Slugging in large diameter pipelines: field measurements, experiments and simulation

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Doctoral theses at NTNU, 2015:95

Omar Al-Saif

Slugging in Large Diameter Pipelines:

Field Measurements, Experiments and Simulation

ISBN 978-82-326-0846-1 (printed version) ISBN 978-82-326-0847-8 (electronic version) ISSN 1503-8181

NTNU Norwegian University of Science and Technology Faculty of Engineering Science and Technology Department of Energy and Process Engineering

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Slugging in Large Diameter Pipelines: Field Measurements, Experiments and Simulation

By:

Omar A. Al-Saif

Thesis submitted in partial fulfilment of the requirements for the degree of Doctor Philosophiae

NTNU – Norwegian University of Science and Technology Faculty of Engineering Science and Technology Department of Energy and Process Engineering

Trondheim, December 2014

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Acknowledgement

I would like to express my deepest gratitude and appreciation for:

 Professor Ole Jørgen Nydal, for being my main supervisor and providing me with all of his kindness and support throughout my PhD experience at NTNU.

 Dr. Mikal Espedal at Saudi Aramco, for being my co-supervisor and all of the advice and help throughout my PhD endeavor at NTNU.

 The flow assurance team at Saudi Aramco, Satya Putra and Ahmed Harb, who made this work possible by providing me with all the support especially during the field measurement period at Saudi Aramco.

 The NTNU multiphase flow lab staff who provided me with all the support and help to conduct my experiments at the lab in a very short notice.

 Saudi Aramco management for providing me with this opportunity to pursuit my PhD at NTNU and allowing me to utilize the data obtained from field measurements in my PhD thesis.

 I would like also to thank my parents, my wife, Toqa, and my kids Zainab, Zahra, Ahmed and the little one, Hasan, who was born during my PhD work. For all your patience and support throughout these years, words are not enough to express my deepest gratitude but all I can say is truly thanks, from the bottom of my heart.

Finally, I would like to dedicate this work to my grandfather, Abu Malik, who passed away about three years ago while I was still pursuing my PhD. He was a very special person to me and to the whole family and I still deeply miss him.

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Table of Figures

FIGURE ‎3-1: GAS-LIQUID FLOW REGIMES IN HORIZONTAL PIPES FROM BRATLAND (2010) ... 32

FIGURE ‎3-2: GAS-LIQUID FLOW REGIMES IN VERTICAL PIPES FROM BRATLAND (2010) ... 32

FIGURE ‎3-3: EXAMPLE OF STEADY STATE FLOW REGIME MAP FOR HORIZONTAL FLOW FROM BRATLAND (2010) ... 32

FIGURE ‎3-4: FLOW PATTERN MAP PROPOSED BY MANDHANE ET AL.(1974) ... 33

FIGURE ‎3-5: FLOW PATTERN MAP PROPOSED BY TAITEL &DUKLER (1976) ... 33

FIGURE ‎3-6: DETAILS OF A SLUG FLOW UNIT FROM A.E.DUKLER &HUBBARD (1975) ... 34

FIGURE ‎3-7: INITIAL GROWTH OF A “PSEUDO-SLUG”(B) AFTER LIQUID BRIDGING OF PIPE FROM BENDIKSEN &ESPEDAL (1992) ... 35

F^IGURE‎3-8:I^{DEAL CROSS}-SECTION GEOMETRY FOR TWO-PHASE STRATIFIED FLOW FROM KRISTIANSEN (2004) ... 36

F^IGURE‎3-9:PROBABILITY DENSITY DISTRIBUTION OF BUBBLE AND SLUG VELOCITIES FROM J.F^{ABRE ET AL}.(1993) ... 40

FIGURE ‎3-10: GAS-LIQUID SLUG FLOW UNIT CELL MADE OF TOTAL SLUG LENGTH (L) DIVIDED INTO SLUG LIQUID BODY LENGTH (LS) AND LONG GAS BUBBLE LENGTH (LB)– FROM KRISTIANSEN (2004) ... 41

