Page 20 - Pipelines and Risers

Contents XVlI

16.1.2 Risk Analysis Objectives ......................................................................................................... 277
16.1.3 Risk Analysis Concepts ........................................................................................................... 278
16.2 Acceptance Criteria .............................................................................................................................. 279
16.2.1 General .............................................................................................................................
16.2.2 Individual Risk ........................................................................................................................ 280
16.2.3 Societal Risk ............................................................................................................................ 280
16.2.4 Environmental Risk ................................................................................................................. 281
16.2.5 Financial Risks ........................................................................................................................ 282
16.3 Identification of Initiating Events ........................................................................................................ 283
16.4 Cause Analysis ..................................................................................................................................... 283
16.4.1 General ..............................................................................................................
16.4.2 Fault Tree Analysis ................................................................................................................. 284
16.4.3 Event Tree Analysis ................................................................................................................ 284
Events ............................................................................................................ 284
....................................................................................................................... 284
....................................................................................................................... 285
16.6 Causes of Risks .................................................................................................................................... 287
16.6.1 General .................................................................................................................................... 287
16.6.2 1" Party Individual Risk .......................................................................................................... 287
16.6.3 Societal, Environmental and Material Loss Risk .................................................................... 288
16.7 Consequence Analysis ......................................................................................................................... 288
16.7.1 Consequence Modeling ........................................................................................................... 288
16.7.2 1 *' Party Individual and Societal Risk ...................................................................................... 291
16.7.3 Environmental Risks ............................................................................................................... 291
16.7.4 Material Loss Risk ................................................................................................................... 291
16.8 Example 1: Risk analysis for a Subsea Gas Pipeline ........................................................................... 292
I 6.8.1 General .................................................................................................................................... 292
16.8.2 Gas Releases ............................................................................................................................ 292
16.8.3 Individual Risk ........................................................................................................................ 294
16.8.4 Societal Risk ............................................................................................................................ 295
16.8.5 Environmental Risk ................................................................................................................. 297
16.8.6 Risk of Material Loss .............................................................................................................. 297
16.8.7 Risk Estimation ....................................................................................................................... 298
16.9 Example 2: Dropped Object Risk Analysis .......................................................................................... 298
16.9.1 General .................................................................................................................................... 298
16.9.2 Acceptable Risk Levels ..............................................................................
16.9.3 Quantitative Cause Analysis .......................................................................
16.9.4 Results ........................................................................... ................................... 301
16.9.5 Consequence Analysis ................................................... .................................................. 302
16.10 References ......................... ................................................................................................. 303
Chapter 17 Route Optimization, Tie-in and Protection 305
17.1 Introduction .......................................................................................................................................... 305
17.2 Pipeline Routing ....................................................................................... .................................... 305
17.2.1 General Principle .............................................................................. .................................... 305
17.2.2 Fabrication. Installation and Operational Cost Considerations ........................................
17.2.3 Route Optimization ..........................................................................................................
17.3 Pipeline Tie-ins ................................................ ........................................................................... 307
17.3.1 Spoolpieces .................................................................................................................................. 307
17.3.2 Lateral Pull ................................................................................................................................... 309
17.3.3 J-Tube Pull-In .............................................................................................................................. 310
17.3.4 Connect and Lay Away .....................................................................................................
17.3.5 Stalk-on ........................................................................................................................................ 315
17.4 Flowline TrenchinglBurying . .......................................................................... 315
17.4.1 Jet Sled ......................................................................................................................................... 315
17.4.2 Ploughing ............ ................................................................................................................... 317