Abstract: Disclosed is a jack-up rig that includes a cantilever platform mounted on a buoyant hull. At least two drilling assemblies are provided on the cantilever platform, each of the drilling assemblies being movable relative to the cantilever platform and being moveable independently from the other drilling assembly or assemblies. Each of the drilling assemblies is also movable within a plane that is parallel to the cantilever platform in both X-direction as well as Y-direction which is orthogonal to the X-direction.

Abstract: A damping system for a heave compensator for an off-shore oil rig includes a hydraulic cylinder having a piston and a housing. The hydraulic cylinder is configured for accepting a hydraulic fluid. There is a flow passage for restricting the flow of the hydraulic fluid during movement of the piston in the housing. The hydraulic fluid is a magnetic fluid and the damping system includes a magnetic fluid management system for controlling a magnetic field at the flow passage. A heave compensator including such a damping system, and a method for controlling the damping of a heave compensator are also disclosed, the method including subjecting a magnetic fluid to a magnetic field at a flow passage for restricting the flow of the magnetic fluid.

Abstract: An apparatus for supporting a flywheel on a floating vessel includes a support for the flywheel; and a tilt sensor for measuring an angle of slope relative to the Earth, the tilt sensor being arranged to detect a change of an angle of slope of the floating vessel relative to the Earth. The apparatus further includes a driver for manoeuvring the support relative to the floating vessel, based on the measured angle of slope from the tilt sensor, wherein the driver is operable to manoeuvre the support so as to counteract a change of an angle of slope of the flywheel relative to the Earth due to the detected change of an angle of slope of the floating vessel.

Abstract: Disclosed is a method and system for tuning a hydraulic model to be used for estimating down hole dynamic pressure as a function of flow rate includes: a) selecting a non-tuned hydraulic model estimating the relative magnitude of the pressure losses in various annulus sections of the well bore; b) applying the non-tuned hydraulic model to give a first order estimate of the pressure gradients and the shear stresses at the drill string; c) applying the same non-tuned model to estimate the flow lift area for two different flow rates, where the first flow rate is zero or much lower than the second flow rate being substantially equal to a typical flow rate obtained during drilling; and d) performing a model tuning test where the string is rotated off bottom while said two different flow rates are used to obtain corresponding string weights.

Abstract: A method for estimating downhole speed and force variables at an arbitrary location of a moving drill string based on surface measurements of the same variables. The method includes a) using properties of said drill string to calculate transfer functions describing frequency-dependent amplitude and phase relations between cross combinations of said speed and force variables at the surface and downhole; b) selecting a base time period; c) measuring surface speed and force variables, conditioning the measured data by applying anti-aliasing and/or decimation filters, and storing the conditioned data, and d) calculating the downhole variables in the frequency domain by applying an integral transform, such as Fourier transform, of the surface variables, multiplying the results with said transfer functions, applying the inverse integral transform to sums of coherent terms and picking points in said base time periods to get time-delayed estimates of the dynamic speed and force variables.

Abstract: A spooling device for facilitating spooling of a wire on a drum winch from a feeding point includes a suspension cradle mounted to the mechanical frame. The suspension cradle supports a rotatable wire sheave or receiving the wire extending form the feeding point and for guiding the wire to a specific location on the drum winch. The suspension cradle having the wire sheave is slideably mounted to the frame in accordance with a curved path. The curved path is configured such that the fleet angle of the wire extending from the feed point is at least partially compensated in order to reduce fringing effects of the wire on the wire sheave during sliding movement of the wire sheave along its curved path.

Abstract: Disclosed is a drilling system for rock drilling with a drill string, wherein the drill string includes at least one bendable drill pipe. The drilling system further includes at least two block and tackle systems for driving an end of the drill string in a first direction; and at least two conveyor devices adapted to guide and bend the drill string between the first direction and a second direction, so as to convert a motion of the drill string between the first direction and the second direction.

Abstract: A torque device for guiding a first torque device member relative to a second torque device member includes the first and second torque device members. Each of the torque device members has an operational axis of rotation and three clamp bodies spaced about the operational axis. The clamp bodies are movable between a retracted passive position and an extended active position. The torque device also includes a guide ring on one of the torque device members. The guide ring includes one or more guide ring sections. In addition, the torque device includes at least two guide elements on the other of the torque device members. Each guide element being movable with one of the clamp bodies of the respective torque device member.

Abstract: Described is an offshore lifting crane, as for a vessel or platform, that includes a support structure, a crane boom connected to the support structure, a winch drum rotatable around its longitudinal axis, a winch drum drive means, and an elongated hoisting member. The hoisting member includes a first end connected to the winch drum and a second end connectable to a load. The hoisting member extends over at least a part of the crane boom, and the winch drum is arranged such that its longitudinal axis is substantially vertical.

Abstract: A method of upgrading a knuckle-boom crane to a heave-compensating crane includes: removing a knuckle-boom from a main boom; mounting a main boom extension to the main boom for increasing the length of the main boom; and mounting a heave-compensating boom at a far end of the main boom extension such that the heave-compensating boom extends in a downward vertical direction (Z) in operational use of the heave-compensating crane. The heave-compensating boom is configured to be pivotable with respect to the main boom extension in both horizontal directions (X, Y). A heave-compensation system is provided to the knuckle-boom crane, wherein the heave-compensation system compensates for horizontal variations by controlling the orientation of the heave-compensating boom relative to the main boom extension, and compensates for vertical variations by means of a further vertical heave-compensation system, such as a winch-based heave-compensation system.

Abstract: 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.

