Abstract: The invention provides a drilling system for drilling subsea wells from a floating mobile offshore drilling unit (MODU), the system comprising a subsea BOP. The system is distinctive in that the subsea BOP has relative small weight and size, the system includes no marine riser but the system comprises: flexible choke and kill lines arranged between the subsea BOP and the MODU, means for drill string guidance and cleaning, for guiding when inserting or taking out a drill string from the BOP and for drill string cleaning when pulling the drill string out from the BOP, means for controlled leakage of seawater into a recovery funnel arranged below the means for drill string cleaning but above the BOP, and means for return from the recovery funnel to the MODU of drilling fluid and seawater leaked into the recovery funnel.

Abstract: The invention provides a drilling system for drilling subsea wells from a floating mobile offshore drilling unit (MODU), the system comprising a subsea BOP. The system is distinctive in that the subsea BOP has relative small weight and size, the system includes no marine riser but the system comprises: flexible choke and kill lines arranged between the subsea BOP and the MODU, means for drill string guidance and cleaning, for guiding when inserting or taking out a drill string from the BOP and for drill string cleaning when pulling the drill string out from the BOP, means for controlled leakage of seawater into a recovery funnel arranged below the means for drill string cleaning but above the BOP, and means for return from the recovery funnel to the MODU of drilling fluid and seawater leaked into the recovery funnel.

Abstract: The present invention relates to an arrangement in a floating drilling and intervention vessel, for controlling a heave compensated drill floor 7 suspended in drill floor compensator cylinders 10. Below the compensated drill floor 7 there is installed a tidal structure (3) suspended in tidal cylinders 2 or wires 25. By adjusting the tidal cylinders 2 or the wires 25 in step with the tide 17 it is achieved that the drill floor compensator cylinders 10 can operate around their middle position regardless of the tide lifting or lowering the vessel 16.

Abstract: The present invention relates to an arrangement to be used when drilling oil/gas wells, especially deep water wells, and the invention gives instructions for how to utilise the riser pipe as part of a high pressure system together with the drilling pipe, namely in that the arrangement comprises a surface blowout preventer (SURBOP) which is connected to a high pressure riser pipe (SR) which in turn is connected to a well blowout preventer (SUBBOP), and a circulation/kill line (TL) communicating between said blowout preventers (SURBOP, SUBBOP), all of which being arranged as a high pressure system for deep water slim hole drilling.

Abstract: A swivelsub comprising a sleeve member which is sealable and lockable by means of the annular preventer of a blowout preventer, with at least one end portion of the sleeve being lockable to the drill string, and with means providing sealing and enable relative rotational movement between said sleeve member and the drill string. The swivelsub forms a sealable and pressure controlling passage for a dril string in a drilling well and is particularly useful for cutting operation of casings in an abandoned well.