FIGURE ‎3-11: PHOTOS OF ENTRAINMENT OF GAS BUBBLES IN VERTICAL AND HORIZONTAL SLUGS FROM JEAN FABRE (2002) ... 44

FIGURE ‎3-12: LONG BUBBLES SHAPE IN VERTICAL AND HORIZONTAL TUBES FROM JEAN FABRE (2002) ... 45

FÎGURE‎3-13:(C0)COEFFICIENT PLOTTED FROM EXPERIMENTS OF NICKLIN ET AL.(1962)^FROMJÊANFÂBRE(2002) ... 45

FÎGURE‎3-14:BUBBLE SHAPE IN HORIZONTAL FLOW WHEN LIQUID VELOCITY INCREASES (TOP TO BOTTOM)^FROMJÊANFÂBRE(2002) ... 46

FÎGURE‎3-15:EXPERIMENTAL DATA BY BÊNDIKSEN(1984)^FROMJÊANFÂBRE(2002) ... 47

FIGURE ‎3-16: VELOCITY PROFILES IN LIQUID SLUGS FROM TAITEL &BARNEA (1990) ... 48

FIGURE ‎3-17: THE PROCESS OF SLUG FORMATION FROM TAITEL &DUKLER (1977) ... 49

FIGURE ‎3-18: SLUG UNIT REPRESENTATION FROM COOK &BEHNIA (2000) ... 51

FIGURE ‎3-19: TYPICAL SLUG SHOWING SLOPE ANGLE (~20DEGREES) FROM COOK &BEHNIA (2000) ... 51

FIGURE ‎3-20: SLUG STATISTICAL ANALYSIS APPROACH ... 53

FIGURE ‎4-1: GAMMA HOLDUP MEASUREMENT –SOURCE-DETECTOR ARRANGEMENT ... 55

FIGURE ‎4-2: ILLUSTRATION OF COMPTON EFFECT FROM MAHER (2006) ... 56

FIGURE ‎4-3: ATTENUATION COEFFICIENTS FOR DIFFERENT MATERIALS WITH CO-60HIGHLIGHTED AT (1253KEV) ... 57

FIGURE ‎4-4: GAMMA ATTENUATION IN (STEEL) WITH VARIOUS ATTENUATION EFFECTS FROM MCALISTER (2012) ... 57

FIGURE ‎4-5: GAMMA ATTENUATION IN (WATER) WITH VARIOUS ATTENUATION EFFECTS FROM MCALISTER (2012) ... 58

FIGURE ‎4-6: CALIBRATION PIPELINE SPOOLS – FROM RIGHT TO LEFT (ONE 42”,TWO 30”,TWO 24”) ... 62

FIGURE ‎5-1:OILFIELD PIPELINE NETWORK –1999,ALVAREZ &AL-AWWAMI (1999) ... 69

FIGURE ‎5-2:OILFIELD SAND DUNES ... 70

FÎGURE‎5-3:GÂMMAMEASUREMENT PRINCIPLE OF O^PERATION&PÎPEMÔUNTING ... 72

F^IGURE‎5-4:P^HASEENVELOPE OF AXL ... 73

FÎGURE‎5-5:GÂSDÊNSITY(K^G/^M3)–TEMPERATURE @(100°F) ... 73

FÎGURE‎5-6:OÎLDÊNSITY(K^G/^M3)–TEMPERATURE @(100°F) ... 74

FÎGURE‎5-7:OÎLVÎSCOSITY(K^G/^M-^H)–TEMPERATURE @(100°F) ... 74

FIGURE ‎5-8:GAS VISCOSITY (KG/M-H)–TEMPERATURE @(100°F) ... 75

FIGURE ‎5-9:GAS-OIL SURFACE TENSION (N/M)–TEMPERATURE @(100°F) ... 75

FIGURE ‎5-10:G2NT1 PIPELINE PROFILE - SLUG VALVE AND GAMMA DENSITOMETER LOCATIONS ... 76

FIGURE ‎5-11:GAMMAS LOCATION WITH RESPECT TO SLUG VALVE AND GOSP-2 ... 77

FIGURE ‎5-12:G2NT1PRODUCTION HEADER PRESSURE AT S-38,MAY 27,1999 ... 78

FIGURE ‎5-13:G2NT1PRODUCTION HEADER PRESSURE AT S-46,MAY 27,1999 ... 78

FIGURE ‎5-14:G2NT1HOLDUP TIME SERIES,(GAMMA-1&2)–(SEPARATE) ... 79

FIGURE ‎5-15:G2NT1HOLDUP TIME SERIES,(GAMMA-1&2) ... 80

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FIGURE ‎5-17:G2NT1HOLDUP TIME SERIES,EXTRACT OF THE LIQUID HOLDUP TIME SERIES,LONG SLUGS ... 81

FIGURE ‎5-18:CROSS CORRELATION OF HOLDUP TIME SERIES,G2NT1PIPELINE ... 82

FIGURE ‎5-19:SLUG DEFINITION AT GAMMA-1,LOCATION G2NT1PIPELINE –(A)(35MINUTES)–(B)(12MINUTES)... 82

FIGURE ‎5-20:SLUG DEFINITION AT GAMMA-2LOCATION,G2NT1PIPELINE –(A)(35MINUTES)–(B)(12MINUTES)... 82

FIGURE ‎5-21:G2NT1,DISTRIBUTION OF TIME BETWEEN TWO SLUG PEAKS,(GAMMA 1&2) ... 83

FIGURE ‎5-22:G2NT1SLUG LENGTH (M)DISTRIBUTION ... 84

FÎGURE‎5-23:G2NT1S^LUGLÊNGTH(NÔ.ÔFDÎA.)DISTRIBUTION ... 84

FÎGURE‎5-24:G2NT1A^VERAGEDS^LUGF^RONT&TÂILVÊLOCITIES ... 85

FÎGURE‎5-25:G2NT1S^LUGF^RONT&TÂILVÊLOCITIES ... 85

FIGURE ‎5-26:G2NT1-HOLDUP AND PRESSURE MEASUREMENT LOCATIONS FOR SIMULATION COMPARISON ... 86

FIGURE ‎5-27:G2NT1OLGAPRESSURE RESULTS –TEMPE.CALCULATIONS (ON/OFF)–(NO SLUG TRACKING,COARSE GRID) ... 87

FIGURE ‎5-28:G2NT1OLGAHOLDUP RESULTS –TEMPE.CALCULATIONS (ON/OFF)–(NO SLUG TRACKING,COARSE GRID)(A)1ST ORDER MASS EQ.SOLUTION –(B)2ND ORDER MASS EQ.SOLUTION ... 87

