1053_3 - univ. of campinas --- gl valve temperature

7/28/2019 1053_3 - Univ. of Campinas --- GL Valve Temperature

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GAS LIFT VALVE TEMPERATURE

DISTRIBUTION: THEORETICAL

AND EXPERIMENTAL ANALYSIS

Marcelo M. Ganzarolli and Carlos A. C. Altemani

State University of Campinas, UNICAMP

Campinas , Brazil

Alcino Resende Almeida

Petrobras Research and Development Center - CENPES

Rio de Janeiro, Brazil


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OUTLINE

Introduction

Experimental Apparatus

Compact Thermal Model

Experimental Results

Numerical Simulation

Final Result


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INTRODUCTION

production oil

injection gas

N2 dome

GLV inside the

mandrel tube

TN2 = f(Toil,Tgas)


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EXPERIMENTAL APPARATUS

CONSTANT LEVEL

CONTROL VALVES

ROTAMETERS

HEATER

WATER

Pexiglas cylinder

with the steel tube

and GLV inside


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Frontal view of the experimental apparatus

20 cm

20 cm

60 cm

HOT WATER

HOT WATER


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Lateral view of the experimental apparatus

COLD FLUID

HOT WATER

HOT WATER

20 cm

20 cm

60 cm


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Cross section of the experimental apparatus

VGL

Mandrel


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Plexiglas tube, mandrel and GLV


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View of the experimental apparatus

heater


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COMPACT THERMAL MODEL

Ttp

TN2

Tbs

Tpi

Tmi

Tms

Tps

Tpd

Tij

Thermal Resistances

Production Temperature

Injection Temperature

GLV and Mandrel Nodes


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FINAL VERSION OF THE THERMAL NETWORK

Tpd

TN2 Tbs

Tij

R=500R=500

R=5

R=2,5

R=37


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THE N2 DOME


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COMPACT MODEL PREDICTIONS

The axial resistance along the GLV body was

much larger than the radial resistance from

the dome to the mandrel tube; The GLV dome temperature would be

determined basically by the circumferential

temperature distribution around the mandrel

tube;

This distribution will be a function of bothfluid temperatures as well as the

corresponding convective heat transfer

coefficients.

EXPERIMENTAL RESULTS


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20 cm

20 cm

60 cm

thermocouple

3

4

5

6

7

11

12

13

14

15

16

18 19

20

21

22

23

26

27

28

17

29

22.429

67.728

67.927

39.426

68.623

57.422

56.821

67.620

68.419

68.518

68.51752.116

34.915

33.414

37.813

32.612

51.211

67.57

67.96

67.85

67.94

67.83

TTHERMOCOUPLE



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30.0

40.0

50.0

60.0

70.0

t=0

t=5 min

t=12 min

T [oC]

N2 bellow

1311375


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NUMERICAL SIMULATION

The heat conduction was numerically simulated for a

cross section of the mandrel tube;

Convective heat transfer coefficients were specified

for both fluid streams.

gasoil

gas

TTTT*T

=

T*=f(position, hgas, hoil)


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TEMPERATURE DISTRIBUTION IN THE

MANDREL CROSS SECTION

*

GLV

T*

(OIL (T*=1)T=1) GAS (T*=0)

T*

*


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MEAN TEMPERATURE AROUND THE GLVT

*T*T

0 100 200 300 400

0.0

0.4

0.8

hOIL/hGAS

10

5

2

1

hOIL(W/m2 K)

T*


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NUMERICAL MODEL CONCLUSION

)h

h

(f*Tgas

oil

=

From definition*T

TN2=Toil + (1-) Tgas

A SIMPLE ( d i t ) THEORY


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oil

A SIMPLE (and approximate) THEORY

Toil TMgTMo Tgas

(hA)-1

oil (Sk)-1

(hA)-1

gas

TMgas

TM = Toil + (1- )TgasTM=(TMo + TMg)/2

Considering typical values for the

heat transfer coefficients and for

the conduction shape factorS

10hA

Sk

)

h

h(f

)h/h()A/A(1

1

gas

oil

gasoil

oilgas

=

+

The expression suggests

a form for the functionalrelationship


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TWO MANDREL CROSS SECTIONS

GLV GLV

75.0* =T73.0* =T


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NUMERICAL SIMULATION RESULTS

1 2 3 4 5 6 7 8 9 10 11

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

hoil/hgas

Numerical Results

Proposed Correlation


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FINAL RESULT

TN2=Toil + (1-) T gas

+

=

gas

oil

h

h

6.11

1


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THE END

1053_3 - univ. of campinas --- gl valve temperature

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