Subsea Pipeline and Risers by Yong Bai
Transcript of Subsea Pipeline and Risers by Yong Bai
SUBSEA PIPELINES AND RISERS
YONG BAI
and
QIANG BAI
2005
ELSEVIER
Amsterdam - Boston - Heidelberg - London - New York - OxfordParis - San Diego - San Francisco - Singapore - Sydney - Tokyo
TABLE OF CONTENTS
Foreword vForeword to "Pipelines and Risers" Book viiPreface ix
PART I: Mechanical Design
Chapter 1 Introduction 31.1 Introduction 31.2 Design Stages and Process 3
1.2.1 Design Stages 31.2.2 Design Process 6
1.3 Design Through Analysis (DTA) 91.4 Pipeline Design Analysis 11
1.4.1 General 111.4.2 Pipeline Stress Checks 111.4.3 Span Analysis 131.4.4 On-bottom Stability Analysis 141.4.5 Expansion Analysis 171.4.6 Buckling Analysis 171.4.7 Pipeline Installation 19
1.5 Pipeline Simulator 211.6 References 24
Chapter 2 Wall-thickness and Material Grade Selection 252.1 Introduction 25
2.1.1 General 252.1.2 Pipeline Design Codes 25
2.2 Material Grade Selection 262.2.1 General Principle 262.2.2 Fabrication, Installation and Operating Cost Considerations 272.2.3 Material Grade Optimization 28
2.3 Pressure Containment (hoop stress) Design 282.3.1 General 282.3.2 Hoop Stress Criterion of DNV (2000) 292.3.3 Hoop Stress Criterion of ABS (2000) 302.3.4 API RP1111 (1998) 31
2.4 Equivalent Stress Criterion 332.5 Hydrostatic Collapse 342.6 Wall Thickness and Length Design for Buckle Arresters 362.7 Buckle Arrester Spacing Design 372.8 References 39
Chapter 3 Buckling/Collapse of Deepwater Metallic Pipes 413.1 Introduction 413.2 Pipe Capacity under Single Load 42
3.2.1 General 423.2.2 External Pressure 433.2.3 Bending Moment Capacity 463.2.4 Pure Bending 483.2.5 Pure Internal Pressure 483.2.6 Pure Tension 483.2.7 Pure Compression 48
3.3 Pipe Capacity under Couple Load 493.3.1 Combined Pressure and Axial Force 493.3.2 Combined External Pressure and Bending 50
Contents
\xial Force and Bending 51:d Area in Compression 52the Fully Plastic Neutral Axis 53ment 54
5858
on versus Finite Element Results 59> Subjected to Single Loads 59i Subjected to Combined Loads 61
65d Strength Design 67
67/iceability Limit 68
: 69Equivalent Stress Criteria 69Criteria for Pipeline 69
ise 7074
ent 74Assessment 75
7777
nt Based on S-N Curves 77nt Based on Ae-N Curves 78
78eria 79train 79; Field Joints Due to Coatings 80
80
Design
eraction 8383
I 83Method 83
8485
Breakout Forces 86m 86
8788
iround Pipes 8989
• 8 9ions Used in the Wave Simulators 89
89:rested Waves 90crested Waves 91
9595
ig and Inertia Forces 95t Forces 99
100lalysis of In-situ Behavior 101
101: Element Model 102blems 102
Contents xiii
7.2.2 Dynamic Analysis Problems 1047.3 Steps in an Analysis and Choice of Analysis Procedure 105
7.3.1 The Static Analysis Procedure 1057.3.2 The Dynamic Analysis Procedure 106
7.4 Element Types Used in the Model 1067.5 Non-linearity and Seabed Model 108
7.5.1 Material Model 1087.5.2 Geometrical Non-linearity 1097.5.3 Boundary Conditions 1097.5.4 Seabed Model 109
7.6 Validation of the Finite Element Model 1097.7 Dynamic Buckling Analysis 1117.8 Cyclic In-place Behaviour during Shutdown Operations 1137.9 References 114
Chapter 8 Expansion, Axial Creeping, Upheaval/Lateral Buckling 1158.1 Introduction 1158.2 Expansion 115
8.2.1 General Principle 1158.2.2 Single Flowlines 116
8.3 Axial Creeping of Flowlines Caused by Soil Ratcheting 1178.3.1 General 1178.3.2 Cyclic Soil/Pipe Interaction Model 1178.3.3 Expansion of a "Long" Flowline with Free ends 1188.3.4 In-situ Expansion Behavior of the Creeping Flowlines 119
8.4 Upheaval Buckling 1208.4.1 General 1208.4.2 Analysis of Up-lifts 1208.4.3 Upheaval Movements 124
8.5 Lateral Buckling 1258.5.1 General 1258.5.2 Lateral Buckling of Straight Line on Flat Seabed 125
8.6 Interaction between Lateral and Upheaval Buckling 1268.7 References 128
Chapter 9 On-bottom Stability 1299.1 Introduction 1299.2 Force Balance: the Simplified Method 1299.3 Acceptance Criteria 130
9.3.1 Allowable Lateral Displacement 1309.3.2 Limit-state Strength Criteria 130
9.4 Special Purpose Program for Stability Analysis 1309.4.1 General 1309.4.2 PONDUS 1319.4.3 PIPE 133
