Abstract: A mobile offshore drilling unit is converted to provide drilling, completion and workover access to multiple dry tree wells from a drilling derrick to allow production and export of oil and gas from high pressure, high temperature reservoirs in deep offshore waters. Existing practice has been for the drilling derrick on a production platform supporting dry tree wells to be moved over a fixed well slot. The present invention provides a movable wellbay that supports multiple top-tensioned subsea well tieback risers, which may be positioned directly below the derrick's rotary table and/or beneath another operating device. The use of top-tensioned subsea well tieback risers supported by the movable wellbay allows the converted facility to drill, complete, maintain, improve and produce from subsea wells through dry trees.

Abstract: A mobile offshore drilling unit is converted to provide drilling, completion and workover access to multiple dry tree wells from a drilling derrick to allow production and export of oil and gas from high pressure, high temperature reservoirs in deep offshore waters. Existing practice has been for the drilling derrick on a production platform supporting dry tree wells to be moved over a fixed well slot. The present invention provides a movable wellbay that supports multiple top-tensioned subsea well tieback risers, which may be positioned directly below the derrick's rotary table and/or beneath another operating device. The use of top-tensioned subsea well tieback risers supported by the movable wellbay allows the converted facility to drill, complete, maintain, improve and produce from subsea wells through dry trees.

Abstract: A pipe handling system is designed for use on an offshore structure, particularly an offshore structure provided with a cantilevered drill floor. The pipe handling system allows to handle significantly longer sections of tubulars, up to 100 feet, if necessary. The pipe handling system transports the pipes from a horizontal pipe rack adjacent to a drill floor to a vertical orientation in a set-back area of the drill floor where the drill string or casing is made up for lowering down hole. The cantilevered drill floor allows to save valuable platform space, while not significantly increasing the cost of the drilling rig. The pipe handling system, while increasing the length of handled tubulars, reduces the number of joints for making of a drill string, thereby significantly reducing the cost of pipe handling operations.

Abstract: An inverted pedestal crane has a base mountable to an underside of a horizontal support structure, such as for example a rig floor. A crane pedestal extends downwardly from the base, and a boom connects pivotally to the pedestal. The pedestal and the crane base rotate about a vertical axis, while the boom moves pivotally in relation to the pedestal. The crane has one main and a pair of auxiliary hydraulic rams for moving the boom during load handling operations. A robust slew bearing assembly mounted above the crane pedestal allows rotation of the base and the pedestal. The slew bearing assembly has a pair of parallel plates, a plurality of centering rollers and a plurality of stabilizing rollers mounted adjacent to an outer circumference of the parallel plates, between the plates. A winch assembly is mounted on top of the base, the winch assembly carrying a cable that extends over a pulley secured to a free end of the boom.