January 23, 2014 1

Inception of Liquid LoadingFoam Flow

Ayantayo Ajani

The University of Tulsa

January 23, 2014 2

Outline

• Introduction• Large Scale Facility

Equipment and Data Collection

• Results• Foam Flow Liquid Loading• Preliminary Conclusions

January 23, 2014 3

Introduction

• Recall from air water flow that when residual pressure drop reaches zero value, liquid loading is initiated in the pipe.

• The concept above will be investigated for foam flow in a 40 ft, 2-in and 4-in vertical pipe.

January 23, 2014 4

Large Scale Facility: Flow Diagram

January 23, 2014 5

Large Scale Facility: Structure

January 23, 2014 6

Large Scale Facility: Mixing Section

January 23, 2014 7

Test Section

• 3 Trapping Sections 2 Quick Closing Valves 2 Pressure Transducers Visualization Box

DP

QCV

QCV

VB

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Facility Design

January 23, 2014 9

Test Matrix – Large Scale Facility

Foamer 2158 Foamer 2557 Foamer 3311

Pipe Diameter, (inch)

2, 4

Vsg, (m/s) 1.85 – 25 (based on pipe diameter/ Values in the range of transition from annular to intermittent flow))

Vsl, (m/s) 0.01, 0.03

Concentrations, (ppm)

400, 800, 1200, 1600, 3000

200, 400, 600, 1000

400, 600, 800, 1000

January 23, 2014 10

Uncertainty Analysis

Parameter Instrument Random Uncertainty

Systematic Uncertainty

Combined Uncertainty

Units

Liquid Flow Rate

Micro Motion Flow Meter 0.018 0.041 0.082 Kg/ min

Gas Flow Rate Micro Motion Flow Meter 0.004 0.031 0.061 Kg/ min

Pressure Rosemount Pressure Transducer

38 174 348 Pa

Pressure Gradient

Rosemount Differential Pressure Transducer

0.1 9 18 Pa/ m

Temperature Rosemount Temperature Transducer

0.0015 0.105 0.21 0C

Gas Velocity - 0.008 0.07 0.14 m /s

Liquid Velocity - 0.00025 0.0004 0.0009 m/ s

January 23, 2014 11

Outline

• Introduction• Large Scale Facility

Equipment and Data Collection

• Results• Foam Flow Liquid Loading• Preliminary Conclusions

January 23, 2014 12

Results: Pressure Gradient:Air-Water, 2-in Pipe

16 m/s16 m/s

January 23, 2014 13

Results: Pressure Gradient:Air-Water, 4-in Pipe

20 m/s

19 m/s

January 23, 2014 14

Results: Liquid Holdup for Air-Water in 2-in and 4-in Pipes

January 23, 2014 15

Observations

• The inception of liquid loading is not very sensitive to liquid velocity. We can assume a constant value over the range of investigation

• Liquid film thickness, based on material balance, is bigger in 4” pipe than in 2” pipe

January 23, 2014 16

Outline

• Introduction• Large Scale Facility

Equipment and Data Collection

• Results• Foam Flow Liquid Loading• Preliminary Conclusions

January 23, 2014 17

Results: S-2158, 400 ppm, 2 inch

6 m/s3.2 m/s

January 23, 2014 18

Results: S-2158, 800 ppm, 2 inch

4.3 m/s

2 m/s

January 23, 2014 19

Results: S-2158, 1200 ppm, 2 inch

3.2 m/s 2 m/s

January 23, 2014 20

Results: S-2158, 1600 ppm, 2 inch

1.4 m/s 1.5 m/s

January 23, 2014 21

Results: S-2158, 3000 ppm, 2 inch

2.8 m/s

January 23, 2014 22

Results: S-2158, 400 ppm, 4 inch

15 m/s16 m/s

January 23, 2014 23

Results: S-2158, 800 ppm, 4 inch

14 m/s 16 m/s

January 23, 2014 24

Results: S-2158, 1200 ppm, 4 inch

8 m/s

3 m/s

January 23, 2014 25

Results: S-2158, 1600 ppm, 4 inch

4 m/s2 m/s

January 23, 2014 26

Results: S-2158, 3000 ppm, 4 inch

6 m/s

January 23, 2014 27

Results: Liquid Holdup for S-2158 in 2-in and 4-in Pipes

January 23, 2014 28

Results: Critical Velocity for S-2158

Avg of VsgC for Vsl = 0.01 & 0.03 m/s

January 23, 2014 29

Results: S-2557, 200 ppm, 2 inch

15 m/s

10 m/s

January 23, 2014 30

Results: S-2557, 400 ppm, 2 inch

11 m/s8.5 m/s

January 23, 2014 31

Results: S-2557, 600 ppm, 2 inch

9 m/s4 m/s

January 23, 2014 32

Results: S-2557, 1000 ppm, 2 inch

5 m/s 3.4 m/s

January 23, 2014 33

Results: S-2557, 200 ppm, 4 inch

19 m/s

15 m/s

January 23, 2014 34

Results: S-2557, 400 ppm, 4 inch

16.5 m/s 14 m/s

January 23, 2014 35

Results: S-2557, 600 ppm, 4 inch

17 m/s9 m/s

January 23, 2014 36

Results: S-2557, 1000 ppm, 4 inch

14.5 m/s13 m/s

January 23, 2014 37

Results: Liquid Holdup for S-2557 in 2-in and 4-in Pipes

January 23, 2014 38

Results: Critical Velocity for S-2557Avg of VsgC for Vsl = 0.01 & 0.03 m/s

January 23, 2014 39

Results: Liquid Holdup for S-3311 in 2-in and 4-in Pipes

January 23, 2014 40

Results: Critical Velocity for S-3311Avg of VsgC for Vsl = 0.01 & 0.03 m/s

January 23, 2014 41

Results: Critical velocity versus Mass unloaded, (%): (Using Concentration at Half Life); 2 inch

January 23, 2014 42

Results: Critical velocity versus Mass unloaded, (%): (Using Concentration at Half Life); 4 inch

January 23, 2014 43

Pressure Gradients

January 23, 2014 44

Results: Pressure Gradient:S-2158, Vsl = 0.01 m/s

January 23, 2014 45

Results: Pressure Gradient:S-2557, Vsl = 0.01 m/s

January 23, 2014 46

Results: Pressure Gradient:S-3311, Vsl = 0.01 m/s

January 23, 2014 47

Outline

• Introduction• Large Scale Facility

Equipment and Data Collection

• Results• Foam Flow Liquid Loading• Preliminary Conclusions

January 23, 2014 48

Preliminary Conclusions

• In the presence of foam, for both 2” and 4” pipes, the inception of liquid loading is postponed

• The impact of foam in 2” pipe is much more significant than in 4” pipe. This is most likely caused by hold up behavior

• We believe that entrained liquid in gas core increases as the pipeline diameter decreases

January 23, 2014 49

Preliminary Conclusions

• Holdup in 2” pipe is smaller than holdup in 4” pipe at low gas velocities for a given concentration of surfactant

• It is possible to predict the behavior of foam efficacy based on small scale experiments

• The pressure drop, for a given surfactant concentration, is much greater in 2” pipe than in 4” pipe compared to air-water

January 23, 2014 50

Inception of Liquid LoadingFoam Flow

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