2009 S. Kenny, Ph.D., P.Eng. Lecture Goals. Historical Overview. Students will be able to: Lecture 18 Pipeline Installation

Transcription

1 Lecture 18 Pipeline Installation Shawn Kenny, Ph.D., P.Eng. Assistant Professor Faculty of Engineering and Applied Science Memorial University of Newfoundland Lecture Goals Students will be able to: understand various methods to install offshore pipeline systems. 2 Timeline World War II 1940 s and 1950 s Gulf of Mexico Late 1960 s North Sea Early performance Mechanical breakdowns Weather downtime Technology Advancement Forties pipeline lay vessels in 2 seasons lay vessel 3 months Historical Overview Ref: CombinedOps (2005) 3 1

2 Construction Envelope 4 Pipe Lay Assessment Overall performance Flexibility Efficiency Limited onshore logistics/support Capital construction cost Expensive to mobilize 5 Normal Lay 10 m tolerance Monitored Lay Pipeline crossing Lateral separation Installation Notes Boulder fields, geohazards 2.5 m tolerance 6 2

3 Installation Notes Boulder Obstruction Clearance Laid on seabed 15 m corridor Trenched 20 m corridor Sweeping < 0.5 m diameter Grappling 0.5 m to 1.2 m diameter Monitored lay > 1.2 m diameter 7 Work Scope Pre-sweeping Trenching Rock dumping Span correction Intervention 8 Techniques Surface, near surface Controlled depth, middepth Near-bottom, bottom traints Wave/current load, fatigue Stability, flotation units Applied tension Coating systems 9 Tow Methods 3

4 Tow Methods (cont.) Onshore fabrication Integrity qualification No practical configuration limit Shoreline acreage Subsea infrastructure Weather window 10 Alternate Methods Ref: Beaujean (2004) 11 Spread Ref: Duke Energy Ref: Saipem 12 4

5 S-Lay Construction Vessel Characteristics 2nd generation Box-hull, ship-shape (>40) 3rd generation Anchored semi-submersible (~4) 4th generation Dynamic positioning (~2) Shallow water installation (~15m to < 300m) Deeper water installation Stinger length, departure angle, wave motion High tension, potential coating damage, positioning Ref: MMS (2001) 13 J-Lay Construction Vessel Characteristics Dynamic positioning Semi-submersible or ship shaped (~6) Near vertical departure Tension at sagbend, reduced wave motions, no stinger Precise installation Deeper water (> 300m) Mass distribution, vessel stability Line-up, welding, field joints (multiple joints) Ref: MMS (2001) 14 Lay Vessel Positioning Anchor Vessels Simplicity, cost, and reliability No complex systems Mooring lines, anchor handing vessels Anchor dragging, impact and relocation Positioning (particularly in deep water) Interaction with seabed obstacles 15 5

6 Lay Vessel Positioning (cont.) Dynamic Positioning Positioning and maneuverability Water depth independent Complex systems System reliability, redundancy Potential damage following pipeline buckling Fuel costs Underwater hazards 16 2 nd Generation S-Lay SaipemCastoro nd Generation S-Lay SaipemCastoro

7 3 rd Generation S-Lay SaipemCastoro rd Generation S-Lay SaipemCastoro th Generation S-Lay Allseas Solitaire Ref: Allseas 21 7

8 J-Lay Saipem Heerema Balder 23 Reel Lay Vessels Timeline 1960 s Gulf of Mexico Configuration Horizontal l& vertical reel Rigid/flexible flowlines, pipelines, bundles, umbilicals Fast lay rates (1-3km/hr) Concrete coating Lay vessel &wall thickness selection Pipeline diameter limits on spool length, logistics ~75km of 4 OD versus ~10km 16 OD Cold working 24 8

9 Reel Lay Torch Midnight Wrangler CSO Deep Blue 25 References eni it/index asp Beaujean, S. (2004). Pipeline exposed. World Pipelines,4(4), pp CombinedOps (2005). MMS (2001). Overview of Gulf of Mexico OCS Oil and Gas Pipelines: Installation, Potential Impacts, and Mitigation Measures. MMS , 16p. Ley, T. (2005). Going with the flow. World Pipelines,5(4), pp [2005 5(4) FlowLay.pdf] 26 9