Noble Drilling A/s

Kristian Hansen

Jesper Holck

Konstantin Puskarskij

Christian Schmidt

A method for mitigating the effects of cable wear in an active heave compensated hoisting system of an offshore vessel in a locked to bottom mode of operation is disclosed. The method comprises supporting an upper end of a string which is connected to a subsea well from a travelling block of the hoisting system, wherein the travelling block is suspended from a crown block via a cable. The method further comprises operating an active heave compensation system to control a drawworks of the hoisting system to pay in and out the cable to compensate for motion of the offshore vessel and maintain a target overpull in the string. The method further comprises adjusting a ballast system of the offshore vessel to vary the draft of the vessel, and controlling the drawworks in accordance with the variation in the draft of the vessel to cause a length of cable to slip through the hoisting system and maintain the target overpull in the string.

Method and system for mitigating cable wear in a hoisting system

Well centre assembly for an offshore drilling rig and associated method. There is described a well centre assemblyfor an offshore drilling rig. The well centre assemblycomprises a diverter assemblyand a movement control system. The movement control systemis operable between the diverter assemblyand a supporting structureof the rig. In use, the movement control systemcontrols or permits relative movement between the diverter assemblyand the supporting structure. A connector such as a riserconnected to the diverter assemblyduring deployment, while deployed or during retrieval of the risermay experience external forces such as from tidal, wind and/or wave movement at a water surface, which may cause the positioning and/or orientation of the riserto vary. The movement control systemmay control the movement of the diverter assemblyso as to compensate for movement of the riser

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Fredensborg, Denmark

Kristian Hansen