FÎGURE‎5-29:G2NT1OLGAP^RESSURERÊSULTS–S^LUGT^RACKINGDC=50,150–(TÊMP.CALCULATION OFF,CÔARSEG^RID,1^STO^RDER MASS EQ.SOLUTION) ... 89

FIGURE ‎5-30: G2NT1OLGAPRESSURE RESULTS –SLUG TRACKING DC=500,800–(TEMP.CALCULATION OFF,COARSE GRID,1ST O^RDERM^ASSE^Q.S^OLUTION) ... 90

FIGURE ‎5-31: G2NT1OLGAHOLDUP RESULTS –SLUG TRACKING DC=50–(TEMP.CALCULATION OFF,COARSE GRID,1ST ORDER MASS EQ.SOLUTION)–(20 MINUTES SPAN) ... 90

FIGURE ‎5-32: G2NT1OLGAHOLDUP RESULTS –SLUG TRACKING DC=50–(TEMP.CALCULATION OFF,COARSE GRID,1ST ORDER MASS EQ.SOLUTION)–(50 MINUTES SPAN) ... 91

FIGURE ‎5-33: OLGA PIPELINE SECTIONS – DEFAULT GRIDDING OPTION (COARSE GRID) ... 91

FÎGURE‎5-34:G2NT1CÔARSEG^RIDSÊCTIONLÊNGTHRÂTIO ... 92

FÎGURE‎5-35:G2NT1–HISTOGRAM OF CÔARSEG^RIDSÊCTIONSIZES IN METERS ... 92

FÎGURE‎5-36:OLGA PIPELINE SECTIONS –(5^METER)FÎXEDSÊCTIONLÊNGTH(^{FINE GRID}) ... 93

FIGURE ‎5-37: G2NT1OLGAPRESSURE RESULTS –COARSE VS.FINE GRID –(TEMP.CALCULATION OFF,NO SLUG TRACKING,1ST ORDER MASS EQ.SOLUTION) ... 93

FIGURE ‎5-38: G2NT1OLGAPRESSURE RESULTS –COARSE VS.FINE GRID –(TEMP.CALCULATION OFF,SLUG TRACKING DC=50,1ST O^RDERM^ASSE^Q.S^OLUTION) ... 94

FIGURE ‎5-39: G2NT1OLGAPRESSURE RESULTS –1ST ORDER VS.2ND ORDER –(TEMP.CALCULATION OFF,NO SLUG TRACKING,COARSE GRID) ... 95

FIGURE ‎5-40: G2NT1OLGAHOLDUP RESULTS –1ST ORDER VS.2ND ORDER –(TEMP.CALCULATION OFF,NO SLUG TRACKING,COARSE GRID) ... 95

FÎGURE‎5-41:G2NT1LÊDAF^LOWP^RESSURERÊSULTS–(NO SLUG CAPTURING,CÔARSEG^RID)– ... 96

FÎGURE‎5-42:G2NT1LÊDAF^LOWP^RESSURERÊSULTS–TÊMP.CALCULATIONS (ON/OFF)– ... 97

FIGURE ‎5-43: G2NT1LEDAFLOW PRESSURE RESULTS –NORMAL ORDER VS.HIGH ORDER – ... 97

FIGURE ‎5-44: G2NT1LEDAFLOW HOLDUP RESULTS –NORMAL ORDER VS.HIGH ORDER – ... 98

FIGURE ‎5-45: G2NT1LEDAFLOW RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE –(COARSEGRID,TEMP.CALC.OFF)(A)PRESSURE RESULTS –(B)HOLDUP RESULTS ... 99

FIGURE ‎5-46: G2NT1LEDAFLOW RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE –(FINEGRID,TEMP.CALC.OFF)(A)PRESSURE RÊSULTS–(^B)HÔLDUPRÊSULTS ... 99

FIGURE ‎5-47: G2NT1LEDAFLOW PRESSURE RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE – ... 100

FIGURE ‎5-48: G2NT1LEDAFLOW PRESSURE RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE – ... 100

FIGURE ‎5-49: G2NT1LEDAFLOW HOLDUP RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE – ... 101

FIGURE ‎5-50: G2NT1LEDAFLOW HOLDUP RESULTS –NO SLUG CAPTURE VS.SLUG CAPTURE – ... 101

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FIGURE ‎5-51: G2NT1PIPELINE –SLUG VALVE OLGASIMULATION STUDY –(COARSE GRID,1ST ORDER,NO-SLUGTRACKING) ... 103

