Drillship

Mobile drilling unit built on a self-propelled, ship-shape hull with a moonpool through which the riser and BOP stack pass. Drillships typically carry DP-3 station-keeping for ultra-deepwater fields beyond economic anchoring (~3,000+ m water depth), large variable deckload, and substantial mud and brine bulk capacity. They transit between fields under their own power. The IMO MODU Code governs safety design; recent generations operate in 12,000-foot water depths with dual derricks and redundant subsea systems for offline activity.