Abstract: A modular substation (10) for subsea applications includes a plurality of modular DC/AC converters (32) configured for converting DC electrical power transmitted along a DC transmission link (24) into AC electrical power for supplying to a plurality of subsea loads (56). The plurality of modular DC/AC converters (32) is configured to couple in series to the DC transmission link (24) and couple in parallel to an AC distribution network (52). At least a first modular DC/AC converter (32) is configured to be selectively electrically and mechanically disconnected from the DC transmission link (24) and the AC distribution network (52) to facilitate maintenance of the first modular DC/AC converters (32) while the AC distribution network (52) continues to supply AC electrical power to at least one of the plurality of subsea loads (56). The modular substation (10) also comprises protection and bypass circuits (26) intended to isolate faulty DC/AC converters (32) and to facilitate safe maintenance and repair.

Abstract: An actuator assist apparatus for use with an actuator has a housing and a piston member slidably disposed in the housing. The piston member divides the interior of the housing into a first fluid chamber and a second fluid chamber. The actuator assist apparatus is configurable between a first, primed, configuration and an activated configuration. A force applicator is configured to store energy when the apparatus is in the primed configuration and release the energy to move the piston member relative to the housing. Movement of the piston member applies a force which assists in urging the actuator towards an extended configuration, thereby reducing the minimum operating pressure of the actuator.

Abstract: The present disclosure relates to a calibration device for calibrating a virtual flow meter of a production system. The production system includes components for transferring fluid, where the virtual flow meter is configured to estimate a flow rate of the fluid based on property values of the components and values of variable parameters of the components. The calibration device includes a sensitivity determining module configured to calculate a first sensitivity, where the first sensitivity is used to indicate a degree of change of the values of the variable parameters relative to disturbance of the property values, and a calibration module configured to calibrate the virtual flow meter according to the first sensitivity.

Abstract: The present approach relates to establishing metrics for the computation of uncertainty boundaries for mean values for pressure and temperature drop error and mean values for mass flow error. Using such metric, sensor inaccuracies may be accounted for in the calibration and/or estimation processes of a virtual flow meter. For example, these values may be employed in the assessment of improvement in a calibration process of virtual flow meters, which will facilitate maintaining the accuracy of such virtual flow meters.

Abstract: A detection apparatus and method arranged to detect defects within a flexible pipe at least partially surrounded by seawater. The detection apparatus comprises a seawater electrode, an impedance monitor and a processor. The seawater electrode is arranged to be in contact with seawater surrounding at least part of a flexible pipe. The impedance monitor is arranged to measure the impedance between a metallic structural component of the flexible pipe extending at least partially along the length of the flexible pipe and the seawater electrode in response to an electrical test signal applied to the seawater electrode. The processor is arranged to determine the distance from the seawater electrode to a pipe defect electrically connecting the metallic structural component to seawater using the measured impedance.

Abstract: A detection apparatus and method arranged to detect defects within a flexible pipe at least partially surrounded by seawater. The detection apparatus comprises a seawater electrode, an impedance monitor and a processor. The seawater electrode is arranged to be in contact with seawater surrounding at least part of a flexible pipe. The impedance monitor is arranged to measure the impedance between a metallic structural component of the flexible pipe extending at least partially along the length of the flexible pipe and the seawater electrode in response to an electrical test signal applied to the seawater electrode. The processor is arranged to determine the distance from the seawater electrode to a pipe defect electrically connecting the metallic structural component to seawater using the measured impedance.