Project SHEET PowerGas - PGN Submarine Pipeline project Singapore / indonesia

Boskalis Offshore: skills, features singapore section resources, experience Client PowerGas Ltd Boskalis Offshore brings together the offshore skills, resources and experience of Royal Boskalis Location Singapore Port Westminster nv. The offshore capabilities of Period July 2001 - July 2003 Boskalis include rectification works for pipeline/cable and platform installation, Contractor Jan De Nul - Boskalis JV construction of pipeline shore approaches and landfalls, offshore mineral mining, offshore supply features indonesia section and support services and decommissioning Client PT Perusahaan Gas Negara services. Boskalis provides clients with tailored, (Persero), (PGN) project-specific for above dredge related offshore services, as illustrated by the following Location Pulau Batam project summary. Period July 2002 - July 2003

The PowerGas - PGN submarine Contractor Boskalis - IDROS JO pipeline The pipeline between Pulau Pemping, Indonesia, and Pulau Sakra, Singapore, is the final link of the transportation system for natural gas from onshore fields on South Sumatra to Singapore. The successful completion of the Engineering, Procurement and Construction contracts for the 27-kilometres 28-inch gas pipeline with a 96-core fibre optic cable in one of the busiest ports and shipping traffic zones of the world marked a milestone for Boskalis. The scope of work comprised not only seabed preparations and protective rock berm installation - Boskalis A B Offshore core activities - but also pipeline manufacturing and installation. A Location map Singapore B Location map Indonesia EPC scope of work C Landfall and shallow shore approach at The following comprehensive scope of work has Pulau Pemping, Indonesia been completed on a lump sum basis in two countries, with two clients and under three ‚‚ Design verification of both a rock berm (drop and drag of 22-tonnes different contracts: anchors in Singapore waters) and its filter layer (impact on cable of falling rock). ‚‚ Construction of two landfalls: a cofferdam ‚‚ Procurement of 2,150,000 tonnes of rock armour and filter material and and 200-metres pipe pull at Pulau Sakra and a installation over a length of 25 kilometres. in shallow with 700-metres pipe pull ‚‚ Hydro-testing, drying and precommissioning \ of pipeline system. at Pulau Pemping. ‚‚ Seabed preparation for pipe lay: trench Trench works dredging and seabed levelling. In Singapore waters the Marine Port Authority required a pipeline top level ‚‚ Procurement and installation of 28-inch below 28m-CD. A 8-kilometres long trench with depths up to 15 metres below concrete coated line pipe, grade X-70, and original seabed was dredged by the Trailing Suction Hopper Dredger “Queen 96-core double armoured fibre optic cable. of the Netherlands” and the Cutter Suction Dredger “Marco Polo”. This capital

C 01 — 2012 The information contained in this data sheet is for guidance purposes only and may be subject to changes. © Boskalis. All rights reserved. installation works.Pipelineengineersonboard “Cetus” toexecutethesepre-layrock mobilised theSideStoneDumpingVessel up to70metresandinstrongcurrents.Boskalis were installedalongtheroute,inwaterdepths the nearshoreareas.77pre-layrocksupports assisted by“Jerommeke”and“ZinkoonV”in the heavydutyGrabDredge“oomai”, carried outinwaterdepthsupto50metresby outcrops, sandwavesandclayhills,were Dredging works,involvingremovalofrock after detailedengineering. dredging androckplacementworksweredefined and stresses.Theoptimumrouteassociated required toavoidunacceptablepipelinespans Elimination ofirregularitiesalongtheroutewas Seabed levelling Dredgers “Jerommeke”and“ZinkoonV”. soils androck,werecarriedoutbytheBackhoe metres. Thesedredgingworks,invariouscohesive areas wherewaterdepthswerelessthan13 In Indonesiathepipelinehadtobetrenchedin and“BarentZanen”. “WD Fairway” executed bytheTrailing SuctionHopperDredgers rock. Lateronmaintenancedredgingwas material, including125,000cubicmetresfresh dredging involvedsome700,000cubicmetresof D E F Singapore /ndonesia PowerGas -GNSubmarineipelineproject ensured successfulcompletionintime. prevailing currentsupto3knotsandwaterdepths70metres, developed rockinstallationsoftwareenabledaccurateplacementin “Pompei”. Specialcurrentmeasurementsystemsandlinkedin-house “Zinkoon VI”and“Zeepaard”,SideStoneDumpingVessels “Cetus”and months. TherockinstallationspreadconsistedoftheFallPipeBarges More thantwomilliontonnesofrockwereinstalledinarecordtime4.5 rocks. for protectionofthefibreopticcableagainstdirectimpactfromlargerarmour optimised andtheapprovalcriteriawereset.Arockfilterlayerwasdesigned anchor havebeenverifiedbymodeltests.Basedthereonthedesignswere designsforprotectionagainstdropanddragofa22-tonnes The rockarmour Rock ArmourProtecion piggybacked withonlymanualhandling. were generatedtocomeupwiththesafestandmostefficientmethod: attention. Numerousinstallationmethodsandwaysofprotectingthecable fragilefibreopticcablewasgivenspecial The installationofthevery passing duringpipelay. crudecarrier lay bargeandMarineAdvisorstobeputonboardevery forthepipe anchorpatterns crossing methodstatementthatinvolvedshorter Very LargeCrudeCarriersbytheSingaporeMaritimeAcademyresultedina had tocrossthreebusytrafficlanes.A3D-simulationstudyonsafepassageof and barge DLB264.ThepipelinehadtobelaidinthebusySingaporePort The pipelayworksweresubcontractedtoGlobalIndustries,whoutilised Pipe andcablelay “Cetus” monitoredthequalityandprogress of the work. I H G F E grabDredger“Goomai”duringseabedlevelling D G I TSHD “Queenofthe Netherlands” Pipe laybargeatSingaporelandfall optic cable 28-inch pipelinewithpiggybacked96-core fibre Karimun rockstockpile SSDV “Cetus” in Indonesia H www.boskalis.com [email protected] F +317869555 T +317869000 The Netherlands 3350 AAPapendrecht PO Box43 Royal BoskalisWestminster N.V.