FIGURE ‎5-52: G2NT1PIPELINE –SLUG VALVE LEDAFLOW SIMULATION STUDY –(COARSE GRID,NORMAL ORDER,NO-SLUGCAPTURING) ... 103

FIGURE ‎5-53:G1ST3 PIPELINE PROFILE - SLUG VALVE AND GAMMA DENSITOMETER LOCATIONS ... 104

FIGURE ‎5-54:G1ST3PRODUCTION HEADER PRESSURE AT S-27,JUNE 7,1999(DOWNHILL MEASUREMENT) ... 106

FIGURE ‎5-55:G1ST3MANUAL READINGS OF WH PRESSURE AT S-27,JUNE 8,1999(DOWNHILL MEASUREMENT) ... 106

FIGURE ‎5-56:G1ST3MANUAL READINGS OF WH PRESSURE AT S-19,JUNE 9,1999(UPHILL MEASUREMENT) ... 107

FIGURE ‎5-57:G1ST3PRESSURE UPSTREAM AND DOWNSTREAM OF SLUG VALVE,DOWNHILL,JUNE 8,1999 ... 108

FIGURE ‎5-58:G1ST3PRESSURE DIFFERENTIAL ACROSS SLUG VALVE,DOWNHILL,JUNE 8,1999 ... 108

FIGURE ‎5-59:G1ST3PIPELINE –UPHILL GAMMA MEASUREMENT LOCATION ... 109

FIGURE ‎5-60:G1ST3HOLDUP TIME SERIES,UPHILL,JUNE 9,1999,(30 MINUTES) ... 109

FIGURE ‎5-61:G1ST3HOLDUP TIME SERIES,UPHILL,JUNE 9,1999,(10 MINUTES) ... 110

FIGURE ‎5-62:G1ST3HOLDUP TIME SERIES,JUNE 9,1999,(UPHILL)-(1 MINUTE)-(DENSE &SPARSE ZONE) ... 110

FÎGURE‎5-63:G1ST3HOLDUP TIME SERIES,JÛNE9,1999,(U^PHILL)-(1^MINUTE)-(LÔNGS^LUGS) ... 111

FÎGURE‎5-64:G1ST3HOLDUP TIME SERIES,JÛNE9,1999,(U^PHILL)-(LÔNGS^LUGS) ... 111

F^IGURE‎5-65:G1ST3HOLDUP TIME SERIES,J^UNE9,1999,(U^PHILL)-(1^MINUTE)-(S^HORTS^LUGS) ... 112

FIGURE ‎5-66:G1ST3HOLDUP TIME SERIES,JUNE 9,1999,(UPHILL)-(SHORT SLUGS) ... 112

FIGURE ‎5-67:G1ST3CROSS CORRELATION OF TWO GAMMAS,JUNE 9,1999,(UPHILL) ... 113

FIGURE ‎5-68:SLUG DEFINITION AT GAMMA-1LOCATION -G1ST3PIPELINE ... 113

FIGURE ‎5-69:SLUG DEFINITION AT GAMMA-2LOCATION -G1ST3PIPELINE ... 114

FIGURE ‎5-70:G1ST3–DISTRIBUTION OF SLUG FREQUENCY (TIME BETWEEN TWO PEAKS)(SECONDS) ... 114

FIGURE ‎5-71:G1ST3–SLUG LENGTH DISTRIBUTION (METERS) ... 115

FIGURE ‎5-72:G1ST3–SLUG LENGTH DISTRIBUTION (NO. OF DIAMETERS) ... 115

FIGURE ‎5-73:G1ST3–AVERAGE SLUG (FRONT &TAIL)VELOCITIES ... 116

FIGURE ‎5-74:G1ST3–SLUGS FRONT &TAIL VELOCITIES ... 116

FIGURE ‎5-75:G1ST3–DOWNHILL GAMMA MEASUREMENT LOCATION ... 117

FIGURE ‎5-76:G1ST3–HOLDUP TIME SERIES –DOWNHILL MEASUREMENT –(70 MIN) ... 117

FIGURE ‎5-77:G1ST3–HOLDUP TIME SERIES –DOWNHILL MEASUREMENT –(40 MIN) ... 118

FIGURE ‎5-78:G1ST3OLGAPRESSURE RESULTS –SLUG TRACKING (DC=150) VS.NO-SLUG TRACKING SIMULATIONS ... 120

FÎGURE‎5-79:G1ST3OLGAP^RESSURERÊSULTS–S^LUGT^RACKING(DC=50)^VS.NÔ-S^LUGT^RACKINGSÎMULATIONS ... 120

FÎGURE‎5-80:G1ST3OLGAP^RESSURERÊSULTS–S^LUGT^RACKING(DC=500,800)^VS.NÔ-S^LUGT^RACKINGSÎMULATIONS ... 121

FÎGURE‎5-81:G1ST3U^PHILLOLGAHÔLDUPRÊSULTS–NÔN-S^LUGT^{RACKING VS}.HÔLDUPMEASUREMENTS ... 122

FIGURE ‎5-82:G1ST3UPHILL OLGAHOLDUP RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=150) ... 123

FIGURE ‎5-83:G1ST3UPHILL OLGAHOLDUP RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50) ... 123

