The invention relates to a vessel comprising a moonpool, a firing line hoist system, a stationary main deck for storing equipment and/or tubulars, and a mobile working deck having a front deck section and a rear deck section. The working deck can be moved between a working position and a transporting position. A rear deck lift system is provided for lifting and lowering a rear deck section between the working position and the transporting position. A front deck guide system is provided for guiding a front deck section in a substantially horizontal direction between the working position and the transporting position.

The disclosure relates to a system and method for determining whether a kick or loss has occurred from a well in real time, wherein the well has a marine diverter having a rotating control device. The marine diverter system may measure flow rate in real time of a drilling fluid entering the wellbore and provide a means of measuring flow rate of the drilling fluid out of the wellbore and riser. The marine diverter system may further determine displacement and velocity of displacement of rig heave motion in real time and use the foregoing steps, given a known internal diameter of the riser and a known external diameter of a drill pipe, and employing a drilling fluid volume balance equation: (Volumetric flow rate-in)−(Volumetric flow rate-out)−(Change in riser annular Volume per unit time)=X, to determine whether the kick or loss has occurred in real time.

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.

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.

A platform assembly (10) for providing a work area around a well riser (16) is disclosed. The platform assembly (10) comprises a platform (26) configured to be attached to the well riser (16). The platform assembly (10) further comprises a plurality of tensioning means (28) for supporting the platform (26) relative to a vessel (14) and for supporting the riser (16). At least part of tensioning means (28) is configured to change in length relative to another part of tensioning means (28) responsive to angular motion of the riser (16) and the vessel (14).

A well intervention semisubmersible vessel and method including a drilling rig further including a non-elevated derrick floor and a handling tower having a single point land out without riser tensioners. The vessel may also include a flush drill floor, a flush moonpool door, a lift frame and personnel access walkway wherein the lift frame is capable of being skidded into position by a skidding system capable of providing personnel access and wherein the skidding system comprises a plurality of skidding rails, at least one remotely operated vehicle, an intervention rising system and storage area, a crane, a moonpool and handling area, a moonpool trolley, at least one fluid pump, and/or at least one tank.

A well intervention semisubmersible vessel and method including a drilling rig further including a non-elevated derrick floor and a handling tower having a single point land out without riser tensioners. The vessel may also include a flush drill floor, a flush moonpool door, a lift frame and personnel access walkway wherein the lift frame is capable of being skidded into position by a skidding system capable of providing personnel access and wherein the skidding system comprises a plurality of skidding rails, at least one remotely operated vehicle, an intervention rising system and storage area, a crane, a moonpool and handling area, a moonpool trolley, at least one fluid pump, and/or at least one tank.

An apparatus, system and method to purify water is disclosed. Pumps and energy recovery devices for taking water from an intake, filtering the water to remove solid contaminates before running the filtered water through the reverse osmosis system to the discharge device and purified water lines are described. The system may comprise a control panel that controls the plurality of filters, plurality of reverse osmosis membranes, purified water line and effluent discharge device, to achieve favorable water purification. A method that utilizes the apparatus and/or system is described herein.

An apparatus, system and method to purify water is disclosed. Pumps and energy recovery devices for taking water from an intake, filtering the water to remove solid contaminates before running the filtered water through the reverse osmosis system to the discharge device and purified water lines are described. The system may comprise a control panel that controls the plurality of filters, plurality of reverse osmosis membranes, purified water line and effluent discharge device, to achieve favorable water purification. A method that utilizes the apparatus and/or system is described herein.

A system for moving items on a rig floor (2), the system comprising a plurality of skids (30-35) and a network of rails (10) for guiding the plurality of skids, each skid of said plurality of skids for supporting an item, and each skid having rail engagement members for engaging at least one rail of said network of rails. The rig floor may form part of a drilling rig such as a drill ship (1) used in the construction of oil and gas wells.