A newly developed freestanding drilling riser enables quicker disconnect in case of hurricane, saving costly downtime for deepwater wells.

It's hurricane season in the Gulf of Mexico, and it looks like a storm is headed directly toward your deepwater drilling operations. With conventional drilling risers, it will take 3 or 4 days to pull up all those riser joints, secure the rig and move the crew to safety. And if the storm veers off, you will lose 3 or 4 more days putting it back together again.
But with a Free-Standing Drilling Riser (FSDR) from Cameron, it will only take 12 hours to disconnect the riser (Figure 1). So when the storm veers away the day before it was expected to hit, you never even have to stop production. This can add up to more than US $1 million in savings in waters deeper than 6,000 ft (1,830 m).
A simpler version of the freestanding production riser Cameron developed for Placid Oil Co. and EEX, the FSDR has a disconnect point that is 300 ft to 600 ft (92 m to 183 m) below the water's surface. Variable buoyancy joints are installed just below the disconnect point, and these are filled with air to support the riser below it and its contents when a hurricane approaches. Shear rams at the top of the riser can cut the drillpipe once the air cans are filled, and the freestanding portion can survive hurricanes and loop currents up to 4 knots, even filled with 17 lb/gal mud.
Once the FSDR is installed, a smaller, less expensive drilling rig can be used to rejoin the top portion of the drilling riser to the freestanding part and continue drilling. This multivessel approach could save the operator considerable money, especially during batch drilling operations.
Free parking
A side benefit of the FSDR is the ability to "park" the riser over a dummy wellhead while performing other operations in the drilling vessel's moonpool, such as installing a subsea Christmas tree, doing a workover, or servicing the blowout preventer stack.

Comments