Page 21 - Pipelines and Risers

XVIII Contents

17.4.3 Mechanical Cutters ....................................................................................................................... 319
17.5 Flowline Rockdumping ........................................................................................................................ 319
1 7.5.1 Side Dumping .............................................................................................................................. 322
17.5.2 Fall Pipe ....................................................................................................................................... 322
17.5.3 Bottom Dropping ......................................................................................................................... 322
17.6 Equipment Dayrates ............................................................................................................................. 323
17.7 References ............................................................................................................................................ 323

Chapter IS Pipeline Inspection, Maintenance and Repair 325
18.1 Operations ............................................................................................................................................ 325
18.1 . 1 Operating Philosophy .......... .................................................................................................... 325
18.1.2 Pipeline Security .......................................................................................................................... 325
18.1.3 Operational Pigging ..................................................................................................................... 327
18.1.4 Pipeline Shutdown ....................................................................................................................... 329
18.1.5 Pipeline Depressurization ............................................................................................................. 330
18.2 Inspection by Intelligent Pigging ......................................................................................................... 330
18.2.1 General ......................................................................................................................................... 330
18.2.2 Metal Loss Inspection Techniques ............................................................................................... 331
18.2.3 Intelligent Pigs for Purposes other than Metal Loss Detection .................................................... 338
18.3 Maintenance ......................................................................................................................................... 340
18.3.1 General ......................................................................................................................................... 340
18.3.2 Pipeline Valves ............................................................................................................................ 341
18.3.3 Pig Traps ...................................................................................................................................... 341
18.3.4 Pipeline Location Markers ........................................................................................................... 341
18.4 Pipeline Repair Methods ...................................................................................................................... 342
18.4.1 Conventional Repair Methods ...................................................................................................... 342
18.4.2 General Maintenance Repair ........................................................................................................ 343
18.5 Deepwater Pipeline Repair ................................................................................................................... 350
18.5.1 General ......................................................................................................................................... 350
18.5.2 Diverless Repair- Research and Development ............................................................................. 350
18.5.3 Deepwater Pipeline Repair Philosophy ........................................................................................ 351
18.6 References ............................................................................................................................................ 352
Chapter 19 Use of High Strength Steel 353

19.1 Review of Usage of High Strength Steel Linepipes ............................................................................. 353
19.1.1 Usage ofX7O Linepipe ................................................................................................................ 353
19.1.2 Usage ofX80 Linepipe ................................................................................................................ 357
19.1.3 Grades Above X80 ....................................................................................................................... 362
19.2 Potential Benefits and Disadvantages of High Strength Steel .............................................................. 367
19.2.1 Potential Benefits of High Strength Steels ................................................................................... 367
19.2.2 Potential Disadvantages of High Strength Steels ......................................................................... 369
19.3 Welding of High Strength Linepipe ..................................................................................................... 371
19.3.1 Applicability of Standard Welding Techniques ........................................................................... 371
19.3.2 Field Welding Project Experience ............................................................................................... 373
19.4 Cathodic Protection .............................................................................................................................. 374
19.5 Fatigue and Fracture of High Strength Steel ........................................................................................ 375
19.6 Material Property Requirements .......................................................................................................... 376
19.6.1 General ......................................................................................................................................... 376
19.6.2 Material Property Requirement in Circumferential Direction ...................................................... 376
19.6.3 Material Property Requirement in Longitudinal Direction .......................................................... 377
19.6.4 Comparisons of Material Properly Requirements ........................................................................ 377
19.7 References ............................................................................................................................................ 379