A subsea drilling method and system controls drilling fluid pressure in the borehole of a subsea well, and separates gas from the drilling fluid. Drilling fluid is pumped into the borehole through a drill string and returned through an annulus between the drill string and the well bore and between the drill string and a riser. Drilling fluid pressure is controlled by draining fluid out of the riser or a BOP at a level between the seabed and the surface in order to adjust the hydrostatic head of drilling fluid in the riser. The drained drilling fluid and gas is separated in a subsea separator, where the gas is vented to the surface through a vent line, and the fluid is pumped to the surface via a subsea pump. A closing device and a choke line and valve can release pressure after a gas kick in the well.

The invention is a system for controlling the relative movement of a load P, comprising at least one main damper having a longitudinal action of stroke C and two ends with one end being connected to a frame and the other being connected to the load. A compensation device is included having at least one secondary damper of longitudinal action with two ends with one end being secured to the frame and the other end is connected to the end of the main damper connected to the load The secondary damper is arranged so that, at one point of stroke C, the secondary damper has an action orthogonal in direction to the direction of the movement.

A casing hanger and annulus sealing device running tool for deepwater drilling and a method for using the same. The running tool includes a spindle connected to a hollow suspension structure via a torque transmission structure, one end of the spindle slidably passes through a hollow piston, the suspension structure rotates with the spindle and slide along the piston, the inner cavity of the torque transmission structure communicates with that of the suspension structure to form a piston cavity; the piston cavity and the piston form a hydraulic piston structure; and one end of the suspension structure away from the torque transmission structure can rotatably hook to and lift upward to release the annulus sealing device, and one end of the piston away from the torque transmission structure can radially expand to hook to the casing hanger and can radially contract to release the casing hanger.

A casing hanger and annulus sealing device running tool for deepwater drilling and a method for using the same. The running tool includes a spindle connected to a hollow suspension structure via a torque transmission structure, one end of the spindle slidably passes through a hollow piston, the suspension structure rotates with the spindle and slide along the piston, the inner cavity of the torque transmission structure communicates with that of the suspension structure to form a piston cavity; the piston cavity and the piston form a hydraulic piston structure; and one end of the suspension structure away from the torque transmission structure can rotatably hook to and lift upward to release the annulus sealing device, and one end of the piston away from the torque transmission structure can radially expand to hook to the casing hanger and can radially contract to release the casing hanger.

A drilling or work-over vessel (10) is disclosed comprising a number of operational equipment (300), wherein the drilling or work-over vessel comprises at least one operational control and/or state unit (100) comprising at least one processing unit (102), wherein the at least one operational control and/or state unit (100) comprises or are in connection with a memory and/or storage (103), and at least one sensor unit (200), wherein the at least one sensor unit (200) is adapted to obtain one or more measured physical values and to provide data representing the one or more measured physical values and/or derived values thereof to the at least one operational control and/or state unit (100), the memory and/or storage (103) comprises a data representation of a computational physics model of at least a part of the drilling or work-over rig, and the at least one processing unit (102) is adapted to derive data representing an estimation of one or more physical states (such as defined by limits of forces, relative motion between operational equipment and vessel, or between other two pieces of operational equipment) estimated to act on at least one operational equipment (300) in response to the data representing the one or more measured physical values and/or derived values thereof as provided by the at least one sensor unit (200).

A drilling or work-over vessel (10) is disclosed comprising a number of operational equipment (300), wherein the drilling or work-over vessel comprises at least one operational control and/or state unit (100) comprising at least one processing unit (102), wherein the at least one operational control and/or state unit (100) comprises or are in connection with a memory and/or storage (103), and at least one sensor unit (200), wherein the at least one sensor unit (200) is adapted to obtain one or more measured physical values and to provide data representing the one or more measured physical values and/or derived values thereof to the at least one operational control and/or state unit (100), the memory and/or storage (103) comprises a data representation of a computational physics model of at least a part of the drilling or work-over rig, and the at least one processing unit (102) is adapted to derive data representing an estimation of one or more physical states (such as defined by limits of forces, relative motion between operational equipment and vessel, or between other two pieces of operational equipment) estimated to act on at least one operational equipment (300) in response to the data representing the one or more measured physical values and/or derived values thereof as provided by the at least one sensor unit (200).

A drilling conductor supported within a suction anchor is installed by lowering the suction anchor through the top of a frame of a subsea processing unit. The base of the frame defines a landing area for the suction anchor and supports a fixing system for fixing the suction anchor to the frame. When the suction anchor has been embedded into the seabed beneath the processing unit, the frame is fixed to the suction anchor to form a structural unit that includes the conductor, the suction anchor and the frame. Additional equipment such as a blow-out presenter or a Christmas tree is lowered through the top of the frame and onto the conductor that is supported by the embedded suction anchor.

A drilling conductor supported within a suction anchor is installed by lowering the suction anchor through the top of a frame of a subsea processing unit. The base of the frame defines a landing area for the suction anchor and supports a fixing system for fixing the suction anchor to the frame. When the suction anchor has been embedded into the seabed beneath the processing unit, the frame is fixed to the suction anchor to form a structural unit that includes the conductor, the suction anchor and the frame. Additional equipment such as a blow-out presenter or a Christmas tree is lowered through the top of the frame and onto the conductor that is supported by the embedded suction anchor.

An installation frame for a horizontal directional drilling operation can include a pair of front uprights supporting a front crossbar disposed therebetween and selectively vertically movable. An installation frame can include a pair of rear uprights supporting a rear crossbar disposed therebetween and selectively vertically movable, wherein the front crossbar and the rear crossbar are configured to support a casing for a drill at a predetermined drill angle relative to a floor of a body of water.

A system for operation on a subsea well, the system comprising at least one storage unit configured to store tubulars; a subsea mast unit comprising at least two string handling devices configured to handle a tubular string of a plurality of connected tubulars, wherein at least one of the string handling devices is configured to move vertically relative to the other of the string handling devices, and is configured to add a vertical downforce to the tubular string; and at least one handling arrangement for moving tubulars between the at least one storage unit and one of the string handling devices simultaneously with handling of the tubular string by at least one of the string handling devices. A method of lowering a tubular string into a subsea well is also provided.