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LoI to classify two multi-activity jack-ups

Tuesday, 15 May 2018

Chinese yard China Merchants Heavy Industry (CMHI) has an order for two multi-activity jack-up offshore units from Dutch customer OOS Energy B.V. which is affiliated with Netherlands-based Overdulve Offshore Services (OOS) International.

Rendering of the multi-activity jack-up unit for OOS (Illustration: DNV GL)

CMHI has signed a letter of intent for classification of the units with DNV GL. The 96m-long, 4-legged, self-elevating multi-activity units (MAUs) will mainly be used in decommissioning of other offshore oil and gas field platforms. Construction is scheduled to start later this year. For OOS Energy, these will be the first of the company’s units to be classed by DNV GL. The MAUs will also be equipped for light drilling operations to close wells. In addition, they can deconstruct the top side of an oil rig’s structure, and remove the jacket structure which goes right down to the sea floor. Two cranes will be fitted, one with a maximum hook height of 92m and one with a maximum hook height of 122m above deck. The cranes will have a combined lifting capacity of about 2,400 tonnes and can work in tandem to dismantle decommissioned offshore structures.
The cranes can lift parts onto the MAU’s own deck, enabling the vessel to transport them back to shore. The unit is also equipped to install next generation wind turbines. The MAUs will be able to operate in 55m water depth in harsh conditions such as those found in the North Sea. In calmer waters the units can operate in 80m of water depth.
The units will be self-propelled by four steerable thrusters, and are also equipped with a dynamic positioning system (DP2 system), ensuring safe positioning near the platform. Four dual-fuel main generators, located in two separate engine rooms, provide power for propulsion, cranes, the drilling package and all auxiliary functions.