9.5 Use of FE Analysis for Intervention Design 1339.5.1 Design Procedure 1339.5.2 Seabed Intervention 1339.5.3 Effect of Seabed Intervention 135
9.6 References 136Chapter 10 Vortex-induced Vibrations (VIV) and Fatigue 137
10.1 Introduction 13710.2 Free-span VIV Analysis Procedure 139
10.2.1 Structural Analysis 13910.2.2 Hydrodynamic Description , 13910.2.3 Soil Stiffness Analysis 14110.2.4 Vibration Amplitude and Stress Range Analysis 14310.2.5 Fatigue Model 143
10.3 Fatigue Design Criteria 14410.3.1 Accumulated Fatigue Damage 14410.3.2 S-N Curves 144
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10.4 Response Amplitude 14410.4.1 In-line VIV in Current Dominated Conditions 14410.4.2 Cross-flow VIV in Combined Wave and Current 147
10.5 Modal Analysis 14810.5.1 General 14810.5.2 Single Span Modal Analysis 14910.5.3 Multiple Span Modal Analysis 149
10.6 Example Cases 15010.6.1 General 15010.6.2 Fatigue Assessment 152
10.7 References 154Chapter 11 Force Model and Wave Fatigue 155
11.1 Introduction 15511.2 Fatigue Analysis 155
11.2.1 Fatigue of Free-spanning Pipelines 15511.2.2 Fatigue Damage Assessment Procedure 15811.2.3 Fatigue Damage Acceptance Criteria 15911.2.4 Fatigue Damage Calculated Using Time Domain Solution 15911.2.5 Fatigue Damage Calculated Using Frequency Domain Solution 160
11.3 Force Model 16111.3.2 Modal Analysis 16311.3.3 Time Domain Solution 16411.3.4 Frequency Domain Solution 168
11.4 Comparisons of Frequency Domain and Time Domain Approaches 17011.5 Conclusions and Recommendations 17111.6 References 172
Chapter 12 Trawl Impact, Pullover and Hooking Loads 17312.1 Introduction 17312.2 Trawl Gears 173
12.2.1 Basic Types of Trawl Gear 17312.2.2 Largest Trawl Gear in Present Use 174
12.3 Acceptance Criteria 17412.3.1 Acceptance Criteria for Impact Response Analyses 17412.3.2 Acceptance Criteria for Pullover Response Analyses 175
12.4 Impact Response Analysis 17512.4.1 General 17512.4.2 Methodology for Impact Response Analysis 17512.4.3 Steel Pipe and Coating Stiffness 17812.4.4 Trawl Board Stiffness, Mass and Hydrodynamic Added Mass 18112.4.5 Impact Response 183
12.5 Pullover Loads 18412.6 Finite Element Model for Pullover Response Analyses 186
12.6.1 General 18612.6.2 Finite Element Models 18612.6.3 Analysis Methodology 187
12.7 Case Study 18812.7.1 General 18812.7.2 Trawl Pull-over for Pipelines on an Uneven Seabed 188
12.8 References 194Chapter 13 Pipe-in-pipe and Bundle Systems 195
13.1 Introduction 19513.2 Pipe-in-pipe System 195
13.2.1 General 19513.2.2 Why Pipe-in-pipe Systems 19613.2.3 Configuration 19713.2.4 Structural Design and Analysis 19813.2.5 Wall-thickness Design and Material Selection 20013.2.6 Failure Modes 20113.2.7 Design Criteria 201
Contents xv
13.2.8 Insulation Considerations 20313.2.9 Fabrication and Field Joints 20313.2.10 Installation 204
13.3 Bundle System 20513.3.1 General 20513.3.2 Bundle Configurations 20613.3.3 Design Requirements for Bundle System 20613.3.4 Bundle Safety Class Definition 20713.3.5 Functional Requirement 20713.3.6 Insulation and Heat-up System 20813.3.7 Umbilicals in Bundle 20913.3.8 Design Loads 20913.3.9 Installation by CDTM 216
13.4 References 218Chapter 14 Seismic Design 219
14.1 Introduction 21914.2 Pipeline Seismic Design Guidelines 220
14.2.1 Seismic Design Methodology 22014.2.2 Seismic Level of Design 22314.2.3 Analysis Examples 223
14.3 Conclusions 22814.4 References 228
Chapter 15 Corrosion Prevention 22915.1 Introduction 22915.2 Fundamentals of Cathodic Protection 22915.3 Pipeline Coatings 231
15.3.1 Internal Coatings 23115.3.2 External Coatings 231
15.4 CP Design Parameters 23215.4.1 Design Life 23215.4.2 Current Density 23215.4.3 Coating Breakdown Factor 23415.4.4 Anode Material Performance 23515.4.5 Resistivity 23515.4.6 Anode Utilization Factor 235
15.5 Galvanic Anodes System Design 23615.5.1 Selection of Anodes Type 23615.5.2 CP Design Practice 23715.5.3 Anode Spacing Determination 23815.5.4 Commonly Used Galvanic Anodes 23815.5.5 Pipeline CP System Retrofit 23915.5.6 Internal Corrosion Inhibitors : 239
15.6 References 240Chapter 16 Asgard Flowlines Design Examples 241
16.1 Introduction 24116.2 Wall-thickness and Linepipe Material Selection 242
