• Advanced PVT & EOS Fluid Characterization

---

Course Overview

 

The knowledge of petroleum fluid phase behavior plays a crucial role throughout the Oil & Gas industry, from reserves estimation to reservoir production to surface processing to transportation and storage. Phase behavior modeling is vital, but often taken for granted. Whether an equation of state or a simple black-oil model is used, it needs to be specifically built and tuned to the experimental PVT data for each unique fluid. Only then can the model be used to make the necessary engineering predictions.

 

The masterclass is prepared mainly with the job requirements of reservoir engineering and process engineering in mind, although pipeline, transportation, and refining engineers would also benefit. Prior phase behavior experience would be helpful, but not required. A full range of relevant topics will be covered, including basic thermodynamics, black-oil and EOS modeling, PVT experiments, estimation of in situ reservoir compositions, black-oil properties from an EOS, and multi-contact miscibility.

 

Classroom exercises with actual PVT data will provide hands-on experience with PhazeComp, state-of-the-art EOS characterization and phase behavior modeling software from Zick Technologies, Inc. Participants will leave with enhanced abilities to analyze and utilize PVT data, and to build and use EOS and black-oil petroleum fluid phase behavior models.

 

Course Objectives:

• UNDERSTAND Basic Petroleum Fluid Thermodynamics (Phase Behavior and the Relationships between Pressure, Volume, Temperature and Composition)
• DISCOVER Black-Oil and Equation-of-State Phase Behavior Modeling
• APPLY Accurate and Proper PVT Experiments for Petroleum Fluids
• GAIN in depth knowledge on EOS Fluid Characterization Techniques - Developing and Tuning
• PRACTICE accurate estimation of In Situ Reservoir Fluid Compositions
• OBTAIN Black-Oil Properties from a Tuned EOS
• UNDERSTAND Minimum Miscibility Pressures and Enrichments for Multi-Contact Miscible Displacements

 

Specially Designed For:

Intended for the reservoir, production, or processing engineers or managers who would like to learn more about:

• Basic Petroleum Fluid Thermodynamics (Phase Behavior and the Relationships between Pressure, Volume, Temperature and Composition)
• Black-Oil and Equation-of-State Phase Behavior Modeling
• PVT Experiments for Petroleum Fluids
• EOS Fluid Characterization Techniques — Developing and Tuning
• Estimation of In Situ Reservoir Fluid Compositions
• Obtaining Black-Oil Properties from a Tuned EOS
• Minimum Miscibility Pressures and Enrichments for Multi-Contact Miscible Displacements

 

From Oil & Gas industry, particularly the sub-sectors below:

• Upstream Oil & Gas Production
• Gas Processing & Oil Refining
• Downstream Petrochemical / Chemical
• Oil & Gas Transportation & Storage

 

Course Outline

 

DAY 1

 

1)     Basic Thermodynamics

a)     Gibb’s phase rule

b)    Single component

i)      Ideal gas law

ii)     Generalized compressibility factor

iii)    Phase transitions and phase equilibrium

iv)    Pressure-Volume-Temperature (PVT) relationships

(1)   P-T (vapor pressure) diagrams

(2)   P-V diagrams

v)     Equation-of-state (EOS) representations

(1)   Van der Waals EOS

(2)   Generalized 5-parameter cubic EOS

(3)   Soave-Redlich-Kwong EOS

(4)   Peng-Robinson EOS

(5)   Peneloux volume shift parameter

(6)   EOS advantages and limitations

c)     Two components

i)      PVT/compositional relationships

(1)   P-T diagrams (phase envelopes)

(2)   P-x diagrams (phase envelopes)

(3)   P-V diagrams

(4)   K-values

ii)     EOS representations

(1)   Binary interaction parameters

(2)   Advantages and limitations

iii)    Black-oil representations

(1)   Two components: surface oil and surface gas

(2)   Two phases: reservoir oil and reservoir gas

(3)   Phase equilibrium and phase property dependencies

(a)   Composition (amounts of surface oil and surface gas)

(b)   Pressure (through formation volume factors, gas/oil and oil/gas ratios)

d)    Three or more components

i)      PVT/compositional relationships

(1)   P-T diagrams (phase envelopes)

(2)   P-x diagrams (phase envelopes, swelling diagrams)

(3)   Ternary diagrams

(4)   Quaternary diagrams

 

DAY 2

 