FIGURE ‎5-84:G1ST3UPHILL OLGAHOLDUP RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800) ... 123

FIGURE ‎5-85:G1ST3DOWNHILL OLGAHOLDUP RESULTS –NON-SLUG TRACKING VS.HOLDUP MEASUREMENT ... 124

FIGURE ‎5-86:G1ST3DOWNHILL OLGAHOLDUP RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50,150) ... 124

FIGURE ‎5-87:G1ST3PIPELINE OLGACOARSE GRID ... 125

FIGURE ‎5-88:G1ST3PIPELINE OLGAFINE GRID (5 METER) ... 125

FIGURE ‎5-89:G1ST3PIPELINE OLGAPRESSURE RESULTS:COARSE GRID VS.FINE GRID ... 126

FIGURE ‎5-90:G1ST3UPHILL PIPELINE OLGAHOLDUP RESULTS:COARSE GRID VS.FINE GRID ... 126

FIGURE ‎5-91:G1ST3DOWNHILL PIPELINE OLGAHOLDUP RESULTS:COARSE GRID VS.FINE GRID ... 127

FIGURE ‎5-92:G1ST3LEDAFLOW COARSE GRID (LEFT) AND FINE GRID (RIGHT)SECTIONS... 127

FIGURE ‎5-93:G1ST3LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (COARSE GRID) ... 128

FIGURE ‎5-94:G1ST3LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (FINE GRID) ... 128

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FIGURE ‎5-96:G1ST3UPHILL LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (FINE GRID) ... 129

FIGURE ‎5-97:G1ST3DOWNHILL LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (COARSE GRID) ... 130

FIGURE ‎5-98:G1ST3DOWNHILL LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (FINE GRID) ... 130

FIGURE ‎5-99:G1ST3PIPELINE –SLUG VALVE OLGASIMULATION STUDY –(FINE GRID,2ND ORDER,NO-SLUGTRACKING) ... 132

FIGURE ‎5-100:G1ST3PIPELINE –SLUG VALVE LEDAFLOW SIMULATION STUDY –(FINE GRID,HIGH ORDER,NO-SLUGCAPTURING) ... 132

FIGURE ‎5-101: G2NT2 PIPELINE PROFILE - SLUG VALVE AND GAMMA DENSITOMETER LOCATIONS ... 133

F^IGURE‎5-102:G2NT2PRODUCTION HEADER PRESSURE AT S-50,35% REDUCED RATE,M^AY24,1999 ... 134

FÎGURE‎5-103:G2NT2HOLDUP TIME SERIES,N^{ORMAL RATE},MÂY23,1999,(120^MINUTES)-(GÂMMA-1&2) ... 135

FÎGURE‎5-104:G2NT2HOLDUP TIME SERIES,N^{ORMAL RATE},MÂY23,1999,(20^MINUTES)-(GÂMMA-1&2) ... 135

FIGURE ‎5-105: G2NT2HOLDUP TIME SERIES,NORMAL RATE,MAY 23,1999,(10 MINUTES)-(GAMMA-1&2) ... 136

FIGURE ‎5-106: CROSS CORRELATION OF HOLDUP TIME SERIES –G2NT2PIPELINE –NORMAL RATE ... 136

FIGURE ‎5-107: G2NT2SLUG FREQUENCY DISTRIBUTION (MINUTES)–NORMAL RATE ... 137

FIGURE ‎5-108: G2NT2SLUG LENGTH DISTRIBUTION (METERS)–NORMAL RATE ... 137

FIGURE ‎5-109: G2NT2SLUG LENGTH DISTRIBUTION (NO. OF DIA.)–NORMAL RATE ... 138

FIGURE ‎5-110: G2NT2FRONT &TAIL VELOCITIES DISTRIBUTION (M/SEC)–NORMAL RATE ... 138

FIGURE ‎5-111: G2NT2AVERAGE FRONT &TAIL VELOCITY DISTRIBUTION (M/SEC)–NORMAL RATE ... 139

FIGURE ‎5-112: G2NT2HOLDUP TIME SERIES,REDUCED RATE,MAY 24,1999,(120 MINUTES)-(GAMMA-1&2) ... 139

FIGURE ‎5-115:G2NT2OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.HOLDUP MEASUREMENT (NORMAL RATE) ... 142

FIGURE ‎5-116:G2NT2OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50) ... 142

FÎGURE‎5-117:G2NT2OLGAHÔLDUPSÎMULATION–NÔN-S^LUGT^{RACKING VS}.S^LUGT^RACKING(DC=150) ... 143

FÎGURE‎5-118:G2NT2OLGAHÔLDUPSÎMULATION–NÔN-S^LUGT^{RACKING VS}.S^LUGT^RACKING(DC=500,800) ... 143

FÎGURE‎5-119:G2NT2OLGAP^RESSURERÊSULTS–NÔN-S^LUGT^{RACKING VS}.P^RESSUREMEASUREMENT (RÊDUCEDRÂTE) ... 144

FIGURE ‎5-120:G2NT2OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50) ... 145

FIGURE ‎5-121:G2NT2OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=150) ... 145

