Subsea Tree Installation – Paragon HZ1, K18 Field

Offshore lifts require solid preparations and an experienced crew

Wintershall needed to install a subsea tree, intended to be positioned in a well at K18, owned and operated by the same company.

Wintershall needed lifting assistance and requested Conbit to provide lifting crew, lifting and sea fastening equipment, lift plans, and loadout and sea-fastening procedures.

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Watch how we prepare and execute

The Conbit crew assisted lifting the Subsea tree from the supply vessel

Project location

The well is located in the K18 field, a concession owned and operated by Wintershall. The drill rig in the field was Paragon HZ1 (formerly known as Noble George Sauvageau).

The project team used the supply vessel “Island Endeavour” for the transport. The module was located in the vessel’s aft to maximize the distance between the vessel and the rig legs.

Conbit crew and equipment

Conbit provided lifting supervision during the loadout when the module arrived in the quayside in Den Helder. They supervised the loadout onto the barge, sea transport, and offshore lifting work. Conbit’s highly skilled lifting supervisors have extensive experience with all kinds of lifts. However, the offshore lifts were definitely the most challenging projects. They require a good sense of the motions combined with the available lifting speed. Most of Conbit’s offshore lifts are performed using high-speed winches. But in this project, the available winch was used.

Conbit also supplied all the sling arrangements and the rigging components. The main item was the sling configuration with an SWL of 55 tonnes. Conbit also provided the material and equipment required for sea fastening and load spreading. The load spreading was required onboard the supply vessel and on the quayside.

Loadout and sea fastening

Conbit’s involvement started on the quayside, where Conbit’s crew supervised the loadout and sea-fastening of the subsea tree. The module was loaded in the aft of the supply vessel to minimize the distance between the vessel and the platform during the offshore lift.

Offshore lift

The offshore lift was carried out with the drill tower winch. The OIM of the drill rig was in direct communication with Conbit's lifting supervisor and the captain of the supply vessel. Conbit's crew was also present on the supply vessel to connect the rigging and to release the sea-fastening. The OIM initiated the offshore lift on Conbit's lifting supervisor's advice and was performed successfully.

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