DRILLING FOR TIMEPartnership approach leads to faster rig turnaround

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At the end of 2013 Bas Loohuis, Offshore Conversion Group Commercial Manager at Damen

Shiprepair, heard of a project to upgrade a drilling rig owned by Rowan Companies.

The rig was the Rowan Viking which, at 124 meters long by 95 meters wide and 170 meters high,

is one of the largest jack-up drilling rigs in the North Sea.

This novel idea combined two approaches that areused regularly. The first approach is to place thecrane on the platform itself, and to use prefab legextensions held in place by the crane while they arewelded onto the top of the existing legs. The secondapproach is to place the crane on the quay side andto lengthen the rig’s legs by stick building extensionsonto them. The method suggested by Bas was tocarry out the leg extension work using prefabextensions with a large crane on the quay sideinstead with a smaller crane on the platform. Thiswould free up the platform for the other modificationsto take place at the same time.

The whole suggestion raised a few eyebrows butalso offered to save 30 days of turnaround time.

Bas visited the Aberdeen offices of Rowan Compa niesto discuss the upgrade and how Damen might beable to assist. The main work required was a legextension, increasing the platform’s leg height from170 meters to 180 meters. There was also a five yearperiodic survey scheduled in order to comply withNorwegian law as well as some other modifications.

The best of both worldsThere were other companies interested in the projectwith more experience in such rig upgrades thanDamen, but Bas had an idea that caught Rowan’sattention. He suggested the extensions could becarried out by using a large crane on the quay side,rather than the usual way using a crane on theplatform deck.

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The whole suggestion raised a feweyebrows but also offered to savearound 30 days of turnaround time.

A time saving of this magnitude was particularlyappealing to Rowan as they were working to a firmdeadline.

Planning with partnersThis approach had never been tried before; Basneeded to convince Rowan that Damen couldcombine the best of both worlds – the stick built andmodular extension approaches – to deliver a majortime saving. He sat down with Mammoet andanother company Palfinger to see if they could worktogether to come up with a proposal. Theyconcluded that it could be done by combining theirequipment and expertise: a Mammoet PTC 35 craneto lift the modules and Palfinger’s JUMP system– ajack-up maintenance platform from which the

MAMMOET METHOD (100 DAYS):The drilling rig arrives at the dock.The PTC 35 is assembled on the quay side while initialactivities take place at the platform.Modular leg extensions are lifted and held in place bythe PTC 35. Between lifts other activities can continueon the platform.

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CONVENTIONAL METHOD (130 DAYS):Drilling rig arrives at the dock.The drilling rig platform is cleared.A crane is assembled on the platform. The leg extensionsare placed beside the craneThe platform is raised to enable the crane to reach the topof the legs and hold the leg extension at place.Once the legs are extended the platform is lowered andthe crane removed.Platform equipment is reinstalled and other activitiescan resume.

engineers could safely reach the working area onthe legs.

The quality of the partnership and thoroughness ofthe plan won Rowan over and convinced them thatthis new approach would save them a considerableamount of time.

The plan comes togetherIn order to actually carry out their plan the threecompanies quickly swung into action. The 200meter high PTC 35 was assembled, ready toperform its quay side lifts and by the end of May2014 the first leg extension was hoisted up to aheight of 170 meters. It was then carefullypositioned, with centimeter precision, onto the firstleg. For two days the crane held the extension inposition while it was fastened and welded onto theleg by engineers working safely on the elevatedJUMP maintenance platform.

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This process was repeated for the other two legs.Once the leg extension was complete, the cranewas swiftly disassembled and packed intocontainers, ready to head off on its next adventure.The three companies’ teamwork ensured the focuson safety was maintained throughout: the legextension process passed off with no lost timeincidents.

Partnership working was a key part of the successof the project as Bas explained: “The only way thatDamen could successfully fulfill all the requirementsof the contract was through good and closecooperation with our partners. It was an absoluteteam effort that helped to get the Rowan Viking upand running so quickly – an important achievementfor our customer, given that these types of rigscommand considerable daily rates, running to sixdigit figures.” n

Bolt from the blueThere are some factors you simply

cannot control; like the weather.

During the project a storm hit the

quayside one evening and the

PTC 35 was struck by lightning.

Despite the power and energy of

the bolt the PTC 35 was ready for

action, after some necessary safety

checks, and the project continued

as planned the following day.

5FACTS ABOUTLIGHTNING

1 BILLION VOLTSThe amount of electricitya lightning bolt can contain

20,000 °CHotter than thesurface of the sun

3 MILESThe average length

of a bolt

3 CENTIMETERSThe approximatewidth of a bolt

100 PER SECONDThe frequency of lightning

hitting the earth