Abrasive Water Jet Cutting: Energy Resources Technology

A CASE STUDY

www.intermoor.com

AbstractInterMoor’s abrasive water jet cutting system has been used for decommissioning of offshore platforms in the Gulf of Mexico since 2003. In July 2009, InterMoor crews removed a Guardian Platform in 88 ft of water.

Site DetailsLocation: ST138

Distance: 115.2 miles south of New Orleans

Water Depth: 88 ft

Operating Barge: D-85

Crane Capacity: 500 tons

Platform Details

Platform Type: Guardian

Estimated Weight: 549 tons

Conductors: 13 3/8 in, 20 in, 30 in

Pin Piles: 2 each, 48 in

Caisson: 48 in diameter opening up to 60 in diameter at mudline

The Arrival

Upon arrival at South Timbalier Block 138, the topsides had been loaded onto the materials barge. InterMoor personnel were transferred to the barge and set up their equipment while the structural supports were removed and sea-fastened for transport. When the barge captain was ready to begin the cut, the crew and equipment were standing by.

Preparing for the Cut

Prior to deploying the tool, a sounding was taken. The pile needed to be cleaned to a depth of at least 16 ft below the mudline so that the cut could be made at the regulation depth of 15 ft below the mudline. Barge personnel deployed the airlift and began jetting out the pile.

As the pile was being jetted, InterMoor personnel pressure tested the tool to ensure the nozzle, hoses and pumps were functioning properly. In addition, they prepared the rigging to deploy to a depth of 103 ft from the pile top. Following the jetting, the depth of the sea floor within the pile was confirmed by another sounding.

Abrasive Water Jet Cutting: Energy Resources Technology

A CASE STUDY

www.intermoor.com

Deployment of the Tool

The rigging had been adjusted so that the tool came to a depth of 16 ft below the mudline and was lifted from the deck and lowered into the pile.

Recovery of Platform

Following the completion of the cuts, the crew asked if the cut could be verified by lifting on the pile. The piles had been severed and were recovered to the deck.

Once the piles, caisson and conductors had been secured to the materials barge, it was time for the InterMoor crew to depart the vessel via a crew boat. The personnel and equipment were off-loaded and returned to the dock.

When the stakes are high, InterMoor delivers quality services for your fixed platform decommissioning needs.

Mud removal from pipe

Pressure testing the system

Recovering the caisson to the deck

CATegoRy DAySCutting 2

Transit 1

ToTAL 3

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