16.2.1 General 24216.2.2 Linepipe Material Selection 24216.2.3 Wall-thickness Design 242
16.3 Limit State Strength Criteria 24316.3.1 General 24316.3.2 Bursting Under Combined Loading 24316.3.3 Local Buckling/Collapse 24316.3.4 Fracture 24416.3.5 Low-cycle Fatigue 24416.3.6 Ratcheting 245
16.4 Installation and On-bottom Stability 24716.4.1 Installation Design 24716.4.2 On-bottom Stability 248
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16.5 Design for Global Buckling, Fishing Gear Loads and VIV 24916.5.1 General 24916.5.2 Global Buckling 25016.5.3 Trawlboard 25216.5.4 Vortex Induced Vibrations (VIV) 255
16.6 Asgard Transport Project 25816.7 References 258
PART III: Flow Assurance
Chapter 17 Subsea System Engineering 26317.1 Introduction 263
17.1.1 Flow Assurance Challenges 26317.1.2 Flow Assurance Concerns 264
17.2 Typical Flow Assurance Process 26517.2.1 General 26517.2.2 Fluid Characterization and Property Assessments 26517.2.3 Steady State Hydraulic and Thermal Performance Analyses 26817.2.4 Transient Hydraulic and Thermal Performances Analyses 268
17.3 System Design and Operability 27217.3.1 Well Start-up & Shut-in 27317.3.2 Flowline Blowdown 275
17.4 References 276Chapter 18 Hydraulics 277
18.1 Introduction 27718.2 Composition and Properties of Hydrocarbons 277
18.2.1 Hydrocarbons Composition 27718.2.2 Equation of State 27918.2.3 Hydrocarbons Properties 280
18.3 Emulsion 28218.3.1 General , 28218.3.2 Effect of Emulsion on Viscosity 28318.3.3 Prevention of Emulsion 285
18.4 Phase Behavior 28518.4.1 Black Oils 28618.4.2 Volatile Oils 28618.4.3 Condensate 28618.4.4 Wet Gases 28718.4.5 Dry Gases 28718.4.6 Computer Models ; 288
18.5 Hydrocarbon Flow 28918.5.1 General 28918.5.2 Single-phase Flow 29018.5.3 Multi-phase Flow 29518.5.4 Comparison of Two-phase Flow Correlations 298
18.6 Slugging and Liquid Handling 30218.6.1 General 30218.6.2 Hydrodynamic Slugging 30418.6.3 Terrain Slugging 30518.6.4 Start-up Slugging 30618.6.5 Pigging 30618.6.6 Slugging Prediction 30718.6.7 Slug Detection and Control Systems 30818.6.8 Slug Catcher Sizing 308
18.7 Pressure Surge 30818.7.1 Fundamentals of Pressure Surge 30818.7.2 When Is Pressure Surge Analysis Required? 309
18.8 Line Sizing 310
Contents xvii
18.8.1 Hydraulic Calculation 31018.8.2 Criteria 31118.8.3 Maximum Operating Velocities 31218.8.4 Minimum Operation Velocities 31318.8.5 Wells 31318.8.6 Gas Lift 314
18.9 References 315Chapter 19 Heat Transfer and Thermal Insulation 317
19.1 Introduction 31719.2 Heat Transfer Fundamentals 318
19.2.1 Heat Conduction 31819.2.2 Convection 32019.2.3 Buried Pipeline Heat Transfer 32319.2.4 Soil Thermal Conductivity 325
19.3 U-value 32619.3.1 Overall Heat Transfer Coefficient 32619.3.2 Achievable U-values 32919.3.3 U-value for Buried Pipe 330
19.4 Steady State Heat Transfer 33119.4.1 Temperature Prediction along Pipeline 33119.4.2 Steady State Insulation Performance 332
19.5 Transient Heat Transfer 33319.5.1 Cool Down 33419.5.2 Transient Insulation Performance 337
19.6 Thermal Management Strategy and Insulation 33819.6.1 External Insulation Coating System 34019.6.2 Pipe-in-pipe System 34419.6.3 Bundling 34619.6.4 Burial 34619.6.5 Direct Heating 34719.6.6 Hot Fluid Heating (Indirect Heating) 349
19.7 References 34919.8 Appendix: U-value and Cooldown Time Calculation Sheet 351
Chapter 20 Hydrates 35720.1 Introduction 35720.2 Physics and Phase Behavior 359
20.2.1 General 35920.2.2 Hydrate Formation and Dissociation 36020.2.3 Effects of Salt, MeOH, Gas Composition 36320.2.4 Mechanism of Hydrate Inhibition 365
20.3 Hydrate Prevention 36720.3.1 Thermodynamic Inhibitors 36820.3.2 Low-dosage Hydrate Inhibitors 36920.3.3 Low Pressure 36920.3.4 Water Removal 37020.3.5 Thermal Insulation 37020.3.6 Active Heating 370
20.4 Hydrate Remediation 37120.4.1 Depressurization 37220.4.2 Thermodynamic Inhibitors 37320.4.3 Active Heating 37320.4.4 Mechanical Methods 37420.4.5 Safety Considerations 374
20.5 Hydrate Control Design Philosophies 37420.5.1 Selection of Hydrate Control 37420.5.2 Cold Flow Technology 37820.5.3 Hydrates Control Design Process 37920.5.4 Hydrates Control Design and Operation Guideline 379
