Page 18 - Pipelines and Risers

Contents xv

12.2.3 Pipelay Reel Ships ....................................................................................................................... 183
12.2.4 Tow or Pull Vessels ..................................................................................................................... 184
12.3 Software OFFPIPE and Code Requirements ........................................................................................ 185
12.3.1 OFFPIPE .............................................................................................................
12.3.2 Code Requirements .....................................................................................
12.4 Physical Background for Installation ..................................................................
12.4.1 S-lay Method ...............................................................................................
12.4.2 Static Configuration ....................................................................................
12.4.3 Curvature in Sagbend ..................................................................................
12.4.4 Hydrostatic Pressure ....................................................................................
12.4.5 Curvature in Overbend ................................................................................................................. 192
12.4.6 Strain Concentration and Residual Strain .................................................................................... 193
12.4.7 Rigid Section in the Pipeline ........................................................................................................ 193
12.4.8 Dry weightlsubmerged weight ..................................................................................................... 194
12.4.9 Theoretical Aspects of Pipe Rotation ..............................................................................
12.4.10 Installation Behaviour of Pipe with Residual Curvature .......................................................... 201
12.5 Finite Element Analysis Procedure for Installation of In-line Valves .................................................. 204
12.5.1 Finding Static Configuration ........................................................................................................ 204
12.5.2 Pipeline Sliding on Stinger .............................................................................................. . 207
12.5.3 Installation of In-line Valve ......................................................................................................... 208
12.6 Two Medium Pipeline Design Concept ............................................................................................... 209
12.6.1 Introduction .................................................................................................................................. 209
12.6.2 Wall-thickness Design for Three Medium and Two Medium Pipelines ...........
12.6.3 Implication to Installation, Testing and Operation ............................................
12.6.4 Installing Free Flooding Pipelines ................................................................................................ 211
12.6.5 S-Lay vs . J-Lay ......................... .......................................................
12.6.6 Economic Implication ......................................................... ....................................... 215
12.7 References ................................................................................... ...........................

Chapter 13 Reliability-Based Strength Design of Pipelines 219
13 . 1 General ................................................................................................................................................. 219
13.2 Reliability-based Design ...................................................................................................................... 220
13.2.1 General ......................................................................................................................................... 220

13.3.2 Classification of Uncertainties ........
13.3.4 Determination of Statistical Values .............................................................................................. 223
13.4 Calibration of Safety Factors ............................................................................................................... 223
13.4.1 General ......................................................................................................................................... 223
13.4.2 Target Reliability Levels .............................................................................................................. 224
13.5 BucklingKollapse of Corroded Pipes .................................................................................................. 224
13.5.1 Buckling/Collapse ........................................................................................................................ 224
13.5.2 Analytical Capacity Equation ....................................................................................................... 225
13.5.3 Design Format .............................................................................................................................. 225
13.5.4 Limit-State Function ................. ............................................................. . 225
13.5.5 Calibration of Safety Factors ..... ........................................................................................... 226
13.6 Conclusions .......................................................................................................................................... 227
13.7 References ............. . 227