Five Reservoir Fluids

47
The Five Reservoir Fluids Black Volatile Retrograde Wet Dry Oil Oil Gas Gas Gas

Transcript of Five Reservoir Fluids

Page 1: Five Reservoir Fluids

The Five Reservoir Fluids

Black Volatile Retrograde Wet Dry

Oil Oil Gas Gas Gas

Page 2: Five Reservoir Fluids

Objectives

The Five Reservoir Fluids

Page 3: Five Reservoir Fluids

Phase Diagrams of Mixtures of

Ethane and n-Heptane

10

9

8

7

6

5

4

3

2

1

No. Wt % ethane

1 100.00

2 90.22

3 70.22

4 50.25

5 29.91

6 9.78

7 6.14

8 3.27

9 1.25

10 n-Heptane

Composition

1400

1200

1000

400

600

800

200

0 200 300 400 500 100

Pre

ss

ure

, p

sia

Temperature, °F

Page 4: Five Reservoir Fluids

Phase Diagram - Typical Black Oil

Black Oil

Critical point

Pre

ssu

re,

psia

Separator

Pressure path in reservoir

Dewpoint line

% Liquid

Temperature, °F

Page 5: Five Reservoir Fluids

Phase Diagram of a Typical Volatile Oil

Pre

ssu

re

Temperature, °F

Separator

% Liquid

Volatile oil

Pressure path in reservoir

3

2

1 Critical point

Page 6: Five Reservoir Fluids

Phase Diagram of Near-Critical Fluid

Temperature, °F

Pre

ss

ure

, p

sia

50 100 150 200 250 300 350 0

1000

3000

2000

4000

5000

Dewpoint

line Bubblepoint

line

Estimated critical

point

15%

15%

10%

10%

5%

5% 0%

10 5

15 20

30 25

40 35

50

60

70 80 90

100

Page 7: Five Reservoir Fluids

Phase Diagram of a Typical Retrograde Gas

3

Separator

% Liquid

Pressure path in reservoir

1

2 Retrograde gas

Critical point

Pre

ssu

re

Temperature

Page 8: Five Reservoir Fluids

Phase Diagram of Retrograde Gas

Temperature, °F

Pre

ss

ure

, p

sia

50 100 150 200 250 300 350 0

1000

3000

2000

4000

5000

Dewpoint line

Estimated critical point

15%

15%

10%

10%

5% liquid

5% 0%

30%

40%

40%

10%

20%

Page 9: Five Reservoir Fluids

Phase Diagram of Typical Wet Gas P

ressu

re

Temperature

% Liquid

2

1

Pressure path in reservoir

Wet gas

Critical point

Separator

Page 10: Five Reservoir Fluids

Phase Diagram of Typical Dry Gas P

ressu

re

Temperature

% Liquid

2

1

Pressure path in reservoir

Dry gas

Separator

Page 11: Five Reservoir Fluids

Phase Diagram of a Reservoir Fluid

Temperature, °F

-200 -150 -100 -50 0 50

1400

1300

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

Pre

ssu

re,

psia

Critical point

Page 12: Five Reservoir Fluids

The Five

Reservoir

Fluids

Black Oil

Critical point

Pre

ss

ure

, p

sia

Separator

Pressure path in reservoir

Dewpoint line

% Liquid

Temperature, °F

Pre

ss

ure

Temperature

Separator

% Liquid

Volatile oil

Pressure path in reservoir

3

2

1 Critical point

3

Separator

% Liquid

Pressure path in reservoir

1

2 Retrograde gas

Critical

point Pre

ss

ure

Temperature

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Wet gas

Critical point

Separator

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Dry gas

Separator

Retrograde Gas Wet Gas Dry Gas

Black Oil Volatile Oil

Page 13: Five Reservoir Fluids

The Five

Reservoir

Fluids

Black Oil

Critical point

Pre

ss

ure

, p

sia

Separator

Pressure path in reservoir

Dewpoint line

% Liquid

Temperature, °F

Pre

ss

ure

Temperature

Separator

% Liquid

Volatile oil

Pressure path in reservoir

3

2

1 Critical point

3

Separator

% Liquid

Pressure path in reservoir

1

2 Retrograde gas

Critical

point Pre

ss

ure

Temperature

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Wet gas

Critical point

Separator

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Dry gas

Separator

Retrograde Gas Wet Gas Dry Gas

Black Oil Volatile Oil

Page 14: Five Reservoir Fluids

The Five

Reservoir

Fluids

Black Oil

Critical point

Pre

ss

ure

, p

sia

Separator

Pressure path in reservoir

Dewpoint line

% Liquid

Temperature, °F

Pre

ss

ure

Temperature

Separator

% Liquid

Volatile oil

Pressure path in reservoir

3

2

1 Critical point

3

Separator

% Liquid

Pressure path in reservoir

1

2 Retrograde gas

Critical

point Pre

ss

ure

Temperature

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Wet gas

Critical point

Separator

Pre

ss

ure

Temperature

% Liquid

2

1

Pressure path in reservoir

Dry gas

Separator

Retrograde Gas Wet Gas Dry Gas

Black Oil Volatile Oil

Page 15: Five Reservoir Fluids

Components of Naturally

Occurring Petroleum Fluids Component Composition,

mole percent

Hydrogen sulfide 4.91Carbon dioxide 11.01Nitrogen 0.51Methane 57.70Ethane 7.22Propane 4.45i-Butane 0.96n-Butane 1.95i-Pentane 0.78n-Pentane 0.71Hexanes 1.45Heptanes plus 8.35

