Well Enhancer Maintenance and Support Vessel, United Kingdom


Well Enhancer is a maintenance and support vessel (MSV) built to execute well intervention, diving support and offshore construction operations.

"Well Enhancer is built with three separate engine rooms to provide high redundancy and safety."

The vessel was built in accordance with the rules and regulations of Det Norske Veritas (DNV) and UK Maritime and Coastguard Agency Regulations. She also meets the requirements of UK Health and Safety Executive.

The vessel was designed and built by IHC Merwede's shipyard at Krimpen in Rotterdam, The Netherlands. It was delivered in the second half of 2009. Helix Energy Solutions Group owns the vessel, while its subsidiary Well Ops is the operator.

Design of the MSV

The vessel is of type-22 design series developed by IHC Merwede Offshore & Marine. Type-22 design allows for the development of a multifunctional platform with dynamic positioning (DP) Class-3 propulsion.

The vessel's design was further enhanced to accommodate a 150t multipurpose tower, twin bell saturated diving system for 18 divers and a twin work class ROV (remotely operated vehicle) system.

The entire midship of the vessel was adapted so she can be used as both a diving support vessel (DSV) and a well intervention vessel. There are two dedicated moon pools for diving support operation. A working moon pool measuring 51.38m2 is provided for well intervention operation.

The vessel also features a 1,100m² work deck with deck strength of 10t/m². An aluminium-made helicopter deck is also provided. The vessel is equipped with a fixed foam fire fighting system and can be used for regular operations of helicopters.

An anti-heeling system is provided to minimise the impact of heeling moments generated due to load lifting activities. An active interring stabilisation system is provided to maintain the vessel's stability during periodic roll movements brought on by waves.

The deadweight at 6.25m design draught is 6,750t. The overall length of the vessel is 131.70m and length between perpendiculars is 117.70m. The moulded breadth and depth to main deck are 22m and 9.5m respectively.

Construction of the Well Enhancer vessel

The vessel was ordered in November 2006. Construction was commenced one year later in November 2007. The ship was launched in May 2008 and delivery took place in August 2009.

Accommodation onboard

A total of 100 people can be accommodated onboard in 65 cabins. There are five Captain class cabins, seven Officer cabins, 18 one-man cabins and 35 two-man cabins. All the cabins are furnished with private facilities. A sickbay is available for the treatment of the sick or injured.

Engine room and propulsion

Well Enhancer is built with three separate engine rooms to provide high redundancy and safety to diving and well intervention operations. Two engine rooms are located forward, while the third one is located aft.

The vessel's power plant is comprised of four main and two auxiliary generating sets. Each of the nine-cylinder MAN diesel type L27/38 main generators can produce 2,970kW at 720rpm.

The two auxiliary engines, each producing 1,500kW at 720rpm, are of five-cylinder. An emergency generator of 232kW is also provided. A second emergency generator set of 750kW output is reserved for diving operation.

Main propulsion is provided by two Wartsila Lips azimuth fixed pitch propellers (FPP), each of 3,000kW capacity.

The vessel's DP ability and manoeuvring are complemented by two Rolls Royce controllable pitch tunnel bow thrusters and a Wartsila retractable controllable pitch azimuth thruster installed forward.

Deck equipment

The vessel is outfitted with a 100mt offshore crane with an outreach capacity of 15m. There are two auxiliary cranes, each with a 5t safe working load (SWL) capacity. The main deepwater deployment is performed through a 150t active / passive heave compensated winch system.

Main suppliers and subcontractors involved in constructing the Well Enhancer MSV

The complete electrical installation was carried out by GTI West Industry. Siemens acted as a knowledge partner and was also responsible for the supply and integration of the electrical propulsion drive plant. The navigation and communication systems were supplied by Alphatron Marine.

Diving installation facilities were supplied by Drass Galeazzi, while the deck handling system for the subsea equipment was provided by IHC Offshore Systems.

"Well Enhancer is a maintenance and support vessel (MSV) built to execute well intervention."

Fuel and lube oil separators were supplied by Alfa Laval, plate heat exchangers by AMW Marine, steel plates and profiles by De Boer Staal, fresh water maker by Edaircon, scaffolding and safety facilities by ESS Scaffolding Services, lifeboats by Fr. Fassmer and hydraulic piping by GS-Hydro Benelux.

Noise and vibration calculations and sea trial measurements were undertaken by Adviesbureau Intersona. DP system came from Konsberg Maritime Ship Systems and MAN diesel generators were supplied by MAN Diesel Benelux. Rolls-Royce Marine supplied bowthrusters and intering stabiliser system. The multipurpose deepwater deployment tower was designed and built by Huisman-Itrec.