Chevron Gorgon Jansz

General information

ClientChevron Australia 
ProjectChevron Gorgon Jansz 
Year2012 – 2014  
LocationNorth West Shelf, offshore Western Australia 
VesselsLorelay, Solitaire, Calamity Jane 
Max. water depth2164 m (7100 ft)

Scope of work

  • Installation of 6 trunklines and 15 infield pipelines (totalling 659,769 m), with diameters ranging from 6-inch to 34-inch
  • Installation of various structures including 36 PLETs, 734 mattresses and 12 adjustable pipe supports
  • Trenching of more than 120 km of pipeline
  • Flooding, gauging and hydro testing of pipelines
  • Fabrication and installation of 11 buckle initiators

Project specials

  • Super scarp crossings (700 m free-hanging pipelines)
  • Structure installations
  • Fabrication of 11 buckle initiators to maximum allowable sea states (based on Solitaire  workability)
  • Very shallow water recovery of 34-inch pre-installed pipeline tails with Lorelay
  • Narrow tolerances on large PLET installations in deep water
  • Free span crossings (700 m free-hanging pipelines over the scarp); extremely challenging welding criteria
  • Extensive pipe supply chain from Malaysia to Dampier and onwards to vessels
  • Welding of corrosion-resistant alloy (CRA) lined pipe to high standards, including use of internal weld inspection tool
  • Laydown of the 30-inch pipeline in 1350 m of water depth with 50+ buoyancy modules

Pipe characteristics

136.0216.62512.0DNV SMLS 450
62.2746.62514.0DNV SMLS 450
28.8677.62522.5DNV SMLS 450
64.0898.62512.0DNV SMLS 450
62.3288.62513.5DNV SMLS 450
55.1068.62514.3DNV SMLS 450
28.8879.62521.0DNV SMLS 360
8.2082427.1+3.0DNV DSAW 450 + UNO 316L
0.1072427.1+3.0DNV DSAW 450 + UNO 625
0.0742444.3+3.0DNV DSAW 450 + UNO 316L
21.7702631.2+3.0DNV DSAW 450 + UNO 316L
1.2892631.7+3.0DNV DSAW 450 + UNO 625
40.2493034.2DNV DSAW 450
30.4473036.6DNV DSAW 450
0.6673056.9DNV DSAW 450
61.7333431.2DNV DSAW 450
57.6543438DNV DSAW 459