100.00Properties of heptanes plusSpecific Gravity 0.807Molecular Weight 142 lb/lb mole

Page 16: Five Reservoir Fluids

Initial Producing GLR

Correlates With C7+

0

20000

40000

60000

80000

100000

0 10 20 30 40 50

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

ga

s/liq

uid

ra

tio

, s

cf/

ST

B

Dewpoint gas

Bubblepoint oil

Page 17: Five Reservoir Fluids

Initial Producing GLR

Correlates With C7+

10

100

1000

10000

100000

1000000

0.1 1 10 100

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

ga

s/liq

uid

ra

tio

, s

cf/

ST

B

Dewpoint gas

Bubblepoint oil

Page 18: Five Reservoir Fluids

Initial Producing GLR

Correlates With C7+

100

1000

10000

100000

0.1 1 10 100

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas/o

il r

ati

o, scf/

ST

B

Page 19: Five Reservoir Fluids

Initial Producing GLR

Correlates With C7+

10

100

1000

10000

0 20 40 60 80 100

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas

/liq

uid

rati

o, scf/

ST

B

Page 20: Five Reservoir Fluids

Initial Producing GLR

Correlates With C7+

0

10000

20000

30000

40000

50000

0 5 10 15 20 25 30

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas/o

il r

ati

o, scf/

ST

B

Dewpoint gas

Bubblepoint oil

Page 21: Five Reservoir Fluids

Retrograde Gases and Volatile

Oils - What’s the Difference?

2000

3000

4000

5000

10 11 12 13 14 15

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas/liq

uid

rati

o, scf/

ST

B

Page 22: Five Reservoir Fluids

Oils and Gases - What’s the

Difference?

2000

3000

4000

5000

10 11 12 13 14 15

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas

/liq

uid

rati

o, scf/

ST

B

Page 23: Five Reservoir Fluids

Oils and Gases - What’s the

Difference?

2000

5000

10 11 12 13 14 15

Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

gas/liq

uid

rati

o, scf/

ST

B

3200

Page 24: Five Reservoir Fluids

Oil

res bbl oil

STB Bo =

Se

pa

rato

r

Stock tank

p > pb

scf

STB Rsb =

res bbl

STB

scf

scf

res bbl gas

Mscf Bg =

Gas res bbl

scf

Black Oils and Volatile

Oils-What’s the Difference?

Page 25: Five Reservoir Fluids

Jacoby and Berry Calculations

Volatile oil material balance (1)

Conventional material balance

2400 1600 800 0

2000

0

4000

6000

Pre

ssu

re,

psia

Stock-tank oil production, MSTB

Volatile oil

method

Conventional

method

0 3000 6000 0

50

100

Pressure, psia

Gas s

atu

rati

on

%

po

re s

pace

Stock-tank oil production, MSTB

0

120000

0

40000

160000

Volatile oil material balance (1)

Conventional material balance

80000

1000 2000

Se

pa

rato

r g

as

/oil

ra

tio

scf/

ST

B

Page 26: Five Reservoir Fluids

Jacoby and Berry Calculations -

Compared With Actual Production

Stock-tank oil production

0

120000

0

40000

160000

Volatile oil material balance (1)

Conventional material balance

80000

1 2

Sep

ara

tor

gas/o

il r

ati

o

scf/

ST

B

Actual performance

Volatile oil material balance (1)

Conventional material balance

2400 1600 800 0

2000

0

4000

6000

Pre

ssu

re,

psia

Stock-tank oil production

Actual

performance

Page 27: Five Reservoir Fluids

Three Gases - What Are the

Differences?

• Dry gas - gas at surface is same as gas

in reservoir

• Wet gas - recombined surface gas and

condensate represents gas in reservoir

• Retrograde gas - recombined surface

gas and condensate represents the gas

in the reservoir But not the total

reservoir fluid (retrograde condensate

stays in reservoir)

