Page 88: of Offshore Engineer Magazine (Sep/Oct 2013)

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Subsea

Dive-support vessel,

Joanne Morrison, deploys the SHARC tool during plug and abandonment operations.

P&A costs slashed by new cutting tool

By Victor Schmidt platform topsides and related in-water special air mixes under saturation ecommissioning is on the rise structures removed, then the remain- conditions and working for extended and the cost to industry will ing support leg stubs are cut below periods at depth. They jet soils from be about US$80 billion over the mudline and extracted to leave an around the legs until the required

D the next 25 years to plug and abandon unobstructed seabed. depth is reached, cut the stubs, and more than 5,000 wells, clear fowlines, Fixed platforms are limited to con- then backfll the excavation after stub and remove related structures. Is there tinental shelf water depths with most removal. All this activity is done under a way to improve the decommission- structures in water depths less than the constant danger of potential burial ing process, increase effectiveness, 600ft. Standard operations to remove from sloughing slopes. A standard and improve worker safety? There are tubulars requires divers, breathing operation can take four to fve days many steps in the decom- to completely remove the missioning process and each stubs.

one will be scrutinized and To make better use of improved as decommission- divers, avoid slip-slope ing becomes routine. hazards, and reduce

Chet Morrison Contractors operational cost, CMC (CMC) has developed a piece developed a subsea of equipment that accom- hydraulic abrasive rotating plishes part of the process: cutter (SHARC) that can removing surface casing remove well strings and and embedded jacket legs. stubs without the need

Once wells are plugged, the for major soil removal. casings cut and pulled, and According to CMC, the tool can be positioned over the well or stub by divers or

During a cutting test onshore, remotely by ROV. The tool the SHARC tool was able to is inserted into the hollow cut through three cemented tube. It is then lowered to casing segments.

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