SUMMARY - PIPELINE DESIGN REQUIREMENTS Flow Assurance Issues ( Module 1) Strength y Hydraulics – incl. Two-Phase Flow y Stability – Laying y Welding y Installation – Laying y Towing y Trenching y Upheaval Buckling y Corrosion
Multiphase Flow in Flowlines
Installation
Further Aspects to considers : y Inspection y Monitoring y Intervention y Repair y Abandonment Inspection
PIPELINE / FLOWLINE ROUTE SURVEY y DESIGN y CONSTRUCTION y AS-BUILT y OPERATIONAL
MALAMPAYA Gas Field Pipeline Route
Seabed Bathemetry
Side scan sonar and sub-seabed profiling for route planning
LORELAY PIPELAY VESSEL
BALDER
6 × 12m pipe welded on deck and lifted to “j” lay tower.
In-line Sled welded into line
APACHE – REEL SHIP (Note now replaced by Apache 11)
Apache was the first self-propelled vessel ever built for laying pipe from a reel. It used a vertical reel, a concept first introduced by Santa Fe at the 1975 Offshore Technology Conference. The vertical reel, with the adjustable stern ramp, allowed the lay angle to be increased or decreased depending on water depth and pipe properties. The preliminary design basis is for the laying of 16-inch, 12-inch, and smaller pipes in 800m of water. The reel has a certain capacity (See separate Table), but containing several 10’s of Km the pipe is normally laid in less than 24 hours.
APACHE REEL SHIP RANGE OF RAMP ANGLES 18 – 70 Degrees
MAIN REEL Pipe Dia Length 4” 100 Km 6” 64 Km 10” 24 Km 14” 12 Km 16” 6 Km
320 REEL Pipe Dia Length 2” 50 Km 4” 13 Km 6” 7 Km 200 REEL Pipe Dia Length 2”
19 Km
4”
6Km
COMPARISON OF PIPELAY VESSEL CAPABILITY ON A SINGLE REEL Pipeline diameter (ins) 18 16
DeepBlue
14
12
10
Skandi
8
6
Ugland Reel
Apache
4
Apache 11
Norlift 2
0 0
10
20
30
40
50
Length (km)
60
70
80
90
100
110
120
FLOWLINE BUNDLES
FLOWLINE BUNDLES
Bundles are welded under factory conditions, pre-formed into complete lengths and tested
The completed pipeline bundle is launched into sheltered waters of the bay, inspected and tested prior to towing out to the field
The drag on the chains during the tow causes the bundle to lift and “fly” through the water clear of the seabed
1. Towhead 2. Bundle 3. Tow off Beach
Final positioning of the bundle at the location is undertaken by winching the neutrally buoyant bundle to a predetermined point on the seabed prior to stabilising and tying in by divers or ROV’s
FLEXIBLE PIPE
BASIC PRODUCTION FROM STEEL TAPES AND EXTRUDED PLASTIC
FLEX INSTALLER VESSEL
LAYING FLEXIBLE PIPE
VERTICAL LAYING
HORIZONTAL LAYING
ANCHOR ACTION AN ARMOUR BACKFILL PROTECTION FOR OFFSHORE PIPELINES FULL PENETRATION FLUKE ANGLE CHANGES STANDARD 140 - 200 LB/FT3 CONCRETE PIPE LAYING ON SURFACE
HIGHER STRENGTH CONCRETE ARMOUR COATING STANDARD TYPE 1 BURIED
1
FLUKE REMOVED FROM BOTTOM
3
2
ANCHOR WALKS ON BACKFILL
STANDARD CONCRETE TYPE 1 WITH CONCRETE (SET ON) ARMOUR COVER
STANDARD CONCRETE TYPE 1 WITH ENGINEERED ARMOUR BACKFILL 4
EXTRA STEEL
5
SPECIAL REINFORCING ARMOUR CONCRETE
6 7
SHAPED ARMOURED SECTION B
HAZARD OF PIPE BEING HIT BY FISHING EQUIPMENT Fishing Trawler
Free Span Point of contact Trawl boards making contact with a pipeline span are less likely to come free when hitting at an angle FLAT OTTER BOARD
PIPELINE / FLOWLINE WITH FREE SPAN
FLEXJET 11 - Small Pipe Burial Vehicle
Pipe Tracker Location System
Pipe Drops to bottom of Trench Backfill Pre-Laid Pipe High Pressure Cutting Jets Fluidise soil Low Pressure Jets excavating soil away from jetting arms