20.6 Recover of Thermodynamic Hydrate Inhibitors 380
xviii Contents
20.7 References 382Chapter 21 Wax and Asphaltenes 383
21.1 Introduction 38321.2 Wax 383
21.2.1 General 38321.2.2 Wax Formation 38421.2.3 Viscosity of Waxy Oil 38721.2.4 Gel Strength 38721.2.5 Wax Deposition 38721.2.6 Wax Deposition Prediction 388
21.3 Wax Management 38921.3.1 General 38921.3.2 Thermal Insulation 38921.3.3 Pigging 39021.3.4 Inhibitor Injection 390
21.4 Wax Remediation 39021.4.1 Wax Remediation Methods 39121.4.2 Assessment of Wax problem 39221.4.3 Wax Control Design Philosophies 392
21.5 Asphaltenes 39221.5.1 General 39221.5.2 Assessment of Asphaltene Problem 39321.5.3 Asphaltene Formation 39521.5.4 Asphaltene Deposition 396
21.6 Asphaltenes Control Design Philosophies 39621.7 References 398
PART IV: Riser EngineeringChapter 22 Design of Deepwater Risers 401
22.1 Description of a Riser System 40122.1.1 General 40122.1.2 System Descriptions 40122.1.3 Flexible Riser Global Configuration 40222.1.4 Component Descriptions 40422.1.5 Catenary and Top Tensioned Risers 406
22.2 Riser Analysis Tools 40722.3 Steel Catenary Riser for Deepwater Environments 408
22.3.1 Design Codes 40822.3.2 Analysis Parameters 40922.3.3 Soil-Riser Interaction 40922.3.4 Pipe Buckling Collapse under Extreme Conditions 41022.3.5 Vortex Induced Vibration Analysis 410
22.4 Stresses and Service Life of Flexible Pipes 41022.5 Drilling and Workover Risers 41122.6 References 411
Chapter 23 Design Codes for Risers and Subsea Systems 41323.1 Introduction 41323.2 Design Criteria for Deepwater Metallic Risers 414
23.2.1 Design Philosophy and Considerations 41423.2.2 Currently Used Design Criteria 41523.2.3 Ultimate Limit State Design Checks 415
23.3 Limit State Design Criteria 41523.3.1 Failure Modes and Limit States 41523.3.2 Acceptance Criteria 416
23.4 Loads, Load Effects and Load Cases 41623.4.1 Loads and Load Effects 41623.4.2 Definition of Load Cases 417
Contents xix
23.4.3 Load Factors 41723.5 Improving Design Codes and Guidelines 418
23.5.1 General 41823.5.2 Flexible Pipes 41823.5.3 Metallic Risers 421
23.6 Regulations and Standards for Subsea Production Systems 42123.7 References 422
Chapter 24 VIV and Wave Fatigue of Risers 42324.1 Introduction 42324.2 Fatigue Causes 423
24.2.1 Wave Fatigue 42324.2.2 VIV Induced Fatigue 425
24.3 Riser VIV Analysis and Suppression 42624.3.1 VIV Predictions 42624.3.2 Theoretical Background 42724.3.3 Riser VIV Analysis Software 42824.3.4 Vortex-induced Vibration Suppression Devices 42924.3.5 VIV Analysis Example 430
24.4 Riser Fatigue due to Vortex-induced Hull Motions (VIM) 43124.4.1 General 43124.4.2 VIM Amplitudes 43224.4.3 Riser Fatigue due to VIM 43324.4.4 VIM Stress Histograms 43424.4.5 Sensitivity Analysis 435
24.5 Challenges and Solutions for Fatigue Analysis 43524.6 Conclusions 43524.7 References 436
Chapter 25 Steel Catenary Risers 43725.1 Introduction 43725.2 SCR Technology Development History 43825.3 Material Selection, Wall-thickness Sizing, Source Services and Clap Pipe 439
25.3.1 Wall Thickness Sizing 43925.3.2 Sour Services and Clad Pipe 440
25.4 SCR Design Analysis 44025.4.1 Initial Design 44025.4.2 Strength and Fatigue Analysis 441
25.5 Welding Technology, S-N Curves and SCF for Welded Connections 44125.5.1 Welding Technology 44125.5.2 S-N Curves and SCF for Welded Connections 442
25.6 UT Inspections and ECA Criteria 44225.7 Flexjoints, Stressjoints and Pulltubes 444
25.7.1 Flexjoints 44425.7.2 Stressjoints 44525.7.3 Pulltubes 445
25.8 Strength Design Challenges and Solutions 44525.8.1 Strength Design Issues 44525.8.2 SCR Hang-off Tensions 44525.8.3 SCR Touchdown Zone Effective Compression 44625.8.4 SCR Touchdown Zone Stress 44625.8.5 Strength Design Solutions 446
25.9 Fatigue Design Challenges and Solutions 44625.9.1 Fatigue Issues 44625.9.2 VIV Design Challenges 44625.9.3 Fatigue Due to Hull Heave Motions and VIM 44725.9.4 Effect of Wall-thickness Tolerance on Submerged Weight and Fatigue 44725.9.5 Effect of Vessel Selection, Hang-off Angle, Riser Orientation 44725.9.6 Combined Frequency and Time Domain Analysis 44825.9.7 Touchdown Soil Effect 44825.9.8 Fatigue Design Solutions 448
