Phase Behavior and Compositional Concepts
are required to determine.

• How much oil or gas is present
• How much can be recovered
• How fast it can be recovered
• Reservoir management and
• strategies

Fluid Properties
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Properties Required for Reservoir Engineering
Calculations

• Formation Volume
• Factor of Oil BO
• Solution Gas-Oil
• Ratio RS
• Oil and Gas Densities ?
• Coefficient of Isothermal
• Compressibility C0

• Formation Volume
• Factor of Gas Bg
• Gas Compressibility
• Factor Z
• Oil - Gas Viscosities ?
• Coefficient of Thermal
• Expansion ?0

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Formation Volume Factor
Well Stream
VSC
Volume at Reservoir Conditions

Bo
Volume at Standard Conditions
VR
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Formation Volume Factor
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Gas - Oil Ratio GOR - RS
Gas
Separator
Stock Tank
Separator Oil
Stock Tank Oil
Volume of Gas at Standard Conditions
GOR
Volume of Oil at Standard Conditions
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Gas - Oil Ratio GOR - RS
Bubble Point
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How to Obtain Fluid Properties
Black Oil Correlations
Laboratory Analysis
Measured Data on Fluid Sample _at_ Reservoir
Conditions
Calculated Data using Validated Correlations On
Specific Oil databases
Compositional Models Equation of States
Calculated Data using Consistent Thermodynamic
Models based on Fluid Compositions
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How to Obtain Fluid Properties

1. Laboratory PVT Analysis

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How to Obtain Fluid Properties
2. Black Oil Correlations
Standing Correlation for Bubble Point
Rs Dissolved Gas to Oil Ratio ?g Gas
Gravity API Oil Stock Tank Density T Reservoir
Temperature in degre F
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How to Obtain Fluid Properties
2. Black Oil Correlations
Restricted to the type of oil from which they
were derived
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How to Obtain Fluid Properties !
3. Compositional Modeling Equation of States
EOS
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How to Obtain Fluid Properties !
3. Compositional Modeling Equation of States
EOS
Based on Flash Calculations and Equilibrium
Criteria
Gas
Equilibrium Ratio
Fluid Mixture
Temperature

Z1 Z2 Z3Zn
Pressure
Liquid
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What are Compositions ?
Hydrocarbons
Solids
Non Hydrocarbons

• Paraffins
• Naphtenes
• Aromatics

• Asphaltenes
• Wax
• Resins

• Oxygen
• Nitrogen
• Sulfur

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What are Compositions ?
NON HYDROCARBON
HYDROCARBON

• N2 upto10
• CO2 4
• H2S 6
• H2, He
• Na, K, Fe, Cu, Zn,
• CaCl2,
• MgCl2 5
• O2

Aliphatic (Paraffin)
Aromatics
Naphtenics
Paraffinics
Olefinis
Cyclic Aliphatics
Alkynes
Alkanes
Alkenes
Laboratory Analysis - C1-C6 and C7
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What are Compositions ?
Alkynes
Alkanes
Alkenes
Cyclic Aliphatics
Aromatics
Cn H2n-2
Cn H2n
Cn H2n
Cn H2n2
Cn Hn
CH
CH
- CH2 - CH2 -
CH
CH
- CH CH -
CH
CH
- CH CH -
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What are Compositions ?
Asphaltene Structure
Wax (Paraffin) Structure
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Phase Behavior and Phase Envelope
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Typical Reservoir Fluid Compositions
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Need Fluid Properties Need Samples
How to Obtain Fluid Samples ?

• Surface Sampling
• Bottom Hole Sampling
• Formation Tester Sampling

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Surface Sampling
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Bottom Hole Sampling

• Preserved Samples
• Reservoirs Conditions
• Selective Sampling Zones
• Sampling early in the life
• of the reservoir with
• minimum disturbance
• Lower overall cost

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Formation Tester Sampling

• Assess reservoir fluid
• quality
• Contamination
• Monitoring
• Insitu Bubble point
• determination

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Is Sample Quality a Concern ?
Typically lt10
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Is Sample Quality a Concern ?

Decisions
Risks
Planning Investments
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Conclusion

• Fluid properties are required in various
  discipline
• of petroleum engineering
• Petroleum fluids are complex mixtures an
  therefore
• accurate properties must be obtained.
  Laboratory analysis
• generally provide reliable data
• The compositional approach is preferred and
  widely used
• Samples may be collected using various methods
  however
• obtaining a representative sample is crucial.