Page 74: of Offshore Engineer Magazine (Sep/Oct 2013)

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Custom-engineered hydrau- into multiple stages. Two types of lic power units (HPUs) were rams were custom-engineered for the job. The frst set of rams will raise built to operate the rams. They the platforms 38.5in. After the legs were designed with redun-

EPIC dancy (two engines, two fuel are pinned off, a second set of rams will be installed that will raise the tanks), so that they would still platforms to 106in. After pinning off be able to safely operate in the event of one total engine once again, the dual-rod rams will continue to raise the platforms to failure.

The deck-raising system was 159.5in.

designed with two different Project experience verifes the control modes, synchronous deck raising system is scalable to over 20,000 metric ton platform and manual. Synchronous is the primary mode and uses weights. In addition, use of multiple, split-sleeve extensions and dual-rod a computer system to send signals to the fow-control rams allows the raising of these large valves for all of the rams. platforms with a high level of opera-

Operators use computer moni- tional effciency and safety.

tors to observe all aspects of

As the probability of extreme waves the raising procedure includ- entering the deck increases with ing leg displacements, cylinder further subsidence, modifcations pressures, and hydraulic oil to facilities should be considered to temperatures. When in manual minimize future adverse effects of mode, operators adjust the fow compaction and subsidence. control valves for each leg.

John Greeves is the

The deck raising technology can be used on multi-platform com- multi-platform bridge-linked com- technical director plexes in a simultaneous and synchro- plex in Southeast Asia to counteract of the Versabar nized process. the subsidence that has occurred at Group of compa- the feld. Synchronized rams will nies. He has raise three platforms and their con- worked in the oil

Southeast Asia project necting bridges about 4m to restore a and gas industry

Versabar has provided engineering safe air gap. Because the current air for more than 20 and equipment for the raising of a gap does not provide enough clear- years, including 10 years for Shell

This GOM platform became unsafe due ance for installation of rams long international. He holds a PhD in to subsidence (left). The jacking system enough to perform the entire lift, the civil/structural engineering and is a (above) raised the deck 14ft to create a process needed to be broken down UK-registered chartered engineer.

safe air gap (right). All photos: Versabar.

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