xx Contents
25.10 Installation and Sensitivity Considerations 44925.10.1 Installation Considerations 44925.10.2 Sensitivity Analysis Considerations 449
25.11 Integrity Monitoring and Management Systems 45025.11.1 Monitoring Systems 45025.11.2 Integrity Management Using Monitored Data 450
25.12 References 450Chapter 26 Top Tensioned Risers 453
26.1 Introduction 45326.2 Top Tension Risers Systems 454
26.2.1 Configuration 45426.2.2 General Design Considerations 45726.2.3 Drilling Risers 458
26.3 TTR Riser Components 45826.3.1 General 45826.3.2 Dry Tree Riser Tensioner System 45826.3.3 Tie-back Connector 45926.3.4 Keel Joint 45926.3.5 Tapered Stress Joint 46126.3.6 Riser Joint Connectors 46126.3.7 Tension Joint & Ring 46326.3.8 Riser Joint in Splash Zone 46426.3.9 Flexible Jumper between Surface Tree and Deck-based Manifold 46426.3.10 Tubing/Casing Hanger 46426.3.11 Air Cans 46526.3.12 Distributed Buoyancy Foam 466
26.4 Modelling and Analysis of Top Tensioned Risers 46726.4.1 General ; 46726.4.2 Stack-up Model and Tension Requirement 46826.4.3 Composite Riser Section 46926.4.4 Vessel Boundary Conditions 47026.4.5 Soil Conditions 47026.4.6 Modelling of Riser Components 47126.4.7 Installation Analysis 474
26.5 Integrated Marine Monitoring System 47526.5.1 General 47526.5.2 IMMS System 47526.5.3 Use of the Monitored Data 476
26.6 References 476Chapter 27 Steel Tube Umbilical & Control Systems 477
27.1 Introduction 47727.1.1 General 47727.1.2 Feasibility Study 47827.1.3 Detailed Design and Installation 47927.1.4 Qualification Tests : 480
27.2 Control Systems 48027.2.1 General 48027.2.2 Control Systems 48027.2.3 Elements of Control System 48127.2.4 Umbilical Technological Challenges and Solutions 482
27.3 Cross-sectional Design of the Umbilical 48527.4 Steel Tube Design Capacity Verification 486
27.4.1 Pressure Containment 48627.4.2 Allowable Bending Radius 486
27.5 Extreme Wave Analysis 48727.6 Manufacturing Fatigue Analysis 488
27.6.1 Accumulated Plastic Strain 48827.6.2 Low Cycle Fatigue 489
27.7 ln-place Fatigue Analysis 489
Contents xxi
27.7.1 Selection of Seastate Data from Wave Scatter Diagram 49027.7.2 Analysis of Finite Element Static Model 49027.7.3 Umbilical Fatigue Analysis Calculations 49027.7.4 Simplified or Enhanced Approach 49127.7.5 Generation of Combined Stress History 49227.7.6 Rainflow Cycle Counting Procedure or Spectral Fatigue Analysis 49327.7.7 Incorporation of Mean Stress Effects in Histogram 493
27.8 Installation Analysis 49427.9 Required On-seabed Length for Stability 49527.10 References .- 495
Chapter 28 Flexible Risers and Flowlines 49728.1 Introduction 49728.2 Flexible Pipe Cross Section 497
28.2.1 Carcass 49928.2.2 Internal Polymer Sheath 50028.2.3 Pressure Armor 50028.2.4 Tensile Armor 50028.2.5 External Polymer Sheath 50128.2.6 Other Layers and Configurations 501
28.3 End Fitting and Annulus Venting Design 50128.3.1 End Fitting Design and Top Stiffener (or Bellmouth) 50128.3.2 Annulus Venting System 502
28.4 Flexible Riser Design : 50328.4.1 Design Analysis 50328.4.2 Riser System Interface Design 50428.4.3 Current Design Limitations 506
28.5 References 507Chapter 29 Hybrid Risers 509
29.1 Introduction 50929.2 General Description of Hybrid Risers 511
29.2.1 Riser Foundation 51129.2.2 Riser Base Spools 51229.2.3 Top and Bottom Transition Forging 51329.2.4 Riser Cross-section 51329.2.5 Buoyancy Tank 51329.2.6 Flexible Jumpers 514
29.3 Sizing of Hybrid Risers , 51429.3.1 Riser Cross-section 51429.3.2 Buoyancy Tanks 51529.3.3 Riser Foundation 51629.3.4 Flexible Jumpers 517
29.4 Preliminary Analysis 51829.5 Strength Analysis 51929.6 Fatigue Analysis 52029.7 Structural and Environmental Monitoring System 520
29.7.1 Riser Fatigue Monitoring Approach 52129.7.2 Structural Monitoring System 52129.7.3 Environmental Monitoring System 52229.7.4 Vessel Mooring and Position 523
29.8 References 523Chapter 30 Drilling Risers 525
30.1 introduction 52530.2 Floating Drilling Equipments 526
30.2.1 Completion and Workover (C/WO) Risers 52630.2.2 Diverter and Motion Compensating Equipment 53030.2.3 Choke and Kill Lines and Drill String 531