FIGURE ‎5-122:G2NT2OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800) ... 146

FIGURE ‎5-123: G2NT2PIPELINE SECTIONS –OLGAGRID OPTIONS (COARSE GRID) ... 146

FIGURE ‎5-124: G2NT2PIPELINE SECTIONS –(FINE GRID (5 METER)) ... 147

FIGURE ‎5-125:G2NT2OLGAHOLDUP SIMULATION –COARSE GRID VS.FINE GRID (NORMAL RATE) ... 147

FIGURE ‎5-126:G2NT2OLGAPRESSURE SIMULATION –COARSE GRID VS.FINE GRID (REDUCED RATE) ... 148

FIGURE ‎5-127:G2NT2LEDAFLOW COARSE GRID (LEFT) AND FINE GRID (RIGHT)SECTIONS ... 149

FIGURE ‎5-128:G2NT2LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (COARSE GRID) ... 150

FIGURE ‎5-129:G2NT2LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (FINE GRID) ... 150

FIGURE ‎5-130:G2NT2LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (COARSE GRID) ... 151

FIGURE ‎5-131:G2NT2LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATIONS (FINE GRID) ... 151

FÎGURE‎5-132:G2NT2PÎPELINE–S^LUGVÂLVEOLGASÎMULATIONS^TUDY–(CÔARSEG^RID,2^NDO^RDER,NÔ-S^LUGT^RACKING) ... 153

FÎGURE‎5-133:G2NT2PÎPELINE–S^LUGVÂLVELÊDAF^LOWSÎMULATIONS^TUDY–(CÔARSEG^RID,HÎGHO^RDER,NÔ-S^LUGCÂPTURING) . 153 FÎGURE‎5-134:G3ST1 PIPELINE PROFILE - SLUG VALVE AND GAMMA DENSITOMETER LOCATIONS ... 154

F^IGURE‎5-135:G3ST1PRODUCTION HEADER PRESSURE AT S-98,N^{ORMAL RATE},J^UNE3,1999,(U^PSTREAMSV) ... 155

FÎGURE‎5-136:G3ST1PRODUCTION HEADER PRESSURE AT S-98,N^{ORMAL RATE},JÛNE5,1999,(DÔWNSTREAMSV)... 156

F^IGURE‎5-137:G3ST1PRODUCTION HEADER PRESSURE AT S-91,N^{ORMAL RATE},J^UNE4,1999, ... 156

FIGURE ‎5-138: ARRANGEMENT OF THE SLUG VALVE,T/LG3ST1 ... 157

FIGURE ‎5-139: G3ST1PRESSURE UPSTREAM AND DOWNSTREAM OF SLUG VALVE,NORMAL RATE,JUNE 2,1999 ... 157

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FIGURE ‎5-140: G3ST1PRESSURE DIFFERENTIAL ACROSS SLUG VALVE,NORMAL RATE,JUNE 2,1999 ... 158

FIGURE ‎5-141: G3ST1HOLDUP TIME SERIES,UPSTREAM SLUG VALVE,(220 MINUTES)-(GAMMA-1&2) ... 159

FIGURE ‎5-144: G3ST1CROSS CORRELATION OF TWO GAMMAS –UPSTREAM SLUG VALVE ... 160

FIGURE ‎5-145: G3ST1SLUG FREQUENCY DISTRIBUTION (MINUTES)–UPSTREAM SLUG VALVE ... 161

FIGURE ‎5-146: G3ST1SLUG LENGTH DISTRIBUTION (METERS)–UPSTREAM SLUG VALVE ... 161

FÎGURE‎5-147:G3ST1A^VERAGEF^RONT&TÂILVÊLOCITYDISTRIBUTION (^M/^SEC)–U^PSTREAMS^LUGVÂLVE ... 162

FÎGURE‎5-148:G3ST1HOLDUP TIME SERIES,DÔWNSTREAMS^LUGVÂLVE,(220^MINUTES)-(GÂMMA-1&2) ... 163

FÎGURE‎5-149:G3ST1HOLDUP TIME SERIES,DÔWNSTREAMS^LUGVÂLVE,(80^MINUTES)-(GÂMMA-1&2) ... 164

FIGURE ‎5-150: G3ST1HOLDUP TIME SERIES,DOWNSTREAM SLUG VALVE,(20 MINUTES)-(GAMMA-1&2) ... 164

FIGURE ‎5-151: G3ST1CROSS CORRELATION OF TWO GAMMAS –DOWNSTREAM SLUG VALVE ... 165

FIGURE ‎5-152:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.HOLDUP MEASUREMENT (UPSTREAM) ... 167

FIGURE ‎5-153:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50)–(UPSTREAM) ... 167

FIGURE ‎5-154:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=150)–(UPSTREAM) ... 168

FIGURE ‎5-155:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800)–(UPSTREAM) ... 168

FIGURE ‎5-156:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.HOLDUP MEASUREMENT (DOWNSTREAM) ... 169

FIGURE ‎5-157:G3ST1OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50)–(DOWNSTREAM) ... 170

FIGURE ‎5-159:G3ST1OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.PRESSURE MEASUREMENTS ... 171

