1. Understanding Hydrocarbon Fluid Properties and Behavior
Djamel Eddine Ouzzane
Reservoir Engineer
Sonatrach-bp
9/17/2018
SPE Continuing Education

2. SPE Continuing Education
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
9/17/2018
SPE Continuing Education

3. SPE Continuing Education
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
9/17/2018
SPE Continuing Education

4. 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
9/17/2018
SPE Continuing Education

5. SPE Continuing Education
Formation Volume Factor
Oil
Gas
Well Stream
VSC
Volume at Reservoir Conditions = Bo
Volume at Standard Conditions VR
9/17/2018
SPE Continuing Education

6. SPE Continuing Education
Formation Volume Factor
Bubble Point
9/17/2018
SPE Continuing Education

7. SPE Continuing Education
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
9/17/2018
SPE Continuing Education

8. SPE Continuing Education
Gas - Oil Ratio
GOR - RS
Bubble Point
9/17/2018
SPE Continuing Education

9. How to Obtain Fluid Properties
Laboratory Analysis
Black Oil Correlations
Measured Data on
Fluid
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
9/17/2018
SPE Continuing Education

10. SPE Continuing Education
How to Obtain Fluid Properties
Laboratory PVT Analysis
9/17/2018
SPE Continuing Education

11. SPE Continuing Education
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
9/17/2018
SPE Continuing Education

12. Restricted to the type of oil from which they were derived
How to Obtain Fluid Properties
2. Black Oil Correlations
Restricted to the type of oil from which they were derived
9/17/2018
SPE Continuing Education

13. SPE Continuing Education
How to Obtain Fluid Properties !
3. Compositional Modeling Equation of States EOS
9/17/2018
SPE Continuing Education

14. SPE Continuing Education
How to Obtain Fluid Properties !
3. Compositional Modeling
Equation of States EOS
Based on Flash Calculations and Equilibrium Criteria
Gas
Y1 Y2 Y3…Yn
X1 X2 X3…Xn
Equilibrium
Ratio
Fluid Mixture
Temperature Ki Yi Xi =
Z1 Z2 Z3…Zn
Pressure
Liquid
9/17/2018
SPE Continuing Education

15. SPE Continuing Education
What are Compositions ?
Hydrocarbons
Solids
Non
Hydrocarbons
Paraffins
Naphtenes
Aromatics
Asphaltenes
Wax
Resins
Oxygen
Nitrogen
Sulfur
9/17/2018
SPE Continuing Education

16. SPE Continuing Education
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
Paraffinics
Olefinis
Naphtenics
Alkanes
Alkenes
Alkynes
Cyclic Aliphatics
Laboratory Analysis - C1-C6 and C7+
9/17/2018
SPE Continuing Education

17. SPE Continuing Education
What are Compositions ?
Alkanes
Alkenes
Alkynes
Cyclic Aliphatics
Aromatics
Cn H2n+2
Cn H2n
Cn H2n-2
Cn H2n
Cn Hn CH CH
- CH2 - CH2 - CH CH
- CH = CH - CH CH
- CH CH -
CH2
9/17/2018
SPE Continuing Education

18. Wax (Paraffin) Structure
What are Compositions ?
Asphaltene Structure
Wax (Paraffin) Structure
9/17/2018
SPE Continuing Education

19. Phase Behavior and Phase Envelope
Bubble point
line
Liquid
Vapour
Dew point 10 20 40
2-phase Region A B D E F
1000
2000
3000
4000
5000
6000
7000
8000 60 80
100
120
140
160
180
200
Temperature ( o C)
Pressure (psia)
Critical Point
Dew Point Region
Bubble Point Region
9/17/2018
SPE Continuing Education

20. Typical Reservoir Fluid Compositions
9/17/2018
SPE Continuing Education

21. Need Fluid Properties = Need Samples
How to Obtain Fluid Samples ?
Surface Sampling
Bottom Hole Sampling
Formation Tester Sampling
9/17/2018
SPE Continuing Education

22. SPE Continuing Education
Surface Sampling
9/17/2018
SPE Continuing Education

23. SPE Continuing Education
Bottom Hole Sampling
Preserved Samples
Reservoirs Conditions
Selective Sampling Zones
Sampling early in the life
of the reservoir with
minimum disturbance
Lower overall cost
9/17/2018
SPE Continuing Education

24. Formation Tester Sampling
Assess reservoir fluid
quality
Contamination
Monitoring
Insitu Bubble point
determination
9/17/2018
SPE Continuing Education

25. Is Sample Quality a Concern ?
Fluid Property Uncertainty
Sample’s Poor Quality
Maximum
Acceptable
Uncertainty
Typically <10 %
9/17/2018
SPE Continuing Education

26. Is Sample Quality a Concern ?$
Risks
Decisions
Planning Investments
9/17/2018
SPE Continuing Education

27. SPE Continuing Education
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.
9/17/2018
SPE Continuing Education