30.3 Key Components of Subsea Production Systems 53230.3.1 Subsea Wellhead Systems 53230.3.2 BOP 532
xxii Contents
30.3.3 Tree and Tubing Hanger System 53330.4 Riser Design Criteria 533
30.4.1 Operability Limits 53330.4.2 Component Capacities 534
30.5 Drilling Riser Analysis Model 53430.5.1 Drilling Riser Stack-up Model 53430.5.2 Vessel Motion Data 53530.5.3 Environmental Conditions 53530.5.4 Cyclic P-y Curves for Soil 536
30.6 Drilling Riser Analysis Methodology 53630.6.1 Running and Retrieve Analysis 53630.6.2 Operability Analysis 53930.6.3 Weak Point Analysis 54030.6.4 Drift-off Analysis 54130.6.5 VIV Analysis 54230.6.6 Wave Fatigue Analysis 54330.6.7 Hang-off Analysis 54330.6.8 Dual Operation Interference Analysis 54430.6.9 Contact Wear Analysis 54530.6.10 Recoil Analysis 546
30.7 References 547Chapter 31 Integrity Management of Flexibles and Umbilicals 549
31.1 Introduction 54931.2 Failure Statistics 55031.3 Risk Management Methodology 55231.4 Failure Drivers 552
31.4.1 Temperature 55231.4.2 Pressure 55331.4.3 Product Fluid Composition 55431.4.4 Service Loads 55431.4.5 Ancillary Components 555
31.5 Failure Modes 55531.5.1 Fatigue 55531.5.2 Corrosion 55531.5.3 Erosion 55631.5.4 Pipe Blockage or Flow Restriction 55631.5.5 Accidental Damage 556
31.6 Integrity Management Strategy 55631.6.1 Flexible Pipe Integrity Management System 55631.6.2 Installation Procedures 55831.6.3 Gas Diffusion Calculations 55831.6.4 Dropped Object Reporting/Deck Lifting & Handling Procedures 55831.6.5 Vessel Exclusion Zone 55831.6.6 Fatigue Life Re-analysis of Pipes 55831.6.7 High Integrity Pressure Protection System (HIPPS) 558
31.7 Inspection Measures 55831.7.1 General Visual Inspection (GVI) / Close Visual Inspection (CVI) 55831.7.2 Cathodic Protection Survey 559
31.8 Monitoring 55931.8.1 Inspection and Monitoring Systems 55931.8.2 Bore Fluid Parameter Monitoring 559
31.9 Testing and Analysis Measures 56031.9.1 Coupon Sampling and Analysis 56031.9.2 Vacuum Testing of Riser Annulus 56031.9.3 Radiography 560
31.10 Steel Tube Umbilical Risk Analysis and Integrity Management 56131.10.1 Risk Assessment 56131.10.2 Integrity Management Strategy 561
31.11 References 562
Contents xxiii
PART V: Welding and Installation
Chapter 32 Use of High Strength Steel 56532.1 Introduction 56532.2 Review of Usage of High Strength Steel Linepipes 565
32.2.1 Usage of X70 Linepipe 56532.2.2 Usage of X80 Linepipe Onshore 56832.2.3 Grades Above X80 572
32.3 Potential Benefits and Disadvantages of High Strength Steel 57232.3.1 Potential Benefits of High Strength Steels 57232.3.2 Potential Disadvantages of High Strength Steels 575
32.4 Welding of High Strength Linepipe 57632.4.1 Applicability of Standard Welding Techniques 57632.4.2 Field Welding Project Experience 578
32.5 Cathodic Protection 57932.6 Fatigue and Fracture of High Strength Steel 58032.7 Material Property Requirements 581
32.7.1 Material Property Requirement in Circumferential Direction 58132.7.2 Material Property Requirement in Longitudinal Direction 58132.7.3 Comparisons of Material Property Requirements 582
32.8 References 583Chapter 33 Welding and Defect Acceptance 585
33.1 Introduction 58533.2 Weld Repair Analysis 585
33.2.1 Allowable Excavation Lengths for Plastic Collapse 58633.2.2 Allowable Excavation Lengths Using Different Assessments 587
33.3 Allowable Excavation Length Assessment 58933.3.1 Description of Pipeline Being Installed 58933.3.2 Analysis Method 58933.3.3 Analysis Results 591
33.4 Conclusions 59333.5 References 595
Chapter 34 Installation Design 59734.1 Introduction 59734.2 Pipeline Installation Vessels 597
34.2.1 Pipelay Semi-submersibles 59834.2.2 Pipelay Ships and Barges 60234.2.3 Pipelay Reel Ships 60334.2.4 Tow or Pull Vessels 604
34.3 Software OFFPIPE and Code Requirements 60534.3.1 OFFPIPE 60534.3.2 Code Requirements 606
34.4 Physical Background for Installation 60634.4.1 S-lay Method 60634.4.2 Static Configuration 60834.4.3 Curvature in Sagbend 60834.4.4 Hydrostatic Pressure 61034.4.5 Curvature in Overbend 61234.4.6 Strain Concentration and Residual Strain 61234.4.7 Rigid Section in the Pipeline 61334.4.8 Dry Weight/Submerged Weight 61434.4.9 Theoretical Aspects of Pipe Rotation 61634.4.10 Installation Behaviour of Pipe with Residual Curvature 621
