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PETE 310

Lecture # 17

Chapter 10 Properties of BlackOils - Reservoir Fluid Studies

Fluid Properties for ReservoirEngineering Processes

The fluid properties of interest to theReservoir Engineer are those that affectthe mobility of fluids within thereservoirs these are used in materialbalance calculationsProperties at surface conditions for

transportation and sales (API, viscosity,oil quality)

Fluid Properties for ReservoirEngineering Processes

PVT properties are determined from 5specific lab procedures

Flash liberation tests Differential Liberation Tests

Viscosity Measurements

Separator Tests

Compositional measurements

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Fluid Properties Determined

Oil Properties Bubble Point Pressure

Bo

Rs Bt Co and o

Gas properties z

Bg and gCompositions oil & gas

Oil Sampling Procedures

Bottom hole or subsurface samples

Separator Samples

SAMPLE BEFORE RESERVOIRPRESSURE DROPS BELOW Pb

1.Flash Vaporization Test

Temperature of Test = Reservoir Temperature

Vt1

Vt2

Vt3=Vb

Vt5

Vt4

oil oil oiloil

oil

gas gas

Hg Hg HgHg

Hg

P1

>> Pb

P2

> Pb

P3

= Pb

P4

< Pb

P5

< P4

1 2 3 4 5

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1.Flash Vaporization Test

Properties determined

Pb

Co

Determination of Pb

Determination of Co

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2.Differential SeparationTest

gas

oil

oil oiloil

oil

gas

Hg

Hg

HgHg

Hg

P 1 = Pb P 2 < Pb P 2 < Pb P 2 < Pb P 3 < P 2 < Pb

1 2 3 4 5

gas

oil

Gas off

Temperature of Test = Reservoir Temperature

2.Differential SeparationTest

Properties Determined

Oil formation volume factor at the BubblePoint pressure Bodb and below the bubblepoint pressure Bod

Solution gas-oil ratio at the Bubble Pointpressure Rsdb and below the bubble pointpressure Rsd

Isothermal compressibility (derived property)

3. Separator Tests

Tests performed at a combinationof different Temperature andPressure pairs

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3. Separator Tests

Goals: Maximize API, minimize BoSb& RsSb

Optimization of Separator 2Conditions

3160

3180

3200

3220

3240

3260

3280

3300

SolutionGasOilRatioatPb(Rsb)

2.76

2.78

2.80

2.82

2.84

2.86

FormationVolumeFactoratPb(Bob)

50 100 150 200 250 300

Separator 2 Pressure (psia)

High Pressure Separator @ 900 psia and

TSep2

= 75oF

100 F

Comparison between 1 & 2Separators Stages (volatile oil)

3360

3380

3400

3420

3440

3460

SolutionGasOilRatioatPb(Rsb)

2.90

2.92

2.94

2.96

FormationVolumeFactoratPb(Bob)

400 500 600 700 800 900 1000

Separator 1 Pressure (psia)

Low Pressure Separator @ 300 psia and

TSep1

= 160oF

75F

One Separator Stage

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Typical PVT Properties for aBlack Oil and a Volatile Oil

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

FormationVolumeFactor(Bo)

0 1000 2000 3000 4000 5000

Pressure (psia)

Black Oil

Volatile Oil

Black Oil Correlation

TR

=180oF

Pb

Pb

Typical PVT Properties for aBlack Oil and a Volatile Oil

0

1000

2000

3000

4000

SolutionGasOilRatio(Rs)

0 1000 2000 3000 4000 5000

Pressure (psia)

Black Oil

Volatile Oil

Black Oil Correlation

TR

=180oF

Pb

Pb

Nomenclature

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4. Compositional Tests

http://www.rpi.edu/dept/chem-eng/Biotech-Environ/CHROMO/chroanim.html

http://www.rpi.edu/dept/chem-eng/Biotech-Environ/CHROMO/chromintro.html