Project Data Sheet

PO Box 43, 3350 AA Papendrecht, The NetherlandsTelephone +31 (0)78 69 69 000, telefax +31 (0)78 69 69 555e-mail royal@boskalis.nl, internet www.boskalis.com

INTRODUCTION - BOSKALIS OFFSHORE:SKILLS, RESOURCES, EXPERIENCEBoskalis Offshore brings together the offshore skills,resources and experience of Royal BoskalisWestminster.The group’s offshore capabilities include seabedrectification works for pipeline/cable and platforminstallation, construction of pipeline shore approachesand landfalls, offshore mineral mining, offshore supplyand support services and decommissioning services.Boskalis provides clients with tailored, project-specificsolutions for above dredge related offshore services,as illustrated by the following project summary.

PROJECT DESCRIPTION

The existing live 28” East Java Gas Pipeline runs off-shore from the Kangean Block, close to PagerunganBesar Island, Kangean Islands, Indonesia, through theMadura Strait and onshore via Porong to Surabaya,Indonesia’s second largest city.

East Java Gas Pipeline

Free Span Rectification Project

During a survey campaign in 2006 initiated by theowners of the East Java Gas Pipeline, PT. PertaminaGas and PT. Trans Javagas Pipeline, a large number ofcritical spans were identified, many of which above thethreshold for vortex induced vibrations. BoskalisOffshore, through its Indonesian entity PT. BoskalisInternational Indonesia, was contracted to rectify799 critical spans by means of installing a total of804 rock berms.These berms reduce span lengths and prevent thatthe critical span length will be exceeded within theremaining lifetime of the pipeline.

SAFETY, HEALTH AND ENVIRONMENT

During the preparation phase, a great deal of attentionwas paid to Safety, Health and Environment.Subcontractors were stimulated to assess theiroperations and to carry them out in a safe way, whichcan be illustrated with the following examples. Therock on the trucks was covered during road transportto prevent rock from falling off, drivers worked in shiftsto ensure that enough rest was taken, flagmen wereemployed at busy intersections, sufficient lightingwas ensured and key personnel had to be able tocommunicate in English.

Regular meetings were held to discuss identified risksand proposed mitigation measures, toolbox meetingswere held to emphasize safe operations and at all

a): The DPFV Seahorse

moors for loading.

b): Location map.

c): First stage rock

production by means of

blasting at the Hocim

quarry.

d): Second stage rock

production by means of

crushing at the Holcim

quarry.

The information contained in this data sheet is for guidance purposes only and may be subject to changes. © Boskalis. All rights reserved.

a)

Client: PT. Pertamina GasLocation: Madura Strait, East Java,

IndonesiaPeriod: October - December 2008Contractor: PT. Boskalis International

Indonesia / Boskalis Offshore

b)

c)

d)

times operations were supervised by the ProjectManagement Team.

A good follow-up of these preparations and excellentcooperation between subcontractors, suppliers andBoskalis led to an incident free project execution.

SUPPORT BERM INSTALLATION

For the support berm installation works Boskalisdeployed its dynamically positioned fallpipe vessel(DPFV) Seahorse. This vessel, with a carrying capacityof 18,000 tons of rock, is able to position its fallpipedirectly above the live pipeline, meanwhile ensuringsufficient vertical clearance to compensate for currentand swell. The DP Class II capabilities of the vesselallow for accurate dumping with a minimum of lossesresulting in a short project execution time.

One load of 1-5” rock was brought from Norway andadditional loads were loaded in Indonesia. Rock wassupplied by a quarry operating in the inlands of EastJava, delivering rock via the road to a temporarystockpile at the port of Paiton. During loading the 1-5”rock was transported by truck from the temporarystockpile to the feeder and via a conveyor belt into theholds of the DPFV Seahorse. The entire temporarysupply chain for rock supply, from quarry to Seahorse,was purposely set up for the execution of this project.

Prior to commencement of the rock dumpingoperations, a pre-survey was carried out bySeahorse’s ROV, equipped with multibeamechosounders. This survey was used to identify thestart and end points of the free spans. Subsequently,the design per span location was prepared and theberms were installed. A post-survey was carried out toensure that the berms were installed as specified.When the results of the post-survey were satisfactory,the vessel moved to the next position.

IN-HOUSE ENGINEERING

Hydronamic, the engineering department withinthe Boskalis Group, provided project support,including preparation of the theoretical design, impactassessment for rock dumping on a live pipeline andreference rock stability calculations.

In addition, a design flowchart was prepared toguarantee maximum efficiency on the seeminglyendless number of span locations. As a result of thisand by the choice for a dynamically positioned fallpipevessel to install the support berms vessel time on sitewas minimized, obviously being very advantageouslyfor the client.

In total, the DPFV Seahorse rectified 799 spans byinstalling 804 berms, using 1-5” rock. The project wascompleted to client’s full satisfaction, on schedule andwithin budget.

Project Data Sheet

East Java Gas Pipeline (continued)

e): Overview complete

loading set-up at

Paiton jetty.

f): Continuous rock supply.

g): Final testing of the

loading bridge at the

temporary stockpile.

f)

e)

The information contained in this data sheet is for guidance purposes only and may be subject to changes. © Boskalis. All rights reserved.

g)

EP 10 / 2009