34.5 Finite Element Analysis Procedure for Installation of In-line Valves 62434.5.1 Finding Static Configuration 62434.5.2 Pipeline Sliding on Stinger 62634.5.3 Installation of In-line Valve 628
34.6 Two Medium Pipeline Design Concept 628
xxiv Contents
34.6.1 Introduction 62834.6.2 Wall-thickness Design for Three Medium and Two Medium Pipelines 62934.6.3 Implication to Installation, Testing and Operation 63034.6.4 Installing Free Flooding Pipelines 63134.6.5 S-lay vs. J-lay 63234.6.6 Economic Implication 634
34.7 References 636Chapter 35 Route Optimization, Tie-in and Protection 637
35.1 Introduction 63735.2 Pipeline Routing 637
35.2.1 General Principle 63735.2.2 Fabrication, Installation and Operational Cost Considerations 63835.2.3 Route Optimization 638
35.3 Pipeline Tie-ins 63935.3.1 Spoolpieces 63935.3.2 Lateral Pull 63935.3.3 J-tube Pull-in 64135.3.4 Connect and Lay Away 64235.3.5 Stalk-on 642
35.4 Flowline Trenching/Burying 64735.4.1 Jet Sled 64735.4.2 Ploughing 64935.4.3 Mechanical Cutters 649
35.5 Flowline Rockdumping 65335.5.1 Side Dumping 65335.5.2 Fall Pipe 65335.5.3 Bottom Dropping 653
35.6 Equipment Dayrates 65435.7 References 654
Chapter 36 Pipeline Inspection, Maintenance and Repair 65536.1 Operations 655
36.1.1 Operating Philosophy 65536.1.2 Pipeline Security 65536.1.3 Operational Pigging 65736.1.4 Pipeline Shutdown 66036.1.5 Pipeline Depressurization 660
36.2 Inspection by Intelligent Pigging 66136.2.1 General 66136.2.2 Metal Loss Inspection Techniques 66136.2.3 Intelligent Pigs for Purposes other than Metal Loss Detection 668
36.3 Maintenance 67036.3.1 General 67036.3.2 Pipeline Valves 67136.3.3 Pig Traps 67136.3.4 Pipeline Location Markers 671
36.4 Pipeline Repair Methods 67236.4.1 Conventional Repair Methods 67236.4.2 General Maintenance Repair 673
36.5 Deepwater Pipeline Repair 68036.5.1 General 68036.5.2 Diverless Repair Research and Development 68036.5.3 Deepwater Pipeline Repair Philosophy 681
36.6 References 682
PART VI: Integrity ManagementChapter 37 Reliability-based Strength Design of Pipelines 685
37.1 Introduction 685
Contents xxv
37.1.1 General 68537.1.2 Calculation of Failure Probability 685
37.2 Uncertainty Measures 68537.2.1 Selection of Distribution Functions 68637.2.2 Determination of Statistical Values 686
37.3 Calibration of Safety Factors 68637.3.1 General 68637.3.2 Target Reliability Levels 686
37.4 Reliability-based Determination of Corrosion Allowance 68737.4.1 General 68737.4.2 Reliability Model 68837.4.3 Design Examples 68937.4.4 Discussions 69437.4.5 Recommendations 695
37.5 References 695Chapter 38 Corroded Pipelines 697
38.1 Introduction 69738.2 Corrosion Defect Predictions 697
38.2.1 Corrosion Defect Inspection 69738.2.2 Corrosion Defect Growth 69838.2.3 CO2 Corrosion Defects 698
38.3 Remaining Strength of Corroded Pipe 70638.3.1 NG-18 Criterion 70738.3.2 B31G Criterion 70738.3.3 Evaluation of Existing Criteria 70938.3.4 Corrosion Mechanism 70938.3.5 Material Parameters 71238.3.6 Problems Excluded in the B31G Criteria 713
38.4 New Remaining Strength Criteria for Corroded Pipe 71438.4.1 Development of New Criteria 71438.4.2 Evaluation of New Criteria 717
38.5 Reliability-based Design 71738.5.1 Target Failure Probability 71738.5.2 Design Equation and Limit State Function 71838.5.3 Uncertainty 72038.5.4 Safety Level in the B31G Criteria 72138.5.5 Reliability-based Calibration 722
38.6 Re-qualification Example Applications 72338.6.1 Design Basis 72338.6.2 Condition Assessment 72638.6.3 Rehabilitation 731
38.7 References 731Chapter 39 Residual Strength of Dented Pipes with Cracks 733
39.1 Introduction 73339.2 Limit-state based Criteria for Dented Pipe 733
39.2.1 General 73339.2.2 Serviceability Limit-state (Out of Roundness) 73439.2.3 Bursting Criterion for Dented Pipes 73439.2.4 Fracture Criterion for Dented Pipes with Cracks 73539.2.5 Fatigue Criterion for Dented Pipes 73539.2.6 Moment Criterion for Buckling and Collapse of Dented Pipes 736