FIGURE ‎5-160:G3ST1OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=50) ... 172

FÎGURE‎5-162:G3ST1OLGAP^RESSURERÊSULTS–NÔN-S^LUGT^{RACKING VS}.S^LUGT^RACKING(DC=500,800) ... 173

FÎGURE‎5-163:G3ST1PÎPELINESÊCTIONS–OLGAG^RIDO^PTIONS(CÔARSEG^RID) ... 173

FÎGURE‎5-164:G3ST1PÎPELINESÊCTIONS–(FÎNEG^RID(5^METER)) ... 174

FIGURE ‎5-165:G3ST1OLGAHOLDUP SIMULATION –COARSE GRID VS.FINE GRID (UPSTREAM) ... 174

FIGURE ‎5-166:G3ST1OLGAHOLDUP SIMULATION –COARSE GRID VS.FINE GRID (DOWNSTREAM) ... 175

FIGURE ‎5-167:G3ST1OLGAPRESSURE SIMULATION –COARSE GRID VS.FINE GRID (JUNE 5,1999) ... 175

FIGURE ‎5-168:G3ST1LEDAFLOW COARSE GRID (LEFT) AND FINE GRID (RIGHT) ... 176

FIGURE ‎5-169:G3ST1LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (COARSE GRID) ... 177

FIGURE ‎5-170:G3ST1LEDAFLOW PRESSURE RESULTS –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (FINE GRID) ... 177

FIGURE ‎5-171:G3ST1LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (COARSE GRID)(UPSTREAM) .. 178

FIGURE ‎5-172:G3ST1LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (FINE GRID)(UPSTREAM) ... 178

FIGURE ‎5-173:G3ST1LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (COARSE GRID)(DOWNSTREAM) ... 179

FIGURE ‎5-174:G3ST1LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (FINE GRID)(DOWNSTREAM) . 179 FIGURE ‎5-175:G3ST1PIPELINE –SLUG VALVE OLGASIMULATION STUDY –(COARSE GRID,2ND ORDER,NO-SLUGTRACKING) ... 181

FIGURE ‎5-176:G3ST1PIPELINE –SLUG VALVE LEDAFLOW SIMULATION STUDY –(COARSE GRID,HIGH ORDER,NO-SLUGCAPTURING) .. 181

FIGURE ‎5-177: G3ST2 PIPELINE PROFILE – SLUG VALVE AND GAMMA DENSITOMETER LOCATIONS ... 182

FIGURE ‎5-178:G3ST2 PIPELINE –LOCATION OF GAMMAS WITH RESPECT TO SLUG VALVE (UPSTREAM SV ... 183

FIGURE ‎5-179:G3ST2PRODUCTION HEADER PRESSURE AT S-95,NORMAL OPENING,MAY 29,1999,(DOWNSTREAM SV) ... 184

FIGURE ‎5-180:G3ST2PRODUCTION HEADER PRESSURE AT S-95,RESTRICTED OPENING,MAY 30,1999,(DOWNSTREAM SV) ... 184

FIGURE ‎5-181:G3ST2PRODUCTION HEADER PRESSURE AT S-95,NORMAL OPENING,JUNE 6,1999,(UPSTREAM SV) ... 185

FIGURE ‎5-182:G3ST2PRESSURE UPSTREAM AND DOWNSTREAM OF SLUG VALVE,NORMAL OPENING,MAY 29,1999 ... 186

FIGURE ‎5-183:G3ST2PRESSURE DIFFERENTIAL ACROSS SLUG VALVE,NORMAL OPENING,MAY 29,1999 ... 186

(17)

