Page 28: of Offshore Engineer Magazine (Aug/Sep 2015)

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DEEPWATER INTERVENTION

Finding an

Already deployed off Brazil and West

Africa, Jerry Lee investigates a new way to alternative intervene on wells — from the drill pipe.

Animated picture of the ocean foor properties of Vallourec.

Image from Vallourec.

Photo from

DPR-2500m 5K System Stack-up at P-XXII rig (Brazil).

FMC Technologies.

could be an issue, the DPRIS can be delivered with resistance to

SSC, as well as other forms of corrosion-assisted cracking. The resistance is incorporated as part of the structure of the steel itself. “We use special chemical compositions of the steel and special processing,” says Michael Jellison, senior vice president of engineering, Grant Prideco, part of National Oilwell Varco (NOV) Wellbore Technologies.

Simply put, the drill pipe intervention system is a tube that is upset on the ends (a forging technique that thickens the wall at the tool joint) with highly specialized male and female connec- tions. The major difference between normal drill pipe and drill pipe intervention system is the incorporation of a high-pres- sure, gas-tight seal. “In general, DPRIS gives you access to the urbing the cost of already expensive offshore drilling well. It allows you to connect to the well and perform various and completions programs has to be the mindset of types of completions or intervention riser functions. It’s really a

C many oil and gas companies, especially after the oil means to get access to the well or to install critical components price plummeted. Companies must look into ways to mitigate on top of the well,” Jellison says. these costs. One possibility could be the deployment of drill Within one system, users have simultaneous access to a pipe riser intervention systems (DPRIS). completions and intervention system. DPRIS is applicable for

DPRIS is a completions workover riser system that uses use with Xmas trees with fragile studs, Xmas tree and tubing an adapter near the surface and pipe similar to drill pipe for hanger installation, retrieval, testing, hydrate disassociation, constructing a passage to the wellhead. The ruggedness and downhole valves maintenance, well test, sand removal, and robustness of the connection allow for numerous makeup and more, says Luiz Fonseca, service manager for subsea services at breakouts, while the threading profle results in fast-joint con- FMC Technologies. nection and fast tripping speed. “Furthermore, the systems are able to operate as early produc-

To allow the passage of tools, the inner diameter (ID) of the tion risers (EPR), providing a system that can perform long-term pipe is optimized. However, the outer diameter (OD) is main- well testing. In the past, this system represented the sole produc- tained, allowing the use of normal pipe handling equipment, tion system of one basin, working at a foating, drilling, produc- make and break procedures, and crew. Also, these intervention tion, storage and offoading (FDPSO) vessel,” Fonseca says.

systems are lighter than typical riser technologies, so they can With more than 50 systems operating around the world, be used by a larger range of platforms. The system’s character- DPRIS popularity is gaining momentum.

istics make the system convenient to deploy and cost-effcient The frst system was developed in the mid-1990s to fulfll due to the speed of connections makeup and breakout, which a request by Petrobras for a rugged system that could hand eliminates the need for additional crew and equipment. numerous makeups and breakouts. The results was the adapta- Moreover, in sour wells where sulfde stress cracking (SSC) tion of drill pipes for gas-tightness.

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