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

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

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

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

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

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

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

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

How to Obtain Fluid Properties Laboratory Analysis Black Oil Correlations Measured Data on Fluid Sample @ 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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