2)     Equation-of-state Phase Behavior Modeling

a)     Software

b)    Input requirements

i)      EOS

ii)     List of components

iii)    Characterization parameters

iv)    Composition, temperature, pressure

v)     Specifications for experiments to simulate

c)     Additional useful input

i)      Correlation parameters

ii)     Gamma distribution parameters

iii)    Component boiling points and specific gravities

iv)    Experimental data (for tuning the characterization)

d)    Component property estimations

e)     Gamma distribution fitting

f)     Plus fraction characterization

i)      Gamma splitting

ii)     Pseudocomponent property estimations

g)    Pseudoization

i)      Component lumping

ii)     Pseudocomponent property estimations

 

DAY 3

 

3)     PVT Experiments for Petroleum Fluids

a)     Traditional black oil experiments

i)      Saturation pressure determinations

ii)     Density (API gravity) measurements

iii)    Separator tests

iv)    Constant composition expansions

v)     Differential liberations

vi)    Constant volume depletions

b)    Building black oil tables directly from PVT data

c)     Compositional experiments

i)      Molecular weight measurements

ii)     Compositional analyses

(1)   True boiling point distillation

(2)   Simulated distillation by gas chromatography

(3)   Crude assays

iii)    Equilibrium phase compositions

iv)    Swelling experiments

v)     Multi-contact vaporization experiments

vi)    Slim tube displacements

 

DAY 4

 

4)     EOS Characterization Tuning

a)     Picking the right software

b)    Inputting measured compositions

c)     Tuning correlations to honor molecular weights and densities

d)    Deciding on component strategy (to pseudoize early or late)

e)     Fitting a gamma distribution

f)     Initializing the characterization

i)      Specifying the component suite

ii)      Estimating initial characterization parameters

(1)   Library properties

(2)   Gamma distribution properties

(3)   Correlated properties

g)    Inputting measured data

i)      All sample compositions, adjusted for potential lab errors

(1)   Molecular weight measurement errors

(2)   Gas chromatography errors

(3)   Inconsistencies with separator gas/oil ratios

ii)     All PVT and compositional data from all PVT experiments

iii)    Choosing weight factors for all data

h)     Guidelines for choosing regression variables

i)      Leave previously tuned correlations alone

ii)     Choose parameters with the least certainty and the most influence

(1)   Binary interaction parameters

(2)   Critical properties and/or boiling point of the heaviest pseudocomponent

(3)   Critical properties and/or boiling points of other pseudocomponents

iii)    Keep parameters physically realistic and monotonic with carbon number

(1)   Bound all adjustments realistically

(2)   Adjust as few properties as absolutely necessary

(3)   Adjust properties for groups of components uniformly

(4)   Adjust critical properties rather than EOS A and B parameters

(5)   Adjust specific gravities rather than volume shifts

(6)   Adjust boiling points rather than acentric factors

iv)    Regress on viscosity parameters separately

(1)   Fit phase behavior data first, with no weighting on viscosity data

(2)   Fit weighted viscosity data with all non-viscosity parameters frozen

i)      Trial and error

i)      Try modifying the data weighting

ii)     Try modifying the choice of regression variables

iii)    Learn to recognize data outliers and discrepancies

iv)    Learn to recognize good matches from poor matches

5)     Estimating Reservoir Fluid Compositions

a)     The “Equilibrium Contact Mixing” method

b)    Mathematical decontamination

c)     Gravity induced thermodynamic segregation

 

DAY 5

 

6)     Black Oil Properties from a Tuned EOS

a)     Advantages

i)      More accurate than experimentally derived black oil tables

ii)     Flexibility in choice of samples, depletion processes, and surface processes

iii)    Consistency between black oil and compositional simulation

b)    Procedure

i)      Specify the oil and/or gas samples

ii)     Specify the all-important surface process

iii)    Simulate appropriate depletion experiment(s)

iv)    Pass equilibrium phases from each stage through surface process

v)     Determine surface amounts and properties for each depleted fluid

vi)    Manipulate results into reservoir simulator format

7)     Minimum Miscibility Pressures and Enrichments

a)     Mechanisms

i)      Condensing gas drive

ii)     Vaporizing gas drive

iii)    Condensing/vaporizing gas drive

b)    Experimental determination

c)     EOS predictions

i)      Slim tube simulations

ii)     Multi-cell, multi-contact mixing simulations

iii)    Predictions by the method of characteristics