39.3 Fracture of Pipes with Longitudinal Cracks 73739.3.1 Failure Pressure of Pipes with Longitudinal Cracks 73739.3.2 Burst Pressure of Pipes Containing Combined Dent and Longitudinal Notch 73839.3.3 Burst Strength Criteria 742
39.4 Fracture of Pipes with Circumferential Cracks 74239.4.1 Fracture Condition and Critical Stress 74239.4.2 Material Toughness, Kmat 74339.4.3 Net Section Stress, an 743
xxvi Contents
39.4.4 Maximum Allowable Axial Stress 74339.5 Reliability-based Assessment 743
39.5.1 Design Formats vs. LSF 74339.5.2 Uncertainty Measure 744
39.6 Design Examples 74539.6.1 Case Description 74539.6.2 Parameter Measurements 74539.6.3 Reliability Assessments 74539.6.4 Sensitivity Study 748
39.7 References 749Chapter 40 Integrity Management of Subsea Systems 751
40.1 Introduction 75140.1.1 General 75140.1.2 Risk Analysis Objectives 75140.1.3 Risk Analysis Concepts 75140.1.4 Risk Based Inspection and Integrity Management (RBIM) 752
40.2 Acceptance Criteria 75340.2.1 General 75340.2.2 Risk of Individuals 75340.2.3 Societal Risk 75440.2.4 Environmental Risk 75440.2.5 Financial Risks 755
40.3 Identification of Initiating Events 75640.4 Cause Analysis 756
40.4.1 General 75640.4.2 Fault Tree Analysis 75640.4.3 Event Tree Analysis 757
40.5 Probability of Initiating Events 75740.5.1 General 75740.5.2 HOE Frequency 757
40.6 Causes of Risks 75940.6.1 General 75940.6.2 Is1 Party Individual Risk 76040.6.3 Societal, Environmental and Material Loss Risk 760
40.7 Failure Probability Estimation Based on Qualitative Review and Databases 76140.8 Failure Probability Estimation Based on Structural Reliability Methods 764
40.8.1 General 76440.8.2 Simplified Calculations of Reliability Index and Failure Probability 76440.8.3 Strength/Resistance Models 76540.8.4 Evaluation of Strength Uncertainties 765
40.9 Consequence Analysis 76640.9.1 Consequence Modeling 76640.9.2 Estimation of Failure Consequence 769
40.10 Example 1: Risk Analysis for a Subsea Gas Pipeline 77140.10.1 General 77140.10.2 Gas Releases 77140.10.3 Individual Risk 77340.10.4 Societal Risk 77440.10.5 Environmental Risk 77540.10.6 Risk of Material Loss 77540.10.7 Risk Estimation 776
40.11 Example 2: Dropped Object Risk Analysis 77740.11.1 General 77740.11.2 Acceptable Risk Levels 77740.11.3 Quantitative Cause Analysis 77740.11.4 Results 77940.11.5 Consequence Analysis 781
40.12 Example 3: Example Use of RBIM to Reduce Operation Costs 78140.12.1 General 781
Contents xxvii
40.12.2 Inspection Frequency for Corroded Pipelines 78140.12.3 Examples of Prioritising Tasks 784
40.13 References 785Chapter 41 LCC Modeling as a Decision Making Tool in Pipeline Design 787
41.1 Introduction 78741.1.1 General 78741.1.2 Probabilistic vs. Deterministic LCC Models 78741.1.3 Economic Value Analysis 788
41.2 Initial Cost 78941.2.1 General 78941.2.2 Management 79041.2.3 Design/Engineering Services 79141.2.4 Materials and Fabrication 79241.2.5 Marine Operations 79241.2.6 Operation 792
41.3 Financial Risk 79241.3.1 General 79241.3.2 Probability of Failure 79241.3.3 Consequence 793
41.4 Time Value of Money 79541.5 Fabrication Tolerance Example Using the Life-cycle Cost Model 795
41.5.1 General 79541.5.2 Background 79641.5.3 Step 1-Definition of Structure 79641.5.4 Step 2-Quality Aspect Considered 79641.5.5 Step 3-Failure Modes Considered 79641.5.6 Step 4-Limit State Equations 79641.5.7 Step 5- Definition of Parameters and Variables 79941.5.8 Step 6-Reliability Analysis 80241.5.9 Step 7-Cost of Consequence 80341.5.10 Step 8- Calculation of Expected Costs 80341.5.11 Step 9- Initial Cost 80441.5.12 Step 10-Comparison of Life-cycle Costs 804
41.6 On-Bottom Stability Example 80541.6.1 Introduction 80541.6.2 Step 1-Definition of System 80541.6.3 Step 2- Quality Aspects Considered 80541.6.4 Step 3- Failure Modes 80541.6.5 Step 4- Limit State Equations 80641.6.6 Step 5-Definition of Variables and Parameters 80641.6.7 Step 6- Reliability Analysis 80641.6.8 Step 7- Cost of Consequence 80641.6.9 Step 8- Expected Cost 80641.6.10 Step 9- Initial Cost 80741.6.11 Step 10- Comparison of Life-cycle Cost 807
41.7 References 807
SUBJECT INDEX 809