xiv

FIGURE ‎5-185:G3ST2PRESSURE DIFFERENTIAL ACROSS SLUG VALVE,REST.OPENING,MAY 30,1999 ... 187

FIGURE ‎5-186: G3ST2HOLDUP TIME SERIES,UPSTREAM SLUG VALVE,NORMAL OPENING,(220 MINUTES)-(GAMMA-1&2) ... 188

FIGURE ‎5-187: G3ST2HOLDUP TIME SERIES,UPSTREAM SLUG VALVE,NORMAL OPENING,(SLUGS)-(GAMMA-1&2) ... 189

FIGURE ‎5-188: G3ST2HOLDUP TIME SERIES,UPSTREAM SLUG VALVE,NORMAL OPENING,(WAVES)-(GAMMA-1&2) ... 189

FIGURE ‎5-189: G3ST2CROSS CORRELATION OF TWO GAMMAS –UPSTREAM SLUG VALVE,NORMAL OPENING ... 190

FIGURE ‎5-190: G3ST2HOLDUP TIME SERIES,DOWNSTREAM SLUG VALVE,NORMAL OPENING,(250 MINUTES)-(GAMMA-1&2) ... 191

FÎGURE‎5-191:G3ST2HOLDUP TIME SERIES,DÔWNSTREAMS^LUGVÂLVE,NÔRMALO^PENING,(50^MINUTES)-(GÂMMA-1&2) ... 191

FIGURE ‎5-194: G3ST2CROSS CORRELATION OF TWO GAMMAS –DOWNSTREAM SLUG VALVE,NORMAL OPENING ... 193

FIGURE ‎5-195: G3ST2DISTRIBUTION OF SLUG FREQUENCY –DOWNSTREAM SLUG VALVE,NORMAL OPENING ... 193

FIGURE ‎5-196: G3ST2DISTRIBUTION OF SLUG LENGTH (M)–DOWNSTREAM SLUG VALVE,NORMAL OPENING ... 194

FIGURE ‎5-197: G3ST2DISTRIBUTION OF SLUG LENGTH (NO. OF DIA.)–DOWNSTREAM SLUG VALVE,NORMAL OPENING ... 194

FIGURE ‎5-198: G3ST2HOLDUP TIME SERIES,DOWNSTREAM SLUG VALVE,RESTRICTED OPENING,(250 MINUTES)-(GAMMA-1&2) ... 195

FIGURE ‎5-199: G3ST2HOLDUP TIME SERIES,DOWNSTREAM SLUG VALVE,RESTRICTED OPENING,(60 MINUTES)-(GAMMA-1&2)... 196

FIGURE ‎5-202: G3ST2CROSS CORRELATION OF TWO GAMMAS –DOWNSTREAM SLUG VALVE,RESTRICTED OPENING ... 197

FIGURE ‎5-203: G3ST2DISTRIBUTION OF SLUG FREQUENCY –DOWNSTREAM SLUG VALVE,RESTRICTED OPENING ... 198

FIGURE ‎5-204: G3ST2DISTRIBUTION OF SLUG LENGTH (NO. OF DIA.)–DOWNSTREAM SLUG VALVE,RESTRICTED OPENING ... 198

FIGURE ‎5-205: G3ST2DISTRIBUTION OF SLUG LENGTH (METERS)–DOWNSTREAM SLUG VALVE,RESTRICTED OPENING ... 199

FÎGURE‎5-206:G3ST2OLGAHÔLDUPSÎMULATION–NÔN-S^LUGT^{RACKING VS}.HÔLDUPMEASUREMENT (U^PSTREAM) ... 200

FÎGURE‎5-207:G3ST2OLGAHÔLDUPSÎMULATION–NÔN-S^LUGT^{RACKING VS}.S^LUGT^RACKING(DC=50)–(U^PSTREAM) ... 201

FÎGURE‎5-208:G3ST2OLGAHÔLDUPSÎMULATION–NÔN-S^LUGT^{RACKING VS}.S^LUGT^RACKING(DC=150)–(U^PSTREAM) ... 201

FIGURE ‎5-209:G3ST2OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800)–(UPSTREAM) ... 202

FIGURE ‎5-210: G3ST2OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.HOLDUP MEASUREMENT –(DOWNSTREAM) ... 202

FIGURE ‎5-213:G3ST2OLGAHOLDUP SIMULATION –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800)–(DOWNSTREAM) .. 204

FIGURE ‎5-214:G3ST2OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.PRESSURE MEASUREMENTS ... 204

FIGURE ‎5-217:G3ST2OLGAPRESSURE RESULTS –NON-SLUG TRACKING VS.SLUG TRACKING (DC=500,800) ... 206

FIGURE ‎5-218: G3ST2PIPELINE SECTIONS –OLGAGRID OPTIONS (COARSE GRID) ... 206

FIGURE ‎5-219: G3ST2PIPELINE SECTIONS –(FINE GRID (5 METER)) ... 207

FIGURE ‎5-220:G3ST2OLGAHOLDUP SIMULATION –COARSE GRID VS.FINE GRID (UPSTREAM) ... 207

FÎGURE‎5-221:G3ST2OLGAHÔLDUPSÎMULATION–CÔARSEG^{RID VS}.FÎNEG^RID(DÔWNSTREAM) ... 208

FÎGURE‎5-222:G3ST2OLGAP^RESSURESÎMULATION–CÔARSEG^{RID VS}.FÎNEG^RID(DÔWNSTREAM) ... 208

FÎGURE‎5-223:G3ST2LÊDAF^LOWCÔARSEG^RID(^LEFT)ÂNDFÎNEG^RID(^RIGHT) ... 209

FÎGURE‎5-224:G3ST2LÊDAF^LOWP^RESSURERÊSULTS–S^LUGCAPTURING VS.NÔN-S^LUGCÂPTURINGSÎMULATION(CÔARSEG^RID) ... 210

FÎGURE‎5-225:G3ST2LÊDAF^LOWP^RESSURERÊSULTS–S^LUGCAPTURING VS.NÔN-S^LUGCÂPTURINGSÎMULATION(FÎNEG^RID) ... 210

FÎGURE‎5-226:G3ST2LÊDAF^LOWHÔLDUP–S^LUGCAPTURING VS.NÔN-S^LUGCÂPTURINGSÎMULATION(CÔARSEG^RID)(U^PSTREAM) .. 211

FIGURE ‎5-227:G3ST2LEDAFLOW HOLDUP –SLUG CAPTURING VS.NON-SLUG CAPTURING SIMULATION (FINE GRID)(UPSTREAM) ... 211