SYSTEM AND METHOD FOR CONTROLLING THE PRESSURE IN A HYDROCARBON WELL

A system (10) for managed pressure drilling, or for workover of a hydrocarbon well with a wellhead, the system comprising a floating structure that is located in a body of water (41). A method is also described for connecting up the system for managed pressure drilling or well workover. The floating structure comprises a drill floor (13) and a work deck (14) that is movably arranged in an essentially vertical direction in relation to the drill floor. The system further comprises a riser (28) and a slip joint (32) that is connected to the underside of the work floor and to the upper end of the riser such that the work deck can be moved relative to the riser. The riser extends from the slip joint down to a wellhead valve device (40) arranged on the wellhead of the hydrocarbon well. The floating arrangement also comprises heave-compensated riser tensioners (17) which are connected to the slip joint such that the riser is held under tension. The system further comprises a BOP (38) that is arranged on the work deck and a high-pressure riser (29) that is arranged through the riser and the slip joint and is connected to the BOP on the work deck and to the wellhead valve device, thereby forming a continuous high-pressure connection from the work deck down to the hydrocarbon well (45).