Page 28: Five Reservoir Fluids

Compressibility Factors of a Rich Gas-

Condensate as Functions of Pressure

Gas-phase

Two-phase

0 1000 2000 3000 4000

Pressure, psia

0.5

0.6

0.7

0.8

0.9

1.0 C

om

pre

ss

ibilit

y f

ac

tor,

z

Page 29: Five Reservoir Fluids

Two-Phase Compressibility Factor as a Function of

Pseudoreduced Pressure for All Available Data

0 0.0

4 8 12 16 20 24

0.5

1.0

1.5

2.0

Ac

tua

l tw

o-p

ha

se

Z f

ac

tor

Pseudoreduced pressure

Page 30: Five Reservoir Fluids

Two-Phase Compressibility Factor as a Function of

Pseudoreduced Pressure for Data Set 1

0 0.0

4 8 12 16 20 24

0.5

1.0

1.5

2.0

Ac

tua

l tw

o-p

ha

se

Z f

ac

tor

Pseudoreduced pressure

Page 31: Five Reservoir Fluids

Two-Phase Compressibility Factor as a Function of

Pseudoreduced Pressure for Data Set 2

0 0.0

4 8 12 16 20 24

0.5

1.0

1.5

2.0

Ac

tua

l tw

o-p

ha

se

Z f

ac

tor

Pseudoreduced pressure

Page 32: Five Reservoir Fluids

0

50000

0 30Heptanes plus in reservoir fluid, mole %

Init

ial p

rod

uc

ing

ga

s/o

il r

ati

o, s

cf/

ST

B

Retrograde

gas

Volatile

oil

Wet

gas

Dry

gas

Black

oil

Dewpoint gas

Bubblepoint oil

Page 33: Five Reservoir Fluids

Field Identification

BlackOil

VolatileOil

RetrogradeGas

WetGas

DryGas

InitialProducingGas/LiquidRatio, scf/STB

<1750 1750 to3200

> 3200 > 15,000* 100,000*

Initial Stock-Tank Liquid

Gravity, API

< 45 > 40 > 40 Up to 70 NoLiquid

Color of Stock-Tank Liquid

Dark Colored LightlyColored

WaterWhite

NoLiquid

*For Engineering Purposes

Page 34: Five Reservoir Fluids

Laboratory Analysis

BlackOil

VolatileOil

RetrogradeGas

WetGas

DryGas

PhaseChange inReservoir

Bubblepoint Bubblepoint Dewpoint NoPhase

Change

NoPhase

Change

HeptanesPlus, MolePercent

> 20% 20 to 12.5 < 12.5 < 4* < 0.8*

OilFormationVolumeFactor atBubblepoint

< 2.0 > 2.0 - - -

*For Engineering Purposes

Page 35: Five Reservoir Fluids

Primary Production Trends G

OR

GO

R

GO

R

GO

R

GO

R

Time Time Time

Time Time Time Time Time

Time Time

No

liquid

No

liquid

Dry

Gas

Wet

Gas

Retrograde

Gas

Volatile

Oil

Black

Oil

A

PI

A

PI

A

PI

A

PI

A

PI

Page 36: Five Reservoir Fluids

Exercise 1

Determine reservoir fluid type from

field data.

Page 37: Five Reservoir Fluids

Plot of Exercise 1 Data

0 0 12 24 36 48 60 72

50

51

52

53

54

55

60

59

58

57

56

100000

90000

80000

70000

60000

50000

40000

30000

10000

20000

Months since start of 1967

Pro

du

cin

g

ga

s/o

il r

ati

o, s

cf/

ST

B

Sto

ck

-tan

k

liqu

id g

ravity, A

PI

Page 38: Five Reservoir Fluids

Exercise 2

Determine reservoir fluid type from

field data.

Page 39: Five Reservoir Fluids

Exercise 3

Determine reservoir fluid type

from field data.

Page 40: Five Reservoir Fluids

Plot of Exercise 3 Data

100

200

300

400

500

0 2 4 6 8 10 12

Months since start of production

Pro

du

cin

g

ga

s/o

il r

ati

o, s

cf/

ST

B

Page 41: Five Reservoir Fluids

Plot of Exercise 3 Data

Three-Month Running Average

Months since start of production

Pro

du

cin

g

gas

/oil r

ati

o, scf/

ST

B

100

200

300

400

500

0 2 4 6 8 10 12

Page 42: Five Reservoir Fluids

Exercise 4

Determine reservoir fluid type

from field data.

Page 43: Five Reservoir Fluids

Plot of Exercise 4 Data

Three-Month Running Average

28000

37000

0 13

Months since start of production

Pro

du

cin

g

gas/o

il r

ati

o, scf/

ST

B

Page 44: Five Reservoir Fluids

Exercise 5

Determine reservoir fluid type

from field data.

Page 45: Five Reservoir Fluids

Plot of Exercise 5 Data

50000

200000

1981 1988Year

Pro

du

cin

g

gas/o

il r

ati

o,

scf/

ST

B

40

55

1981 1988

Sto

ck-t

an

k

liq

uid

gra

vit

y, A

PI

Year

Page 46: Five Reservoir Fluids

Exercise 6

0

25

50

75

100

125

150

175

200

0 24 48 72 96 120

Months since start of 1966

Ye

ild

, S

TB

/MM

sc

f

Page 47: Five Reservoir Fluids

Exercise 7

0

50000

0 24Months since start of production

Pro

du

cin

g

ga

s/o

il r

ati

o, s

cf/

ST

B