Abstract: A method for detecting and localizing a valve leak in a piston machine having a shaft includes: attaching one or more vibration sensor to a valve block of the piston machine; measuring the vibrations from at least one of the vibration sensors; attaching a sensor to the piston machine where the sensor is designed to produce, directly or indirectly, an angular shaft position signal for the shaft; determining, directly or indirectly, an angular shaft position signal for the shaft; transforming vibration signals from the one or more vibration sensors into one envelope signal representing an instant vibration level; using the angular position signal for constructing window functions that pick the envelope signal in selected angular shaft sectors; using the window functions to find sector based averages of the vibration level; and comparing said averages with a critical ambient vibration level to detect and localize leaks in one or two valves.

Abstract: A method for reducing cogging torque effects of an electrical permanent magnet machine includes running an “a” test and a “b” test with different cogging compensation signals. A first value is calculated by multiplying a complex cogging amplitude of the compensation signal applied for the “a” test with a complex amplitude of a vibration signal resulting from cogging torque of the “b” test. A second value is calculated by multiplying a complex cogging amplitude of the compensation signal applied for the “b” test with a complex amplitude of the vibration signal resulting from cogging torque of the “a” test. A desired complex cogging compensation amplitude is calculated by dividing the difference between the first and second values by a difference between the complex amplitudes of the vibration signals resulting from the “b” test and the “a” test. A cogging compensation torque is applied to the machine based on the desired complex cogging compensation amplitude.

Abstract: A lifting tool for opposing twisting of generally submerged ropes. The lifting tool includes a body with a center axis, an operable lock configured to selectively limit movement of a rope connector through the body, and a structure coupled to the body and configured to couple to a hoist or crane. The lifting tool also includes at least one rudder positioned at a radial distance from the center axis to oppose rotation of the lifting tool.

Abstract: A method for changing a chain wheel, a first chain wheel being on an axle, the method comprising (a) positioning a hydraulic cylinder at least partially within the axle. In addition, the method comprises (b) moving the first chain wheel off the axle with the hydraulic cylinder. Further, the method comprises (c) connecting the first chain wheel to a conveying device while the first chain wheel is held in position by the hydraulic cylinder. Still further, the method comprises (d) connecting a second chain wheel to the hydraulic cylinder while the second chain wheel is held in position by the conveying device. Moreover, the method comprises (e) moving the second chain wheel onto the axle with the hydraulic cylinder.

Abstract: A method for treating pipe string sections being in a set-back and being arranged in a vertical position comprises arranging a remote-controllable manipulator at least at one of the threaded portions of the pipe string sections. In addition, the method comprises providing the remote-controllable manipulator with a tool. The tool is arranged to at least clean or lubricate said threaded portion. Further, the method comprises moving the tool to a threaded portion which is to be treated and at least clean or lubricate the threaded portion.

Abstract: A method for reducing resonant vibrations and dynamic loads of cranes, whose horizontal and vertical motion of the pay load are controlled by a boom winch controlling the luffing motion of a pivoting boom and a hoist winch controlling the vertical distance between a boom tip and the load. Where the method includes determining the resonance frequencies of the coupled crane boom and load system, either experimentally or theoretically at least from data on inertia of the boom and stiffness of at least a boom rope, a hoist rope, a pedestal and an A-frame. The method further includes automatically generating a damping motion in at least one of said winches, that counteracts dynamic oscillations in the crane, and adding this damping motion to the motion determined by a crane operator.

Abstract: A system for storing one or more tubulars comprises a drilling deck including a hole offset from a wellbore centerline. In addition, the system comprises a rack unit coupled to the drilling deck and extending downward from the hole in the drilling deck. The rack unit comprises a tubular housing having a longitudinal axis, an upper end, and a lower end opposite the upper end. The rack unit also comprises a first rack disposed within the body, wherein the first rack is moveably coupled to the body.

Abstract: A capture basket system for use below an underdeck pipehandling machine on a drill rig. The capture basket system includes a capture basket to retain a falling object such as a pipe. The capture basket is coupled to a structure of the drill rig by an energy absorber that includes an elongated element.

Abstract: An apparatus for recuperation of hydraulic energy from an actuator comprises a first hydraulic machine having a first drive and a second hydraulic machine having a second drive mechanically coupled to the first drive. The first hydraulic machine is in hydraulic communication with an actuator, and the second hydraulic machine (20) is in hydraulic communication with an accumulator.

Abstract: A method for lift compensation of an item (12) which is connected to a vessel (1) by means of a rope (4) which is coiled around the rope drum (6) of a lifting device (2), the lifting device (2) being provided with a heave compensator (20), a controller (30) of the heave compensator (20) controlling the effect of the driving device (32, 34, 42) of the rope drum (6) on the basis of a heave term and a deviation term, the method comprising: —bringing a correction term into the heave compensation when, because of environmental forces, the force on the rope (4) falls outside a first limit (d, e); and—leaving the correction term out when the force on the rope (4) is within a second limit (c, f), the second limit (c, f) being equal to or different from the first limit (d, e).

Abstract: A method and a device for hoisting an item at sea with a hoisting device comprises moving the item between a plurality of different height levels. In addition, the method comprises alternately supporting the load of the item with a first hoisting rope and a second hoisting rope while moving the item between the plurality of different height levels. Further, the method comprises arranging the first hoisting rope and the second hoisting rope to extend in parallel along at least part of the distance between the item and the hoisting device. Still further, the method comprises releasably connecting the first hoisting rope to the second hoisting rope. Moreover, the method comprises suspending the second hoisting rope from a hanger when the second hoisting rope is supporting the load of the item. The method also comprises connecting the hanger to an arm of the hoisting device.

Abstract: A mouse hole damper device positioned at the bottom portion of a mouse hole pipe, the mouse hole damper being arranged to dampen an impact from an object falling in the mouse hole pipe, and the mouse hole damper including a material which has been worked into forming walls around elongated openings, and the material being arranged in such a way that the openings are substantially parallel to the longitudinal axis of the mouse hole pipe.

Abstract: A method for reducing cogging torque effects of an electrical permanent magnet machine includes running an “a” test and a “b” test with different cogging compensation signals. A first value is calculated by multiplying a complex cogging amplitude of the compensation signal applied for the “a” test with a complex amplitude of a vibration signal resulting from cogging torque of the “b” test. A second value is calculated by multiplying a complex cogging amplitude of the compensation signal applied for the “b” test with a complex amplitude of the vibration signal resulting from cogging torque of the “a” test. A desired complex cogging compensation amplitude is calculated by dividing the difference between the first and second values by a difference between the complex amplitudes of the vibration signals resulting from the “b” test and the “a” test. A cogging compensation torque is applied to the machine based on the desired complex cogging compensation amplitude.

Abstract: A method for changing a chain wheel, a first chain wheel being on an axle, the method comprising (a) positioning a hydraulic cylinder at least partially within the axle. In addition, the method comprises (b) moving the first chain wheel off the axle with the hydraulic cylinder. Further, the method comprises (c) connecting the first chain wheel to a conveying device while the first chain wheel is held in position by the hydraulic cylinder. Still further, the method comprises (d) connecting a second chain wheel to the hydraulic cylinder while the second chain wheel is held in position by the conveying device. Moreover, the method comprises (e) moving the second chain wheel onto the axle with the hydraulic cylinder.