Heavy well intervention vessel punches above its weight

OCTOBER 14, 2015 — Ulstein Design and Solutions BV and German deep drilling systems specialist Herrenknecht Vertical GmbH are using this week’s Offshore Energy 2015 exhibition in Amsterdam to present a future oriented design for a heavy well intervention vessel.

Able to work in water depths up to 2,500 m (8,250 ft), the Ulstein DX105. This heavy well intervention vessel design featuring the HVG Terra Invader 750 drill tower.

The Herrenknecht equipment is fully integrated into a compact design, specifically aimed at cost efficiency in medium and heavy well intervention operations, claimed to punch well over its weight in terms drilling capabilities

A large, free work deck with direct access to the moonpool, allows the vessel to carry a large diversity of additional well equipment, such as:

• Coiled tubing equipment
• Wireline equipment
• Storage of multiple Xmas trees and other subsea equipment
• Cementing equipment and storage of extra drill pipes, risers and casings
• Well testing equipment
• Future well technologies

The HVG drill tower consist of an A-frame structure, allowing for easy access to the drill floor.

“By using an automated horizontal racking system, a light substructure could be realized, which in combination with the weight saving A-frame solution resulted in a lower CoG,” says Dennis Vollmar of Herrenknecht Vertical. “And that of course improves also the operational envelope of the vessel.”

“Over the last decade, deepwater drilling has taken off, meaning that in the near future these wells will need servicing and maintenance,” says Bram Lambregts, deputy director at Ulstein Design & Solutions B.V. “Its higher payloads and mobilization speed compared to semi-submersibles ensure that the Ulstein DX105 is less dependent on nearby infrastructures. This is of great importance for well intervention operations in remote areas and harsh environments, which is further enhanced by applying the proven Ulstein X-Bow to increase the operational window of the vessel.”

Main dimensions of the vessel are:

Loa 154.4 m

Lbp 148.2 m

Beam (molded) 29.4 m

Depth 11.2 m

Draft (operational) 7.5 m

Deadweight ca 13,000 t

Speed 15 kn

Installed power 6 x 4,200 kW

Positioning DP3

Free deck space 1,500 m2

Cargo hold 850 m2

Complement 100 persons