Abstract: A system on a marine vessel or platform supports a load while allowing heave compensation. The load is supported via a hydraulic actuator. A transformer of the system includes a power source and at least one hydraulic pump/motor, for communicating energy between any two of: the hydraulic actuator; a hydraulic accumulator; and a power source. A valve associated with the pump/motor is switchable during at least one cycle of the pump/motor for selectively providing fluid communication between a drive chamber of the pump/motor and any of the hydraulic actuator, the hydraulic accumulator, and a hydraulic fluid reservoir, via at least one port of the drive chamber, so as to allow a desired displacement of hydraulic fluid from the pump/motor to be obtained.

Abstract: A method of building an offshore windmill includes, using a 3D-heave-compensated crane, placing on a windmill pedestal a lifting jack having a receiving region, and fixing the lifting jack to the windmill pedestal such that the lifting jack can be later removed, and such that a windmill column can be placed within the receiving region directly on the windmill pedestal. The windmill generator is installed using the 3D-heave-compensated crane. The windmill column is partially erected on the windmill pedestal using the 3D-heave-compensated crane and the lifting jack. Before the windmill is fully erected, windmill blades are placed on the windmill generator using the 3D-heave-compensated crane, and the erection of the windmill column on the windmill pedestal is completed using at least the lifting jack. Using the 3D-heave-compensated crane, the lifting jack is removed from the windmill pedestal.

Abstract: An apparatus for applying torque about an operational axis of rotation includes a first torque device member. In addition, the apparatus includes an actuator support configured to move radially relative the operational axis and configured to be restricted from rotating in a plane oriented perpendicular to the operational axis. Further, the apparatus includes a first torque actuator pivotally coupled to the first torque device member and the actuator support. Still further, the apparatus includes a rod or a second torque actuator pivotally coupled to the first torque device member and the actuator support. Moreover, the apparatus includes a second torque device member coupled to the first torque device member and disposed about the operational axis of rotation. The actuator support is pivotally coupled to the second torque device member and is configured to pivot about a first pivot axis towards and away from the operational axis of rotation.

Abstract: A system for storing and handling pipes between a pipe rack and a derrick includes pipe-receiving chambers that are positioned around a centre region, and an elevator for lifting and descending the pipes into the chambers. The elevator, located in the centre region in between the receiving chambers, is configured for selecting one of the receiving chambers and for lifting and descending a respective pipe into the selected chamber.

Abstract: A drilling unit on a deck of a floating vessel, includes a drill tower structure with a heave-compensation system, a winch mounted at or near the deck, a crown block mounted at a top side of the drill tower structure and at least one wire rope between the winch and the crown block. The heave-compensation system includes a slideable support frame configured to be moved in a direction substantially parallel to the axial direction of the drill tower structure. Either the winch or the crown block is positioned within the slideable support frame such that a distance between the winch and the crown block is controlled by at least one electric motor or linear actuator. In an alternative embodiment in which a crown block in not employed, the winch is placed in the slideable support frame at the top side of the drill tower structure.

Abstract: A system for hoisting a load on a drilling rig includes: a hoisting means having an elongated hoisting member and an elongated hoisting member drive means; a drill string rotation means suspended from an end of the elongated hoisting member; a support structure having a first side and a second side and being adapted to support at least a portion of the weight the drill string rotation means; a first elongated hoisting member guiding means connected to the support structure; and a counterweight connected to the elongated hoisting member at the second side of the support structure. The elongated hoisting member is reeved over the first elongated hoisting member guiding means from the first to the second side of the support structure. The drill string rotation means is suspended from the elongated hoisting member at the first side of the support structure.

Abstract: A method for drilling a borehole includes selecting a lower pressure limit and an upper pressure limit for a drilling fluid at a drilling location in the borehole. In addition, the method includes activating a pump to circulate the drilling fluid down a drill string and up an annulus disposed about the drill string. Further, the method includes operating the pump to maintain the drilling fluid at the drilling location at a pressure between the upper and the lower pressure limits. Still further, the method includes deactivating the pump to stop circulating the drilling fluid up the annulus. The method also includes sealing the drilling fluid in the annulus at a selected time after deactivating the pump and maintaining the pressure of the drilling fluid at the drilling location between the lower and the upper pressure limits.

Abstract: A method for estimating downhole speed and force variables at an arbitrary location of a moving drill string based on surface measurements of the same variables. The method includes a) using properties of said drill string to calculate transfer functions describing frequency-dependent amplitude and phase relations between cross combinations of said speed and force variables at the surface and downhole; b) selecting a base time period; c) measuring surface speed and force variables, conditioning the measured data by applying anti-aliasing and/or decimation filters, and storing the conditioned data, and d) calculating the downhole variables in the frequency domain by applying an integral transform, such as Fourier transform, of the surface variables, multiplying the results with said transfer functions, applying the inverse integral transform to sums of coherent terms and picking points in said base time periods to get time-delayed estimates of the dynamic speed and force variables.

Abstract: There are described methods for controlling the direction of a wellbore trajectory during directional sliding drilling by means of a drill string having a drill bit rotatable, by means of a mud motor, around a drill bit rotation axis at its lower end, the direction of the drill bit rotation axis defining a tool face, wherein one of the methods comprises the following steps: a2) obtaining data indicative of the torque of the mud motor; and b2) calculating a reactive twist angle of the drill string by multiplying the obtained torque from step a2) by the torsional drill string compliance, wherein the method further comprises the step of: c2) rotating the drill string, by means of a drill string rotation means, an angle substantially equal to but in the opposite direction of the calculated reactive twist angle. There are also described systems for executing the methods as well as computer program products comprising instructions for causing a processor to perform the methods as described herein.